Merge BlockchainDB into upstream

32 files changed, 9648 insertions, 149 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index efc9c02f6..e454b92fd 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -89,6 +89,7 @@ endfunction ()
 add_subdirectory(common)
 add_subdirectory(crypto)
 add_subdirectory(cryptonote_core)
+add_subdirectory(blockchain_db)
 add_subdirectory(mnemonics)
 add_subdirectory(rpc)
 add_subdirectory(wallet)
@@ -100,3 +101,5 @@ add_subdirectory(miner)
 add_subdirectory(simplewallet)
 add_subdirectory(daemonizer)
 add_subdirectory(daemon)
+
+add_subdirectory(blockchain_converter)
diff --git a/src/blockchain_converter/CMakeLists.txt b/src/blockchain_converter/CMakeLists.txt
new file mode 100644
index 000000000..660650980
--- /dev/null
+++ b/src/blockchain_converter/CMakeLists.txt
@@ -0,0 +1,115 @@
+# Copyright (c) 2014-2015, The Monero Project
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this list of
+#    conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list
+#    of conditions and the following disclaimer in the documentation and/or other
+#    materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors may be
+#    used to endorse or promote products derived from this software without specific
+#    prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set(blockchain_converter_sources
+  blockchain_converter.cpp
+  )
+
+set(blockchain_converter_private_headers)
+
+bitmonero_private_headers(blockchain_converter
+	  ${blockchain_converter_private_headers})
+
+set(blockchain_import_sources
+  blockchain_import.cpp
+  )
+
+set(blockchain_import_private_headers
+  import.h
+  fake_core.h
+  )
+
+bitmonero_private_headers(blockchain_import
+	  ${blockchain_import_private_headers})
+
+set(blockchain_export_sources
+  blockchain_export.cpp
+  )
+
+set(blockchain_export_private_headers
+  import.h
+  blockchain_export.h
+  )
+
+bitmonero_private_headers(blockchain_export
+	  ${blockchain_export_private_headers})
+
+
+
+if (BLOCKCHAIN_DB STREQUAL DB_LMDB)
+bitmonero_add_executable(blockchain_converter
+  ${blockchain_converter_sources}
+  ${blockchain_converter_private_headers})
+
+target_link_libraries(blockchain_converter
+  LINK_PRIVATE
+    cryptonote_core
+	p2p
+	blockchain_db
+    ${CMAKE_THREAD_LIBS_INIT})
+
+add_dependencies(blockchain_converter
+	version)
+set_property(TARGET blockchain_converter
+	PROPERTY
+	OUTPUT_NAME "blockchain_converter")
+endif ()
+
+bitmonero_add_executable(blockchain_import
+  ${blockchain_import_sources}
+  ${blockchain_import_private_headers})
+
+target_link_libraries(blockchain_import
+  LINK_PRIVATE
+    cryptonote_core
+	blockchain_db
+	p2p
+    ${CMAKE_THREAD_LIBS_INIT})
+
+add_dependencies(blockchain_import
+	version)
+set_property(TARGET blockchain_import
+	PROPERTY
+	OUTPUT_NAME "blockchain_import")
+
+bitmonero_add_executable(blockchain_export
+  ${blockchain_export_sources}
+  ${blockchain_export_private_headers})
+
+target_link_libraries(blockchain_export
+  LINK_PRIVATE
+    cryptonote_core
+	p2p
+	blockchain_db
+    ${CMAKE_THREAD_LIBS_INIT})
+
+add_dependencies(blockchain_export
+	version)
+set_property(TARGET blockchain_export
+	PROPERTY
+	OUTPUT_NAME "blockchain_export")
diff --git a/src/blockchain_converter/README.md b/src/blockchain_converter/README.md
new file mode 100644
index 000000000..00160c6b9
--- /dev/null
+++ b/src/blockchain_converter/README.md
@@ -0,0 +1,54 @@
+
+For importing into the LMDB database, compile with `DATABASE=lmdb`
+
+e.g.
+
+`DATABASE=lmdb make release`
+
+This is also the default compile setting on the blockchain branch.
+
+By default, the exporter will use the original in-memory database (blockchain.bin) as its source.
+This default is to make migrating to an LMDB database easy, without having to recompile anything.
+To change the source, adjust `SOURCE_DB` in `src/blockchain_converter/blockchain_export.h` according to the comments.
+
+# Usage:
+
+See also each utility's "--help" option.
+
+## Export an existing in-memory database
+
+`$ blockchain_export`
+
+This loads the existing blockchain, for whichever database type it was compiled for, and exports it to `$MONERO_DATA_DIR/export/blockchain.raw`
+
+## Import the exported file
+
+`$ blockchain_import`
+
+This imports blocks from `$MONERO_DATA_DIR/export/blockchain.raw` into the current database.
+
+Defaults: `--batch on`, `--batch size 20000`, `--verify on`
+
+Batch size refers to number of blocks and can be adjusted for performance based on available RAM.
+
+Verification should only be turned off if importing from a trusted blockchain.
+
+```bash
+# use default settings to import blockchain.raw into database
+$ blockchain_import
+
+# fast import with large batch size, verification off
+$ blockchain_import --batch-size 100000 --verify off
+
+# LMDB flags can be set by appending them to the database type:
+# flags: nosync, nometasync, writemap, mapasync
+$ blockchain_import --database lmdb#nosync
+$ blockchain_import --database lmdb#nosync,nometasync
+```
+
+## Blockchain converter with batching
+`blockchain_converter` has also been updated and includes batching for faster writes. However, on lower RAM systems, this will be slower than using the exporter and importer utilities. The converter needs to keep the blockchain in memory for the duration of the conversion, like the original bitmonerod, thus leaving less memory available to the destination database to operate.
+
+```bash
+$ blockchain_converter --batch on --batch-size 20000
+```
diff --git a/src/blockchain_converter/blockchain_converter.cpp b/src/blockchain_converter/blockchain_converter.cpp
new file mode 100644
index 000000000..c3c6d0918
--- /dev/null
+++ b/src/blockchain_converter/blockchain_converter.cpp
@@ -0,0 +1,299 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "include_base_utils.h"
+#include "common/util.h"
+#include "warnings.h"
+#include "crypto/crypto.h"
+#include "cryptonote_config.h"
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "misc_language.h"
+#include "cryptonote_core/blockchain_storage.h"
+#include "blockchain_db/blockchain_db.h"
+#include "cryptonote_core/blockchain.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+#include "cryptonote_core/tx_pool.h"
+#include "common/command_line.h"
+#include "serialization/json_utils.h"
+#include "include_base_utils.h"
+#include "version.h"
+#include <iostream>
+
+
+unsigned int epee::g_test_dbg_lock_sleep = 0;
+
+namespace
+{
+
+// CONFIG
+bool opt_batch   = true;
+bool opt_resume  = true;
+bool opt_testnet = false;
+
+// number of blocks per batch transaction
+// adjustable through command-line argument according to available RAM
+uint64_t db_batch_size = 20000;
+
+}
+
+namespace po = boost::program_options;
+
+using namespace cryptonote;
+using namespace epee;
+
+struct fake_core
+{
+  Blockchain dummy;
+  tx_memory_pool m_pool;
+
+  blockchain_storage m_storage;
+
+#if !defined(BLOCKCHAIN_DB)
+  // for multi_db_runtime:
+  fake_core(const boost::filesystem::path &path, const bool use_testnet) : dummy(m_pool), m_pool(&dummy), m_storage(m_pool)
+#else
+  // for multi_db_compile:
+  fake_core(const boost::filesystem::path &path, const bool use_testnet) : dummy(m_pool), m_pool(dummy), m_storage(&m_pool)
+#endif
+  {
+    m_pool.init(path.string());
+    m_storage.init(path.string(), use_testnet);
+  }
+};
+
+int main(int argc, char* argv[])
+{
+  uint64_t height = 0;
+  uint64_t start_block = 0;
+  uint64_t end_block = 0;
+  uint64_t num_blocks = 0;
+
+  boost::filesystem::path default_data_path {tools::get_default_data_dir()};
+  boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
+
+
+  po::options_description desc_cmd_only("Command line options");
+  po::options_description desc_cmd_sett("Command line options and settings options");
+  const command_line::arg_descriptor<uint32_t> arg_log_level   =  {"log-level", "", LOG_LEVEL_0};
+  const command_line::arg_descriptor<uint64_t> arg_batch_size  =  {"batch-size", "", db_batch_size};
+  const command_line::arg_descriptor<bool>     arg_testnet_on  = {
+    "testnet"
+      , "Run on testnet."
+      , opt_testnet
+  };
+  const command_line::arg_descriptor<uint64_t> arg_block_number =
+  {"block-number", "Number of blocks (default: use entire source blockchain)",
+    0};
+
+  command_line::add_arg(desc_cmd_sett, command_line::arg_data_dir, default_data_path.string());
+  command_line::add_arg(desc_cmd_sett, command_line::arg_testnet_data_dir, default_testnet_data_path.string());
+  command_line::add_arg(desc_cmd_sett, arg_log_level);
+  command_line::add_arg(desc_cmd_sett, arg_batch_size);
+  command_line::add_arg(desc_cmd_sett, arg_testnet_on);
+  command_line::add_arg(desc_cmd_sett, arg_block_number);
+
+  command_line::add_arg(desc_cmd_only, command_line::arg_help);
+
+  const command_line::arg_descriptor<bool> arg_batch  =  {"batch",
+    "Batch transactions for faster import", true};
+  const command_line::arg_descriptor<bool> arg_resume =  {"resume",
+        "Resume from current height if output database already exists", true};
+
+  // call add_options() directly for these arguments since command_line helpers
+  // support only boolean switch, not boolean argument
+  desc_cmd_sett.add_options()
+    (arg_batch.name,  make_semantic(arg_batch),  arg_batch.description)
+    (arg_resume.name, make_semantic(arg_resume), arg_resume.description)
+    ;
+
+  po::options_description desc_options("Allowed options");
+  desc_options.add(desc_cmd_only).add(desc_cmd_sett);
+
+
+  po::variables_map vm;
+  bool r = command_line::handle_error_helper(desc_options, [&]()
+  {
+    po::store(po::parse_command_line(argc, argv, desc_options), vm);
+    po::notify(vm);
+
+    return true;
+  });
+  if (!r)
+    return 1;
+
+  int log_level = command_line::get_arg(vm, arg_log_level);
+  opt_batch     = command_line::get_arg(vm, arg_batch);
+  opt_resume    = command_line::get_arg(vm, arg_resume);
+  db_batch_size = command_line::get_arg(vm, arg_batch_size);
+
+  if (command_line::get_arg(vm, command_line::arg_help))
+  {
+    std::cout << CRYPTONOTE_NAME << " v" << MONERO_VERSION_FULL << ENDL << ENDL;
+    std::cout << desc_options << std::endl;
+    return 1;
+  }
+
+  if (! opt_batch && ! vm["batch-size"].defaulted())
+  {
+    std::cerr << "Error: batch-size set, but batch option not enabled" << ENDL;
+    return 1;
+  }
+  if (! db_batch_size)
+  {
+    std::cerr << "Error: batch-size must be > 0" << ENDL;
+    return 1;
+  }
+
+  log_space::get_set_log_detalisation_level(true, log_level);
+  log_space::log_singletone::add_logger(LOGGER_CONSOLE, NULL, NULL);
+  LOG_PRINT_L0("Starting...");
+
+  std::string src_folder;
+  opt_testnet = command_line::get_arg(vm, arg_testnet_on);
+  auto data_dir_arg = opt_testnet ? command_line::arg_testnet_data_dir : command_line::arg_data_dir;
+  src_folder = command_line::get_arg(vm, data_dir_arg);
+  boost::filesystem::path dest_folder(src_folder);
+
+  num_blocks = command_line::get_arg(vm, arg_block_number);
+
+  if (opt_batch)
+  {
+    LOG_PRINT_L0("batch:   " << std::boolalpha << opt_batch << std::noboolalpha
+        << "  batch size: " << db_batch_size);
+  }
+  else
+  {
+    LOG_PRINT_L0("batch:   " << std::boolalpha << opt_batch << std::noboolalpha);
+  }
+  LOG_PRINT_L0("resume:  " << std::boolalpha << opt_resume  << std::noboolalpha);
+  LOG_PRINT_L0("testnet: " << std::boolalpha << opt_testnet << std::noboolalpha);
+
+  fake_core c(src_folder, opt_testnet);
+
+  height = c.m_storage.get_current_blockchain_height();
+
+  BlockchainDB *blockchain;
+  blockchain = new BlockchainLMDB(opt_batch);
+  dest_folder /= blockchain->get_db_name();
+  LOG_PRINT_L0("Source blockchain: " << src_folder);
+  LOG_PRINT_L0("Dest blockchain:   " << dest_folder.string());
+  LOG_PRINT_L0("Opening dest blockchain (BlockchainDB " << blockchain->get_db_name() << ")");
+  blockchain->open(dest_folder.string());
+  LOG_PRINT_L0("Source blockchain height: " << height);
+  LOG_PRINT_L0("Dest blockchain height:   " << blockchain->height());
+
+  if (opt_resume)
+    // next block number to add is same as current height
+    start_block = blockchain->height();
+
+  if (! num_blocks || (start_block + num_blocks > height))
+    end_block = height - 1;
+  else
+    end_block = start_block + num_blocks - 1;
+
+  LOG_PRINT_L0("start height: " << start_block+1 << "  stop height: " <<
+            end_block+1);
+
+  if (start_block > end_block)
+  {
+    LOG_PRINT_L0("Finished: no blocks to add");
+    delete blockchain;
+    return 0;
+  }
+
+  if (opt_batch)
+    blockchain->batch_start();
+  uint64_t i = 0;
+  for (i = start_block; i < end_block + 1; ++i)
+  {
+    // block: i  height: i+1  end height: end_block + 1
+    if ((i+1) % 10 == 0)
+    {
+      std::cout << "\r                   \r" << "height " << i+1 << "/" <<
+        end_block+1 << " (" << (i+1)*100/(end_block+1)<< "%)" << std::flush;
+    }
+    // for debugging:
+    // std::cout << "height " << i+1 << "/" << end_block+1
+    //   << " ((" << i+1 << ")*100/(end_block+1))" << "%)" << ENDL;
+
+    block b = c.m_storage.get_block(i);
+    size_t bsize = c.m_storage.get_block_size(i);
+    difficulty_type bdiff = c.m_storage.get_block_cumulative_difficulty(i);
+    uint64_t bcoins = c.m_storage.get_block_coins_generated(i);
+    std::vector<transaction> txs;
+    std::vector<crypto::hash> missed;
+
+    c.m_storage.get_transactions(b.tx_hashes, txs, missed);
+    if (missed.size())
+    {
+      std::cout << ENDL;
+      std::cerr << "Missed transaction(s) for block at height " << i + 1 << ", exiting" << ENDL;
+      delete blockchain;
+      return 1;
+    }
+
+    try
+    {
+      blockchain->add_block(b, bsize, bdiff, bcoins, txs);
+
+      if (opt_batch)
+      {
+        if ((i < end_block) && ((i + 1) % db_batch_size == 0))
+        {
+          std::cout << "\r                   \r";
+          std::cout << "[- batch commit at height " << i + 1 << " -]" << ENDL;
+          blockchain->batch_stop();
+          blockchain->batch_start();
+          std::cout << ENDL;
+          blockchain->show_stats();
+        }
+      }
+    }
+    catch (const std::exception& e)
+    {
+      std::cout << ENDL;
+      std::cerr << "Error adding block " << i << " to new blockchain: " << e.what() << ENDL;
+      delete blockchain;
+      return 2;
+    }
+  }
+  if (opt_batch)
+  {
+    std::cout << "\r                   \r" << "height " << i << "/" <<
+      end_block+1 << " (" << (i)*100/(end_block+1)<< "%)" << std::flush;
+    std::cout << ENDL;
+    std::cout << "[- batch commit at height " << i << " -]" << ENDL;
+    blockchain->batch_stop();
+  }
+  std::cout << ENDL;
+  blockchain->show_stats();
+  std::cout << "Finished at height: " << i << "  block: " << i-1 << ENDL;
+
+  delete blockchain;
+  return 0;
+}
diff --git a/src/blockchain_converter/blockchain_export.cpp b/src/blockchain_converter/blockchain_export.cpp
new file mode 100644
index 000000000..dc5c7cadc
--- /dev/null
+++ b/src/blockchain_converter/blockchain_export.cpp
@@ -0,0 +1,396 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <algorithm>
+#include <cstdio>
+#include <fstream>
+#include <boost/iostreams/copy.hpp>
+#include <atomic>
+
+#include <boost/archive/binary_oarchive.hpp>
+#include <boost/archive/binary_iarchive.hpp>
+#include <boost/iostreams/stream_buffer.hpp>
+#include <boost/iostreams/stream.hpp>
+#include <boost/iostreams/device/back_inserter.hpp>
+#include <boost/iostreams/filtering_streambuf.hpp>
+#include <boost/iostreams/filter/bzip2.hpp>
+#include "common/command_line.h"
+#include "version.h"
+#include "blockchain_export.h"
+#include "cryptonote_core/cryptonote_boost_serialization.h"
+
+#include "import.h"
+
+unsigned int epee::g_test_dbg_lock_sleep = 0;
+
+static int max_chunk = 0;
+static size_t height;
+
+namespace po = boost::program_options;
+
+using namespace cryptonote;
+using namespace epee;
+
+bool BlockchainExport::open(const boost::filesystem::path& dir_path)
+{
+  if (boost::filesystem::exists(dir_path))
+  {
+    if (!boost::filesystem::is_directory(dir_path))
+    {
+      LOG_PRINT_RED_L0("export directory path is a file: " << dir_path);
+      return false;
+    }
+  }
+  else
+  {
+    if (!boost::filesystem::create_directory(dir_path))
+    {
+      LOG_PRINT_RED_L0("Failed to create directory " << dir_path);
+      return false;
+    }
+  }
+
+  std::string file_path = (dir_path / BLOCKCHAIN_RAW).string();
+  m_raw_data_file = new std::ofstream();
+  m_raw_data_file->open(file_path , std::ios_base::binary | std::ios_base::out| std::ios::trunc);
+  if (m_raw_data_file->fail())
+    return false;
+
+  m_output_stream = new boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>>(m_buffer);
+  m_raw_archive = new boost::archive::binary_oarchive(*m_output_stream);
+  if (m_raw_archive == NULL)
+    return false;
+
+  return true;
+}
+
+void BlockchainExport::flush_chunk()
+{
+  m_output_stream->flush();
+  char buffer[STR_LENGTH_OF_INT + 1];
+  int chunk_size = (int) m_buffer.size();
+  if (chunk_size > BUFFER_SIZE)
+  {
+    LOG_PRINT_L0("WARNING: chunk_size " << chunk_size << " > BUFFER_SIZE " << BUFFER_SIZE);
+  }
+  sprintf(buffer, STR_FORMAT_OF_INT, chunk_size);
+  m_raw_data_file->write(buffer, STR_LENGTH_OF_INT);
+  if (max_chunk < chunk_size)
+  {
+    max_chunk = chunk_size;
+  }
+  long pos_before = m_raw_data_file->tellp();
+  std::copy(m_buffer.begin(), m_buffer.end(), std::ostreambuf_iterator<char>(*m_raw_data_file));
+  m_raw_data_file->flush();
+  long pos_after = m_raw_data_file->tellp();
+  long num_chars_written = pos_after - pos_before;
+  if ((int) num_chars_written != chunk_size)
+  {
+    LOG_PRINT_RED_L0("INTERNAL ERROR: num chars wrote NEQ buffer size. height = " << height);
+  }
+
+  m_buffer.clear();
+  delete m_raw_archive;
+  delete m_output_stream;
+  m_output_stream = new boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>>(m_buffer);
+  m_raw_archive = new boost::archive::binary_oarchive(*m_output_stream);
+}
+
+void BlockchainExport::serialize_block_to_text_buffer(const block& block)
+{
+  *m_raw_archive << block;
+}
+
+void BlockchainExport::buffer_serialize_tx(const transaction& tx)
+{
+  *m_raw_archive << tx;
+}
+
+void BlockchainExport::buffer_write_num_txs(const std::list<transaction> txs)
+{
+  int n = txs.size();
+  *m_raw_archive << n;
+}
+
+void BlockchainExport::write_block(block& block)
+{
+  serialize_block_to_text_buffer(block);
+  std::list<transaction> txs;
+
+  uint64_t block_height = boost::get<txin_gen>(block.miner_tx.vin.front()).height;
+
+  // put coinbase transaction first
+  transaction coinbase_tx = block.miner_tx;
+  crypto::hash coinbase_tx_hash = get_transaction_hash(coinbase_tx);
+#if SOURCE_DB == DB_MEMORY
+  const transaction* cb_tx_full = m_blockchain_storage->get_tx(coinbase_tx_hash);
+#else
+  transaction cb_tx_full = m_blockchain_storage->get_db().get_tx(coinbase_tx_hash);
+#endif
+
+#if SOURCE_DB == DB_MEMORY
+  if (cb_tx_full != NULL)
+  {
+    txs.push_back(*cb_tx_full);
+  }
+#else
+  // TODO: should check and abort if cb_tx_full equals null_hash?
+  txs.push_back(cb_tx_full);
+#endif
+
+  // now add all regular transactions
+  BOOST_FOREACH(const auto& tx_id, block.tx_hashes)
+  {
+#if SOURCE_DB == DB_MEMORY
+    const transaction* tx = m_blockchain_storage->get_tx(tx_id);
+#else
+    transaction tx = m_blockchain_storage->get_db().get_tx(tx_id);
+#endif
+
+#if SOURCE_DB == DB_MEMORY
+    if(tx == NULL)
+    {
+      if (! m_tx_pool)
+        throw std::runtime_error("Aborting: tx == NULL, so memory pool required to get tx, but memory pool isn't enabled");
+      else
+      {
+        transaction tx;
+        if(m_tx_pool->get_transaction(tx_id, tx))
+          txs.push_back(tx);
+        else
+          throw std::runtime_error("Aborting: tx not found in pool");
+      }
+    }
+    else
+      txs.push_back(*tx);
+#else
+    txs.push_back(tx);
+#endif
+  }
+
+  // serialize all txs to the persistant storage
+  buffer_write_num_txs(txs);
+  BOOST_FOREACH(const auto& tx, txs)
+  {
+    buffer_serialize_tx(tx);
+  }
+
+  // These three attributes are currently necessary for a fast import that adds blocks without verification.
+  bool include_extra_block_data = true;
+  if (include_extra_block_data)
+  {
+#if SOURCE_DB == DB_MEMORY
+    size_t block_size = m_blockchain_storage->get_block_size(block_height);
+#else
+    size_t block_size = m_blockchain_storage->get_db().get_block_size(block_height);
+#endif
+#if SOURCE_DB == DB_MEMORY
+    difficulty_type cumulative_difficulty = m_blockchain_storage->get_block_cumulative_difficulty(block_height);
+#else
+    difficulty_type cumulative_difficulty = m_blockchain_storage->get_db().get_block_cumulative_difficulty(block_height);
+#endif
+#if SOURCE_DB == DB_MEMORY
+    uint64_t coins_generated = m_blockchain_storage->get_block_coins_generated(block_height);
+#else
+    // TODO TEST to verify that this is the equivalent. make sure no off-by-one error with block height vs block number
+    uint64_t coins_generated = m_blockchain_storage->get_db().get_block_already_generated_coins(block_height);
+#endif
+
+    *m_raw_archive << block_size;
+    *m_raw_archive << cumulative_difficulty;
+    *m_raw_archive << coins_generated;
+  }
+}
+
+bool BlockchainExport::BlockchainExport::close()
+{
+  if (m_raw_data_file->fail())
+    return false;
+
+  m_raw_data_file->flush();
+  delete m_raw_archive;
+  delete m_output_stream;
+  delete m_raw_data_file;
+  return true;
+}
+
+
+#if SOURCE_DB == DB_MEMORY
+bool BlockchainExport::store_blockchain_raw(blockchain_storage* _blockchain_storage, tx_memory_pool* _tx_pool, boost::filesystem::path& output_dir, uint64_t requested_block_height)
+#else
+bool BlockchainExport::store_blockchain_raw(Blockchain* _blockchain_storage, tx_memory_pool* _tx_pool, boost::filesystem::path& output_dir, uint64_t requested_block_height)
+#endif
+{
+  uint64_t block_height = 0;
+  m_blockchain_storage = _blockchain_storage;
+  m_tx_pool = _tx_pool;
+  uint64_t progress_interval = 100;
+  std::string refresh_string = "\r                                    \r";
+  LOG_PRINT_L0("Storing blocks raw data...");
+  if (!BlockchainExport::open(output_dir))
+  {
+    LOG_PRINT_RED_L0("failed to open raw file for write");
+    return false;
+  }
+  block b;
+  LOG_PRINT_L0("source blockchain height: " <<  m_blockchain_storage->get_current_blockchain_height());
+  LOG_PRINT_L0("requested block height: " << requested_block_height);
+  if ((requested_block_height > 0) && (requested_block_height < m_blockchain_storage->get_current_blockchain_height()))
+    block_height = requested_block_height;
+  else
+  {
+    block_height = m_blockchain_storage->get_current_blockchain_height();
+    LOG_PRINT_L0("Using block height of source blockchain: " << block_height);
+  }
+  for (height=0; height < block_height; ++height)
+  {
+    crypto::hash hash = m_blockchain_storage->get_block_id_by_height(height);
+    m_blockchain_storage->get_block_by_hash(hash, b);
+    write_block(b);
+    if (height % NUM_BLOCKS_PER_CHUNK == 0) {
+      flush_chunk();
+    }
+    if (height % progress_interval == 0) {
+      std::cout << refresh_string;
+      std::cout << "height " << height << "/" << block_height << std::flush;
+    }
+  }
+  if (height % NUM_BLOCKS_PER_CHUNK != 0)
+  {
+    flush_chunk();
+  }
+  std::cout << refresh_string;
+  std::cout << "height " << height << "/" << block_height << ENDL;
+
+  LOG_PRINT_L0("longest chunk was " << max_chunk << " bytes");
+  return BlockchainExport::close();
+}
+
+
+int main(int argc, char* argv[])
+{
+  uint32_t log_level = 0;
+  uint64_t block_height = 0;
+  std::string import_filename = BLOCKCHAIN_RAW;
+
+  boost::filesystem::path default_data_path {tools::get_default_data_dir()};
+  boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
+
+  po::options_description desc_cmd_only("Command line options");
+  po::options_description desc_cmd_sett("Command line options and settings options");
+  const command_line::arg_descriptor<uint32_t> arg_log_level   =  {"log-level",  "", log_level};
+  const command_line::arg_descriptor<uint64_t> arg_block_height =  {"block-number", "", block_height};
+  const command_line::arg_descriptor<bool>     arg_testnet_on  = {
+    "testnet"
+      , "Run on testnet."
+      , false
+  };
+
+
+  command_line::add_arg(desc_cmd_sett, command_line::arg_data_dir, default_data_path.string());
+  command_line::add_arg(desc_cmd_sett, command_line::arg_testnet_data_dir, default_testnet_data_path.string());
+  command_line::add_arg(desc_cmd_sett, arg_log_level);
+  command_line::add_arg(desc_cmd_sett, arg_block_height);
+  command_line::add_arg(desc_cmd_sett, arg_testnet_on);
+
+  command_line::add_arg(desc_cmd_only, command_line::arg_help);
+
+  po::options_description desc_options("Allowed options");
+  desc_options.add(desc_cmd_only).add(desc_cmd_sett);
+
+  po::variables_map vm;
+  bool r = command_line::handle_error_helper(desc_options, [&]()
+  {
+    po::store(po::parse_command_line(argc, argv, desc_options), vm);
+    po::notify(vm);
+    return true;
+  });
+  if (! r)
+    return 1;
+
+  if (command_line::get_arg(vm, command_line::arg_help))
+  {
+    std::cout << CRYPTONOTE_NAME << " v" << MONERO_VERSION_FULL << ENDL << ENDL;
+    std::cout << desc_options << std::endl;
+    return 1;
+  }
+
+  log_level    = command_line::get_arg(vm, arg_log_level);
+  block_height = command_line::get_arg(vm, arg_block_height);
+
+  log_space::get_set_log_detalisation_level(true, log_level);
+  log_space::log_singletone::add_logger(LOGGER_CONSOLE, NULL, NULL);
+  LOG_PRINT_L0("Starting...");
+  LOG_PRINT_L0("Setting log level = " << log_level);
+
+  bool opt_testnet = command_line::get_arg(vm, arg_testnet_on);
+
+  std::string m_config_folder;
+
+  auto data_dir_arg = opt_testnet ? command_line::arg_testnet_data_dir : command_line::arg_data_dir;
+  m_config_folder = command_line::get_arg(vm, data_dir_arg);
+  boost::filesystem::path output_dir {m_config_folder};
+  output_dir /= "export";
+  LOG_PRINT_L0("Export directory: " << output_dir.string());
+
+  // If we wanted to use the memory pool, we would set up a fake_core.
+
+#if SOURCE_DB == DB_MEMORY
+  // blockchain_storage* core_storage = NULL;
+  // tx_memory_pool m_mempool(*core_storage); // is this fake anyway? just passing in NULL! so m_mempool can't be used anyway, right?
+  // core_storage = new blockchain_storage(&m_mempool);
+
+  blockchain_storage* core_storage = new blockchain_storage(NULL);
+  LOG_PRINT_L0("Initializing source blockchain (in-memory database)");
+  r = core_storage->init(m_config_folder, opt_testnet);
+#else
+  // Use Blockchain instead of lower-level BlockchainDB for two reasons:
+  // 1. Blockchain has the init() method for easy setup
+  // 2. exporter needs to use get_current_blockchain_height(), get_block_id_by_height(), get_block_by_hash()
+  //
+  // cannot match blockchain_storage setup above with just one line,
+  // e.g.
+  //   Blockchain* core_storage = new Blockchain(NULL);
+  // because unlike blockchain_storage constructor, which takes a pointer to
+  // tx_memory_pool, Blockchain's constructor takes tx_memory_pool object.
+  LOG_PRINT_L0("Initializing source blockchain (BlockchainDB)");
+  Blockchain* core_storage = NULL;
+  tx_memory_pool m_mempool(*core_storage);
+  core_storage = new Blockchain(m_mempool);
+  r = core_storage->init(m_config_folder, opt_testnet);
+#endif
+
+  CHECK_AND_ASSERT_MES(r, false, "Failed to initialize source blockchain storage");
+  LOG_PRINT_L0("Source blockchain storage initialized OK");
+  LOG_PRINT_L0("Exporting blockchain raw data...");
+
+  BlockchainExport be;
+  r = be.store_blockchain_raw(core_storage, NULL, output_dir, block_height);
+  CHECK_AND_ASSERT_MES(r, false, "Failed to export blockchain raw data");
+  LOG_PRINT_L0("Blockchain raw data exported OK");
+}
diff --git a/src/blockchain_converter/blockchain_export.h b/src/blockchain_converter/blockchain_export.h
new file mode 100644
index 000000000..43e25c039
--- /dev/null
+++ b/src/blockchain_converter/blockchain_export.h
@@ -0,0 +1,87 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include <boost/archive/binary_oarchive.hpp>
+#include <boost/iostreams/stream_buffer.hpp>
+#include <boost/iostreams/stream.hpp>
+#include <boost/iostreams/device/back_inserter.hpp>
+#include "cryptonote_core/cryptonote_basic.h"
+#include "cryptonote_core/blockchain_storage.h"
+#include "cryptonote_core/blockchain.h"
+#include "blockchain_db/blockchain_db.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+
+// CONFIG: choose one of the three #define's
+//
+// DB_MEMORY is a sensible default for users migrating to LMDB, as it allows
+// the exporter to use the in-memory blockchain while the other binaries
+// work with LMDB, without recompiling anything.
+//
+#define SOURCE_DB DB_MEMORY
+// #define SOURCE_DB DB_LMDB
+// to use global compile-time setting (DB_MEMORY or DB_LMDB):
+// #define SOURCE_DB BLOCKCHAIN_DB
+
+using namespace cryptonote;
+
+class BlockchainExport
+{
+public:
+#if SOURCE_DB == DB_MEMORY
+  bool store_blockchain_raw(cryptonote::blockchain_storage* cs, cryptonote::tx_memory_pool* txp,
+      boost::filesystem::path& output_dir, uint64_t use_block_height=0);
+#else
+  bool store_blockchain_raw(cryptonote::Blockchain* cs, cryptonote::tx_memory_pool* txp,
+      boost::filesystem::path& output_dir, uint64_t use_block_height=0);
+#endif
+
+protected:
+#if SOURCE_DB == DB_MEMORY
+  blockchain_storage* m_blockchain_storage;
+#else
+  Blockchain* m_blockchain_storage;
+#endif
+
+  tx_memory_pool* m_tx_pool;
+  typedef std::vector<char> buffer_type;
+  std::ofstream * m_raw_data_file;
+  boost::archive::binary_oarchive * m_raw_archive;
+  buffer_type m_buffer;
+  boost::iostreams::stream<boost::iostreams::back_insert_device<buffer_type>>* m_output_stream;
+
+  // open export file for write
+  bool open(const boost::filesystem::path& dir_path);
+  bool close();
+  void write_block(block& block);
+  void serialize_block_to_text_buffer(const block& block);
+  void buffer_serialize_tx(const transaction& tx);
+  void buffer_write_num_txs(const std::list<transaction> txs);
+  void flush_chunk();
+};
diff --git a/src/blockchain_converter/blockchain_import.cpp b/src/blockchain_converter/blockchain_import.cpp
new file mode 100644
index 000000000..6b432ccc6
--- /dev/null
+++ b/src/blockchain_converter/blockchain_import.cpp
@@ -0,0 +1,756 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <atomic>
+#include <cstdio>
+#include <algorithm>
+#include <fstream>
+
+#include <boost/filesystem.hpp>
+#include <boost/iostreams/stream.hpp>
+#include <boost/archive/binary_iarchive.hpp>
+#include "cryptonote_core/cryptonote_basic.h"
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "cryptonote_core/cryptonote_boost_serialization.h"
+#include "serialization/json_utils.h" // dump_json()
+#include "include_base_utils.h"
+#include "common/command_line.h"
+#include "version.h"
+
+#include <lmdb.h> // for db flag arguments
+
+#include "import.h"
+#include "fake_core.h"
+
+unsigned int epee::g_test_dbg_lock_sleep = 0;
+
+// CONFIG
+static bool opt_batch   = true;
+static bool opt_verify  = true; // use add_new_block, which does verification before calling add_block
+static bool opt_resume  = true;
+static bool opt_testnet = true;
+
+// number of blocks per batch transaction
+// adjustable through command-line argument according to available RAM
+static uint64_t db_batch_size = 20000;
+
+static std::string refresh_string = "\r                                    \r";
+
+
+namespace po = boost::program_options;
+
+using namespace cryptonote;
+using namespace epee;
+
+
+int parse_db_arguments(const std::string& db_arg_str, std::string& db_engine, int& mdb_flags)
+{
+  std::vector<std::string> db_args;
+  boost::split(db_args, db_arg_str, boost::is_any_of("#"));
+  db_engine = db_args.front();
+  boost::algorithm::trim(db_engine);
+
+  if (db_args.size() == 1)
+  {
+    return 0;
+  }
+  else if (db_args.size() > 2)
+  {
+    std::cerr << "unrecognized database argument format: " << db_arg_str << ENDL;
+    return 1;
+  }
+
+  std::string db_arg_str2 = db_args[1];
+  boost::split(db_args, db_arg_str2, boost::is_any_of(","));
+  for (auto& it : db_args)
+  {
+    boost::algorithm::trim(it);
+    if (it.empty())
+      continue;
+    LOG_PRINT_L1("LMDB flag: " << it);
+    if (it == "nosync")
+    {
+      mdb_flags |= MDB_NOSYNC;
+    }
+    else if (it == "nometasync")
+    {
+      mdb_flags |= MDB_NOMETASYNC;
+    }
+    else if (it == "writemap")
+    {
+      mdb_flags |= MDB_WRITEMAP;
+    }
+    else if (it == "mapasync")
+    {
+      mdb_flags |= MDB_MAPASYNC;
+    }
+    else
+    {
+      std::cerr << "unrecognized database flag: " << it << ENDL;
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+int count_blocks(std::string& import_file_path)
+{
+  boost::filesystem::path raw_file_path(import_file_path);
+  boost::system::error_code ec;
+  if (!boost::filesystem::exists(raw_file_path, ec))
+  {
+    LOG_PRINT_L0("import file not found: " << raw_file_path);
+    throw std::runtime_error("Aborting");
+  }
+  std::ifstream import_file;
+  import_file.open(import_file_path, std::ios_base::binary | std::ifstream::in);
+
+  uint64_t h = 0;
+  if (import_file.fail())
+  {
+    LOG_PRINT_L0("import_file.open() fail");
+    throw std::runtime_error("Aborting");
+  }
+  LOG_PRINT_L0("Scanning blockchain from import file...");
+  char buffer1[STR_LENGTH_OF_INT + 1];
+  block b;
+  transaction tx;
+  bool quit = false;
+  uint64_t bytes_read = 0;
+  int progress_interval = 10;
+
+  while (! quit)
+  {
+    int chunk_size;
+    import_file.read(buffer1, STR_LENGTH_OF_INT);
+    if (!import_file) {
+      std::cout << refresh_string;
+      LOG_PRINT_L1("End of import file reached");
+      quit = true;
+      break;
+    }
+    h += NUM_BLOCKS_PER_CHUNK;
+    if (h % progress_interval == 0)
+    {
+      std::cout << refresh_string << "block height: " << h <<
+        std::flush;
+    }
+    bytes_read += STR_LENGTH_OF_INT;
+    buffer1[STR_LENGTH_OF_INT] = '\0';
+    chunk_size = atoi(buffer1);
+    if (chunk_size > BUFFER_SIZE)
+    {
+      std::cout << refresh_string;
+      LOG_PRINT_L0("WARNING: chunk_size " << chunk_size << " > BUFFER_SIZE " << BUFFER_SIZE
+          << "  height: " << h);
+      throw std::runtime_error("Aborting: chunk size exceeds buffer size");
+    }
+    if (chunk_size > 100000)
+    {
+      std::cout << refresh_string;
+      LOG_PRINT_L0("WARNING: chunk_size " << chunk_size << " > 100000" << "  height: "
+          << h);
+    }
+    else if (chunk_size <= 0) {
+      std::cout << refresh_string;
+      LOG_PRINT_L0("ERROR: chunk_size " << chunk_size << " <= 0" << "  height: " << h);
+      throw std::runtime_error("Aborting");
+    }
+    // skip to next expected block size value
+    import_file.seekg(chunk_size, std::ios_base::cur);
+    if (! import_file) {
+      std::cout << refresh_string;
+      LOG_PRINT_L0("ERROR: unexpected end of import file: bytes read before error: "
+          << import_file.gcount() << " of chunk_size " << chunk_size);
+      throw std::runtime_error("Aborting");
+    }
+    bytes_read += chunk_size;
+    std::cout << refresh_string;
+
+    LOG_PRINT_L3("Total bytes scanned: " << bytes_read);
+  }
+
+  import_file.close();
+
+  std::cout << ENDL;
+  std::cout << "Done scanning import file" << ENDL;
+  std::cout << "Total bytes scanned: " << bytes_read << ENDL;
+  std::cout << "Height: " << h << ENDL;
+
+  return h;
+}
+
+template <typename FakeCore>
+int import_from_file(FakeCore& simple_core, std::string& import_file_path)
+{
+#if !defined(BLOCKCHAIN_DB)
+  static_assert(std::is_same<fake_core_memory, FakeCore>::value || std::is_same<fake_core_lmdb, FakeCore>::value,
+      "FakeCore constraint error");
+#endif
+#if !defined(BLOCKCHAIN_DB) || (BLOCKCHAIN_DB == DB_LMDB)
+  if (std::is_same<fake_core_lmdb, FakeCore>::value)
+  {
+    // Reset stats, in case we're using newly created db, accumulating stats
+    // from addition of genesis block.
+    // This aligns internal db counts with importer counts.
+    simple_core.m_storage.get_db().reset_stats();
+  }
+#endif
+  boost::filesystem::path raw_file_path(import_file_path);
+  boost::system::error_code ec;
+  if (!boost::filesystem::exists(raw_file_path, ec))
+  {
+    LOG_PRINT_L0("import file not found: " << raw_file_path);
+    return false;
+  }
+
+  uint64_t source_height = count_blocks(import_file_path);
+  LOG_PRINT_L0("import file blockchain height: " << source_height);
+
+  std::ifstream import_file;
+  import_file.open(import_file_path, std::ios_base::binary | std::ifstream::in);
+
+  uint64_t h = 0;
+  if (import_file.fail())
+  {
+    LOG_PRINT_L0("import_file.open() fail");
+    return false;
+  }
+  char buffer1[STR_LENGTH_OF_INT + 1];
+  char buffer_block[BUFFER_SIZE];
+  block b;
+  transaction tx;
+  int quit = 0;
+  uint64_t bytes_read = 0;
+
+  uint64_t start_height = 1;
+  if (opt_resume)
+    start_height = simple_core.m_storage.get_current_blockchain_height();
+
+  // Note that a new blockchain will start with a height of 1 (block number 0)
+  // due to genesis block being added at initialization.
+
+  // CONFIG
+  // TODO: can expand on this, e.g. with --block-number option
+  uint64_t stop_height = source_height;
+
+  // These are what we'll try to use, and they don't have to be a determination
+  // from source and destination blockchains, but those are the current
+  // defaults.
+  LOG_PRINT_L0("start height: " << start_height << "  stop height: " <<
+      stop_height);
+
+  bool use_batch = false;
+  if (opt_batch)
+  {
+    if (simple_core.support_batch)
+      use_batch = true;
+    else
+      LOG_PRINT_L0("WARNING: batch transactions enabled but unsupported or unnecessary for this database engine - ignoring");
+  }
+
+  if (use_batch)
+    simple_core.batch_start();
+
+  LOG_PRINT_L0("Reading blockchain from import file...");
+  std::cout << ENDL;
+
+  // Within the loop, we skip to start_height before we start adding.
+  // TODO: Not a bottleneck, but we can use what's done in count_blocks() and
+  // only do the chunk size reads, skipping the chunk content reads until we're
+  // at start_height.
+  while (! quit)
+  {
+    int chunk_size;
+    import_file.read(buffer1, STR_LENGTH_OF_INT);
+    if (! import_file) {
+      std::cout << refresh_string;
+      LOG_PRINT_L0("End of import file reached");
+      quit = 1;
+      break;
+    }
+    bytes_read += STR_LENGTH_OF_INT;
+    buffer1[STR_LENGTH_OF_INT] = '\0';
+    chunk_size = atoi(buffer1);
+    if (chunk_size > BUFFER_SIZE)
+    {
+      LOG_PRINT_L0("WARNING: chunk_size " << chunk_size << " > BUFFER_SIZE " << BUFFER_SIZE);
+      throw std::runtime_error("Aborting: chunk size exceeds buffer size");
+    }
+    if (chunk_size > 100000)
+    {
+      LOG_PRINT_L0("WARNING: chunk_size " << chunk_size << " > 100000");
+    }
+    else if (chunk_size < 0) {
+      LOG_PRINT_L0("ERROR: chunk_size " << chunk_size << " < 0");
+      return 2;
+    }
+    import_file.read(buffer_block, chunk_size);
+    if (! import_file) {
+      LOG_PRINT_L0("ERROR: unexpected end of import file: bytes read before error: "
+          << import_file.gcount() << " of chunk_size " << chunk_size);
+      return 2;
+    }
+    bytes_read += chunk_size;
+    LOG_PRINT_L3("Total bytes read: " << bytes_read);
+
+    if (h + NUM_BLOCKS_PER_CHUNK < start_height + 1)
+    {
+      h += NUM_BLOCKS_PER_CHUNK;
+      continue;
+    }
+    if (h > stop_height)
+    {
+      LOG_PRINT_L0("Specified height reached - stopping.  height: " << h << "  block: " << h-1);
+      quit = 1;
+      break;
+    }
+
+    try
+    {
+      boost::iostreams::basic_array_source<char> device(buffer_block, chunk_size);
+      boost::iostreams::stream<boost::iostreams::basic_array_source<char>> s(device);
+      boost::archive::binary_iarchive a(s);
+
+      int display_interval = 1000;
+      int progress_interval = 10;
+      for (int chunk_ind = 0; chunk_ind < NUM_BLOCKS_PER_CHUNK; chunk_ind++)
+      {
+        h++;
+        if (h % display_interval == 0)
+        {
+          std::cout << refresh_string;
+          LOG_PRINT_L0("loading block height " << h);
+        }
+        else
+        {
+          LOG_PRINT_L3("loading block height " << h);
+        }
+        try {
+          a >> b;
+        }
+        catch (const std::exception& e)
+        {
+          std::cout << refresh_string;
+          LOG_PRINT_RED_L0("exception while de-archiving block, height=" << h);
+          quit = 1;
+          break;
+        }
+        LOG_PRINT_L2("block prev_id: " << b.prev_id << ENDL);
+
+        if (h % progress_interval == 0)
+        {
+          std::cout << refresh_string << "block " << h-1
+            << std::flush;
+        }
+
+        std::vector<transaction> txs;
+
+        int num_txs;
+        try
+        {
+          a >> num_txs;
+        }
+        catch (const std::exception& e)
+        {
+          std::cout << refresh_string;
+          LOG_PRINT_RED_L0("exception while de-archiving tx-num, height=" << h);
+          quit = 1;
+          break;
+        }
+        for(int tx_num = 1; tx_num <= num_txs; tx_num++)
+        {
+          try {
+                a >> tx;
+          }
+          catch (const std::exception& e)
+          {
+            LOG_PRINT_RED_L0("exception while de-archiving tx, height=" << h <<", tx_num=" << tx_num);
+            quit = 1;
+            break;
+          }
+          // if (tx_num == 1) {
+          //   std::cout << "coinbase transaction" << ENDL;
+          // }
+          // crypto::hash hsh = null_hash;
+          // size_t blob_size = 0;
+          // NOTE: all tx hashes except for coinbase tx are available in the block data
+          // get_transaction_hash(tx, hsh, blob_size);
+          // LOG_PRINT_L0("tx " << tx_num << "  " << hsh << " : " << ENDL);
+          // LOG_PRINT_L0(obj_to_json_str(tx) << ENDL);
+
+          // add blocks with verification.
+          // for Blockchain and blockchain_storage add_new_block().
+          if (opt_verify)
+          {
+            if (tx_num == 1) {
+              continue; // coinbase transaction. no need to insert to tx_pool.
+            }
+            // crypto::hash hsh = null_hash;
+            // size_t blob_size = 0;
+            // get_transaction_hash(tx, hsh, blob_size);
+            tx_verification_context tvc = AUTO_VAL_INIT(tvc);
+            bool r = true;
+            r = simple_core.m_pool.add_tx(tx, tvc, true);
+            if (!r)
+            {
+              LOG_PRINT_RED_L0("failed to add transaction to transaction pool, height=" << h <<", tx_num=" << tx_num);
+              quit = 1;
+              break;
+            }
+          }
+          else
+          {
+            // for add_block() method, without (much) processing.
+            // don't add coinbase transaction to txs.
+            //
+            // because add_block() calls
+            // add_transaction(blk_hash, blk.miner_tx) first, and
+            // then a for loop for the transactions in txs.
+            if (tx_num > 1)
+            {
+              txs.push_back(tx);
+            }
+          }
+        }
+
+        if (opt_verify)
+        {
+          block_verification_context bvc = boost::value_initialized<block_verification_context>();
+          simple_core.m_storage.add_new_block(b, bvc);
+
+          if (bvc.m_verifivation_failed)
+          {
+            LOG_PRINT_L0("Failed to add block to blockchain, verification failed, height = " << h);
+            LOG_PRINT_L0("skipping rest of import file");
+            // ok to commit previously batched data because it failed only in
+            // verification of potential new block with nothing added to batch
+            // yet
+            quit = 1;
+            break;
+          }
+          if (! bvc.m_added_to_main_chain)
+          {
+            LOG_PRINT_L0("Failed to add block to blockchain, height = " << h);
+            LOG_PRINT_L0("skipping rest of import file");
+            // make sure we don't commit partial block data
+            quit = 2;
+            break;
+          }
+        }
+        else
+        {
+          size_t block_size;
+          difficulty_type cumulative_difficulty;
+          uint64_t coins_generated;
+
+          a >> block_size;
+          a >> cumulative_difficulty;
+          a >> coins_generated;
+
+          std::cout << refresh_string;
+          LOG_PRINT_L2("block_size: " << block_size);
+          LOG_PRINT_L2("cumulative_difficulty: " << cumulative_difficulty);
+          LOG_PRINT_L2("coins_generated: " << coins_generated);
+
+          try
+          {
+            simple_core.add_block(b, block_size, cumulative_difficulty, coins_generated, txs);
+          }
+          catch (const std::exception& e)
+          {
+            std::cout << refresh_string;
+            LOG_PRINT_RED_L0("Error adding block to blockchain: " << e.what());
+            quit = 2; // make sure we don't commit partial block data
+            break;
+          }
+        }
+
+        if (use_batch)
+        {
+          if (h % db_batch_size == 0)
+          {
+            std::cout << refresh_string;
+            std::cout << ENDL << "[- batch commit at height " << h << " -]" << ENDL;
+            simple_core.batch_stop();
+            simple_core.batch_start();
+            std::cout << ENDL;
+#if !defined(BLOCKCHAIN_DB) || (BLOCKCHAIN_DB == DB_LMDB)
+            simple_core.m_storage.get_db().show_stats();
+#endif
+          }
+        }
+      }
+    }
+    catch (const std::exception& e)
+    {
+      std::cout << refresh_string;
+      LOG_PRINT_RED_L0("exception while reading from import file, height=" << h);
+      return 2;
+    }
+  } // while
+
+  import_file.close();
+
+  if (use_batch)
+  {
+    if (quit > 1)
+    {
+      // There was an error, so don't commit pending data.
+      // Destructor will abort write txn.
+    }
+    else
+    {
+      simple_core.batch_stop();
+    }
+#if !defined(BLOCKCHAIN_DB) || (BLOCKCHAIN_DB == DB_LMDB)
+    simple_core.m_storage.get_db().show_stats();
+#endif
+    if (h > 0)
+      LOG_PRINT_L0("Finished at height: " << h << "  block: " << h-1);
+  }
+  std::cout << ENDL;
+  return 0;
+}
+
+int main(int argc, char* argv[])
+{
+  std::string import_filename = BLOCKCHAIN_RAW;
+#if defined(BLOCKCHAIN_DB) && (BLOCKCHAIN_DB == DB_MEMORY)
+  std::string default_db_engine = "memory";
+#else
+  std::string default_db_engine = "lmdb";
+#endif
+
+  uint32_t log_level = LOG_LEVEL_0;
+  std::string dirname;
+  std::string db_arg_str;
+
+  boost::filesystem::path default_data_path {tools::get_default_data_dir()};
+  boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
+
+  po::options_description desc_cmd_only("Command line options");
+  po::options_description desc_cmd_sett("Command line options and settings options");
+  const command_line::arg_descriptor<uint32_t> arg_log_level   =  {"log-level",  "", log_level};
+  const command_line::arg_descriptor<uint64_t> arg_batch_size  =  {"batch-size", "", db_batch_size};
+  const command_line::arg_descriptor<bool>     arg_testnet_on  = {
+    "testnet"
+      , "Run on testnet."
+      , false
+  };
+  const command_line::arg_descriptor<bool>     arg_count_blocks = {
+    "count-blocks"
+      , "Count blocks in import file and exit"
+      , false
+  };
+  const command_line::arg_descriptor<std::string> arg_database = {
+    "database", "available: memory, lmdb"
+      , default_db_engine
+  };
+  const command_line::arg_descriptor<bool> arg_verify =  {"verify",
+    "Verify blocks and transactions during import", true};
+  const command_line::arg_descriptor<bool> arg_batch  =  {"batch",
+    "Batch transactions for faster import", true};
+  const command_line::arg_descriptor<bool> arg_resume =  {"resume",
+    "Resume from current height if output database already exists", true};
+
+  command_line::add_arg(desc_cmd_sett, command_line::arg_data_dir, default_data_path.string());
+  command_line::add_arg(desc_cmd_sett, command_line::arg_testnet_data_dir, default_testnet_data_path.string());
+  command_line::add_arg(desc_cmd_sett, arg_log_level);
+  command_line::add_arg(desc_cmd_sett, arg_batch_size);
+  command_line::add_arg(desc_cmd_sett, arg_testnet_on);
+  command_line::add_arg(desc_cmd_sett, arg_database);
+
+  command_line::add_arg(desc_cmd_only, arg_count_blocks);
+  command_line::add_arg(desc_cmd_only, command_line::arg_help);
+
+  // call add_options() directly for these arguments since
+  // command_line helpers support only boolean switch, not boolean argument
+  desc_cmd_sett.add_options()
+    (arg_verify.name, make_semantic(arg_verify), arg_verify.description)
+    (arg_batch.name,  make_semantic(arg_batch),  arg_batch.description)
+    (arg_resume.name, make_semantic(arg_resume), arg_resume.description)
+    ;
+
+  po::options_description desc_options("Allowed options");
+  desc_options.add(desc_cmd_only).add(desc_cmd_sett);
+
+  po::variables_map vm;
+  bool r = command_line::handle_error_helper(desc_options, [&]()
+  {
+    po::store(po::parse_command_line(argc, argv, desc_options), vm);
+    po::notify(vm);
+    return true;
+  });
+  if (! r)
+    return 1;
+
+  log_level     = command_line::get_arg(vm, arg_log_level);
+  opt_verify    = command_line::get_arg(vm, arg_verify);
+  opt_batch     = command_line::get_arg(vm, arg_batch);
+  opt_resume    = command_line::get_arg(vm, arg_resume);
+  db_batch_size = command_line::get_arg(vm, arg_batch_size);
+
+  if (command_line::get_arg(vm, command_line::arg_help))
+  {
+    std::cout << CRYPTONOTE_NAME << " v" << MONERO_VERSION_FULL << ENDL << ENDL;
+    std::cout << desc_options << std::endl;
+    return 1;
+  }
+
+  if (! opt_batch && ! vm["batch-size"].defaulted())
+  {
+    std::cerr << "Error: batch-size set, but batch option not enabled" << ENDL;
+    exit(1);
+  }
+  if (! db_batch_size)
+  {
+    std::cerr << "Error: batch-size must be > 0" << ENDL;
+    exit(1);
+  }
+
+  std::vector<std::string> db_engines {"memory", "lmdb"};
+
+  opt_testnet = command_line::get_arg(vm, arg_testnet_on);
+  auto data_dir_arg = opt_testnet ? command_line::arg_testnet_data_dir : command_line::arg_data_dir;
+  dirname = command_line::get_arg(vm, data_dir_arg);
+  db_arg_str = command_line::get_arg(vm, arg_database);
+
+  log_space::get_set_log_detalisation_level(true, log_level);
+  log_space::log_singletone::add_logger(LOGGER_CONSOLE, NULL, NULL);
+  LOG_PRINT_L0("Starting...");
+  LOG_PRINT_L0("Setting log level = " << log_level);
+
+  boost::filesystem::path file_path {dirname};
+  std::string import_file_path;
+
+  import_file_path = (file_path / "export" / import_filename).string();
+
+  if (command_line::has_arg(vm, arg_count_blocks))
+  {
+    count_blocks(import_file_path);
+    exit(0);
+  }
+
+
+  std::string db_engine;
+  int mdb_flags = 0;
+  int res = 0;
+  res = parse_db_arguments(db_arg_str, db_engine, mdb_flags);
+  if (res)
+  {
+    std::cerr << "Error parsing database argument(s)" << ENDL;
+    exit(1);
+  }
+
+  if (std::find(db_engines.begin(), db_engines.end(), db_engine) == db_engines.end())
+  {
+    std::cerr << "Invalid database engine: " << db_engine << std::endl;
+    exit(1);
+  }
+
+  LOG_PRINT_L0("database: " << db_engine);
+  LOG_PRINT_L0("verify:  " << std::boolalpha << opt_verify << std::noboolalpha);
+  if (opt_batch)
+  {
+    LOG_PRINT_L0("batch:   " << std::boolalpha << opt_batch << std::noboolalpha
+        << "  batch size: " << db_batch_size);
+  }
+  else
+  {
+    LOG_PRINT_L0("batch:   " << std::boolalpha << opt_batch << std::noboolalpha);
+  }
+  LOG_PRINT_L0("resume:  " << std::boolalpha << opt_resume  << std::noboolalpha);
+  LOG_PRINT_L0("testnet: " << std::boolalpha << opt_testnet << std::noboolalpha);
+
+  std::cout << "import file path: " << import_file_path << ENDL;
+  std::cout << "database path:    " << file_path.string() << ENDL;
+
+  try
+  {
+
+  // fake_core needed for verification to work when enabled.
+  //
+  // NOTE: don't need fake_core method of doing things when we're going to call
+  // BlockchainDB add_block() directly and have available the 3 block
+  // properties to do so. Both ways work, but fake core isn't necessary in that
+  // circumstance.
+
+  // for multi_db_runtime:
+#if !defined(BLOCKCHAIN_DB)
+  if (db_engine == "lmdb")
+  {
+    fake_core_lmdb simple_core(dirname, opt_testnet, opt_batch, mdb_flags);
+    import_from_file(simple_core, import_file_path);
+  }
+  else if (db_engine == "memory")
+  {
+    fake_core_memory simple_core(dirname, opt_testnet);
+    import_from_file(simple_core, import_file_path);
+  }
+  else
+  {
+    std::cerr << "database engine unrecognized" << ENDL;
+    exit(1);
+  }
+
+  // for multi_db_compile:
+#else
+  if (db_engine != default_db_engine)
+  {
+    std::cerr << "Invalid database engine for compiled version: " << db_engine << std::endl;
+    exit(1);
+  }
+#if BLOCKCHAIN_DB == DB_LMDB
+  fake_core_lmdb simple_core(dirname, opt_testnet, opt_batch, mdb_flags);
+#else
+  fake_core_memory simple_core(dirname, opt_testnet);
+#endif
+
+  import_from_file(simple_core, import_file_path);
+#endif
+
+  }
+  catch (const DB_ERROR& e)
+  {
+    std::cout << std::string("Error loading blockchain db: ") + e.what() + " -- shutting down now" << ENDL;
+    exit(1);
+  }
+
+  // destructors called at exit:
+  //
+  // ensure db closed
+  //   - transactions properly checked and handled
+  //   - disk sync if needed
+  //
+  // fake_core object's destructor is called when it goes out of scope. For an
+  // LMDB fake_core, it calls Blockchain::deinit() on its object, which in turn
+  // calls delete on its BlockchainDB derived class' object, which closes its
+  // files.
+}
diff --git a/src/blockchain_converter/fake_core.h b/src/blockchain_converter/fake_core.h
new file mode 100644
index 000000000..f82b05d04
--- /dev/null
+++ b/src/blockchain_converter/fake_core.h
@@ -0,0 +1,165 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include <boost/filesystem.hpp>
+#include "cryptonote_core/blockchain.h" // BlockchainDB
+#include "cryptonote_core/blockchain_storage.h" // in-memory DB
+#include "blockchain_db/blockchain_db.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+
+using namespace cryptonote;
+
+
+#if !defined(BLOCKCHAIN_DB) || BLOCKCHAIN_DB == DB_LMDB
+
+struct fake_core_lmdb
+{
+  Blockchain m_storage;
+  tx_memory_pool m_pool;
+  bool support_batch;
+  bool support_add_block;
+
+  // for multi_db_runtime:
+#if !defined(BLOCKCHAIN_DB)
+  fake_core_lmdb(const boost::filesystem::path &path, const bool use_testnet=false, const bool do_batch=true, const int mdb_flags=0) : m_pool(&m_storage), m_storage(m_pool)
+  // for multi_db_compile:
+#else
+  fake_core_lmdb(const boost::filesystem::path &path, const bool use_testnet=false, const bool do_batch=true, const int mdb_flags=0) : m_pool(m_storage), m_storage(m_pool)
+#endif
+  {
+    m_pool.init(path.string());
+
+    BlockchainDB* db = new BlockchainLMDB();
+
+    boost::filesystem::path folder(path);
+
+    folder /= db->get_db_name();
+
+    LOG_PRINT_L0("Loading blockchain from folder " << folder.c_str() << " ...");
+
+    const std::string filename = folder.string();
+    try
+    {
+      db->open(filename, mdb_flags);
+    }
+    catch (const std::exception& e)
+    {
+      LOG_PRINT_L0("Error opening database: " << e.what());
+      throw;
+    }
+
+    m_storage.init(db, use_testnet);
+    if (do_batch)
+      m_storage.get_db().set_batch_transactions(do_batch);
+    support_batch = true;
+    support_add_block = true;
+  }
+  ~fake_core_lmdb()
+  {
+    m_storage.deinit();
+  }
+
+  uint64_t add_block(const block& blk
+                            , const size_t& block_size
+                            , const difficulty_type& cumulative_difficulty
+                            , const uint64_t& coins_generated
+                            , const std::vector<transaction>& txs
+                            )
+  {
+    return m_storage.get_db().add_block(blk, block_size, cumulative_difficulty, coins_generated, txs);
+  }
+
+  void batch_start()
+  {
+    m_storage.get_db().batch_start();
+  }
+
+  void batch_stop()
+  {
+    m_storage.get_db().batch_stop();
+  }
+
+};
+#endif
+
+#if !defined(BLOCKCHAIN_DB) || BLOCKCHAIN_DB == DB_MEMORY
+
+struct fake_core_memory
+{
+  blockchain_storage m_storage;
+  tx_memory_pool m_pool;
+  bool support_batch;
+  bool support_add_block;
+
+  // for multi_db_runtime:
+#if !defined(BLOCKCHAIN_DB)
+  fake_core_memory(const boost::filesystem::path &path, const bool use_testnet=false) : m_pool(&m_storage), m_storage(m_pool)
+#else
+  // for multi_db_compile:
+  fake_core_memory(const boost::filesystem::path &path, const bool use_testnet=false) : m_pool(m_storage), m_storage(&m_pool)
+#endif
+  {
+    m_pool.init(path.string());
+    m_storage.init(path.string(), use_testnet);
+    support_batch = false;
+    support_add_block = false;
+  }
+  ~fake_core_memory()
+  {
+    LOG_PRINT_L3("fake_core_memory() destructor called - want to see it ripple down");
+    m_storage.deinit();
+  }
+
+  uint64_t add_block(const block& blk
+                            , const size_t& block_size
+                            , const difficulty_type& cumulative_difficulty
+                            , const uint64_t& coins_generated
+                            , const std::vector<transaction>& txs
+                            )
+  {
+    // TODO:
+    // would need to refactor handle_block_to_main_chain() to have a direct add_block() method like Blockchain class
+    throw std::runtime_error("direct add_block() method not implemented for in-memory db");
+    return 2;
+  }
+
+  void batch_start()
+  {
+    LOG_PRINT_L0("WARNING: [batch_start] opt_batch set, but this database doesn't support/need transactions - ignoring");
+  }
+
+  void batch_stop()
+  {
+    LOG_PRINT_L0("WARNING: [batch_stop] opt_batch set, but this database doesn't support/need transactions - ignoring");
+  }
+
+};
+
+#endif
diff --git a/src/blockchain_converter/import.h b/src/blockchain_converter/import.h
new file mode 100644
index 000000000..632b4c0d9
--- /dev/null
+++ b/src/blockchain_converter/import.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+// TODO: bounds checking is done before writing to buffer, but buffer size
+// should be a sensible maximum
+#define BUFFER_SIZE 1000000
+#define NUM_BLOCKS_PER_CHUNK 1
+#define STR_LENGTH_OF_INT 9
+#define STR_FORMAT_OF_INT "%09d"
+#define BLOCKCHAIN_RAW "blockchain.raw"
diff --git a/src/blockchain_db/CMakeLists.txt b/src/blockchain_db/CMakeLists.txt
new file mode 100644
index 000000000..adbe804aa
--- /dev/null
+++ b/src/blockchain_db/CMakeLists.txt
@@ -0,0 +1,76 @@
+# Copyright (c) 2014-2015, The Monero Project
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this list of
+#    conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list
+#    of conditions and the following disclaimer in the documentation and/or other
+#    materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors may be
+#    used to endorse or promote products derived from this software without specific
+#    prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set(blockchain_db_sources
+  blockchain_db.cpp
+  lmdb/db_lmdb.cpp
+  )
+
+if (NOT STATIC)
+  set(blockchain_db_sources
+  ${blockchain_db_sources}
+  berkeleydb/db_bdb.cpp
+  )
+endif()
+
+
+set(blockchain_db_headers)
+
+set(blockchain_db_private_headers
+  blockchain_db.h
+  lmdb/db_lmdb.h
+  )
+
+if (NOT STATIC)
+  set(blockchain_db_private_headers
+  ${blockchain_db_private_headers}
+  berkeleydb/db_bdb.h
+  )
+endif()
+
+bitmonero_private_headers(blockchain_db
+  ${crypto_private_headers})
+bitmonero_add_library(blockchain_db
+  ${blockchain_db_sources}
+  ${blockchain_db_headers}
+  ${blockchain_db_private_headers})
+target_link_libraries(blockchain_db
+  LINK_PUBLIC
+    common
+    crypto
+    cryptonote_core
+    ${Boost_DATE_TIME_LIBRARY}
+    ${Boost_PROGRAM_OPTIONS_LIBRARY}
+    ${Boost_SERIALIZATION_LIBRARY}
+    ${LMDB_LIBRARY}
+    ${BDB_LIBRARY}
+  LINK_PRIVATE
+    ${Boost_FILESYSTEM_LIBRARY}
+    ${Boost_SYSTEM_LIBRARY}
+    ${Boost_THREAD_LIBRARY}
+    ${EXTRA_LIBRARIES})
diff --git a/src/blockchain_db/berkeleydb/db_bdb.cpp b/src/blockchain_db/berkeleydb/db_bdb.cpp
new file mode 100644
index 000000000..4b254500b
--- /dev/null
+++ b/src/blockchain_db/berkeleydb/db_bdb.cpp
@@ -0,0 +1,1689 @@
+// Copyright (c) 2014, The Monero Project
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "db_bdb.h"
+
+#include <boost/filesystem.hpp>
+#include <memory>  // std::unique_ptr
+#include <cstring>  // memcpy
+
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "crypto/crypto.h"
+#include "profile_tools.h"
+
+using epee::string_tools::pod_to_hex;
+
+namespace
+{
+
+template <typename T>
+inline void throw0(const T &e)
+{
+  LOG_PRINT_L0(e.what());
+  throw e;
+}
+
+template <typename T>
+inline void throw1(const T &e)
+{
+  LOG_PRINT_L1(e.what());
+  throw e;
+}
+
+//  cursor needs to be closed when it goes out of scope,
+//  this helps if the function using it throws
+struct bdb_cur
+{
+  bdb_cur(DbTxn* txn, Db* dbi)
+  {
+    if (dbi->cursor(txn, &m_cur, 0))
+      throw0(cryptonote::DB_ERROR("Error opening db cursor"));
+    done = false;
+  }
+
+  ~bdb_cur() { close(); }
+
+  operator Dbc*() { return m_cur; }
+  operator Dbc**() { return &m_cur; }
+  Dbc* operator->() { return m_cur; }
+
+  void close()
+  {
+    if (!done)
+    {
+      m_cur->close();
+      done = true;
+    }
+  }
+
+private:
+  Dbc* m_cur;
+  bool done;
+};
+
+const char* const BDB_BLOCKS = "blocks";
+const char* const BDB_BLOCK_TIMESTAMPS = "block_timestamps";
+const char* const BDB_BLOCK_HEIGHTS = "block_heights";
+const char* const BDB_BLOCK_HASHES = "block_hashes";
+const char* const BDB_BLOCK_SIZES = "block_sizes";
+const char* const BDB_BLOCK_DIFFS = "block_diffs";
+const char* const BDB_BLOCK_COINS = "block_coins";
+
+const char* const BDB_TXS = "txs";
+const char* const BDB_TX_UNLOCKS = "tx_unlocks";
+const char* const BDB_TX_HEIGHTS = "tx_heights";
+const char* const BDB_TX_OUTPUTS = "tx_outputs";
+
+const char* const BDB_OUTPUT_TXS = "output_txs";
+const char* const BDB_OUTPUT_INDICES = "output_indices";
+const char* const BDB_OUTPUT_AMOUNTS = "output_amounts";
+const char* const BDB_OUTPUT_KEYS = "output_keys";
+
+const char* const BDB_SPENT_KEYS = "spent_keys";
+
+template<typename T>
+struct Dbt_copy: public Dbt
+{
+  Dbt_copy(const T &t): t_copy(t)
+  {
+    init();
+  }
+
+  Dbt_copy()
+  {
+    init();
+  }
+
+  void init()
+  {
+    set_data(&t_copy);
+    set_size(sizeof(T));
+    set_ulen(sizeof(T));
+    set_flags(DB_DBT_USERMEM);
+  }
+
+  operator T()
+  {
+    return t_copy;
+  }
+private:
+  T t_copy;
+};
+
+template<>
+struct Dbt_copy<cryptonote::blobdata>: public Dbt
+{
+  Dbt_copy(const cryptonote::blobdata &bd) : m_data(new char[bd.size()])
+  {
+    memcpy(m_data.get(), bd.data(), bd.size());
+    set_data(m_data.get());
+    set_size(bd.size());
+    set_ulen(bd.size());
+    set_flags(DB_DBT_USERMEM);
+  }
+private:
+  std::unique_ptr<char[]> m_data;
+};
+
+struct Dbt_safe : public Dbt
+{
+  Dbt_safe()
+  {
+    set_data(NULL);
+    set_flags(DB_DBT_MALLOC);
+  }
+  ~Dbt_safe()
+  {
+    void* buf = get_data();
+    if (buf != NULL)
+    {
+      free(buf);
+    }
+  }
+};
+
+} // anonymous namespace
+
+namespace cryptonote
+{
+
+void BlockchainBDB::add_block( const block& blk
+              , const size_t& block_size
+              , const difficulty_type& cumulative_difficulty
+              , const uint64_t& coins_generated
+              , const crypto::hash& blk_hash
+              )
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<crypto::hash> val_h(blk_hash);
+  if (m_block_heights->exists(*m_write_txn, &val_h, 0) == 0)
+    throw1(BLOCK_EXISTS("Attempting to add block that's already in the db"));
+
+  if (m_height > 0)
+  {
+    Dbt_copy<crypto::hash> parent_key(blk.prev_id);
+    Dbt_copy<uint32_t> parent_h;
+    if (m_block_heights->get(*m_write_txn, &parent_key, &parent_h, 0))
+    {
+      LOG_PRINT_L3("m_height: " << m_height);
+      LOG_PRINT_L3("parent_key: " << blk.prev_id);
+      throw0(DB_ERROR("Failed to get top block hash to check for new block's parent"));
+    }
+    uint32_t parent_height = parent_h;
+    if (parent_height != m_height)
+      throw0(BLOCK_PARENT_DNE("Top block is not new block's parent"));
+  }
+
+  Dbt_copy<uint32_t> key(m_height + 1);
+
+  Dbt_copy<blobdata> blob(block_to_blob(blk));
+  auto res = m_blocks->put(*m_write_txn, &key, &blob, 0);
+  if (res)
+    throw0(DB_ERROR("Failed to add block blob to db transaction."));
+
+  Dbt_copy<size_t> sz(block_size);
+  if (m_block_sizes->put(*m_write_txn, &key, &sz, 0))
+    throw0(DB_ERROR("Failed to add block size to db transaction."));
+
+  Dbt_copy<uint64_t> ts(blk.timestamp);
+  if (m_block_timestamps->put(*m_write_txn, &key, &ts, 0))
+    throw0(DB_ERROR("Failed to add block timestamp to db transaction."));
+
+  Dbt_copy<difficulty_type> diff(cumulative_difficulty);
+  if (m_block_diffs->put(*m_write_txn, &key, &diff, 0))
+    throw0(DB_ERROR("Failed to add block cumulative difficulty to db transaction."));
+
+  Dbt_copy<uint64_t> coinsgen(coins_generated);
+  if (m_block_coins->put(*m_write_txn, &key, &coinsgen, 0))
+    throw0(DB_ERROR("Failed to add block total generated coins to db transaction."));
+
+  if (m_block_heights->put(*m_write_txn, &val_h, &key, 0))
+    throw0(DB_ERROR("Failed to add block height by hash to db transaction."));
+
+  if (m_block_hashes->put(*m_write_txn, &key, &val_h, 0))
+    throw0(DB_ERROR("Failed to add block hash to db transaction."));
+}
+
+void BlockchainBDB::remove_block()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  if (m_height == 0)
+    throw0(BLOCK_DNE ("Attempting to remove block from an empty blockchain"));
+
+  Dbt_copy<uint32_t> k(m_height);
+  Dbt_copy<crypto::hash> h;
+  if (m_block_hashes->get(*m_write_txn, &k, &h, 0))
+      throw1(BLOCK_DNE("Attempting to remove block that's not in the db"));
+
+  if (m_blocks->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block to db transaction"));
+
+  if (m_block_sizes->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block size to db transaction"));
+
+  if (m_block_diffs->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block cumulative difficulty to db transaction"));
+
+  if (m_block_coins->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block total generated coins to db transaction"));
+
+  if (m_block_timestamps->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block timestamp to db transaction"));
+
+  if (m_block_heights->del(*m_write_txn, &h, 0))
+      throw1(DB_ERROR("Failed to add removal of block height by hash to db transaction"));
+
+  if (m_block_hashes->del(*m_write_txn, &k, 0))
+      throw1(DB_ERROR("Failed to add removal of block hash to db transaction"));
+}
+
+void BlockchainBDB::add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<crypto::hash> val_h(tx_hash);
+
+  if (m_txs->exists(*m_write_txn, &val_h, 0) == 0)
+      throw1(TX_EXISTS("Attempting to add transaction that's already in the db"));
+
+  Dbt_copy<blobdata> blob(tx_to_blob(tx));
+  if (m_txs->put(*m_write_txn, &val_h, &blob, 0))
+    throw0(DB_ERROR("Failed to add tx blob to db transaction"));
+
+  Dbt_copy<uint64_t> height(m_height + 1);
+  if (m_tx_heights->put(*m_write_txn, &val_h, &height, 0))
+    throw0(DB_ERROR("Failed to add tx block height to db transaction"));
+
+  Dbt_copy<uint64_t> unlock_time(tx.unlock_time);
+  if (m_tx_unlocks->put(*m_write_txn, &val_h, &unlock_time, 0))
+    throw0(DB_ERROR("Failed to add tx unlock time to db transaction"));
+}
+
+void BlockchainBDB::remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<crypto::hash> val_h(tx_hash);
+  if (m_txs->exists(*m_write_txn, &val_h, 0))
+      throw1(TX_DNE("Attempting to remove transaction that isn't in the db"));
+
+  if (m_txs->del(*m_write_txn, &val_h, 0))
+      throw1(DB_ERROR("Failed to add removal of tx to db transaction"));
+  if (m_tx_unlocks->del(*m_write_txn, &val_h, 0))
+      throw1(DB_ERROR("Failed to add removal of tx unlock time to db transaction"));
+  if (m_tx_heights->del(*m_write_txn, &val_h, 0))
+      throw1(DB_ERROR("Failed to add removal of tx block height to db transaction"));
+
+  remove_tx_outputs(tx_hash, tx);
+
+  if (m_tx_outputs->del(*m_write_txn, &val_h, 0))
+      throw1(DB_ERROR("Failed to add removal of tx outputs to db transaction"));
+
+}
+
+void BlockchainBDB::add_output(const crypto::hash& tx_hash, const tx_out& tx_output, const uint64_t& local_index)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<uint32_t> k(m_num_outputs + 1);
+  Dbt_copy<crypto::hash> v(tx_hash);
+
+  if (m_output_txs->put(*m_write_txn, &k, &v, 0))
+    throw0(DB_ERROR("Failed to add output tx hash to db transaction"));
+  if (m_tx_outputs->put(*m_write_txn, &v, &k, 0))
+    throw0(DB_ERROR("Failed to add tx output index to db transaction"));
+
+  Dbt_copy<uint64_t> val_local_index(local_index);
+  if (m_output_indices->put(*m_write_txn, &k, &val_local_index, 0))
+    throw0(DB_ERROR("Failed to add tx output index to db transaction"));
+
+  Dbt_copy<uint64_t> val_amount(tx_output.amount);
+  if (m_output_amounts->put(*m_write_txn, &val_amount, &k, 0))
+    throw0(DB_ERROR("Failed to add output amount to db transaction."));
+
+  if (tx_output.target.type() == typeid(txout_to_key))
+  {
+    Dbt_copy<crypto::public_key> val_pubkey(boost::get<txout_to_key>(tx_output.target).key);
+    if (m_output_keys->put(*m_write_txn, &k, &val_pubkey, 0))
+      throw0(DB_ERROR("Failed to add output pubkey to db transaction"));
+  }
+
+  m_num_outputs++;
+}
+
+void BlockchainBDB::remove_tx_outputs(const crypto::hash& tx_hash, const transaction& tx)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+
+  bdb_cur cur(*m_write_txn, m_tx_outputs);
+
+  Dbt_copy<crypto::hash> k(tx_hash);
+  Dbt_copy<uint32_t> v;
+
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR("Attempting to remove a tx's outputs, but none found."));
+  }
+  else if (result)
+  {
+    throw0(DB_ERROR("DB error attempting to get an output"));
+  }
+  else
+  {
+    db_recno_t num_elems = 0;
+    cur->count(&num_elems, 0);
+
+    for (uint64_t i = 0; i < num_elems; ++i)
+    {
+      const tx_out tx_output = tx.vout[i];
+      remove_output(v, tx_output.amount);
+      if (i < num_elems - 1)
+      {
+        cur->get(&k, &v, DB_NEXT_DUP);
+      }
+    }
+  }
+
+  cur.close();
+}
+
+// TODO: probably remove this function
+void BlockchainBDB::remove_output(const tx_out& tx_output)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__ << " (unused version - does nothing)");
+  return;
+}
+
+void BlockchainBDB::remove_output(const uint64_t& out_index, const uint64_t amount)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<uint32_t> k(out_index);
+
+  auto result = m_output_indices->del(*m_write_txn, &k, 0);
+  if (result == DB_NOTFOUND)
+  {
+    LOG_PRINT_L0("Unexpected: global output index not found in m_output_indices");
+  }
+  else if (result)
+  {
+    throw1(DB_ERROR("Error adding removal of output tx index to db transaction"));
+  }
+
+  result = m_output_txs->del(*m_write_txn, &k, 0);
+  // if (result != 0 && result != DB_NOTFOUND)
+  //    throw1(DB_ERROR("Error adding removal of output tx hash to db transaction"));
+  if (result == DB_NOTFOUND)
+  {
+    LOG_PRINT_L0("Unexpected: global output index not found in m_output_txs");
+  }
+  else if (result)
+  {
+    throw1(DB_ERROR("Error adding removal of output tx hash to db transaction"));
+  }
+
+  result = m_output_keys->del(*m_write_txn, &k, 0);
+  if (result == DB_NOTFOUND)
+  {
+      LOG_PRINT_L0("Unexpected: global output index not found in m_output_keys");
+  }
+  else if (result)
+    throw1(DB_ERROR("Error adding removal of output pubkey to db transaction"));
+
+  remove_amount_output_index(amount, out_index);
+
+  m_num_outputs--;
+}
+
+void BlockchainBDB::remove_amount_output_index(const uint64_t amount, const uint64_t global_output_index)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_cur cur(*m_write_txn, m_output_amounts);
+
+  Dbt_copy<uint64_t> k(amount);
+  Dbt_copy<uint32_t> v;
+
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  db_recno_t num_elems = 0;
+  cur->count(&num_elems, 0);
+
+  uint64_t amount_output_index = 0;
+  uint64_t goi = 0;
+  bool found_index = false;
+  for (uint64_t i = 0; i < num_elems; ++i)
+  {
+    goi = v;
+    if (goi == global_output_index)
+    {
+      amount_output_index = i;
+      found_index = true;
+      break;
+    }
+    cur->get(&k, &v, DB_NEXT_DUP);
+  }
+  if (found_index)
+  {
+    // found the amount output index
+    // now delete it
+    result = cur->del(0);
+    if (result)
+      throw0(DB_ERROR(std::string("Error deleting amount output index ").append(boost::lexical_cast<std::string>(amount_output_index)).c_str()));
+  }
+  else
+  {
+    // not found
+    throw1(OUTPUT_DNE("Failed to find amount output index"));
+  }
+  cur.close();
+}
+
+void BlockchainBDB::add_spent_key(const crypto::key_image& k_image)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<crypto::key_image> val_key(k_image);
+  if (m_spent_keys->exists(*m_write_txn, &val_key, 0) == 0)
+      throw1(KEY_IMAGE_EXISTS("Attempting to add spent key image that's already in the db"));
+
+  Dbt_copy<char> val('\0');
+  if (m_spent_keys->put(*m_write_txn, &val_key, &val, 0))
+    throw1(DB_ERROR("Error adding spent key image to db transaction."));
+}
+
+void BlockchainBDB::remove_spent_key(const crypto::key_image& k_image)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  Dbt_copy<crypto::key_image> k(k_image);
+  auto result = m_spent_keys->del(*m_write_txn, &k, 0);
+  if (result != 0 && result != DB_NOTFOUND)
+      throw1(DB_ERROR("Error adding removal of key image to db transaction"));
+}
+
+blobdata BlockchainBDB::output_to_blob(const tx_out& output)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  blobdata b;
+  if (!t_serializable_object_to_blob(output, b))
+    throw1(DB_ERROR("Error serializing output to blob"));
+  return b;
+}
+
+tx_out BlockchainBDB::output_from_blob(const blobdata& blob) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  std::stringstream ss;
+  ss << blob;
+  binary_archive<false> ba(ss);
+  tx_out o;
+
+  if (!(::serialization::serialize(ba, o)))
+    throw1(DB_ERROR("Error deserializing tx output blob"));
+
+  return o;
+}
+
+uint64_t BlockchainBDB::get_output_global_index(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  bdb_cur cur(txn, m_output_amounts);
+
+  Dbt_copy<uint64_t> k(amount);
+  Dbt_copy<uint32_t> v;
+
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  db_recno_t num_elems;
+  cur->count(&num_elems, 0);
+
+  if (num_elems <= index)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but output not found"));
+
+  for (uint64_t i = 0; i < index; ++i)
+  {
+    cur->get(&k, &v, DB_NEXT_DUP);
+  }
+
+  uint64_t glob_index = v;
+
+  cur.close();
+
+  txn.commit();
+
+  return glob_index;
+}
+
+void BlockchainBDB::check_open() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  if (!m_open)
+    throw0(DB_ERROR("DB operation attempted on a not-open DB instance"));
+}
+
+BlockchainBDB::~BlockchainBDB()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+
+  if (m_open)
+  {
+    close();
+  }
+}
+
+BlockchainBDB::BlockchainBDB(bool batch_transactions)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  // initialize folder to something "safe" just in case
+  // someone accidentally misuses this class...
+  m_folder = "thishsouldnotexistbecauseitisgibberish";
+  m_open = false;
+
+  m_batch_transactions = batch_transactions;
+  m_write_txn = nullptr;
+  m_height = 0;
+}
+
+void BlockchainBDB::open(const std::string& filename, const int db_flags)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+
+  if (m_open)
+    throw0(DB_OPEN_FAILURE("Attempted to open db, but it's already open"));
+
+  boost::filesystem::path direc(filename);
+  if (boost::filesystem::exists(direc))
+  {
+    if (!boost::filesystem::is_directory(direc))
+      throw0(DB_OPEN_FAILURE("DB needs a directory path, but a file was passed"));
+  }
+  else
+  {
+    if (!boost::filesystem::create_directory(direc))
+      throw0(DB_OPEN_FAILURE(std::string("Failed to create directory ").append(filename).c_str()));
+  }
+
+  m_folder = filename;
+
+  try
+  {
+
+    //Create BerkeleyDB environment
+    m_env = new DbEnv(0);  // no flags needed for DbEnv
+
+    uint32_t db_env_open_flags = DB_CREATE | DB_INIT_MPOOL | DB_INIT_LOCK
+                               | DB_INIT_LOG | DB_INIT_TXN | DB_RECOVER
+                               | DB_THREAD;
+
+    // last parameter left 0, files will be created with default rw access
+    m_env->open(filename.c_str(), db_env_open_flags, 0);
+
+    // begin transaction to init dbs
+    bdb_txn_safe txn;
+    m_env->txn_begin(NULL, txn, 0);
+
+    // create Dbs in the environment
+    m_blocks = new Db(m_env, 0);
+    m_block_heights = new Db(m_env, 0);
+    m_block_hashes = new Db(m_env, 0);
+    m_block_timestamps = new Db(m_env, 0);
+    m_block_sizes = new Db(m_env, 0);
+    m_block_diffs = new Db(m_env, 0);
+    m_block_coins = new Db(m_env, 0);
+
+    m_txs = new Db(m_env, 0);
+    m_tx_unlocks = new Db(m_env, 0);
+    m_tx_heights = new Db(m_env, 0);
+    m_tx_outputs = new Db(m_env, 0);
+
+    m_output_txs = new Db(m_env, 0);
+    m_output_indices = new Db(m_env, 0);
+    m_output_amounts = new Db(m_env, 0);
+    m_output_keys = new Db(m_env, 0);
+
+    m_spent_keys = new Db(m_env, 0);
+
+    // Tell DB about Dbs that need duplicate support
+    // Note: no need to tell about sorting,
+    //   as the default is insertion order, which we want
+    m_tx_outputs->set_flags(DB_DUP);
+    m_output_amounts->set_flags(DB_DUP);
+
+    // Tell DB about fixed-size values.
+    m_block_hashes->set_re_len(sizeof(crypto::hash));
+    m_block_timestamps->set_re_len(sizeof(uint64_t));
+    m_block_sizes->set_re_len(sizeof(size_t));  // should really store block size as uint64_t...
+    m_block_diffs->set_re_len(sizeof(difficulty_type));
+    m_block_coins->set_re_len(sizeof(uint64_t));
+
+    m_output_txs->set_re_len(sizeof(crypto::hash));
+    m_output_indices->set_re_len(sizeof(uint64_t));
+    m_output_keys->set_re_len(sizeof(crypto::public_key));
+
+    //TODO: Find out if we need to do Db::set_flags(DB_RENUMBER)
+    //      for the RECNO databases.  We shouldn't as we're only
+    //      inserting/removing from the end, but we'll see.
+
+    // open Dbs in the environment
+    // m_tx_outputs and m_output_amounts must be DB_HASH or DB_BTREE
+    //   because they need duplicate entry support.  The rest are DB_RECNO,
+    //   as it seems that will be the most performant choice.
+    m_blocks->open(txn, BDB_BLOCKS, NULL, DB_RECNO, DB_CREATE, 0);
+
+    m_block_timestamps->open(txn, BDB_BLOCK_TIMESTAMPS, NULL, DB_RECNO, DB_CREATE, 0);
+    m_block_heights->open(txn, BDB_BLOCK_HEIGHTS, NULL, DB_HASH, DB_CREATE, 0);
+    m_block_hashes->open(txn, BDB_BLOCK_HASHES, NULL, DB_RECNO, DB_CREATE, 0);
+    m_block_sizes->open(txn, BDB_BLOCK_SIZES, NULL, DB_RECNO, DB_CREATE, 0);
+    m_block_diffs->open(txn, BDB_BLOCK_DIFFS, NULL, DB_RECNO, DB_CREATE, 0);
+    m_block_coins->open(txn, BDB_BLOCK_COINS, NULL, DB_RECNO, DB_CREATE, 0);
+
+    m_txs->open(txn, BDB_TXS, NULL, DB_HASH, DB_CREATE, 0);
+    m_tx_unlocks->open(txn, BDB_TX_UNLOCKS, NULL, DB_HASH, DB_CREATE, 0);
+    m_tx_heights->open(txn, BDB_TX_HEIGHTS, NULL, DB_HASH, DB_CREATE, 0);
+    m_tx_outputs->open(txn, BDB_TX_OUTPUTS, NULL, DB_HASH, DB_CREATE, 0);
+
+    m_output_txs->open(txn, BDB_OUTPUT_TXS, NULL, DB_RECNO, DB_CREATE, 0);
+    m_output_indices->open(txn, BDB_OUTPUT_INDICES, NULL, DB_RECNO, DB_CREATE, 0);
+    m_output_amounts->open(txn, BDB_OUTPUT_AMOUNTS, NULL, DB_HASH, DB_CREATE, 0);
+    m_output_keys->open(txn, BDB_OUTPUT_KEYS, NULL, DB_RECNO, DB_CREATE, 0);
+
+    m_spent_keys->open(txn, BDB_SPENT_KEYS, NULL, DB_HASH, DB_CREATE, 0);
+
+    DB_BTREE_STAT* stats;
+
+    // DB_FAST_STAT can apparently cause an incorrect number of records
+    // to be returned.  The flag should be set to 0 instead if this proves
+    // to be the case.
+    m_blocks->stat(txn, &stats, DB_FAST_STAT);
+    m_height = stats->bt_nkeys;
+    delete stats;
+
+    // see above comment about DB_FAST_STAT
+    m_output_indices->stat(txn, &stats, DB_FAST_STAT);
+    m_num_outputs = stats->bt_nkeys;
+    delete stats;
+
+    txn.commit();
+  }
+  catch (const std::exception& e)
+  {
+    throw0(DB_OPEN_FAILURE(e.what()));
+  }
+
+  m_open = true;
+}
+
+void BlockchainBDB::close()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  this->sync();
+
+  // FIXME: not yet thread safe!!!  Use with care.
+  m_open = false;
+  m_env->close(DB_FORCESYNC);
+}
+
+void BlockchainBDB::sync()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  try
+  {
+    m_blocks->sync(0);
+    m_block_heights->sync(0);
+    m_block_hashes->sync(0);
+    m_block_timestamps->sync(0);
+    m_block_sizes->sync(0);
+    m_block_diffs->sync(0);
+    m_block_coins->sync(0);
+
+    m_txs->sync(0);
+    m_tx_unlocks->sync(0);
+    m_tx_heights->sync(0);
+    m_tx_outputs->sync(0);
+
+    m_output_txs->sync(0);
+    m_output_indices->sync(0);
+    m_output_amounts->sync(0);
+    m_output_keys->sync(0);
+
+    m_spent_keys->sync(0);
+  }
+  catch (const std::exception& e)
+  {
+    throw0(DB_ERROR(std::string("Failed to sync database: ").append(e.what()).c_str()));
+  }
+}
+
+void BlockchainBDB::reset()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  // TODO: this
+}
+
+std::vector<std::string> BlockchainBDB::get_filenames() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  std::vector<std::string> filenames;
+
+  char *fname, *dbname;
+  const char **pfname, **pdbname;
+
+  pfname = (const char **)&fname;
+  pdbname = (const char **)&dbname;
+
+  m_blocks->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_heights->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_hashes->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_timestamps->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_sizes->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_diffs->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_block_coins->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_txs->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_tx_unlocks->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_tx_heights->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_tx_outputs->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_output_txs->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_output_indices->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_output_amounts->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_output_keys->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  m_spent_keys->get_dbname(pfname, pdbname);
+  filenames.push_back(fname);
+
+  std::vector<std::string> full_paths;
+
+  for (auto& filename : filenames)
+  {
+    boost::filesystem::path p(m_folder);
+    p /= filename;
+    full_paths.push_back(p.string());
+  }
+
+  return full_paths;
+}
+
+std::string BlockchainBDB::get_db_name() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+
+  return std::string("BerkeleyDB");
+}
+
+// TODO: this?
+bool BlockchainBDB::lock()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  return false;
+}
+
+// TODO: this?
+void BlockchainBDB::unlock()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+}
+
+bool BlockchainBDB::block_exists(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+
+  auto get_result = m_block_heights->exists(txn, &key, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    txn.commit();
+    LOG_PRINT_L3("Block with hash " << epee::string_tools::pod_to_hex(h) << " not found in db");
+    return false;
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch block index from hash"));
+
+  txn.commit();
+  return true;
+}
+
+block BlockchainBDB::get_block(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  return get_block_from_height(get_block_height(h));
+}
+
+uint64_t BlockchainBDB::get_block_height(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+  Dbt_copy<uint64_t> result;
+
+  auto get_result = m_block_heights->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+    throw1(BLOCK_DNE("Attempted to retrieve non-existent block height"));
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block height from the db"));
+
+  txn.commit();
+
+  return (uint64_t)result - 1;
+}
+
+block_header BlockchainBDB::get_block_header(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  // block_header object is automatically cast from block object
+  return get_block(h);
+}
+
+block BlockchainBDB::get_block_from_height(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_safe result;
+  auto get_result = m_blocks->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get block from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block from the db"));
+
+  txn.commit();
+
+  blobdata bd;
+  bd.assign(reinterpret_cast<char*>(result.get_data()), result.get_size());
+
+  block b;
+  if (!parse_and_validate_block_from_blob(bd, b))
+    throw0(DB_ERROR("Failed to parse block from blob retrieved from the db"));
+
+  return b;
+}
+
+uint64_t BlockchainBDB::get_block_timestamp(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_copy<uint64_t> result;
+  auto get_result = m_block_timestamps->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get timestamp from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- timestamp not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a timestamp from the db"));
+
+  txn.commit();
+  return result;
+}
+
+uint64_t BlockchainBDB::get_top_block_timestamp() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  // if no blocks, return 0
+  if (m_height == 0)
+  {
+    return 0;
+  }
+
+  return get_block_timestamp(m_height - 1);
+}
+
+size_t BlockchainBDB::get_block_size(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_copy<size_t> result;
+  auto get_result = m_block_sizes->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get block size from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block size not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block size from the db"));
+
+  txn.commit();
+  return result;
+}
+
+difficulty_type BlockchainBDB::get_block_cumulative_difficulty(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__ << "  height: " << height);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_copy<difficulty_type> result;
+  auto get_result = m_block_diffs->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get cumulative difficulty from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- difficulty not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a cumulative difficulty from the db"));
+
+  txn.commit();
+  return result;
+}
+
+difficulty_type BlockchainBDB::get_block_difficulty(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  difficulty_type diff1 = 0;
+  difficulty_type diff2 = 0;
+
+  diff1 = get_block_cumulative_difficulty(height);
+  if (height != 0)
+  {
+    diff2 = get_block_cumulative_difficulty(height - 1);
+  }
+
+  return diff1 - diff2;
+}
+
+uint64_t BlockchainBDB::get_block_already_generated_coins(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_copy<uint64_t> result;
+  auto get_result = m_block_coins->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get generated coins from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block size not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a total generated coins from the db"));
+
+  txn.commit();
+  return result;
+}
+
+crypto::hash BlockchainBDB::get_block_hash_from_height(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> key(height + 1);
+  Dbt_copy<crypto::hash> result;
+  auto get_result = m_block_hashes->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw0(BLOCK_DNE(std::string("Attempt to get hash from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- hash not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block hash from the db."));
+
+  txn.commit();
+  return result;
+}
+
+std::vector<block> BlockchainBDB::get_blocks_range(const uint64_t& h1, const uint64_t& h2) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  std::vector<block> v;
+
+  for (uint64_t height = h1; height <= h2; ++height)
+  {
+    v.push_back(get_block_from_height(height));
+  }
+
+  return v;
+}
+
+std::vector<crypto::hash> BlockchainBDB::get_hashes_range(const uint64_t& h1, const uint64_t& h2) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  std::vector<crypto::hash> v;
+
+  for (uint64_t height = h1; height <= h2; ++height)
+  {
+    v.push_back(get_block_hash_from_height(height));
+  }
+
+  return v;
+}
+
+crypto::hash BlockchainBDB::top_block_hash() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  if (m_height > 0)
+  {
+    return get_block_hash_from_height(m_height - 1);
+  }
+
+  return null_hash;
+}
+
+block BlockchainBDB::get_top_block() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  if (m_height > 0)
+  {
+    return get_block_from_height(m_height - 1);
+  }
+
+  block b;
+  return b;
+}
+
+uint64_t BlockchainBDB::height() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  return m_height;
+}
+
+bool BlockchainBDB::tx_exists(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+
+  TIME_MEASURE_START(time1);
+  auto get_result = m_txs->exists(txn, &key, 0);
+  TIME_MEASURE_FINISH(time1);
+  time_tx_exists += time1;
+  if (get_result == DB_NOTFOUND)
+  {
+    txn.commit();
+    LOG_PRINT_L1("transaction with hash " << epee::string_tools::pod_to_hex(h) << " not found in db");
+    return false;
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch transaction from hash"));
+
+  return true;
+}
+
+uint64_t BlockchainBDB::get_tx_unlock_time(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+  Dbt_copy<uint64_t> result;
+  auto get_result = m_tx_unlocks->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+    throw1(TX_DNE(std::string("tx unlock time with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx unlock time from hash"));
+
+  return result;
+}
+
+transaction BlockchainBDB::get_tx(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+  Dbt_safe result;
+  auto get_result = m_txs->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+    throw1(TX_DNE(std::string("tx with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx from hash"));
+
+  blobdata bd;
+  bd.assign(reinterpret_cast<char*>(result.get_data()), result.get_size());
+
+  transaction tx;
+  if (!parse_and_validate_tx_from_blob(bd, tx))
+    throw0(DB_ERROR("Failed to parse tx from blob retrieved from the db"));
+
+  txn.commit();
+
+  return tx;
+}
+
+uint64_t BlockchainBDB::get_tx_count() const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  DB_BTREE_STAT* stats;
+
+  // DB_FAST_STAT can apparently cause an incorrect number of records
+  // to be returned.  The flag should be set to 0 instead if this proves
+  // to be the case.
+  m_txs->stat(txn, &stats, DB_FAST_STAT);
+  auto num_txs = stats->bt_nkeys;
+  delete stats;
+
+  txn.commit();
+
+  return num_txs;
+}
+
+std::vector<transaction> BlockchainBDB::get_tx_list(const std::vector<crypto::hash>& hlist) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  std::vector<transaction> v;
+
+  for (auto& h : hlist)
+  {
+    v.push_back(get_tx(h));
+  }
+
+  return v;
+}
+
+uint64_t BlockchainBDB::get_tx_block_height(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::hash> key(h);
+  Dbt_copy<uint64_t> result;
+  auto get_result = m_tx_heights->get(txn, &key, &result, 0);
+  if (get_result == DB_NOTFOUND)
+  {
+    throw1(TX_DNE(std::string("tx height with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx height from hash"));
+
+  txn.commit();
+
+  return (uint64_t)result - 1;
+}
+
+//FIXME: make sure the random method used here is appropriate
+uint64_t BlockchainBDB::get_random_output(const uint64_t& amount) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  uint64_t num_outputs = get_num_outputs(amount);
+  if (num_outputs == 0)
+    throw1(OUTPUT_DNE("Attempting to get a random output for an amount, but none exist"));
+
+  return crypto::rand<uint64_t>() % num_outputs;
+}
+
+uint64_t BlockchainBDB::get_num_outputs(const uint64_t& amount) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  bdb_cur cur(txn, m_output_amounts);
+
+  Dbt_copy<uint64_t> k(amount);
+  Dbt_copy<uint64_t> v;
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+  {
+    return 0;
+  }
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get number of outputs of an amount"));
+
+  db_recno_t num_elems = 0;
+  cur->count(&num_elems, 0);
+
+  txn.commit();
+
+  return num_elems;
+}
+
+crypto::public_key BlockchainBDB::get_output_key(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  uint64_t glob_index = get_output_global_index(amount, index);
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> k(glob_index);
+  Dbt_copy<crypto::public_key> v;
+  auto get_result = m_output_keys->get(txn, &k, &v, 0);
+  if (get_result == DB_NOTFOUND)
+    throw0(DB_ERROR("Attempting to get output pubkey by global index, but key does not exist"));
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve an output pubkey from the db"));
+
+  return v;
+}
+
+// As this is not used, its return is now a blank output.
+// This will save on space in the db.
+tx_out BlockchainBDB::get_output(const crypto::hash& h, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  return tx_out();
+}
+
+// As this is not used, its return is now a blank output.
+// This will save on space in the db.
+tx_out BlockchainBDB::get_output(const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  return tx_out();
+}
+
+tx_out_index BlockchainBDB::get_output_tx_and_index_from_global(const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<uint32_t> k(index);
+  Dbt_copy<crypto::hash > v;
+
+  auto get_result = m_output_txs->get(txn, &k, &v, 0);
+  if (get_result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("output with given index not in db"));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch output tx hash"));
+
+  crypto::hash tx_hash = v;
+
+  Dbt_copy<uint64_t> result;
+  get_result = m_output_indices->get(txn, &k, &result, 0);
+  if (get_result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("output with given index not in db"));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch output tx index"));
+
+  txn.commit();
+
+  return tx_out_index(tx_hash, result);
+}
+
+tx_out_index BlockchainBDB::get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  bdb_cur cur(txn, m_output_amounts);
+
+  Dbt_copy<uint64_t> k(amount);
+  Dbt_copy<uint64_t> v;
+
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  db_recno_t num_elems = 0;
+  cur->count(&num_elems, 0);
+
+  if (num_elems <= index)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but output not found"));
+
+  for (uint64_t i = 0; i < index; ++i)
+  {
+    cur->get(&k, &v, DB_NEXT_DUP);
+  }
+
+  uint64_t glob_index = v;
+
+  cur.close();
+
+  txn.commit();
+
+  return get_output_tx_and_index_from_global(glob_index);
+}
+
+std::vector<uint64_t> BlockchainBDB::get_tx_output_indices(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  std::vector<uint64_t> index_vec;
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  bdb_cur cur(txn, m_tx_outputs);
+
+  Dbt_copy<crypto::hash> k(h);
+  Dbt_copy<uint64_t> v;
+  auto result = cur->get(&k, &v, DB_SET);
+  if (result == DB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output by tx hash and tx index, but output not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  db_recno_t num_elems = 0;
+  cur->count(&num_elems, 0);
+
+  for (uint64_t i = 0; i < num_elems; ++i)
+  {
+    index_vec.push_back(v);
+    cur->get(&k, &v, DB_NEXT_DUP);
+  }
+
+  cur.close();
+  txn.commit();
+
+  return index_vec;
+}
+
+std::vector<uint64_t> BlockchainBDB::get_tx_amount_output_indices(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+  std::vector<uint64_t> index_vec;
+  std::vector<uint64_t> index_vec2;
+
+  // get the transaction's global output indices first
+  index_vec = get_tx_output_indices(h);
+  // these are next used to obtain the amount output indices
+
+  transaction tx = get_tx(h);
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  uint64_t i = 0;
+  uint64_t global_index;
+  for (const auto& vout : tx.vout)
+  {
+    uint64_t amount =  vout.amount;
+
+    global_index = index_vec[i];
+
+    bdb_cur cur(txn, m_output_amounts);
+
+    Dbt_copy<uint64_t> k(amount);
+    Dbt_copy<uint64_t> v;
+
+    auto result = cur->get(&k, &v, DB_SET);
+    if (result == DB_NOTFOUND)
+      throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+    else if (result)
+      throw0(DB_ERROR("DB error attempting to get an output"));
+
+    db_recno_t num_elems = 0;
+    cur->count(&num_elems, 0);
+
+    uint64_t amount_output_index = 0;
+    uint64_t output_index = 0;
+    bool found_index = false;
+    for (uint64_t j = 0; j < num_elems; ++j)
+    {
+      output_index = v;
+      if (output_index == global_index)
+      {
+        amount_output_index = j;
+        found_index = true;
+        break;
+      }
+      cur->get(&k, &v, DB_NEXT_DUP);
+    }
+    if (found_index)
+    {
+      index_vec2.push_back(amount_output_index);
+    }
+    else
+    {
+      // not found
+      cur.close();
+      txn.commit();
+      throw1(OUTPUT_DNE("specified output not found in db"));
+    }
+
+    cur.close();
+    ++i;
+  }
+
+  txn.commit();
+
+  return index_vec2;
+}
+
+
+
+bool BlockchainBDB::has_key_image(const crypto::key_image& img) const
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  Dbt_copy<crypto::key_image> val_key(img);
+  if (m_spent_keys->exists(txn, &val_key, 0) == 0)
+  {
+    txn.commit();
+    return true;
+  }
+
+  txn.commit();
+  return false;
+}
+
+// Ostensibly BerkeleyDB has batch transaction support built-in,
+// so the following few functions will be NOP.
+
+void BlockchainBDB::batch_start()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+}
+
+void BlockchainBDB::batch_commit()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+}
+
+void BlockchainBDB::batch_stop()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+}
+
+void BlockchainBDB::batch_abort()
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+}
+
+void BlockchainBDB::set_batch_transactions(bool batch_transactions)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  m_batch_transactions = batch_transactions;
+  LOG_PRINT_L3("batch transactions " << (m_batch_transactions ? "enabled" : "disabled"));
+}
+
+uint64_t BlockchainBDB::add_block( const block& blk
+                                  , const size_t& block_size
+                                  , const difficulty_type& cumulative_difficulty
+                                  , const uint64_t& coins_generated
+                                  , const std::vector<transaction>& txs
+                                  )
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+  m_write_txn = &txn;
+
+  uint64_t num_outputs = m_num_outputs;
+  try
+  {
+    BlockchainDB::add_block(blk, block_size, cumulative_difficulty, coins_generated, txs);
+    m_write_txn = NULL;
+
+    TIME_MEASURE_START(time1);
+    txn.commit();
+    TIME_MEASURE_FINISH(time1);
+    time_commit1 += time1;
+  }
+  catch (const std::exception& e)
+  {
+    m_num_outputs = num_outputs;
+    m_write_txn = NULL;
+    throw;
+  }
+
+  return ++m_height;
+}
+
+void BlockchainBDB::pop_block(block& blk, std::vector<transaction>& txs)
+{
+  LOG_PRINT_L3("BlockchainBDB::" << __func__);
+  check_open();
+
+  bdb_txn_safe txn;
+  if (m_env->txn_begin(NULL, txn, 0))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+  m_write_txn = &txn;
+
+  uint64_t num_outputs = m_num_outputs;
+  try
+  {
+    BlockchainDB::pop_block(blk, txs);
+
+    m_write_txn = NULL;
+    txn.commit();
+  }
+  catch (...)
+  {
+    m_num_outputs = num_outputs;
+    m_write_txn = NULL;
+    throw;
+  }
+
+  --m_height;
+}
+
+}  // namespace cryptonote
diff --git a/src/blockchain_db/berkeleydb/db_bdb.h b/src/blockchain_db/berkeleydb/db_bdb.h
new file mode 100644
index 000000000..d4eb5434c
--- /dev/null
+++ b/src/blockchain_db/berkeleydb/db_bdb.h
@@ -0,0 +1,288 @@
+// Copyright (c) 2014, The Monero Project
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <db_cxx.h>
+
+#include "blockchain_db/blockchain_db.h"
+#include "cryptonote_protocol/blobdatatype.h" // for type blobdata
+
+namespace cryptonote
+{
+
+struct bdb_txn_safe
+{
+  bdb_txn_safe() : m_txn(NULL) { }
+  ~bdb_txn_safe()
+  {
+    LOG_PRINT_L3("bdb_txn_safe: destructor");
+
+    if (m_txn != NULL)
+      abort();
+  }
+
+  void commit(std::string message = "")
+  {
+    if (message.size() == 0)
+    {
+      message = "Failed to commit a transaction to the db";
+    }
+
+    if (m_txn->commit(0))
+    {
+      m_txn = NULL;
+      LOG_PRINT_L0(message);
+      throw DB_ERROR(message.c_str());
+    }
+    m_txn = NULL;
+  }
+
+  void abort()
+  {
+    LOG_PRINT_L3("bdb_txn_safe: abort()");
+    if(m_txn != NULL)
+    {
+      m_txn->abort();
+      m_txn = NULL;
+    }
+    else
+    {
+      LOG_PRINT_L0("WARNING: bdb_txn_safe: abort() called, but m_txn is NULL");
+    }
+  }
+
+  operator DbTxn*()
+  {
+    return m_txn;
+  }
+
+  operator DbTxn**()
+  {
+    return &m_txn;
+  }
+
+  DbTxn* m_txn;
+};
+
+class BlockchainBDB : public BlockchainDB
+{
+public:
+  BlockchainBDB(bool batch_transactions=false);
+  ~BlockchainBDB();
+
+  virtual void open(const std::string& filename, const int db_flags);
+
+  virtual void close();
+
+  virtual void sync();
+
+  virtual void reset();
+
+  virtual std::vector<std::string> get_filenames() const;
+
+  virtual std::string get_db_name() const;
+
+  virtual bool lock();
+
+  virtual void unlock();
+
+  virtual bool block_exists(const crypto::hash& h) const;
+
+  virtual block get_block(const crypto::hash& h) const;
+
+  virtual uint64_t get_block_height(const crypto::hash& h) const;
+
+  virtual block_header get_block_header(const crypto::hash& h) const;
+
+  virtual block get_block_from_height(const uint64_t& height) const;
+
+  virtual uint64_t get_block_timestamp(const uint64_t& height) const;
+
+  virtual uint64_t get_top_block_timestamp() const;
+
+  virtual size_t get_block_size(const uint64_t& height) const;
+
+  virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const;
+
+  virtual difficulty_type get_block_difficulty(const uint64_t& height) const;
+
+  virtual uint64_t get_block_already_generated_coins(const uint64_t& height) const;
+
+  virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const;
+
+  virtual std::vector<block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const;
+
+  virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const;
+
+  virtual crypto::hash top_block_hash() const;
+
+  virtual block get_top_block() const;
+
+  virtual uint64_t height() const;
+
+  virtual bool tx_exists(const crypto::hash& h) const;
+
+  virtual uint64_t get_tx_unlock_time(const crypto::hash& h) const;
+
+  virtual transaction get_tx(const crypto::hash& h) const;
+
+  virtual uint64_t get_tx_count() const;
+
+  virtual std::vector<transaction> get_tx_list(const std::vector<crypto::hash>& hlist) const;
+
+  virtual uint64_t get_tx_block_height(const crypto::hash& h) const;
+
+  virtual uint64_t get_random_output(const uint64_t& amount) const;
+
+  virtual uint64_t get_num_outputs(const uint64_t& amount) const;
+
+  virtual crypto::public_key get_output_key(const uint64_t& amount, const uint64_t& index) const;
+
+  virtual tx_out get_output(const crypto::hash& h, const uint64_t& index) const;
+
+  /**
+   * @brief get an output from its global index
+   *
+   * @param index global index of the output desired
+   *
+   * @return the output associated with the index.
+   * Will throw OUTPUT_DNE if not output has that global index.
+   * Will throw DB_ERROR if there is a non-specific LMDB error in fetching
+   */
+  tx_out get_output(const uint64_t& index) const;
+
+  virtual tx_out_index get_output_tx_and_index_from_global(const uint64_t& index) const;
+
+  virtual tx_out_index get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const;
+
+  virtual std::vector<uint64_t> get_tx_output_indices(const crypto::hash& h) const;
+  virtual std::vector<uint64_t> get_tx_amount_output_indices(const crypto::hash& h) const;
+
+  virtual bool has_key_image(const crypto::key_image& img) const;
+
+  virtual uint64_t add_block( const block& blk
+                            , const size_t& block_size
+                            , const difficulty_type& cumulative_difficulty
+                            , const uint64_t& coins_generated
+                            , const std::vector<transaction>& txs
+                            );
+
+  virtual void set_batch_transactions(bool batch_transactions);
+  virtual void batch_start();
+  virtual void batch_commit();
+  virtual void batch_stop();
+  virtual void batch_abort();
+
+  virtual void pop_block(block& blk, std::vector<transaction>& txs);
+
+private:
+  virtual void add_block( const block& blk
+                , const size_t& block_size
+                , const difficulty_type& cumulative_difficulty
+                , const uint64_t& coins_generated
+                , const crypto::hash& block_hash
+                );
+
+  virtual void remove_block();
+
+  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash);
+
+  virtual void remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx);
+
+  virtual void add_output(const crypto::hash& tx_hash, const tx_out& tx_output, const uint64_t& local_index);
+
+  virtual void remove_output(const tx_out& tx_output);
+
+  void remove_tx_outputs(const crypto::hash& tx_hash, const transaction& tx);
+
+  void remove_output(const uint64_t& out_index, const uint64_t amount);
+  void remove_amount_output_index(const uint64_t amount, const uint64_t global_output_index);
+
+  virtual void add_spent_key(const crypto::key_image& k_image);
+
+  virtual void remove_spent_key(const crypto::key_image& k_image);
+
+  /**
+   * @brief convert a tx output to a blob for storage
+   *
+   * @param output the output to convert
+   *
+   * @return the resultant blob
+   */
+  blobdata output_to_blob(const tx_out& output);
+
+  /**
+   * @brief convert a tx output blob to a tx output
+   *
+   * @param blob the blob to convert
+   *
+   * @return the resultant tx output
+   */
+  tx_out output_from_blob(const blobdata& blob) const;
+
+  /**
+   * @brief get the global index of the index-th output of the given amount
+   *
+   * @param amount the output amount
+   * @param index the index into the set of outputs of that amount
+   *
+   * @return the global index of the desired output
+   */
+  uint64_t get_output_global_index(const uint64_t& amount, const uint64_t& index) const;
+
+  void check_open() const;
+
+  DbEnv* m_env;
+
+  Db* m_blocks;
+  Db* m_block_heights;
+  Db* m_block_hashes;
+  Db* m_block_timestamps;
+  Db* m_block_sizes;
+  Db* m_block_diffs;
+  Db* m_block_coins;
+
+  Db* m_txs;
+  Db* m_tx_unlocks;
+  Db* m_tx_heights;
+  Db* m_tx_outputs;
+
+  Db* m_output_txs;
+  Db* m_output_indices;
+  Db* m_output_amounts;
+  Db* m_output_keys;
+
+  Db* m_spent_keys;
+
+  uint64_t m_height;
+  uint64_t m_num_outputs;
+  std::string m_folder;
+  bdb_txn_safe *m_write_txn;
+
+  bool m_batch_transactions; // support for batch transactions
+};
+
+}  // namespace cryptonote
diff --git a/src/blockchain_db/blockchain_db.cpp b/src/blockchain_db/blockchain_db.cpp
new file mode 100644
index 000000000..d648be44e
--- /dev/null
+++ b/src/blockchain_db/blockchain_db.cpp
@@ -0,0 +1,185 @@
+// Copyright (c) 2014, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "blockchain_db.h"
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "profile_tools.h"
+
+using epee::string_tools::pod_to_hex;
+
+namespace cryptonote
+{
+
+void BlockchainDB::pop_block()
+{
+  block blk;
+  std::vector<transaction> txs;
+  pop_block(blk, txs);
+}
+
+void BlockchainDB::add_transaction(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash* tx_hash_ptr)
+{
+  crypto::hash tx_hash;
+  if (!tx_hash_ptr)
+  {
+    // should only need to compute hash for miner transactions
+    tx_hash = get_transaction_hash(tx);
+    LOG_PRINT_L3("null tx_hash_ptr - needed to compute: " << tx_hash);
+  }
+  else
+  {
+    tx_hash = *tx_hash_ptr;
+  }
+
+  add_transaction_data(blk_hash, tx, tx_hash);
+
+  // iterate tx.vout using indices instead of C++11 foreach syntax because
+  // we need the index
+  if (tx.vout.size() != 0)  // it may be technically possible for a tx to have no outputs
+  {
+    for (uint64_t i = 0; i < tx.vout.size(); ++i)
+    {
+      add_output(tx_hash, tx.vout[i], i);
+    }
+
+    for (const txin_v& tx_input : tx.vin)
+    {
+      if (tx_input.type() == typeid(txin_to_key))
+      {
+        add_spent_key(boost::get<txin_to_key>(tx_input).k_image);
+      }
+    }
+  }
+}
+
+uint64_t BlockchainDB::add_block( const block& blk
+                                , const size_t& block_size
+                                , const difficulty_type& cumulative_difficulty
+                                , const uint64_t& coins_generated
+                                , const std::vector<transaction>& txs
+                                )
+{
+  TIME_MEASURE_START(time1);
+  crypto::hash blk_hash = get_block_hash(blk);
+  TIME_MEASURE_FINISH(time1);
+  time_blk_hash += time1;
+
+  // call out to subclass implementation to add the block & metadata
+  time1 = epee::misc_utils::get_tick_count();
+  add_block(blk, block_size, cumulative_difficulty, coins_generated, blk_hash);
+  TIME_MEASURE_FINISH(time1);
+  time_add_block1 += time1;
+
+  // call out to add the transactions
+
+  time1 = epee::misc_utils::get_tick_count();
+  add_transaction(blk_hash, blk.miner_tx);
+  int tx_i = 0;
+  crypto::hash tx_hash = null_hash;
+  for (const transaction& tx : txs)
+  {
+    tx_hash = blk.tx_hashes[tx_i];
+    add_transaction(blk_hash, tx, &tx_hash);
+    ++tx_i;
+  }
+  TIME_MEASURE_FINISH(time1);
+  time_add_transaction += time1;
+
+  ++num_calls;
+
+  return height();
+}
+
+void BlockchainDB::pop_block(block& blk, std::vector<transaction>& txs)
+{
+  blk = get_top_block();
+
+  remove_block();
+  
+  remove_transaction(get_transaction_hash(blk.miner_tx));
+  for (const auto& h : blk.tx_hashes)
+  {
+    txs.push_back(get_tx(h));
+    remove_transaction(h);
+  }
+}
+
+bool BlockchainDB::is_open()
+{
+  return m_open;
+}
+
+void BlockchainDB::remove_transaction(const crypto::hash& tx_hash)
+{
+  transaction tx = get_tx(tx_hash);
+
+  for (const txin_v& tx_input : tx.vin)
+  {
+    if (tx_input.type() == typeid(txin_to_key))
+    {
+      remove_spent_key(boost::get<txin_to_key>(tx_input).k_image);
+    }
+  }
+
+  // need tx as tx.vout has the tx outputs, and the output amounts are needed
+  remove_transaction_data(tx_hash, tx);
+}
+
+void BlockchainDB::reset_stats()
+{
+  num_calls = 0;
+  time_blk_hash = 0;
+  time_tx_exists = 0;
+  time_add_block1 = 0;
+  time_add_transaction = 0;
+  time_commit1 = 0;
+}
+
+void BlockchainDB::show_stats()
+{
+  LOG_PRINT_L1(ENDL
+    << "*********************************"
+    << ENDL
+    << "num_calls: " << num_calls
+    << ENDL
+    << "time_blk_hash: " << time_blk_hash << "ms"
+    << ENDL
+    << "time_tx_exists: " << time_tx_exists << "ms"
+    << ENDL
+    << "time_add_block1: " << time_add_block1 << "ms"
+    << ENDL
+    << "time_add_transaction: " << time_add_transaction << "ms"
+    << ENDL
+    << "time_commit1: " << time_commit1 << "ms"
+    << ENDL
+    << "*********************************"
+    << ENDL
+  );
+}
+
+}  // namespace cryptonote
diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h
new file mode 100644
index 000000000..04d9c5384
--- /dev/null
+++ b/src/blockchain_db/blockchain_db.h
@@ -0,0 +1,492 @@
+// Copyright (c) 2014, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#ifndef BLOCKCHAIN_DB_H
+#define BLOCKCHAIN_DB_H
+
+#include <list>
+#include <string>
+#include <exception>
+#include "crypto/hash.h"
+#include "cryptonote_core/cryptonote_basic.h"
+#include "cryptonote_core/difficulty.h"
+
+/* DB Driver Interface
+ *
+ * The DB interface is a store for the canonical block chain.
+ * It serves as a persistent storage for the blockchain.
+ *
+ * For the sake of efficiency, the reference implementation will also
+ * store some blockchain data outside of the blocks, such as spent
+ * transfer key images, unspent transaction outputs, etc.
+ *
+ * Transactions are duplicated so that we don't have to fetch a whole block
+ * in order to fetch a transaction from that block.  If this is deemed
+ * unnecessary later, this can change.
+ *
+ * Spent key images are duplicated outside of the blocks so it is quick
+ * to verify an output hasn't already been spent
+ *
+ * Unspent transaction outputs are duplicated to quickly gather random
+ * outputs to use for mixins
+ *
+ * IMPORTANT:
+ * A concrete implementation of this interface should populate these
+ * duplicated members!  It is possible to have a partial implementation
+ * of this interface call to private members of the interface to be added
+ * later that will then populate as needed.
+ *
+ * General:
+ *   open()
+ *   is_open()
+ *   close()
+ *   sync()
+ *   reset()
+ *
+ *   Lock and unlock provided for reorg externally, and for block
+ *   additions internally, this way threaded reads are completely fine
+ *   unless the blockchain is changing.
+ *   bool lock()
+ *   unlock()
+ *
+ * vector<str>   get_filenames()
+ *
+ * Blocks:
+ *   bool        block_exists(hash)
+ *   height      add_block(block, block_size, cumulative_difficulty, coins_generated, transactions)
+ *   block       get_block(hash)
+ *   height      get_block_height(hash)
+ *   header      get_block_header(hash)
+ *   block       get_block_from_height(height)
+ *   size_t      get_block_size(height)
+ *   difficulty  get_block_cumulative_difficulty(height)
+ *   uint64_t    get_block_already_generated_coins(height)
+ *   uint64_t    get_block_timestamp(height) 
+ *   uint64_t    get_top_block_timestamp()
+ *   hash        get_block_hash_from_height(height)
+ *   blocks      get_blocks_range(height1, height2)
+ *   hashes      get_hashes_range(height1, height2)
+ *   hash        top_block_hash()
+ *   block       get_top_block()
+ *   height      height()
+ *   void        pop_block(block&, tx_list&)
+ *
+ * Transactions:
+ *   bool        tx_exists(hash)
+ *   uint64_t    get_tx_unlock_time(hash)
+ *   tx          get_tx(hash)
+ *   uint64_t    get_tx_count()
+ *   tx_list     get_tx_list(hash_list)
+ *   height      get_tx_block_height(hash)
+ *
+ * Outputs:
+ *   index       get_random_output(amount)
+ *   uint64_t    get_num_outputs(amount)
+ *   pub_key     get_output_key(amount, index)
+ *   tx_out      get_output(tx_hash, index)
+ *   hash,index  get_output_tx_and_index_from_global(index)
+ *   hash,index  get_output_tx_and_index(amount, index)
+ *   vec<uint64> get_tx_output_indices(tx_hash)
+ *
+ *
+ * Spent Output Key Images:
+ *   bool        has_key_image(key_image)
+ *
+ * Exceptions:
+ *   DB_ERROR -- generic
+ *   DB_OPEN_FAILURE
+ *   DB_CREATE_FAILURE
+ *   DB_SYNC_FAILURE
+ *   BLOCK_DNE
+ *   BLOCK_PARENT_DNE
+ *   BLOCK_EXISTS
+ *   BLOCK_INVALID -- considering making this multiple errors
+ *   TX_DNE
+ *   TX_EXISTS
+ *   OUTPUT_DNE
+ *   OUTPUT_EXISTS
+ *   KEY_IMAGE_EXISTS
+ */
+
+namespace cryptonote
+{
+
+// typedef for convenience
+typedef std::pair<crypto::hash, uint64_t> tx_out_index;
+
+/***********************************
+ * Exception Definitions
+ ***********************************/
+class DB_EXCEPTION : public std::exception
+{
+  private:
+    std::string m;
+
+  protected:
+    DB_EXCEPTION(const char *s) : m(s) { }
+
+  public:
+    virtual ~DB_EXCEPTION() { }
+
+    const char* what() const throw()
+    {
+      return m.c_str();
+    }
+};
+
+class DB_ERROR : public DB_EXCEPTION
+{
+  public:
+    DB_ERROR() : DB_EXCEPTION("Generic DB Error") { }
+    DB_ERROR(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class DB_OPEN_FAILURE : public DB_EXCEPTION
+{
+  public:
+    DB_OPEN_FAILURE() : DB_EXCEPTION("Failed to open the db") { }
+    DB_OPEN_FAILURE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class DB_CREATE_FAILURE : public DB_EXCEPTION
+{
+  public:
+    DB_CREATE_FAILURE() : DB_EXCEPTION("Failed to create the db") { }
+    DB_CREATE_FAILURE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class DB_SYNC_FAILURE : public DB_EXCEPTION
+{
+  public:
+    DB_SYNC_FAILURE() : DB_EXCEPTION("Failed to sync the db") { }
+    DB_SYNC_FAILURE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class BLOCK_DNE : public DB_EXCEPTION
+{
+  public:
+    BLOCK_DNE() : DB_EXCEPTION("The block requested does not exist") { }
+    BLOCK_DNE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class BLOCK_PARENT_DNE : public DB_EXCEPTION
+{
+  public:
+    BLOCK_PARENT_DNE() : DB_EXCEPTION("The parent of the block does not exist") { }
+    BLOCK_PARENT_DNE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class BLOCK_EXISTS : public DB_EXCEPTION
+{
+  public:
+    BLOCK_EXISTS() : DB_EXCEPTION("The block to be added already exists!") { }
+    BLOCK_EXISTS(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class BLOCK_INVALID : public DB_EXCEPTION
+{
+  public:
+    BLOCK_INVALID() : DB_EXCEPTION("The block to be added did not pass validation!") { }
+    BLOCK_INVALID(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class TX_DNE : public DB_EXCEPTION
+{
+  public:
+    TX_DNE() : DB_EXCEPTION("The transaction requested does not exist") { }
+    TX_DNE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class TX_EXISTS : public DB_EXCEPTION
+{
+  public:
+    TX_EXISTS() : DB_EXCEPTION("The transaction to be added already exists!") { }
+    TX_EXISTS(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class OUTPUT_DNE : public DB_EXCEPTION
+{
+  public:
+    OUTPUT_DNE() : DB_EXCEPTION("The output requested does not exist!") { }
+    OUTPUT_DNE(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class OUTPUT_EXISTS : public DB_EXCEPTION
+{
+  public:
+    OUTPUT_EXISTS() : DB_EXCEPTION("The output to be added already exists!") { }
+    OUTPUT_EXISTS(const char* s) : DB_EXCEPTION(s) { }
+};
+
+class KEY_IMAGE_EXISTS : public DB_EXCEPTION
+{
+  public:
+    KEY_IMAGE_EXISTS() : DB_EXCEPTION("The spent key image to be added already exists!") { }
+    KEY_IMAGE_EXISTS(const char* s) : DB_EXCEPTION(s) { }
+};
+
+/***********************************
+ * End of Exception Definitions
+ ***********************************/
+
+
+class BlockchainDB
+{
+private:
+  /*********************************************************************
+   * private virtual members
+   *********************************************************************/
+
+  // tells the subclass to add the block and metadata to storage
+  virtual void add_block( const block& blk
+                , const size_t& block_size
+                , const difficulty_type& cumulative_difficulty
+                , const uint64_t& coins_generated
+                , const crypto::hash& blk_hash
+                ) = 0;
+
+  // tells the subclass to remove data about the top block
+  virtual void remove_block() = 0;
+
+  // tells the subclass to store the transaction and its metadata
+  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash) = 0;
+
+  // tells the subclass to remove data about a transaction
+  virtual void remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx) = 0;
+
+  // tells the subclass to store an output
+  virtual void add_output(const crypto::hash& tx_hash, const tx_out& tx_output, const uint64_t& local_index) = 0;
+
+  // tells the subclass to remove an output
+  virtual void remove_output(const tx_out& tx_output) = 0;
+
+  // tells the subclass to store a spent key
+  virtual void add_spent_key(const crypto::key_image& k_image) = 0;
+
+  // tells the subclass to remove a spent key
+  virtual void remove_spent_key(const crypto::key_image& k_image) = 0;
+
+
+  /*********************************************************************
+   * private concrete members
+   *********************************************************************/ 
+  // private version of pop_block, for undoing if an add_block goes tits up
+  void pop_block();
+
+  // helper function for add_transactions, to add each individual tx
+  void add_transaction(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash* tx_hash_ptr = NULL);
+
+  // helper function to remove transaction from blockchain
+  void remove_transaction(const crypto::hash& tx_hash);
+
+  uint64_t num_calls = 0;
+  uint64_t time_blk_hash = 0;
+  uint64_t time_add_block1 = 0;
+  uint64_t time_add_transaction = 0;
+
+
+protected:
+
+  mutable uint64_t time_tx_exists = 0;
+  uint64_t time_commit1 = 0;
+
+
+public:
+
+  // virtual dtor
+  virtual ~BlockchainDB() { };
+
+  // reset profiling stats
+  void reset_stats();
+
+  // show profiling stats
+  void show_stats();
+
+  // open the db at location <filename>, or create it if there isn't one.
+  virtual void open(const std::string& filename, const int db_flags = 0) = 0;
+
+  // returns true of the db is open/ready, else false
+  bool is_open();
+
+  // close and sync the db
+  virtual void close() = 0;
+
+  // sync the db
+  virtual void sync() = 0;
+
+  // reset the db -- USE WITH CARE
+  virtual void reset() = 0;
+
+  // get all files used by this db (if any)
+  virtual std::vector<std::string> get_filenames() const = 0;
+
+  // return the name of the folder the db's file(s) should reside in
+  virtual std::string get_db_name() const = 0;
+
+
+  // FIXME: these are just for functionality mocking, need to implement
+  // RAII-friendly and multi-read one-write friendly locking mechanism
+  //
+  // acquire db lock
+  virtual bool lock() = 0;
+
+  // release db lock
+  virtual void unlock() = 0;
+
+  virtual void batch_start() = 0;
+  virtual void batch_stop() = 0;
+  virtual void set_batch_transactions(bool) = 0;
+
+  // adds a block with the given metadata to the top of the blockchain, returns the new height
+  // NOTE: subclass implementations of this (or the functions it calls) need
+  // to handle undoing any partially-added blocks in the event of a failure.
+  virtual uint64_t add_block( const block& blk
+                            , const size_t& block_size
+                            , const difficulty_type& cumulative_difficulty
+                            , const uint64_t& coins_generated
+                            , const std::vector<transaction>& txs
+                            );
+
+  // return true if a block with hash <h> exists in the blockchain
+  virtual bool block_exists(const crypto::hash& h) const = 0;
+
+  // return block with hash <h>
+  virtual block get_block(const crypto::hash& h) const = 0;
+
+  // return the height of the block with hash <h> on the blockchain,
+  // throw if it doesn't exist
+  virtual uint64_t get_block_height(const crypto::hash& h) const = 0;
+
+  // return header for block with hash <h>
+  virtual block_header get_block_header(const crypto::hash& h) const = 0;
+
+  // return block at height <height>
+  virtual block get_block_from_height(const uint64_t& height) const = 0;
+
+  // return timestamp of block at height <height>
+  virtual uint64_t get_block_timestamp(const uint64_t& height) const = 0;
+
+  // return timestamp of most recent block
+  virtual uint64_t get_top_block_timestamp() const = 0;
+
+  // return block size of block at height <height>
+  virtual size_t get_block_size(const uint64_t& height) const = 0;
+
+  // return cumulative difficulty up to and including block at height <height>
+  virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const = 0;
+
+  // return difficulty of block at height <height>
+  virtual difficulty_type get_block_difficulty(const uint64_t& height) const = 0;
+
+  // return number of coins generated up to and including block at height <height>
+  virtual uint64_t get_block_already_generated_coins(const uint64_t& height) const = 0;
+
+  // return hash of block at height <height>
+  virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const = 0;
+
+  // return vector of blocks in range <h1,h2> of height (inclusively)
+  virtual std::vector<block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const = 0;
+
+  // return vector of block hashes in range <h1, h2> of height (inclusively)
+  virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const = 0;
+
+  // return the hash of the top block on the chain
+  virtual crypto::hash top_block_hash() const = 0;
+
+  // return the block at the top of the blockchain
+  virtual block get_top_block() const = 0;
+
+  // return the height of the chain
+  virtual uint64_t height() const = 0;
+
+  // pops the top block off the blockchain.
+  // Returns by reference the popped block and its associated transactions
+  //
+  // IMPORTANT:
+  // When a block is popped, the transactions associated with it need to be
+  // removed, as well as outputs and spent key images associated with
+  // those transactions.
+  virtual void pop_block(block& blk, std::vector<transaction>& txs);
+
+
+  // return true if a transaction with hash <h> exists
+  virtual bool tx_exists(const crypto::hash& h) const = 0;
+
+  // return unlock time of tx with hash <h>
+  virtual uint64_t get_tx_unlock_time(const crypto::hash& h) const = 0;
+
+  // return tx with hash <h>
+  // throw if no such tx exists
+  virtual transaction get_tx(const crypto::hash& h) const = 0;
+
+  // returns the total number of transactions in all blocks
+  virtual uint64_t get_tx_count() const = 0;
+
+  // return list of tx with hashes <hlist>.
+  // TODO: decide if a missing hash means return empty list
+  // or just skip that hash
+  virtual std::vector<transaction> get_tx_list(const std::vector<crypto::hash>& hlist) const = 0;
+
+  // returns height of block that contains transaction with hash <h>
+  virtual uint64_t get_tx_block_height(const crypto::hash& h) const = 0;
+
+  // return global output index of a random output of amount <amount>
+  virtual uint64_t get_random_output(const uint64_t& amount) const = 0;
+
+  // returns the total number of outputs of amount <amount>
+  virtual uint64_t get_num_outputs(const uint64_t& amount) const = 0;
+
+  // return public key for output with global output amount <amount> and index <index>
+  virtual crypto::public_key get_output_key(const uint64_t& amount, const uint64_t& index) const = 0;
+
+  // returns the output indexed by <index> in the transaction with hash <h>
+  virtual tx_out get_output(const crypto::hash& h, const uint64_t& index) const = 0;
+
+  // returns the tx hash associated with an output, referenced by global output index
+  virtual tx_out_index get_output_tx_and_index_from_global(const uint64_t& index) const = 0;
+
+  // returns the transaction-local reference for the output with <amount> at <index>
+  // return type is pair of tx hash and index
+  virtual tx_out_index get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const = 0;
+
+  // return a vector of indices corresponding to the global output index for
+  // each output in the transaction with hash <h>
+  virtual std::vector<uint64_t> get_tx_output_indices(const crypto::hash& h) const = 0;
+  // return a vector of indices corresponding to the amount output index for
+  // each output in the transaction with hash <h>
+  virtual std::vector<uint64_t> get_tx_amount_output_indices(const crypto::hash& h) const = 0;
+
+  // returns true if key image <img> is present in spent key images storage
+  virtual bool has_key_image(const crypto::key_image& img) const = 0;
+
+  bool m_open;
+};  // class BlockchainDB
+
+
+}  // namespace cryptonote
+
+#endif  // BLOCKCHAIN_DB_H
diff --git a/src/blockchain_db/db_types.h b/src/blockchain_db/db_types.h
new file mode 100644
index 000000000..b13007df4
--- /dev/null
+++ b/src/blockchain_db/db_types.h
@@ -0,0 +1,40 @@
+// Copyright (c) 2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+#pragma once
+
+namespace cryptonote
+{
+
+  const std::unordered_set<std::string> blockchain_db_types = 
+  { "lmdb"
+  , "berkeley"
+  };
+
+} // namespace cryptonote
diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
new file mode 100644
index 000000000..8e09dfab2
--- /dev/null
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -0,0 +1,1814 @@
+// Copyright (c) 2014, The Monero Project
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "db_lmdb.h"
+
+#include <boost/filesystem.hpp>
+#include <memory>  // std::unique_ptr
+#include <cstring>  // memcpy
+
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "crypto/crypto.h"
+#include "profile_tools.h"
+
+using epee::string_tools::pod_to_hex;
+
+namespace
+{
+
+template <typename T>
+inline void throw0(const T &e)
+{
+  LOG_PRINT_L0(e.what());
+  throw e;
+}
+
+template <typename T>
+inline void throw1(const T &e)
+{
+  LOG_PRINT_L1(e.what());
+  throw e;
+}
+
+//  cursor needs to be closed when it goes out of scope,
+//  this helps if the function using it throws
+struct lmdb_cur
+{
+  lmdb_cur(MDB_txn* txn, MDB_dbi dbi)
+  {
+    if (mdb_cursor_open(txn, dbi, &m_cur))
+      throw0(cryptonote::DB_ERROR("Error opening db cursor"));
+    done = false;
+  }
+
+  ~lmdb_cur() { close(); }
+
+  operator MDB_cursor*() { return m_cur; }
+  operator MDB_cursor**() { return &m_cur; }
+
+  void close()
+  {
+    if (!done)
+    {
+      mdb_cursor_close(m_cur);
+      done = true;
+    }
+  }
+
+private:
+  MDB_cursor* m_cur;
+  bool done;
+};
+
+template<typename T>
+struct MDB_val_copy: public MDB_val
+{
+  MDB_val_copy(const T &t): t_copy(t)
+  {
+    mv_size = sizeof (T);
+    mv_data = &t_copy;
+  }
+private:
+  T t_copy;
+};
+
+template<>
+struct MDB_val_copy<cryptonote::blobdata>: public MDB_val
+{
+  MDB_val_copy(const cryptonote::blobdata &bd): data(new char[bd.size()])
+  {
+    memcpy(data.get(), bd.data(), bd.size());
+    mv_size = bd.size();
+    mv_data = data.get();
+  }
+private:
+  std::unique_ptr<char[]> data;
+};
+
+auto compare_uint64 = [](const MDB_val *a, const MDB_val *b) {
+  const uint64_t va = *(const uint64_t*)a->mv_data;
+  const uint64_t vb = *(const uint64_t*)b->mv_data;
+  if (va < vb) return -1;
+  else if (va == vb) return 0;
+  else return 1;
+};
+
+const char* const LMDB_BLOCKS = "blocks";
+const char* const LMDB_BLOCK_TIMESTAMPS = "block_timestamps";
+const char* const LMDB_BLOCK_HEIGHTS = "block_heights";
+const char* const LMDB_BLOCK_HASHES = "block_hashes";
+const char* const LMDB_BLOCK_SIZES = "block_sizes";
+const char* const LMDB_BLOCK_DIFFS = "block_diffs";
+const char* const LMDB_BLOCK_COINS = "block_coins";
+
+const char* const LMDB_TXS = "txs";
+const char* const LMDB_TX_UNLOCKS = "tx_unlocks";
+const char* const LMDB_TX_HEIGHTS = "tx_heights";
+const char* const LMDB_TX_OUTPUTS = "tx_outputs";
+
+const char* const LMDB_OUTPUT_TXS = "output_txs";
+const char* const LMDB_OUTPUT_INDICES = "output_indices";
+const char* const LMDB_OUTPUT_AMOUNTS = "output_amounts";
+const char* const LMDB_OUTPUT_KEYS = "output_keys";
+const char* const LMDB_OUTPUTS = "outputs";
+const char* const LMDB_OUTPUT_GINDICES = "output_gindices";
+const char* const LMDB_SPENT_KEYS = "spent_keys";
+
+inline void lmdb_db_open(MDB_txn* txn, const char* name, int flags, MDB_dbi& dbi, const std::string& error_string)
+{
+  if (mdb_dbi_open(txn, name, flags, &dbi))
+    throw0(cryptonote::DB_OPEN_FAILURE(error_string.c_str()));
+}
+
+}  // anonymous namespace
+
+namespace cryptonote
+{
+
+// If m_batch_active is set, a batch transaction exists beyond this class, such
+// as a batch import with verification enabled, or possibly (later) a batch
+// network sync.
+//
+// For some of the lookup methods, such as get_block_timestamp(), tx_exists(),
+// and get_tx(), when m_batch_active is set, the lookup uses the batch
+// transaction. This isn't only because the transaction is available, but it's
+// necessary so that lookups include the database updates only present in the
+// current batch write.
+//
+// A regular network sync without batch writes is expected to open a new read
+// transaction, as those lookups are part of the validation done prior to the
+// write for block and tx data, so no write transaction is open at the time.
+
+void BlockchainLMDB::add_block( const block& blk
+              , const size_t& block_size
+              , const difficulty_type& cumulative_difficulty
+              , const uint64_t& coins_generated
+              , const crypto::hash& blk_hash
+              )
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<crypto::hash> val_h(blk_hash);
+  MDB_val unused;
+  if (mdb_get(*m_write_txn, m_block_heights, &val_h, &unused) == 0)
+    throw1(BLOCK_EXISTS("Attempting to add block that's already in the db"));
+
+  if (m_height > 0)
+  {
+    MDB_val_copy<crypto::hash> parent_key(blk.prev_id);
+    MDB_val parent_h;
+    if (mdb_get(*m_write_txn, m_block_heights, &parent_key, &parent_h))
+    {
+      LOG_PRINT_L3("m_height: " << m_height);
+      LOG_PRINT_L3("parent_key: " << blk.prev_id);
+      throw0(DB_ERROR("Failed to get top block hash to check for new block's parent"));
+    }
+    uint64_t parent_height = *(const uint64_t *)parent_h.mv_data;
+    if (parent_height != m_height - 1)
+      throw0(BLOCK_PARENT_DNE("Top block is not new block's parent"));
+  }
+
+  MDB_val_copy<uint64_t> key(m_height);
+
+  MDB_val_copy<blobdata> blob(block_to_blob(blk));
+  auto res = mdb_put(*m_write_txn, m_blocks, &key, &blob, 0);
+  if (res)
+    throw0(DB_ERROR(std::string("Failed to add block blob to db transaction: ").append(mdb_strerror(res)).c_str()));
+
+  MDB_val_copy<size_t> sz(block_size);
+  if (mdb_put(*m_write_txn, m_block_sizes, &key, &sz, 0))
+    throw0(DB_ERROR("Failed to add block size to db transaction"));
+
+  MDB_val_copy<uint64_t> ts(blk.timestamp);
+  if (mdb_put(*m_write_txn, m_block_timestamps, &key, &ts, 0))
+    throw0(DB_ERROR("Failed to add block timestamp to db transaction"));
+
+  MDB_val_copy<difficulty_type> diff(cumulative_difficulty);
+  if (mdb_put(*m_write_txn, m_block_diffs, &key, &diff, 0))
+    throw0(DB_ERROR("Failed to add block cumulative difficulty to db transaction"));
+
+  MDB_val_copy<uint64_t> coinsgen(coins_generated);
+  if (mdb_put(*m_write_txn, m_block_coins, &key, &coinsgen, 0))
+    throw0(DB_ERROR("Failed to add block total generated coins to db transaction"));
+
+  if (mdb_put(*m_write_txn, m_block_heights, &val_h, &key, 0))
+    throw0(DB_ERROR("Failed to add block height by hash to db transaction"));
+
+  if (mdb_put(*m_write_txn, m_block_hashes, &key, &val_h, 0))
+    throw0(DB_ERROR("Failed to add block hash to db transaction"));
+
+}
+
+void BlockchainLMDB::remove_block()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  if (m_height == 0)
+    throw0(BLOCK_DNE ("Attempting to remove block from an empty blockchain"));
+
+  MDB_val_copy<uint64_t> k(m_height - 1);
+  MDB_val h;
+  if (mdb_get(*m_write_txn, m_block_hashes, &k, &h))
+      throw1(BLOCK_DNE("Attempting to remove block that's not in the db"));
+
+  if (mdb_del(*m_write_txn, m_blocks, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_sizes, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block size to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_diffs, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block cumulative difficulty to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_coins, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block total generated coins to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_timestamps, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block timestamp to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_heights, &h, NULL))
+      throw1(DB_ERROR("Failed to add removal of block height by hash to db transaction"));
+
+  if (mdb_del(*m_write_txn, m_block_hashes, &k, NULL))
+      throw1(DB_ERROR("Failed to add removal of block hash to db transaction"));
+}
+
+void BlockchainLMDB::add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<crypto::hash> val_h(tx_hash);
+  MDB_val unused;
+  if (mdb_get(*m_write_txn, m_txs, &val_h, &unused) == 0)
+      throw1(TX_EXISTS("Attempting to add transaction that's already in the db"));
+
+  MDB_val_copy<blobdata> blob(tx_to_blob(tx));
+  if (mdb_put(*m_write_txn, m_txs, &val_h, &blob, 0))
+    throw0(DB_ERROR("Failed to add tx blob to db transaction"));
+
+  MDB_val_copy<uint64_t> height(m_height);
+  if (mdb_put(*m_write_txn, m_tx_heights, &val_h, &height, 0))
+    throw0(DB_ERROR("Failed to add tx block height to db transaction"));
+
+  MDB_val_copy<uint64_t> unlock_time(tx.unlock_time);
+  if (mdb_put(*m_write_txn, m_tx_unlocks, &val_h, &unlock_time, 0))
+    throw0(DB_ERROR("Failed to add tx unlock time to db transaction"));
+}
+
+void BlockchainLMDB::remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<crypto::hash> val_h(tx_hash);
+  MDB_val unused;
+  if (mdb_get(*m_write_txn, m_txs, &val_h, &unused))
+      throw1(TX_DNE("Attempting to remove transaction that isn't in the db"));
+
+  if (mdb_del(*m_write_txn, m_txs, &val_h, NULL))
+      throw1(DB_ERROR("Failed to add removal of tx to db transaction"));
+  if (mdb_del(*m_write_txn, m_tx_unlocks, &val_h, NULL))
+      throw1(DB_ERROR("Failed to add removal of tx unlock time to db transaction"));
+  if (mdb_del(*m_write_txn, m_tx_heights, &val_h, NULL))
+      throw1(DB_ERROR("Failed to add removal of tx block height to db transaction"));
+
+  remove_tx_outputs(tx_hash, tx);
+
+  if (mdb_del(*m_write_txn, m_tx_outputs, &val_h, NULL))
+      throw1(DB_ERROR("Failed to add removal of tx outputs to db transaction"));
+
+}
+
+void BlockchainLMDB::add_output(const crypto::hash& tx_hash, const tx_out& tx_output, const uint64_t& local_index)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<uint64_t> k(m_num_outputs);
+  MDB_val_copy<crypto::hash> v(tx_hash);
+
+  if (mdb_put(*m_write_txn, m_output_txs, &k, &v, 0))
+    throw0(DB_ERROR("Failed to add output tx hash to db transaction"));
+  if (mdb_put(*m_write_txn, m_tx_outputs, &v, &k, 0))
+    throw0(DB_ERROR("Failed to add tx output index to db transaction"));
+
+  MDB_val_copy<uint64_t> val_local_index(local_index);
+  if (mdb_put(*m_write_txn, m_output_indices, &k, &val_local_index, 0))
+    throw0(DB_ERROR("Failed to add tx output index to db transaction"));
+
+  MDB_val_copy<uint64_t> val_amount(tx_output.amount);
+  if (auto result = mdb_put(*m_write_txn, m_output_amounts, &val_amount, &k, 0))
+    throw0(DB_ERROR(std::string("Failed to add output amount to db transaction").append(mdb_strerror(result)).c_str()));
+
+  if (tx_output.target.type() == typeid(txout_to_key))
+  {
+    MDB_val_copy<crypto::public_key> val_pubkey(boost::get<txout_to_key>(tx_output.target).key);
+    if (mdb_put(*m_write_txn, m_output_keys, &k, &val_pubkey, 0))
+      throw0(DB_ERROR("Failed to add output pubkey to db transaction"));
+  }
+
+
+/****** Uncomment if ever outputs actually need to be stored in this manner
+ *
+  blobdata b = output_to_blob(tx_output);
+
+  v.mv_size = b.size();
+  v.mv_data = &b;
+  if (mdb_put(*m_write_txn, m_outputs, &k, &v, 0))
+    throw0(DB_ERROR("Failed to add output to db transaction"));
+  if (mdb_put(*m_write_txn, m_output_gindices, &v, &k, 0))
+    throw0(DB_ERROR("Failed to add output global index to db transaction"));
+************************************************************************/
+
+  m_num_outputs++;
+}
+
+void BlockchainLMDB::remove_tx_outputs(const crypto::hash& tx_hash, const transaction& tx)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+
+  lmdb_cur cur(*m_write_txn, m_tx_outputs);
+
+  MDB_val_copy<crypto::hash> k(tx_hash);
+  MDB_val v;
+
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+  {
+    LOG_ERROR("Attempting to remove a tx's outputs, but none found.  Continuing, but...be wary, because that's weird.");
+  }
+  else if (result)
+  {
+    throw0(DB_ERROR("DB error attempting to get an output"));
+  }
+  else
+  {
+    size_t num_elems = 0;
+    mdb_cursor_count(cur, &num_elems);
+
+    mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+    for (uint64_t i = 0; i < num_elems; ++i)
+    {
+      const tx_out tx_output = tx.vout[i];
+      remove_output(*(const uint64_t*)v.mv_data, tx_output.amount);
+      if (i < num_elems - 1)
+      {
+        mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+      }
+    }
+  }
+
+  cur.close();
+}
+
+// TODO: probably remove this function
+void BlockchainLMDB::remove_output(const tx_out& tx_output)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__ << " (unused version - does nothing)");
+  return;
+}
+
+void BlockchainLMDB::remove_output(const uint64_t& out_index, const uint64_t amount)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<uint64_t> k(out_index);
+
+/****** Uncomment if ever outputs actually need to be stored in this manner
+  blobdata b;
+  t_serializable_object_to_blob(tx_output, b);
+  k.mv_size = b.size();
+  k.mv_data = &b;
+
+  if (mdb_get(*m_write_txn, m_output_gindices, &k, &v))
+      throw1(OUTPUT_DNE("Attempting to remove output that does not exist"));
+
+  uint64_t gindex = *(uint64_t*)v.mv_data;
+
+  auto result = mdb_del(*m_write_txn, m_output_gindices, &k, NULL);
+  if (result != 0 && result != MDB_NOTFOUND)
+      throw1(DB_ERROR("Error adding removal of output global index to db transaction"));
+
+  result = mdb_del(*m_write_txn, m_outputs, &v, NULL);
+  if (result != 0 && result != MDB_NOTFOUND)
+      throw1(DB_ERROR("Error adding removal of output to db transaction"));
+*********************************************************************/
+
+  auto result = mdb_del(*m_write_txn, m_output_indices, &k, NULL);
+  if (result == MDB_NOTFOUND)
+  {
+    LOG_PRINT_L0("Unexpected: global output index not found in m_output_indices");
+  }
+  else if (result)
+  {
+    throw1(DB_ERROR("Error adding removal of output tx index to db transaction"));
+  }
+
+  result = mdb_del(*m_write_txn, m_output_txs, &k, NULL);
+  // if (result != 0 && result != MDB_NOTFOUND)
+  //    throw1(DB_ERROR("Error adding removal of output tx hash to db transaction"));
+  if (result == MDB_NOTFOUND)
+  {
+    LOG_PRINT_L0("Unexpected: global output index not found in m_output_txs");
+  }
+  else if (result)
+  {
+    throw1(DB_ERROR("Error adding removal of output tx hash to db transaction"));
+  }
+
+  result = mdb_del(*m_write_txn, m_output_keys, &k, NULL);
+  if (result == MDB_NOTFOUND)
+  {
+      LOG_PRINT_L0("Unexpected: global output index not found in m_output_keys");
+  }
+  else if (result)
+    throw1(DB_ERROR("Error adding removal of output pubkey to db transaction"));
+
+  remove_amount_output_index(amount, out_index);
+
+  m_num_outputs--;
+}
+
+void BlockchainLMDB::remove_amount_output_index(const uint64_t amount, const uint64_t global_output_index)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  lmdb_cur cur(*m_write_txn, m_output_amounts);
+
+  MDB_val_copy<uint64_t> k(amount);
+  MDB_val v;
+
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+
+  mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+  uint64_t amount_output_index = 0;
+  uint64_t goi = 0;
+  bool found_index = false;
+  for (uint64_t i = 0; i < num_elems; ++i)
+  {
+    mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+    goi = *(const uint64_t *)v.mv_data;
+    if (goi == global_output_index)
+    {
+      amount_output_index = i;
+      found_index = true;
+      break;
+    }
+    mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+  }
+  if (found_index)
+  {
+    // found the amount output index
+    // now delete it
+    result = mdb_cursor_del(cur, 0);
+    if (result)
+      throw0(DB_ERROR(std::string("Error deleting amount output index ").append(boost::lexical_cast<std::string>(amount_output_index)).c_str()));
+  }
+  else
+  {
+    // not found
+    cur.close();
+    throw1(OUTPUT_DNE("Failed to find amount output index"));
+  }
+  cur.close();
+}
+
+void BlockchainLMDB::add_spent_key(const crypto::key_image& k_image)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<crypto::key_image> val_key(k_image);
+  MDB_val unused;
+  if (mdb_get(*m_write_txn, m_spent_keys, &val_key, &unused) == 0)
+      throw1(KEY_IMAGE_EXISTS("Attempting to add spent key image that's already in the db"));
+
+  char anything = '\0';
+  unused.mv_size = sizeof(char);
+  unused.mv_data = &anything;
+  if (auto result = mdb_put(*m_write_txn, m_spent_keys, &val_key, &unused, 0))
+    throw1(DB_ERROR(std::string("Error adding spent key image to db transaction: ").append(mdb_strerror(result)).c_str()));
+}
+
+void BlockchainLMDB::remove_spent_key(const crypto::key_image& k_image)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  MDB_val_copy<crypto::key_image> k(k_image);
+  auto result = mdb_del(*m_write_txn, m_spent_keys, &k, NULL);
+  if (result != 0 && result != MDB_NOTFOUND)
+      throw1(DB_ERROR("Error adding removal of key image to db transaction"));
+}
+
+blobdata BlockchainLMDB::output_to_blob(const tx_out& output)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  blobdata b;
+  if (!t_serializable_object_to_blob(output, b))
+    throw1(DB_ERROR("Error serializing output to blob"));
+  return b;
+}
+
+tx_out BlockchainLMDB::output_from_blob(const blobdata& blob) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  std::stringstream ss;
+  ss << blob;
+  binary_archive<false> ba(ss);
+  tx_out o;
+
+  if (!(::serialization::serialize(ba, o)))
+    throw1(DB_ERROR("Error deserializing tx output blob"));
+
+  return o;
+}
+
+uint64_t BlockchainLMDB::get_output_global_index(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  lmdb_cur cur(txn, m_output_amounts);
+
+  MDB_val_copy<uint64_t> k(amount);
+  MDB_val v;
+
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+  if (num_elems <= index)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but output not found"));
+
+  mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+  for (uint64_t i = 0; i < index; ++i)
+  {
+    mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+  }
+
+  mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+
+  uint64_t glob_index = *(const uint64_t*)v.mv_data;
+
+  cur.close();
+
+  txn.commit();
+
+  return glob_index;
+}
+
+void BlockchainLMDB::check_open() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (!m_open)
+    throw0(DB_ERROR("DB operation attempted on a not-open DB instance"));
+}
+
+BlockchainLMDB::~BlockchainLMDB()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+
+  // batch transaction shouldn't be active at this point. If it is, consider it aborted.
+  if (m_batch_active)
+    batch_abort();
+}
+
+BlockchainLMDB::BlockchainLMDB(bool batch_transactions)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  // initialize folder to something "safe" just in case
+  // someone accidentally misuses this class...
+  m_folder = "thishsouldnotexistbecauseitisgibberish";
+  m_open = false;
+
+  m_batch_transactions = batch_transactions;
+  m_write_txn = nullptr;
+  m_batch_active = false;
+  m_height = 0;
+}
+
+void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+
+  if (m_open)
+    throw0(DB_OPEN_FAILURE("Attempted to open db, but it's already open"));
+
+  boost::filesystem::path direc(filename);
+  if (boost::filesystem::exists(direc))
+  {
+    if (!boost::filesystem::is_directory(direc))
+      throw0(DB_OPEN_FAILURE("LMDB needs a directory path, but a file was passed"));
+  }
+  else
+  {
+    if (!boost::filesystem::create_directory(direc))
+      throw0(DB_OPEN_FAILURE(std::string("Failed to create directory ").append(filename).c_str()));
+  }
+
+  // check for existing LMDB files in base directory
+  boost::filesystem::path old_files = direc.parent_path();
+  if (boost::filesystem::exists(old_files / "data.mdb") ||
+      boost::filesystem::exists(old_files / "lock.mdb"))
+  {
+    LOG_PRINT_L0("Found existing LMDB files in " << old_files.c_str());
+    LOG_PRINT_L0("Move data.mdb and/or lock.mdb to " << filename << ", or delete them, and then restart");
+    throw DB_ERROR("Database could not be opened");
+  }
+
+  m_folder = filename;
+
+  // set up lmdb environment
+  if (mdb_env_create(&m_env))
+    throw0(DB_ERROR("Failed to create lmdb environment"));
+  if (mdb_env_set_maxdbs(m_env, 20))
+    throw0(DB_ERROR("Failed to set max number of dbs"));
+
+  size_t mapsize = 1LL << 34;
+  if (auto result = mdb_env_set_mapsize(m_env, mapsize))
+    throw0(DB_ERROR(std::string("Failed to set max memory map size: ").append(mdb_strerror(result)).c_str()));
+  if (auto result = mdb_env_open(m_env, filename.c_str(), mdb_flags, 0644))
+    throw0(DB_ERROR(std::string("Failed to open lmdb environment: ").append(mdb_strerror(result)).c_str()));
+
+  // get a read/write MDB_txn
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, 0, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  // open necessary databases, and set properties as needed
+  // uses macros to avoid having to change things too many places
+  lmdb_db_open(txn, LMDB_BLOCKS, MDB_INTEGERKEY | MDB_CREATE, m_blocks, "Failed to open db handle for m_blocks");
+
+  lmdb_db_open(txn, LMDB_BLOCK_TIMESTAMPS, MDB_INTEGERKEY | MDB_CREATE, m_block_timestamps, "Failed to open db handle for m_block_timestamps");
+  lmdb_db_open(txn, LMDB_BLOCK_HEIGHTS, MDB_CREATE, m_block_heights, "Failed to open db handle for m_block_heights");
+  lmdb_db_open(txn, LMDB_BLOCK_HASHES, MDB_INTEGERKEY | MDB_CREATE, m_block_hashes, "Failed to open db handle for m_block_hashes");
+  lmdb_db_open(txn, LMDB_BLOCK_SIZES, MDB_INTEGERKEY | MDB_CREATE, m_block_sizes, "Failed to open db handle for m_block_sizes");
+  lmdb_db_open(txn, LMDB_BLOCK_DIFFS, MDB_INTEGERKEY | MDB_CREATE, m_block_diffs, "Failed to open db handle for m_block_diffs");
+  lmdb_db_open(txn, LMDB_BLOCK_COINS, MDB_INTEGERKEY | MDB_CREATE, m_block_coins, "Failed to open db handle for m_block_coins");
+
+  lmdb_db_open(txn, LMDB_TXS, MDB_CREATE, m_txs, "Failed to open db handle for m_txs");
+  lmdb_db_open(txn, LMDB_TX_UNLOCKS, MDB_CREATE, m_tx_unlocks, "Failed to open db handle for m_tx_unlocks");
+  lmdb_db_open(txn, LMDB_TX_HEIGHTS, MDB_CREATE, m_tx_heights, "Failed to open db handle for m_tx_heights");
+  lmdb_db_open(txn, LMDB_TX_OUTPUTS, MDB_DUPSORT | MDB_CREATE, m_tx_outputs, "Failed to open db handle for m_tx_outputs");
+
+  lmdb_db_open(txn, LMDB_OUTPUT_TXS, MDB_INTEGERKEY | MDB_CREATE, m_output_txs, "Failed to open db handle for m_output_txs");
+  lmdb_db_open(txn, LMDB_OUTPUT_INDICES, MDB_INTEGERKEY | MDB_CREATE, m_output_indices, "Failed to open db handle for m_output_indices");
+  lmdb_db_open(txn, LMDB_OUTPUT_AMOUNTS, MDB_INTEGERKEY | MDB_DUPSORT | MDB_CREATE, m_output_amounts, "Failed to open db handle for m_output_amounts");
+  lmdb_db_open(txn, LMDB_OUTPUT_KEYS, MDB_INTEGERKEY | MDB_CREATE, m_output_keys, "Failed to open db handle for m_output_keys");
+
+/*************** not used, but kept for posterity
+  lmdb_db_open(txn, LMDB_OUTPUTS, MDB_INTEGERKEY | MDB_CREATE, m_outputs, "Failed to open db handle for m_outputs");
+  lmdb_db_open(txn, LMDB_OUTPUT_GINDICES, MDB_CREATE, m_output_gindices, "Failed to open db handle for m_output_gindices");
+*************************************************/
+
+  lmdb_db_open(txn, LMDB_SPENT_KEYS, MDB_CREATE, m_spent_keys, "Failed to open db handle for m_spent_keys");
+
+  mdb_set_dupsort(txn, m_output_amounts, compare_uint64);
+  mdb_set_dupsort(txn, m_tx_outputs, compare_uint64);
+
+  // get and keep current height
+  MDB_stat db_stats;
+  if (mdb_stat(txn, m_blocks, &db_stats))
+    throw0(DB_ERROR("Failed to query m_blocks"));
+  LOG_PRINT_L2("Setting m_height to: " << db_stats.ms_entries);
+  m_height = db_stats.ms_entries;
+
+  // get and keep current number of outputs
+  if (mdb_stat(txn, m_output_indices, &db_stats))
+    throw0(DB_ERROR("Failed to query m_output_indices"));
+  m_num_outputs = db_stats.ms_entries;
+
+  // commit the transaction
+  txn.commit();
+
+  m_open = true;
+  // from here, init should be finished
+}
+
+void BlockchainLMDB::close()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (m_batch_active)
+  {
+    LOG_PRINT_L3("close() first calling batch_abort() due to active batch transaction");
+    batch_abort();
+  }
+  this->sync();
+
+  // FIXME: not yet thread safe!!!  Use with care.
+  mdb_env_close(m_env);
+}
+
+void BlockchainLMDB::sync()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  // Does nothing unless LMDB environment was opened with MDB_NOSYNC or in part
+  // MDB_NOMETASYNC. Force flush to be synchronous.
+  if (auto result = mdb_env_sync(m_env, true))
+  {
+    throw0(DB_ERROR(std::string("Failed to sync database").append(mdb_strerror(result)).c_str()));
+  }
+}
+
+void BlockchainLMDB::reset()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  // TODO: this
+}
+
+std::vector<std::string> BlockchainLMDB::get_filenames() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  std::vector<std::string> filenames;
+
+  boost::filesystem::path datafile(m_folder);
+  datafile /= "data.mdb";
+  boost::filesystem::path lockfile(m_folder);
+  lockfile /= "lock.mdb";
+
+  filenames.push_back(datafile.string());
+  filenames.push_back(lockfile.string());
+
+  return filenames;
+}
+
+std::string BlockchainLMDB::get_db_name() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+
+  return std::string("lmdb");
+}
+
+// TODO: this?
+bool BlockchainLMDB::lock()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  return false;
+}
+
+// TODO: this?
+void BlockchainLMDB::unlock()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+}
+
+bool BlockchainLMDB::block_exists(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+  auto get_result = mdb_get(txn, m_block_heights, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    txn.commit();
+    LOG_PRINT_L3("Block with hash " << epee::string_tools::pod_to_hex(h) << " not found in db");
+    return false;
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch block index from hash"));
+
+  txn.commit();
+  return true;
+}
+
+block BlockchainLMDB::get_block(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  return get_block_from_height(get_block_height(h));
+}
+
+uint64_t BlockchainLMDB::get_block_height(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+  auto get_result = mdb_get(txn, m_block_heights, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+    throw1(BLOCK_DNE("Attempted to retrieve non-existent block height"));
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block height from the db"));
+
+  txn.commit();
+  return *(const uint64_t*)result.mv_data;
+}
+
+block_header BlockchainLMDB::get_block_header(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  // block_header object is automatically cast from block object
+  return get_block(h);
+}
+
+block BlockchainLMDB::get_block_from_height(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(txn, m_blocks, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get block from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block from the db"));
+
+  txn.commit();
+
+  blobdata bd;
+  bd.assign(reinterpret_cast<char*>(result.mv_data), result.mv_size);
+
+  block b;
+  if (!parse_and_validate_block_from_blob(bd, b))
+    throw0(DB_ERROR("Failed to parse block from blob retrieved from the db"));
+
+  return b;
+}
+
+uint64_t BlockchainLMDB::get_block_timestamp(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_block_timestamps, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get timestamp from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- timestamp not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a timestamp from the db"));
+
+  if (! m_batch_active)
+    txn.commit();
+  return *(const uint64_t*)result.mv_data;
+}
+
+uint64_t BlockchainLMDB::get_top_block_timestamp() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  // if no blocks, return 0
+  if (m_height == 0)
+  {
+    return 0;
+  }
+
+  return get_block_timestamp(m_height - 1);
+}
+
+size_t BlockchainLMDB::get_block_size(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_block_sizes, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get block size from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block size not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a block size from the db"));
+
+  if (! m_batch_active)
+    txn.commit();
+  return *(const size_t*)result.mv_data;
+}
+
+difficulty_type BlockchainLMDB::get_block_cumulative_difficulty(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__ << "  height: " << height);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_block_diffs, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get cumulative difficulty from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- difficulty not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a cumulative difficulty from the db"));
+
+  if (! m_batch_active)
+    txn.commit();
+  return *(difficulty_type*)result.mv_data;
+}
+
+difficulty_type BlockchainLMDB::get_block_difficulty(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  difficulty_type diff1 = 0;
+  difficulty_type diff2 = 0;
+
+  diff1 = get_block_cumulative_difficulty(height);
+  if (height != 0)
+  {
+    diff2 = get_block_cumulative_difficulty(height - 1);
+  }
+
+  return diff1 - diff2;
+}
+
+uint64_t BlockchainLMDB::get_block_already_generated_coins(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_block_coins, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(DB_ERROR(std::string("Attempt to get generated coins from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- block size not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve a total generated coins from the db"));
+
+  if (! m_batch_active)
+    txn.commit();
+  return *(const uint64_t*)result.mv_data;
+}
+
+crypto::hash BlockchainLMDB::get_block_hash_from_height(const uint64_t& height) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<uint64_t> key(height);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_block_hashes, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw0(BLOCK_DNE(std::string("Attempt to get hash from height ").append(boost::lexical_cast<std::string>(height)).append(" failed -- hash not in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR(std::string("Error attempting to retrieve a block hash from the db: ").
+          append(mdb_strerror(get_result)).c_str()));
+
+  if (! m_batch_active)
+    txn.commit();
+  return *(crypto::hash*)result.mv_data;
+}
+
+std::vector<block> BlockchainLMDB::get_blocks_range(const uint64_t& h1, const uint64_t& h2) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  std::vector<block> v;
+
+  for (uint64_t height = h1; height <= h2; ++height)
+  {
+    v.push_back(get_block_from_height(height));
+  }
+
+  return v;
+}
+
+std::vector<crypto::hash> BlockchainLMDB::get_hashes_range(const uint64_t& h1, const uint64_t& h2) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  std::vector<crypto::hash> v;
+
+  for (uint64_t height = h1; height <= h2; ++height)
+  {
+    v.push_back(get_block_hash_from_height(height));
+  }
+
+  return v;
+}
+
+crypto::hash BlockchainLMDB::top_block_hash() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  if (m_height != 0)
+  {
+    return get_block_hash_from_height(m_height - 1);
+  }
+
+  return null_hash;
+}
+
+block BlockchainLMDB::get_top_block() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  if (m_height != 0)
+  {
+    return get_block_from_height(m_height - 1);
+  }
+
+  block b;
+  return b;
+}
+
+uint64_t BlockchainLMDB::height() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  return m_height;
+}
+
+bool BlockchainLMDB::tx_exists(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+
+  TIME_MEASURE_START(time1);
+  auto get_result = mdb_get(*txn_ptr, m_txs, &key, &result);
+  TIME_MEASURE_FINISH(time1);
+  time_tx_exists += time1;
+  if (get_result == MDB_NOTFOUND)
+  {
+    if (! m_batch_active)
+      txn.commit();
+    LOG_PRINT_L1("transaction with hash " << epee::string_tools::pod_to_hex(h) << " not found in db");
+    return false;
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch transaction from hash"));
+
+  return true;
+}
+
+uint64_t BlockchainLMDB::get_tx_unlock_time(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+  auto get_result = mdb_get(txn, m_tx_unlocks, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+    throw1(TX_DNE(std::string("tx unlock time with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx unlock time from hash"));
+
+  return *(const uint64_t*)result.mv_data;
+}
+
+transaction BlockchainLMDB::get_tx(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_txs, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+    throw1(TX_DNE(std::string("tx with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx from hash"));
+
+  blobdata bd;
+  bd.assign(reinterpret_cast<char*>(result.mv_data), result.mv_size);
+
+  transaction tx;
+  if (!parse_and_validate_tx_from_blob(bd, tx))
+    throw0(DB_ERROR("Failed to parse tx from blob retrieved from the db"));
+  if (! m_batch_active)
+    txn.commit();
+
+  return tx;
+}
+
+uint64_t BlockchainLMDB::get_tx_count() const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_stat db_stats;
+  if (mdb_stat(txn, m_txs, &db_stats))
+    throw0(DB_ERROR("Failed to query m_txs"));
+
+  txn.commit();
+
+  return db_stats.ms_entries;
+}
+
+std::vector<transaction> BlockchainLMDB::get_tx_list(const std::vector<crypto::hash>& hlist) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  std::vector<transaction> v;
+
+  for (auto& h : hlist)
+  {
+    v.push_back(get_tx(h));
+  }
+
+  return v;
+}
+
+uint64_t BlockchainLMDB::get_tx_block_height(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+
+  MDB_val_copy<crypto::hash> key(h);
+  MDB_val result;
+  auto get_result = mdb_get(*txn_ptr, m_tx_heights, &key, &result);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw1(TX_DNE(std::string("tx height with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str()));
+  }
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch tx height from hash"));
+
+  if (! m_batch_active)
+    txn.commit();
+
+  return *(const uint64_t*)result.mv_data;
+}
+
+//FIXME: make sure the random method used here is appropriate
+uint64_t BlockchainLMDB::get_random_output(const uint64_t& amount) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  uint64_t num_outputs = get_num_outputs(amount);
+  if (num_outputs == 0)
+    throw1(OUTPUT_DNE("Attempting to get a random output for an amount, but none exist"));
+
+  return crypto::rand<uint64_t>() % num_outputs;
+}
+
+uint64_t BlockchainLMDB::get_num_outputs(const uint64_t& amount) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  lmdb_cur cur(txn, m_output_amounts);
+
+  MDB_val_copy<uint64_t> k(amount);
+  MDB_val v;
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+  {
+    return 0;
+  }
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get number of outputs of an amount"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+
+  txn.commit();
+
+  return num_elems;
+}
+
+crypto::public_key BlockchainLMDB::get_output_key(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  uint64_t glob_index = get_output_global_index(amount, index);
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<uint64_t> k(glob_index);
+  MDB_val v;
+  auto get_result = mdb_get(txn, m_output_keys, &k, &v);
+  if (get_result == MDB_NOTFOUND)
+    throw0(DB_ERROR("Attempting to get output pubkey by global index, but key does not exist"));
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve an output pubkey from the db"));
+
+  return *(crypto::public_key*)v.mv_data;
+}
+
+tx_out BlockchainLMDB::get_output(const crypto::hash& h, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  lmdb_cur cur(txn, m_tx_outputs);
+
+  MDB_val_copy<crypto::hash> k(h);
+  MDB_val v;
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output by tx hash and tx index, but output not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+  if (num_elems <= index)
+    throw1(OUTPUT_DNE("Attempting to get an output by tx hash and tx index, but output not found"));
+
+  mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+  for (uint64_t i = 0; i < index; ++i)
+  {
+    mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+  }
+
+  mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+
+  blobdata b;
+  b = *(blobdata*)v.mv_data;
+
+  cur.close();
+  txn.commit();
+
+  return output_from_blob(b);
+}
+
+// As this is not used, its return is now a blank output.
+// This will save on space in the db.
+tx_out BlockchainLMDB::get_output(const uint64_t& index) const
+{
+  return tx_out();
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<uint64_t> k(index);
+  MDB_val v;
+  auto get_result = mdb_get(txn, m_outputs, &k, &v);
+  if (get_result == MDB_NOTFOUND)
+  {
+    throw OUTPUT_DNE("Attempting to get output by global index, but output does not exist");
+  }
+  else if (get_result)
+    throw0(DB_ERROR("Error attempting to retrieve an output from the db"));
+
+  blobdata b = *(blobdata*)v.mv_data;
+
+  return output_from_blob(b);
+}
+
+tx_out_index BlockchainLMDB::get_output_tx_and_index_from_global(const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+  MDB_val_copy<uint64_t> k(index);
+  MDB_val v;
+
+  auto get_result = mdb_get(*txn_ptr, m_output_txs, &k, &v);
+  if (get_result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("output with given index not in db"));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch output tx hash"));
+
+  crypto::hash tx_hash = *(crypto::hash*)v.mv_data;
+
+  get_result = mdb_get(*txn_ptr, m_output_indices, &k, &v);
+  if (get_result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("output with given index not in db"));
+  else if (get_result)
+    throw0(DB_ERROR("DB error attempting to fetch output tx index"));
+  if (! m_batch_active)
+    txn.commit();
+
+  return tx_out_index(tx_hash, *(const uint64_t *)v.mv_data);
+}
+
+tx_out_index BlockchainLMDB::get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  mdb_txn_safe* txn_ptr = &txn;
+  if (m_batch_active)
+    txn_ptr = m_write_txn;
+  else
+  {
+    if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+  }
+  lmdb_cur cur(*txn_ptr, m_output_amounts);
+
+  MDB_val_copy<uint64_t> k(amount);
+  MDB_val v;
+
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+  if (num_elems <= index)
+    throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but output not found"));
+
+  mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+  for (uint64_t i = 0; i < index; ++i)
+  {
+    mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+  }
+
+  mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+
+  uint64_t glob_index = *(const uint64_t*)v.mv_data;
+
+  cur.close();
+
+  if (! m_batch_active)
+    txn.commit();
+
+  return get_output_tx_and_index_from_global(glob_index);
+}
+
+std::vector<uint64_t> BlockchainLMDB::get_tx_output_indices(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  std::vector<uint64_t> index_vec;
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  lmdb_cur cur(txn, m_tx_outputs);
+
+  MDB_val_copy<crypto::hash> k(h);
+  MDB_val v;
+  auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+  if (result == MDB_NOTFOUND)
+    throw1(OUTPUT_DNE("Attempting to get an output by tx hash and tx index, but output not found"));
+  else if (result)
+    throw0(DB_ERROR("DB error attempting to get an output"));
+
+  size_t num_elems = 0;
+  mdb_cursor_count(cur, &num_elems);
+
+  mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+  for (uint64_t i = 0; i < num_elems; ++i)
+  {
+    mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+    index_vec.push_back(*(const uint64_t *)v.mv_data);
+    mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+  }
+
+  cur.close();
+  txn.commit();
+
+  return index_vec;
+}
+
+std::vector<uint64_t> BlockchainLMDB::get_tx_amount_output_indices(const crypto::hash& h) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+  std::vector<uint64_t> index_vec;
+  std::vector<uint64_t> index_vec2;
+
+  // get the transaction's global output indices first
+  index_vec = get_tx_output_indices(h);
+  // these are next used to obtain the amount output indices
+
+  transaction tx = get_tx(h);
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  uint64_t i = 0;
+  uint64_t global_index;
+  BOOST_FOREACH(const auto& vout, tx.vout)
+  {
+    uint64_t amount =  vout.amount;
+
+    global_index = index_vec[i];
+
+    lmdb_cur cur(txn, m_output_amounts);
+
+    MDB_val_copy<uint64_t> k(amount);
+    MDB_val v;
+
+    auto result = mdb_cursor_get(cur, &k, &v, MDB_SET);
+    if (result == MDB_NOTFOUND)
+      throw1(OUTPUT_DNE("Attempting to get an output index by amount and amount index, but amount not found"));
+    else if (result)
+      throw0(DB_ERROR("DB error attempting to get an output"));
+
+    size_t num_elems = 0;
+    mdb_cursor_count(cur, &num_elems);
+
+    mdb_cursor_get(cur, &k, &v, MDB_FIRST_DUP);
+
+    uint64_t amount_output_index = 0;
+    uint64_t output_index = 0;
+    bool found_index = false;
+    for (uint64_t j = 0; j < num_elems; ++j)
+    {
+      mdb_cursor_get(cur, &k, &v, MDB_GET_CURRENT);
+      output_index = *(const uint64_t *)v.mv_data;
+      if (output_index == global_index)
+      {
+        amount_output_index = j;
+        found_index = true;
+        break;
+      }
+      mdb_cursor_get(cur, &k, &v, MDB_NEXT_DUP);
+    }
+    if (found_index)
+    {
+      index_vec2.push_back(amount_output_index);
+    }
+    else
+    {
+      // not found
+      cur.close();
+      txn.commit();
+      throw1(OUTPUT_DNE("specified output not found in db"));
+    }
+
+    cur.close();
+    ++i;
+  }
+
+  txn.commit();
+
+  return index_vec2;
+}
+
+
+
+bool BlockchainLMDB::has_key_image(const crypto::key_image& img) const
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (mdb_txn_begin(m_env, NULL, MDB_RDONLY, txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+
+  MDB_val_copy<crypto::key_image> val_key(img);
+  MDB_val unused;
+  if (mdb_get(txn, m_spent_keys, &val_key, &unused) == 0)
+  {
+    txn.commit();
+    return true;
+  }
+
+  txn.commit();
+  return false;
+}
+
+void BlockchainLMDB::batch_start()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (! m_batch_transactions)
+    throw0(DB_ERROR("batch transactions not enabled"));
+  if (m_batch_active)
+    throw0(DB_ERROR("batch transaction already in progress"));
+  if (m_write_txn)
+    throw0(DB_ERROR("batch transaction attempted, but m_write_txn already in use"));
+  check_open();
+  // NOTE: need to make sure it's destroyed properly when done
+  if (mdb_txn_begin(m_env, NULL, 0, m_write_batch_txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+  // indicates this transaction is for batch transactions, but not whether it's
+  // active
+  m_write_batch_txn.m_batch_txn = true;
+  m_write_txn = &m_write_batch_txn;
+  m_batch_active = true;
+  LOG_PRINT_L3("batch transaction: begin");
+}
+
+void BlockchainLMDB::batch_commit()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (! m_batch_transactions)
+    throw0(DB_ERROR("batch transactions not enabled"));
+  if (! m_batch_active)
+    throw0(DB_ERROR("batch transaction not in progress"));
+  check_open();
+  LOG_PRINT_L3("batch transaction: committing...");
+  TIME_MEASURE_START(time1);
+  m_write_txn->commit();
+  TIME_MEASURE_FINISH(time1);
+  time_commit1 += time1;
+  LOG_PRINT_L3("batch transaction: committed");
+
+  if (mdb_txn_begin(m_env, NULL, 0, m_write_batch_txn))
+    throw0(DB_ERROR("Failed to create a transaction for the db"));
+  if (! m_write_batch_txn.m_batch_txn)
+    throw0(DB_ERROR("m_write_batch_txn not marked as a batch transaction"));
+  m_write_txn = &m_write_batch_txn;
+}
+
+void BlockchainLMDB::batch_stop()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (! m_batch_transactions)
+    throw0(DB_ERROR("batch transactions not enabled"));
+  if (! m_batch_active)
+    throw0(DB_ERROR("batch transaction not in progress"));
+  check_open();
+  LOG_PRINT_L3("batch transaction: committing...");
+  TIME_MEASURE_START(time1);
+  m_write_txn->commit();
+  TIME_MEASURE_FINISH(time1);
+  time_commit1 += time1;
+  // for destruction of batch transaction
+  m_write_txn = nullptr;
+  m_batch_active = false;
+  LOG_PRINT_L3("batch transaction: end");
+}
+
+void BlockchainLMDB::batch_abort()
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  if (! m_batch_transactions)
+    throw0(DB_ERROR("batch transactions not enabled"));
+  if (! m_batch_active)
+    throw0(DB_ERROR("batch transaction not in progress"));
+  check_open();
+  // for destruction of batch transaction
+  m_write_txn = nullptr;
+  // explicitly call in case mdb_env_close() (BlockchainLMDB::close()) called before BlockchainLMDB destructor called.
+  m_write_batch_txn.abort();
+  m_batch_active = false;
+  LOG_PRINT_L3("batch transaction: aborted");
+}
+
+void BlockchainLMDB::set_batch_transactions(bool batch_transactions)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  m_batch_transactions = batch_transactions;
+  LOG_PRINT_L3("batch transactions " << (m_batch_transactions ? "enabled" : "disabled"));
+}
+
+uint64_t BlockchainLMDB::add_block( const block& blk
+                                  , const size_t& block_size
+                                  , const difficulty_type& cumulative_difficulty
+                                  , const uint64_t& coins_generated
+                                  , const std::vector<transaction>& txs
+                                  )
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (! m_batch_active)
+  {
+    if (mdb_txn_begin(m_env, NULL, 0, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+    m_write_txn = &txn;
+  }
+
+  uint64_t num_outputs = m_num_outputs;
+  try
+  {
+    BlockchainDB::add_block(blk, block_size, cumulative_difficulty, coins_generated, txs);
+    if (! m_batch_active)
+    {
+      m_write_txn = NULL;
+
+      TIME_MEASURE_START(time1);
+      txn.commit();
+      TIME_MEASURE_FINISH(time1);
+      time_commit1 += time1;
+    }
+  }
+  catch (...)
+  {
+    m_num_outputs = num_outputs;
+    if (! m_batch_active)
+      m_write_txn = NULL;
+    throw;
+  }
+
+  return ++m_height;
+}
+
+void BlockchainLMDB::pop_block(block& blk, std::vector<transaction>& txs)
+{
+  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
+  check_open();
+
+  mdb_txn_safe txn;
+  if (! m_batch_active)
+  {
+    if (mdb_txn_begin(m_env, NULL, 0, txn))
+      throw0(DB_ERROR("Failed to create a transaction for the db"));
+    m_write_txn = &txn;
+  }
+
+  uint64_t num_outputs = m_num_outputs;
+  try
+  {
+    BlockchainDB::pop_block(blk, txs);
+    if (! m_batch_active)
+    {
+      m_write_txn = NULL;
+
+      txn.commit();
+    }
+  }
+  catch (...)
+  {
+    m_num_outputs = num_outputs;
+    m_write_txn = NULL;
+    throw;
+  }
+
+  --m_height;
+}
+
+}  // namespace cryptonote
diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
new file mode 100644
index 000000000..8f1e07e0d
--- /dev/null
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -0,0 +1,314 @@
+// Copyright (c) 2014, The Monero Project
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#pragma once
+
+#include "blockchain_db/blockchain_db.h"
+#include "cryptonote_protocol/blobdatatype.h" // for type blobdata
+
+#include <lmdb.h>
+
+namespace cryptonote
+{
+
+struct mdb_txn_safe
+{
+  mdb_txn_safe() : m_txn(NULL) { }
+  ~mdb_txn_safe()
+  {
+    LOG_PRINT_L3("mdb_txn_safe: destructor");
+    if (m_txn != NULL)
+    {
+      if (m_batch_txn) // this is a batch txn and should have been handled before this point for safety
+      {
+        LOG_PRINT_L0("WARNING: mdb_txn_safe: m_txn is a batch txn and it's not NULL in destructor - calling mdb_txn_abort()");
+      }
+      else
+      {
+        // Example of when this occurs: a lookup fails, so a read-only txn is
+        // aborted through this destructor. However, successful read-only txns
+        // ideally should have been committed when done and not end up here.
+        //
+        // NOTE: not sure if this is ever reached for a non-batch write
+        // transaction, but it's probably not ideal if it did.
+        LOG_PRINT_L3("mdb_txn_safe: m_txn not NULL in destructor - calling mdb_txn_abort()");
+      }
+      mdb_txn_abort(m_txn);
+    }
+  }
+
+  void commit(std::string message = "")
+  {
+    if (message.size() == 0)
+    {
+      message = "Failed to commit a transaction to the db";
+    }
+
+    if (mdb_txn_commit(m_txn))
+    {
+      m_txn = NULL;
+      LOG_PRINT_L0(message);
+      throw DB_ERROR(message.c_str());
+    }
+    m_txn = NULL;
+  }
+
+  // This should only be needed for batch transaction which must be ensured to
+  // be aborted before mdb_env_close, not after. So we can't rely on
+  // BlockchainLMDB destructor to call mdb_txn_safe destructor, as that's too late
+  // to properly abort, since mdb_env_close would have been called earlier.
+  void abort()
+  {
+    LOG_PRINT_L3("mdb_txn_safe: abort()");
+    if(m_txn != NULL)
+    {
+      mdb_txn_abort(m_txn);
+      m_txn = NULL;
+    }
+    else
+    {
+      LOG_PRINT_L0("WARNING: mdb_txn_safe: abort() called, but m_txn is NULL");
+    }
+  }
+
+  operator MDB_txn*()
+  {
+    return m_txn;
+  }
+
+  operator MDB_txn**()
+  {
+    return &m_txn;
+  }
+
+  MDB_txn* m_txn;
+  bool m_batch_txn = false;
+};
+
+
+class BlockchainLMDB : public BlockchainDB
+{
+public:
+  BlockchainLMDB(bool batch_transactions=false);
+  ~BlockchainLMDB();
+
+  virtual void open(const std::string& filename, const int mdb_flags=0);
+
+  virtual void close();
+
+  virtual void sync();
+
+  virtual void reset();
+
+  virtual std::vector<std::string> get_filenames() const;
+
+  virtual std::string get_db_name() const;
+
+  virtual bool lock();
+
+  virtual void unlock();
+
+  virtual bool block_exists(const crypto::hash& h) const;
+
+  virtual block get_block(const crypto::hash& h) const;
+
+  virtual uint64_t get_block_height(const crypto::hash& h) const;
+
+  virtual block_header get_block_header(const crypto::hash& h) const;
+
+  virtual block get_block_from_height(const uint64_t& height) const;
+
+  virtual uint64_t get_block_timestamp(const uint64_t& height) const;
+
+  virtual uint64_t get_top_block_timestamp() const;
+
+  virtual size_t get_block_size(const uint64_t& height) const;
+
+  virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const;
+
+  virtual difficulty_type get_block_difficulty(const uint64_t& height) const;
+
+  virtual uint64_t get_block_already_generated_coins(const uint64_t& height) const;
+
+  virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const;
+
+  virtual std::vector<block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const;
+
+  virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const;
+
+  virtual crypto::hash top_block_hash() const;
+
+  virtual block get_top_block() const;
+
+  virtual uint64_t height() const;
+
+  virtual bool tx_exists(const crypto::hash& h) const;
+
+  virtual uint64_t get_tx_unlock_time(const crypto::hash& h) const;
+
+  virtual transaction get_tx(const crypto::hash& h) const;
+
+  virtual uint64_t get_tx_count() const;
+
+  virtual std::vector<transaction> get_tx_list(const std::vector<crypto::hash>& hlist) const;
+
+  virtual uint64_t get_tx_block_height(const crypto::hash& h) const;
+
+  virtual uint64_t get_random_output(const uint64_t& amount) const;
+
+  virtual uint64_t get_num_outputs(const uint64_t& amount) const;
+
+  virtual crypto::public_key get_output_key(const uint64_t& amount, const uint64_t& index) const;
+
+  virtual tx_out get_output(const crypto::hash& h, const uint64_t& index) const;
+
+  /**
+   * @brief get an output from its global index
+   *
+   * @param index global index of the output desired
+   *
+   * @return the output associated with the index.
+   * Will throw OUTPUT_DNE if not output has that global index.
+   * Will throw DB_ERROR if there is a non-specific LMDB error in fetching
+   */
+  tx_out get_output(const uint64_t& index) const;
+
+  virtual tx_out_index get_output_tx_and_index_from_global(const uint64_t& index) const;
+
+  virtual tx_out_index get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const;
+
+  virtual std::vector<uint64_t> get_tx_output_indices(const crypto::hash& h) const;
+  virtual std::vector<uint64_t> get_tx_amount_output_indices(const crypto::hash& h) const;
+
+  virtual bool has_key_image(const crypto::key_image& img) const;
+
+  virtual uint64_t add_block( const block& blk
+                            , const size_t& block_size
+                            , const difficulty_type& cumulative_difficulty
+                            , const uint64_t& coins_generated
+                            , const std::vector<transaction>& txs
+                            );
+
+  virtual void set_batch_transactions(bool batch_transactions);
+  virtual void batch_start();
+  virtual void batch_commit();
+  virtual void batch_stop();
+  virtual void batch_abort();
+
+  virtual void pop_block(block& blk, std::vector<transaction>& txs);
+
+private:
+  virtual void add_block( const block& blk
+                , const size_t& block_size
+                , const difficulty_type& cumulative_difficulty
+                , const uint64_t& coins_generated
+                , const crypto::hash& block_hash
+                );
+
+  virtual void remove_block();
+
+  virtual void add_transaction_data(const crypto::hash& blk_hash, const transaction& tx, const crypto::hash& tx_hash);
+
+  virtual void remove_transaction_data(const crypto::hash& tx_hash, const transaction& tx);
+
+  virtual void add_output(const crypto::hash& tx_hash, const tx_out& tx_output, const uint64_t& local_index);
+
+  virtual void remove_output(const tx_out& tx_output);
+
+  void remove_tx_outputs(const crypto::hash& tx_hash, const transaction& tx);
+
+  void remove_output(const uint64_t& out_index, const uint64_t amount);
+  void remove_amount_output_index(const uint64_t amount, const uint64_t global_output_index);
+
+  virtual void add_spent_key(const crypto::key_image& k_image);
+
+  virtual void remove_spent_key(const crypto::key_image& k_image);
+
+  /**
+   * @brief convert a tx output to a blob for storage
+   *
+   * @param output the output to convert
+   *
+   * @return the resultant blob
+   */
+  blobdata output_to_blob(const tx_out& output);
+
+  /**
+   * @brief convert a tx output blob to a tx output
+   *
+   * @param blob the blob to convert
+   *
+   * @return the resultant tx output
+   */
+  tx_out output_from_blob(const blobdata& blob) const;
+
+  /**
+   * @brief get the global index of the index-th output of the given amount
+   *
+   * @param amount the output amount
+   * @param index the index into the set of outputs of that amount
+   *
+   * @return the global index of the desired output
+   */
+  uint64_t get_output_global_index(const uint64_t& amount, const uint64_t& index) const;
+
+  void check_open() const;
+
+  MDB_env* m_env;
+
+  MDB_dbi m_blocks;
+  MDB_dbi m_block_heights;
+  MDB_dbi m_block_hashes;
+  MDB_dbi m_block_timestamps;
+  MDB_dbi m_block_sizes;
+  MDB_dbi m_block_diffs;
+  MDB_dbi m_block_coins;
+
+  MDB_dbi m_txs;
+  MDB_dbi m_tx_unlocks;
+  MDB_dbi m_tx_heights;
+  MDB_dbi m_tx_outputs;
+
+  MDB_dbi m_output_txs;
+  MDB_dbi m_output_indices;
+  MDB_dbi m_output_gindices;
+  MDB_dbi m_output_amounts;
+  MDB_dbi m_output_keys;
+  MDB_dbi m_outputs;
+
+  MDB_dbi m_spent_keys;
+
+  uint64_t m_height;
+  uint64_t m_num_outputs;
+  std::string m_folder;
+  mdb_txn_safe* m_write_txn; // may point to either a short-lived txn or a batch txn
+  mdb_txn_safe m_write_batch_txn; // persist batch txn outside of BlockchainLMDB
+
+  bool m_batch_transactions; // support for batch transactions
+  bool m_batch_active; // whether batch transaction is in progress
+};
+
+}  // namespace cryptonote
diff --git a/src/cryptonote_core/CMakeLists.txt b/src/cryptonote_core/CMakeLists.txt
index 9eed11874..e144a93a2 100644
--- a/src/cryptonote_core/CMakeLists.txt
+++ b/src/cryptonote_core/CMakeLists.txt
@@ -29,6 +29,7 @@
 set(cryptonote_core_sources
   account.cpp
   blockchain_storage.cpp
+  blockchain.cpp
   checkpoints.cpp
   checkpoints_create.cpp
   cryptonote_basic_impl.cpp
@@ -45,6 +46,7 @@ set(cryptonote_core_private_headers
   account_boost_serialization.h
   blockchain_storage.h
   blockchain_storage_boost_serialization.h
+  blockchain.h
   checkpoints.h
   checkpoints_create.h
   connection_context.h
@@ -71,6 +73,7 @@ target_link_libraries(cryptonote_core
     common
     crypto
     otshell_utils
+    blockchain_db
     ${Boost_DATE_TIME_LIBRARY}
     ${Boost_PROGRAM_OPTIONS_LIBRARY}
     ${Boost_SERIALIZATION_LIBRARY}
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
new file mode 100644
index 000000000..0261a5614
--- /dev/null
+++ b/src/cryptonote_core/blockchain.cpp
@@ -0,0 +1,2342 @@
+// Copyright (c) 2014, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// 
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#include <algorithm>
+#include <cstdio>
+#include <boost/archive/binary_oarchive.hpp>
+#include <boost/archive/binary_iarchive.hpp>
+#include <boost/filesystem.hpp>
+
+#include "include_base_utils.h"
+#include "cryptonote_basic_impl.h"
+#include "tx_pool.h"
+#include "blockchain.h"
+#include "blockchain_db/blockchain_db.h"
+#include "cryptonote_format_utils.h"
+#include "cryptonote_boost_serialization.h"
+#include "cryptonote_config.h"
+#include "miner.h"
+#include "misc_language.h"
+#include "profile_tools.h"
+#include "file_io_utils.h"
+#include "common/boost_serialization_helper.h"
+#include "warnings.h"
+#include "crypto/hash.h"
+#include "cryptonote_core/checkpoints_create.h"
+//#include "serialization/json_archive.h"
+
+/* TODO:
+ *  Clean up code:
+ *    Possibly change how outputs are referred to/indexed in blockchain and wallets
+ *
+ */
+
+using namespace cryptonote;
+using epee::string_tools::pod_to_hex;
+
+DISABLE_VS_WARNINGS(4267)
+
+//------------------------------------------------------------------
+Blockchain::Blockchain(tx_memory_pool& tx_pool):m_db(), m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false), m_enforce_dns_checkpoints(false)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+}
+//------------------------------------------------------------------
+//TODO: is this still needed?  I don't think so - tewinget
+template<class archive_t>
+void Blockchain::serialize(archive_t & ar, const unsigned int version)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  if(version < 11)
+    return;
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  ar & m_blocks;
+  ar & m_blocks_index;
+  ar & m_transactions;
+  ar & m_spent_keys;
+  ar & m_alternative_chains;
+  ar & m_outputs;
+  ar & m_invalid_blocks;
+  ar & m_current_block_cumul_sz_limit;
+  /*serialization bug workaround*/
+  if(version > 11)
+  {
+    uint64_t total_check_count = m_db->height() + m_blocks_index.size() + m_transactions.size() + m_spent_keys.size() + m_alternative_chains.size() + m_outputs.size() + m_invalid_blocks.size() + m_current_block_cumul_sz_limit;
+    if(archive_t::is_saving::value)
+    {        
+      ar & total_check_count;
+    }else
+    {
+      uint64_t total_check_count_loaded = 0;
+      ar & total_check_count_loaded;
+      if(total_check_count != total_check_count_loaded)
+      {
+        LOG_ERROR("Blockchain storage data corruption detected. total_count loaded from file = " << total_check_count_loaded << ", expected = " << total_check_count);
+
+        LOG_PRINT_L0("Blockchain storage:" << std::endl << 
+          "m_blocks: " << m_db->height() << std::endl  << 
+          "m_blocks_index: " << m_blocks_index.size() << std::endl  << 
+          "m_transactions: " << m_transactions.size() << std::endl  << 
+          "m_spent_keys: " << m_spent_keys.size() << std::endl  << 
+          "m_alternative_chains: " << m_alternative_chains.size() << std::endl  << 
+          "m_outputs: " << m_outputs.size() << std::endl  << 
+          "m_invalid_blocks: " << m_invalid_blocks.size() << std::endl  << 
+          "m_current_block_cumul_sz_limit: " << m_current_block_cumul_sz_limit);
+
+        throw std::runtime_error("Blockchain data corruption");
+      }
+    }
+  }
+
+
+  LOG_PRINT_L3("Blockchain storage:" << std::endl << 
+      "m_blocks: " << m_db->height() << std::endl  << 
+      "m_blocks_index: " << m_blocks_index.size() << std::endl  << 
+      "m_transactions: " << m_transactions.size() << std::endl  << 
+      "m_spent_keys: " << m_spent_keys.size() << std::endl  << 
+      "m_alternative_chains: " << m_alternative_chains.size() << std::endl  << 
+      "m_outputs: " << m_outputs.size() << std::endl  << 
+      "m_invalid_blocks: " << m_invalid_blocks.size() << std::endl  << 
+      "m_current_block_cumul_sz_limit: " << m_current_block_cumul_sz_limit);
+}
+//------------------------------------------------------------------
+bool Blockchain::have_tx(const crypto::hash &id) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return m_db->tx_exists(id);
+}
+//------------------------------------------------------------------
+bool Blockchain::have_tx_keyimg_as_spent(const crypto::key_image &key_im) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return  m_db->has_key_image(key_im);
+}
+//------------------------------------------------------------------
+// This function makes sure that each "input" in an input (mixins) exists
+// and collects the public key for each from the transaction it was included in
+// via the visitor passed to it.
+template<class visitor_t>
+bool Blockchain::scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // verify that the input has key offsets (that it exists properly, really)
+  if(!tx_in_to_key.key_offsets.size())
+    return false;
+
+  // cryptonote_format_utils uses relative offsets for indexing to the global
+  // outputs list.  that is to say that absolute offset #2 is absolute offset
+  // #1 plus relative offset #2.
+  // TODO: Investigate if this is necessary / why this is done.
+  std::vector<uint64_t> absolute_offsets = relative_output_offsets_to_absolute(tx_in_to_key.key_offsets);
+
+
+  //std::vector<std::pair<crypto::hash, size_t> >& amount_outs_vec = it->second;
+  size_t count = 0;
+  for (const uint64_t& i : absolute_offsets)
+  {
+    try
+    {
+      // get tx hash and output index for output
+      auto output_index = m_db->get_output_tx_and_index(tx_in_to_key.amount, i);
+
+      // get tx that output is from
+      auto tx = m_db->get_tx(output_index.first);
+
+      // make sure output index is within range for the given transaction
+      if (output_index.second >= tx.vout.size())
+      {
+        LOG_PRINT_L0("Output does not exist.  tx = " << output_index.first << ", index = " << output_index.second);
+        return false;
+      }
+
+      // call to the passed boost visitor to grab the public key for the output
+      if(!vis.handle_output(tx, tx.vout[output_index.second]))
+      {
+        LOG_PRINT_L0("Failed to handle_output for output no = " << count << ", with absolute offset " << i);
+        return false;
+      }
+
+      // if on last output and pmax_related_block_height not null pointer
+      if(++count == absolute_offsets.size() && pmax_related_block_height)
+      {
+        // set *pmax_related_block_height to tx block height for this output
+        auto h = m_db->get_tx_block_height(output_index.first);
+        if(*pmax_related_block_height < h)
+        {
+          *pmax_related_block_height = h;
+        }
+      }
+
+    }
+    catch (const OUTPUT_DNE& e)
+    {
+      LOG_PRINT_L0("Output does not exist: " << e.what());
+      return false;
+    }
+    catch (const TX_DNE& e)
+    {
+      LOG_PRINT_L0("Transaction does not exist: " << e.what());
+      return false;
+    }
+
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+uint64_t Blockchain::get_current_blockchain_height() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return m_db->height();
+}
+//------------------------------------------------------------------
+//FIXME: possibly move this into the constructor, to avoid accidentally
+//       dereferencing a null BlockchainDB pointer
+bool Blockchain::init(BlockchainDB* db, const bool testnet)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  if (db == nullptr)
+  {
+    LOG_ERROR("Attempted to init Blockchain with null DB");
+    return false;
+  }
+  if (!db->is_open())
+  {
+    LOG_ERROR("Attempted to init Blockchain with unopened DB");
+    return false;
+  }
+
+  m_db = db;
+
+  // if the blockchain is new, add the genesis block
+  // this feels kinda kludgy to do it this way, but can be looked at later.
+  // TODO: add function to create and store genesis block,
+  //       taking testnet into account
+  if(!m_db->height())
+  {
+    LOG_PRINT_L0("Blockchain not loaded, generating genesis block.");
+    block bl = boost::value_initialized<block>();
+    block_verification_context bvc = boost::value_initialized<block_verification_context>();
+    if (testnet)
+    {
+      generate_genesis_block(bl, config::testnet::GENESIS_TX, config::testnet::GENESIS_NONCE);
+    }
+    else
+    {
+      generate_genesis_block(bl, config::GENESIS_TX, config::GENESIS_NONCE);
+    }
+    add_new_block(bl, bvc);
+    CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed, false, "Failed to add genesis block to blockchain");
+  }
+  // TODO: if blockchain load successful, verify blockchain against both
+  //       hard-coded and runtime-loaded (and enforced) checkpoints.
+  else
+  {
+  }
+
+  // check how far behind we are
+  uint64_t top_block_timestamp = m_db->get_top_block_timestamp();
+  uint64_t timestamp_diff = time(NULL) - top_block_timestamp;
+
+  // genesis block has no timestamp, could probably change it to have timestamp of 1341378000...
+  if(!top_block_timestamp)
+    timestamp_diff = time(NULL) - 1341378000;
+  LOG_PRINT_GREEN("Blockchain initialized. last block: " << m_db->height() - 1 << ", " << epee::misc_utils::get_time_interval_string(timestamp_diff) << " time ago, current difficulty: " << get_difficulty_for_next_block(), LOG_LEVEL_0);
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::store_blockchain()
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  // TODO: make sure if this throws that it is not simply ignored higher
+  // up the call stack
+  try
+  {
+    m_db->sync();
+  }
+  catch (const std::exception& e)
+  {
+    LOG_PRINT_L0(std::string("Error syncing blockchain db: ") + e.what() + "-- shutting down now to prevent issues!");
+    throw;
+  }
+  catch (...)
+  {
+    LOG_PRINT_L0("There was an issue storing the blockchain, shutting down now to prevent issues!");
+    throw;
+  }
+  LOG_PRINT_L0("Blockchain stored OK.");
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::deinit()
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  // as this should be called if handling a SIGSEGV, need to check
+  // if m_db is a NULL pointer (and thus may have caused the illegal
+  // memory operation), otherwise we may cause a loop.
+  if (m_db == NULL)
+  {
+    throw new DB_ERROR("The db pointer is null in Blockchain, the blockchain may be corrupt!");
+  }
+
+  try
+  {
+    m_db->close();
+  }
+  catch (const std::exception& e)
+  {
+    LOG_PRINT_L0(std::string("Error closing blockchain db: ") + e.what());
+  }
+  catch (...)
+  {
+    LOG_PRINT_L0("There was an issue closing/storing the blockchain, shutting down now to prevent issues!");
+  }
+
+  delete m_db;
+  return true;
+}
+//------------------------------------------------------------------
+// This function tells BlockchainDB to remove the top block from the
+// blockchain and then returns all transactions (except the miner tx, of course)
+// from it to the tx_pool
+block Blockchain::pop_block_from_blockchain()
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  block popped_block;
+  std::vector<transaction> popped_txs;
+
+  try
+  {
+    m_db->pop_block(popped_block, popped_txs);
+  }
+  // anything that could cause this to throw is likely catastrophic,
+  // so we re-throw
+  catch (const std::exception& e)
+  {
+    LOG_ERROR("Error popping block from blockchain: " << e.what());
+    throw;
+  }
+  catch (...)
+  {
+    LOG_ERROR("Error popping block from blockchain, throwing!");
+    throw;
+  }
+
+  // return transactions from popped block to the tx_pool
+  for (transaction& tx : popped_txs)
+  {
+    if (!is_coinbase(tx))
+    {
+      cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
+      bool r = m_tx_pool.add_tx(tx, tvc, true);
+      if (!r)
+      {
+        LOG_ERROR("Error returning transaction to tx_pool");
+      }
+    }
+  }
+
+  return popped_block;
+}
+//------------------------------------------------------------------
+bool Blockchain::reset_and_set_genesis_block(const block& b)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  m_transactions.clear();
+  m_spent_keys.clear();
+  m_blocks.clear();
+  m_blocks_index.clear();
+  m_alternative_chains.clear();
+  m_outputs.clear();
+  m_db->reset();
+
+  block_verification_context bvc = boost::value_initialized<block_verification_context>();
+  add_new_block(b, bvc);
+  return bvc.m_added_to_main_chain && !bvc.m_verifivation_failed;
+}
+//------------------------------------------------------------------
+//TODO: move to BlockchainDB subclass
+bool Blockchain::purge_transaction_keyimages_from_blockchain(const transaction& tx, bool strict_check)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+    struct purge_transaction_visitor: public boost::static_visitor<bool>
+  {
+    key_images_container& m_spent_keys;
+    bool m_strict_check;
+    purge_transaction_visitor(key_images_container& spent_keys, bool strict_check):m_spent_keys(spent_keys), m_strict_check(strict_check){}
+
+    bool operator()(const txin_to_key& inp) const
+    {
+      //const crypto::key_image& ki = inp.k_image;
+      auto r = m_spent_keys.find(inp.k_image);
+      if(r != m_spent_keys.end())
+      {
+        m_spent_keys.erase(r);
+      }else
+      {
+        CHECK_AND_ASSERT_MES(!m_strict_check, false, "purge_block_data_from_blockchain: key image in transaction not found");
+      }
+      return true;
+    }
+    bool operator()(const txin_gen& inp) const
+    {
+      return true;
+    }
+    bool operator()(const txin_to_script& tx) const
+    {
+      return false;
+    }
+
+    bool operator()(const txin_to_scripthash& tx) const
+    {
+      return false;
+    }
+  };
+
+  BOOST_FOREACH(const txin_v& in, tx.vin)
+  {
+    bool r = boost::apply_visitor(purge_transaction_visitor(m_spent_keys, strict_check), in);
+    CHECK_AND_ASSERT_MES(!strict_check || r, false, "failed to process purge_transaction_visitor");
+  }
+  return true;
+}
+//------------------------------------------------------------------
+crypto::hash Blockchain::get_tail_id(uint64_t& height) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  height = m_db->height() - 1;
+  return get_tail_id();
+}
+//------------------------------------------------------------------
+crypto::hash Blockchain::get_tail_id() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return m_db->top_block_hash();
+}
+//------------------------------------------------------------------
+/*TODO: this function was...poorly written.  As such, I'm not entirely
+ *      certain on what it was supposed to be doing.  Need to look into this,
+ *      but it doesn't seem terribly important just yet.
+ *
+ * puts into list <ids> a list of hashes representing certain blocks
+ * from the blockchain in reverse chronological order
+ *
+ * the blocks chosen, at the time of this writing, are:
+ *   the most recent 11
+ *   powers of 2 less recent from there, so 13, 17, 25, etc...
+ *
+ */
+bool Blockchain::get_short_chain_history(std::list<crypto::hash>& ids) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  uint64_t i = 0;
+  uint64_t current_multiplier = 1;
+  uint64_t sz = m_db->height();
+
+  if(!sz)
+    return true;
+
+  bool genesis_included = false;
+  uint64_t current_back_offset = 1;
+  while(current_back_offset < sz)
+  {
+    ids.push_back(m_db->get_block_hash_from_height(sz - current_back_offset));
+
+    if(sz-current_back_offset == 0)
+    {
+      genesis_included = true;
+    }
+    if(i < 10)
+    {
+      ++current_back_offset;
+    }
+    else
+    {
+      current_multiplier *= 2;
+      current_back_offset += current_multiplier;
+    }
+    ++i;
+  }
+
+  if (!genesis_included)
+  {
+    ids.push_back(m_db->get_block_hash_from_height(0));
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+crypto::hash Blockchain::get_block_id_by_height(uint64_t height) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  try
+  {
+    return m_db->get_block_hash_from_height(height);
+  }
+  catch (const BLOCK_DNE& e)
+  {
+  }
+  catch (const std::exception& e)
+  {
+    LOG_PRINT_L0(std::string("Something went wrong fetching block hash by height: ") + e.what());
+    throw;
+  }
+  catch (...)
+  {
+    LOG_PRINT_L0(std::string("Something went wrong fetching block hash by height"));
+    throw;
+  }
+  return null_hash;
+}
+//------------------------------------------------------------------
+bool Blockchain::get_block_by_hash(const crypto::hash &h, block &blk) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // try to find block in main chain
+  try
+  {
+    blk = m_db->get_block(h);
+    return true;
+  }
+  // try to find block in alternative chain
+  catch (const BLOCK_DNE& e)
+  {
+    blocks_ext_by_hash::const_iterator it_alt = m_alternative_chains.find(h);
+    if (m_alternative_chains.end() != it_alt) {
+      blk = it_alt->second.bl;
+      return true;
+    }
+  }
+  catch (const std::exception& e)
+  {
+    LOG_PRINT_L0(std::string("Something went wrong fetching block by hash: ") + e.what());
+    throw;
+  }
+  catch (...)
+  {
+    LOG_PRINT_L0(std::string("Something went wrong fetching block hash by hash"));
+    throw;
+  }
+
+  return false;
+}
+//------------------------------------------------------------------
+//FIXME: this function does not seem to be called from anywhere, but
+// if it ever is, should probably change std::list for std::vector
+void Blockchain::get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  for (auto& a : m_db->get_hashes_range(0, m_db->height() - 1))
+  {
+    main.push_back(a);
+  }
+
+  BOOST_FOREACH(const blocks_ext_by_hash::value_type &v, m_alternative_chains)
+    alt.push_back(v.first);
+
+  BOOST_FOREACH(const blocks_ext_by_hash::value_type &v, m_invalid_blocks)
+    invalid.push_back(v.first);
+}
+//------------------------------------------------------------------
+// This function aggregates the cumulative difficulties and timestamps of the
+// last DIFFICULTY_BLOCKS_COUNT blocks and passes them to next_difficulty,
+// returning the result of that call.  Ignores the genesis block, and can use
+// less blocks than desired if there aren't enough.
+difficulty_type Blockchain::get_difficulty_for_next_block() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  std::vector<uint64_t> timestamps;
+  std::vector<difficulty_type> cumulative_difficulties;
+  auto h = m_db->height();
+
+  size_t offset = h - std::min<size_t>(h, static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT));
+
+  if (offset == 0)
+  {
+    ++offset;
+  }
+
+  for(; offset < h; offset++)
+  {
+    timestamps.push_back(m_db->get_block_timestamp(offset));
+    cumulative_difficulties.push_back(m_db->get_block_cumulative_difficulty(offset));
+  }
+  return next_difficulty(timestamps, cumulative_difficulties);
+}
+//------------------------------------------------------------------
+// This function removes blocks from the blockchain until it gets to the
+// position where the blockchain switch started and then re-adds the blocks
+// that had been removed.
+bool Blockchain::rollback_blockchain_switching(std::list<block>& original_chain, uint64_t rollback_height)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // remove blocks from blockchain until we get back to where we should be.
+  while (m_db->height() != rollback_height)
+  {
+    pop_block_from_blockchain();
+  }
+
+  //return back original chain
+  for (auto& bl : original_chain)
+  {
+    block_verification_context bvc = boost::value_initialized<block_verification_context>();
+    bool r = handle_block_to_main_chain(bl, bvc);
+    CHECK_AND_ASSERT_MES(r && bvc.m_added_to_main_chain, false, "PANIC! failed to add (again) block while chain switching during the rollback!");
+  }
+
+  LOG_PRINT_L1("Rollback to height " << rollback_height << " was successful.");
+  if (original_chain.size())
+  {
+    LOG_PRINT_L1("Restoration to previous blockchain successful as well.");
+  }
+  return true;
+}
+//------------------------------------------------------------------
+// This function attempts to switch to an alternate chain, returning
+// boolean based on success therein.
+bool Blockchain::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // if empty alt chain passed (not sure how that could happen), return false
+  CHECK_AND_ASSERT_MES(alt_chain.size(), false, "switch_to_alternative_blockchain: empty chain passed");
+
+  // verify that main chain has front of alt chain's parent block
+  if (!m_db->block_exists(alt_chain.front()->second.bl.prev_id))
+  {
+    LOG_ERROR("Attempting to move to an alternate chain, but it doesn't appear to connect to the main chain!");
+    return false;
+  }
+
+  // pop blocks from the blockchain until the top block is the parent
+  // of the front block of the alt chain.
+  std::list<block> disconnected_chain;
+  while (m_db->top_block_hash() != alt_chain.front()->second.bl.prev_id)
+  {
+    block b = pop_block_from_blockchain();
+    disconnected_chain.push_front(b);
+  }
+
+  auto split_height = m_db->height();
+
+  //connecting new alternative chain
+  for(auto alt_ch_iter = alt_chain.begin(); alt_ch_iter != alt_chain.end(); alt_ch_iter++)
+  {
+    auto ch_ent = *alt_ch_iter;
+    block_verification_context bvc = boost::value_initialized<block_verification_context>();
+
+    // add block to main chain
+    bool r = handle_block_to_main_chain(ch_ent->second.bl, bvc);
+
+    // if adding block to main chain failed, rollback to previous state and
+    // return false
+    if(!r || !bvc.m_added_to_main_chain)
+    {
+      LOG_PRINT_L1("Failed to switch to alternative blockchain");
+
+      // rollback_blockchain_switching should be moved to two different
+      // functions: rollback and apply_chain, but for now we pretend it is
+      // just the latter (because the rollback was done above).
+      rollback_blockchain_switching(disconnected_chain, m_db->height());
+
+      // FIXME: Why do we keep invalid blocks around?  Possibly in case we hear
+      // about them again so we can immediately dismiss them, but needs some
+      // looking into.
+      add_block_as_invalid(ch_ent->second, get_block_hash(ch_ent->second.bl));
+      LOG_PRINT_L1("The block was inserted as invalid while connecting new alternative chain, block_id: " << get_block_hash(ch_ent->second.bl));
+      m_alternative_chains.erase(ch_ent);
+
+      for(auto alt_ch_to_orph_iter = ++alt_ch_iter; alt_ch_to_orph_iter != alt_chain.end(); alt_ch_to_orph_iter++)
+      {
+        add_block_as_invalid((*alt_ch_iter)->second, (*alt_ch_iter)->first);
+        m_alternative_chains.erase(*alt_ch_to_orph_iter);
+      }
+      return false;
+    }
+  }
+
+  // if we're to keep the disconnected blocks, add them as alternates
+  if(!discard_disconnected_chain)
+  {
+    //pushing old chain as alternative chain
+    for (auto& old_ch_ent : disconnected_chain)
+    {
+      block_verification_context bvc = boost::value_initialized<block_verification_context>();
+      bool r = handle_alternative_block(old_ch_ent, get_block_hash(old_ch_ent), bvc);
+      if(!r)
+      {
+        LOG_PRINT_L1("Failed to push ex-main chain blocks to alternative chain ");
+        // previously this would fail the blockchain switching, but I don't
+        // think this is bad enough to warrant that.
+      }
+    }
+  }
+
+  //removing alt_chain entries from alternative chain
+  BOOST_FOREACH(auto ch_ent, alt_chain)
+  {
+    m_alternative_chains.erase(ch_ent);
+  }
+
+  LOG_PRINT_GREEN("REORGANIZE SUCCESS! on height: " << split_height << ", new blockchain size: " << m_db->height(), LOG_LEVEL_0);
+  return true;
+}
+//------------------------------------------------------------------
+// This function calculates the difficulty target for the block being added to
+// an alternate chain.
+difficulty_type Blockchain::get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  std::vector<uint64_t> timestamps;
+  std::vector<difficulty_type> cumulative_difficulties;
+
+  // if the alt chain isn't long enough to calculate the difficulty target
+  // based on its blocks alone, need to get more blocks from the main chain
+  if(alt_chain.size()< DIFFICULTY_BLOCKS_COUNT)
+  {
+    CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+    // Figure out start and stop offsets for main chain blocks
+    size_t main_chain_stop_offset = alt_chain.size() ? alt_chain.front()->second.height : bei.height;
+    size_t main_chain_count = DIFFICULTY_BLOCKS_COUNT - std::min(static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT), alt_chain.size());
+    main_chain_count = std::min(main_chain_count, main_chain_stop_offset);
+    size_t main_chain_start_offset = main_chain_stop_offset - main_chain_count;
+
+    if(!main_chain_start_offset)
+      ++main_chain_start_offset; //skip genesis block
+
+    // get difficulties and timestamps from relevant main chain blocks
+    for(; main_chain_start_offset < main_chain_stop_offset; ++main_chain_start_offset)
+    {
+      timestamps.push_back(m_db->get_block_timestamp(main_chain_start_offset));
+      cumulative_difficulties.push_back(m_db->get_block_cumulative_difficulty(main_chain_start_offset));
+    }
+
+    // make sure we haven't accidentally grabbed too many blocks...maybe don't need this check?
+    CHECK_AND_ASSERT_MES((alt_chain.size() + timestamps.size()) <= DIFFICULTY_BLOCKS_COUNT, false,
+        "Internal error, alt_chain.size()[" << alt_chain.size()
+                                            << "] + vtimestampsec.size()[" << timestamps.size()
+                                            << "] NOT <= DIFFICULTY_WINDOW[]" << DIFFICULTY_BLOCKS_COUNT
+    );
+
+    for (auto it : alt_chain)
+    {
+      timestamps.push_back(it->second.bl.timestamp);
+      cumulative_difficulties.push_back(it->second.cumulative_difficulty);
+    }
+  }
+  // if the alt chain is long enough for the difficulty calc, grab difficulties
+  // and timestamps from it alone
+  else
+  {
+    timestamps.resize(static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT));
+    cumulative_difficulties.resize(static_cast<size_t>(DIFFICULTY_BLOCKS_COUNT));
+    size_t count = 0;
+    size_t max_i = timestamps.size()-1;
+    // get difficulties and timestamps from most recent blocks in alt chain
+    BOOST_REVERSE_FOREACH(auto it, alt_chain)
+    {
+      timestamps[max_i - count] = it->second.bl.timestamp;
+      cumulative_difficulties[max_i - count] = it->second.cumulative_difficulty;
+      count++;
+      if(count >= DIFFICULTY_BLOCKS_COUNT)
+        break;
+    }
+  }
+
+  // calculate the difficulty target for the block and return it
+  return next_difficulty(timestamps, cumulative_difficulties);
+}
+//------------------------------------------------------------------
+// This function does a sanity check on basic things that all miner
+// transactions have in common, such as:
+//   one input, of type txin_gen, with height set to the block's height
+//   correct miner tx unlock time
+//   a non-overflowing tx amount (dubious necessity on this check)
+bool Blockchain::prevalidate_miner_transaction(const block& b, uint64_t height)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CHECK_AND_ASSERT_MES(b.miner_tx.vin.size() == 1, false, "coinbase transaction in the block has no inputs");
+  CHECK_AND_ASSERT_MES(b.miner_tx.vin[0].type() == typeid(txin_gen), false, "coinbase transaction in the block has the wrong type");
+  if(boost::get<txin_gen>(b.miner_tx.vin[0]).height != height)
+  {
+    LOG_PRINT_RED_L1("The miner transaction in block has invalid height: " << boost::get<txin_gen>(b.miner_tx.vin[0]).height << ", expected: " << height);
+    return false;
+  }
+  CHECK_AND_ASSERT_MES(b.miner_tx.unlock_time == height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW,
+                  false,
+                  "coinbase transaction transaction has the wrong unlock time=" << b.miner_tx.unlock_time << ", expected " << height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW);
+
+
+  //check outs overflow
+  //NOTE: not entirely sure this is necessary, given that this function is
+  //      designed simply to make sure the total amount for a transaction
+  //      does not overflow a uint64_t, and this transaction *is* a uint64_t...
+  if(!check_outs_overflow(b.miner_tx))
+  {
+    LOG_PRINT_RED_L1("miner transaction has money overflow in block " << get_block_hash(b));
+    return false;
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+// This function validates the miner transaction reward
+bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  //validate reward
+  uint64_t money_in_use = 0;
+  BOOST_FOREACH(auto& o, b.miner_tx.vout)
+    money_in_use += o.amount;
+
+  std::vector<size_t> last_blocks_sizes;
+  get_last_n_blocks_sizes(last_blocks_sizes, CRYPTONOTE_REWARD_BLOCKS_WINDOW);
+  if (!get_block_reward(epee::misc_utils::median(last_blocks_sizes), cumulative_block_size, already_generated_coins, base_reward)) {
+    LOG_PRINT_L1("block size " << cumulative_block_size << " is bigger than allowed for this blockchain");
+    return false;
+  }
+  if(base_reward + fee < money_in_use)
+  {
+    LOG_PRINT_L1("coinbase transaction spend too much money (" << print_money(money_in_use) << "). Block reward is " << print_money(base_reward + fee) << "(" << print_money(base_reward) << "+" << print_money(fee) << ")");
+    return false;
+  }
+  if(base_reward + fee != money_in_use)
+  {
+    LOG_PRINT_L1("coinbase transaction doesn't use full amount of block reward:  spent: "
+                            << money_in_use << ",  block reward " << base_reward + fee << "(" << base_reward << "+" << fee << ")");
+    return false;
+  }
+  return true;
+}
+//------------------------------------------------------------------
+// get the block sizes of the last <count> blocks, starting at <from_height>
+// and return by reference <sz>.
+void Blockchain::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  auto h = m_db->height();
+
+  // this function is meaningless for an empty blockchain...granted it should never be empty
+  if(h == 0)
+    return;
+
+  // add size of last <count> blocks to vector <sz> (or less, if blockchain size < count)
+  size_t start_offset = h - std::min<size_t>(h, count);
+  for(size_t i = start_offset; i < h; i++)
+  {
+    sz.push_back(m_db->get_block_size(i));
+  }
+}
+//------------------------------------------------------------------
+uint64_t Blockchain::get_current_cumulative_blocksize_limit() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  return m_current_block_cumul_sz_limit;
+}
+//------------------------------------------------------------------
+//TODO: This function only needed minor modification to work with BlockchainDB,
+//      and *works*.  As such, to reduce the number of things that might break
+//      in moving to BlockchainDB, this function will remain otherwise
+//      unchanged for the time being.
+//
+// This function makes a new block for a miner to mine the hash for
+//
+// FIXME: this codebase references #if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+// in a lot of places.  That flag is not referenced in any of the code
+// nor any of the makefiles, howeve.  Need to look into whether or not it's
+// necessary at all.
+bool Blockchain::create_block_template(block& b, const account_public_address& miner_address, difficulty_type& diffic, uint64_t& height, const blobdata& ex_nonce) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  size_t median_size;
+  uint64_t already_generated_coins;
+
+  CRITICAL_REGION_BEGIN(m_blockchain_lock);
+  b.major_version = CURRENT_BLOCK_MAJOR_VERSION;
+  b.minor_version = CURRENT_BLOCK_MINOR_VERSION;
+  b.prev_id = get_tail_id();
+  b.timestamp = time(NULL);
+
+  height = m_db->height();
+  diffic = get_difficulty_for_next_block();
+  CHECK_AND_ASSERT_MES(diffic, false, "difficulty owverhead.");
+
+  median_size = m_current_block_cumul_sz_limit / 2;
+  already_generated_coins = m_db->get_block_already_generated_coins(height - 1);
+
+  CRITICAL_REGION_END();
+
+  size_t txs_size;
+  uint64_t fee;
+  if (!m_tx_pool.fill_block_template(b, median_size, already_generated_coins, txs_size, fee)) {
+    return false;
+  }
+#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+  size_t real_txs_size = 0;
+  uint64_t real_fee = 0;
+  CRITICAL_REGION_BEGIN(m_tx_pool.m_transactions_lock);
+  BOOST_FOREACH(crypto::hash &cur_hash, b.tx_hashes) {
+    auto cur_res = m_tx_pool.m_transactions.find(cur_hash);
+    if (cur_res == m_tx_pool.m_transactions.end()) {
+      LOG_ERROR("Creating block template: error: transaction not found");
+      continue;
+    }
+    tx_memory_pool::tx_details &cur_tx = cur_res->second;
+    real_txs_size += cur_tx.blob_size;
+    real_fee += cur_tx.fee;
+    if (cur_tx.blob_size != get_object_blobsize(cur_tx.tx)) {
+      LOG_ERROR("Creating block template: error: invalid transaction size");
+    }
+    uint64_t inputs_amount;
+    if (!get_inputs_money_amount(cur_tx.tx, inputs_amount)) {
+      LOG_ERROR("Creating block template: error: cannot get inputs amount");
+    } else if (cur_tx.fee != inputs_amount - get_outs_money_amount(cur_tx.tx)) {
+      LOG_ERROR("Creating block template: error: invalid fee");
+    }
+  }
+  if (txs_size != real_txs_size) {
+    LOG_ERROR("Creating block template: error: wrongly calculated transaction size");
+  }
+  if (fee != real_fee) {
+    LOG_ERROR("Creating block template: error: wrongly calculated fee");
+  }
+  CRITICAL_REGION_END();
+  LOG_PRINT_L1("Creating block template: height " << height <<
+    ", median size " << median_size <<
+    ", already generated coins " << already_generated_coins <<
+    ", transaction size " << txs_size <<
+    ", fee " << fee);
+#endif
+
+  /*
+     two-phase miner transaction generation: we don't know exact block size until we prepare block, but we don't know reward until we know
+     block size, so first miner transaction generated with fake amount of money, and with phase we know think we know expected block size
+  */
+  //make blocks coin-base tx looks close to real coinbase tx to get truthful blob size
+  bool r = construct_miner_tx(height, median_size, already_generated_coins, txs_size, fee, miner_address, b.miner_tx, ex_nonce, 11);
+  CHECK_AND_ASSERT_MES(r, false, "Failed to construc miner tx, first chance");
+  size_t cumulative_size = txs_size + get_object_blobsize(b.miner_tx);
+#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+  LOG_PRINT_L1("Creating block template: miner tx size " << get_object_blobsize(b.miner_tx) <<
+    ", cumulative size " << cumulative_size);
+#endif
+  for (size_t try_count = 0; try_count != 10; ++try_count) {
+    r = construct_miner_tx(height, median_size, already_generated_coins, cumulative_size, fee, miner_address, b.miner_tx, ex_nonce, 11);
+
+    CHECK_AND_ASSERT_MES(r, false, "Failed to construc miner tx, second chance");
+    size_t coinbase_blob_size = get_object_blobsize(b.miner_tx);
+    if (coinbase_blob_size > cumulative_size - txs_size) {
+      cumulative_size = txs_size + coinbase_blob_size;
+#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+      LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
+        ", cumulative size " << cumulative_size << " is greater then before");
+#endif
+      continue;
+    }
+
+    if (coinbase_blob_size < cumulative_size - txs_size) {
+      size_t delta = cumulative_size - txs_size - coinbase_blob_size;
+#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+      LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
+        ", cumulative size " << txs_size + coinbase_blob_size <<
+        " is less then before, adding " << delta << " zero bytes");
+#endif
+      b.miner_tx.extra.insert(b.miner_tx.extra.end(), delta, 0);
+      //here  could be 1 byte difference, because of extra field counter is varint, and it can become from 1-byte len to 2-bytes len.
+      if (cumulative_size != txs_size + get_object_blobsize(b.miner_tx)) {
+        CHECK_AND_ASSERT_MES(cumulative_size + 1 == txs_size + get_object_blobsize(b.miner_tx), false, "unexpected case: cumulative_size=" << cumulative_size << " + 1 is not equal txs_cumulative_size=" << txs_size << " + get_object_blobsize(b.miner_tx)=" << get_object_blobsize(b.miner_tx));
+        b.miner_tx.extra.resize(b.miner_tx.extra.size() - 1);
+        if (cumulative_size != txs_size + get_object_blobsize(b.miner_tx)) {
+          //fuck, not lucky, -1 makes varint-counter size smaller, in that case we continue to grow with cumulative_size
+          LOG_PRINT_RED("Miner tx creation has no luck with delta_extra size = " << delta << " and " << delta - 1 , LOG_LEVEL_2);
+          cumulative_size += delta - 1;
+          continue;
+        }
+        LOG_PRINT_GREEN("Setting extra for block: " << b.miner_tx.extra.size() << ", try_count=" << try_count, LOG_LEVEL_1);
+      }
+    }
+    CHECK_AND_ASSERT_MES(cumulative_size == txs_size + get_object_blobsize(b.miner_tx), false, "unexpected case: cumulative_size=" << cumulative_size << " is not equal txs_cumulative_size=" << txs_size << " + get_object_blobsize(b.miner_tx)=" << get_object_blobsize(b.miner_tx));
+#if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
+    LOG_PRINT_L1("Creating block template: miner tx size " << coinbase_blob_size <<
+      ", cumulative size " << cumulative_size << " is now good");
+#endif
+    return true;
+  }
+  LOG_ERROR("Failed to create_block_template with " << 10 << " tries");
+  return false;
+}
+//------------------------------------------------------------------
+// for an alternate chain, get the timestamps from the main chain to complete
+// the needed number of timestamps for the BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW.
+bool Blockchain::complete_timestamps_vector(uint64_t start_top_height, std::vector<uint64_t>& timestamps)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+
+  if(timestamps.size() >= BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW)
+    return true;
+
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  size_t need_elements = BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW - timestamps.size();
+  CHECK_AND_ASSERT_MES(start_top_height < m_db->height(), false, "internal error: passed start_height not < " << " m_db->height() -- " << start_top_height << " >= " << m_db->height());
+  size_t stop_offset = start_top_height > need_elements ? start_top_height - need_elements : 0;
+  while (start_top_height != stop_offset)
+  {
+    timestamps.push_back(m_db->get_block_timestamp(start_top_height));
+    --start_top_height;
+  }
+  return true;
+}
+//------------------------------------------------------------------
+// If a block is to be added and its parent block is not the current
+// main chain top block, then we need to see if we know about its parent block.
+// If its parent block is part of a known forked chain, then we need to see
+// if that chain is long enough to become the main chain and re-org accordingly
+// if so.  If not, we need to hang on to the block in case it becomes part of
+// a long forked chain eventually.
+bool Blockchain::handle_alternative_block(const block& b, const crypto::hash& id, block_verification_context& bvc)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  uint64_t block_height = get_block_height(b);
+  if(0 == block_height)
+  {
+    LOG_PRINT_L1("Block with id: " << epee::string_tools::pod_to_hex(id) << " (as alternative), but miner tx says height is 0.");
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+  // this basically says if the blockchain is smaller than the first
+  // checkpoint then alternate blocks are allowed.  Alternatively, if the
+  // last checkpoint *before* the end of the current chain is also before
+  // the block to be added, then this is fine.
+  if (!m_checkpoints.is_alternative_block_allowed(get_current_blockchain_height(), block_height))
+  {
+    LOG_PRINT_RED_L1("Block with id: " << id
+      << std::endl << " can't be accepted for alternative chain, block height: " << block_height
+      << std::endl << " blockchain height: " << get_current_blockchain_height());
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+
+  //block is not related with head of main chain
+  //first of all - look in alternative chains container
+  auto it_prev = m_alternative_chains.find(b.prev_id);
+  bool parent_in_main = m_db->block_exists(b.prev_id);
+  if(it_prev != m_alternative_chains.end() || parent_in_main)
+  {
+    //we have new block in alternative chain
+
+    //build alternative subchain, front -> mainchain, back -> alternative head
+    blocks_ext_by_hash::iterator alt_it = it_prev; //m_alternative_chains.find()
+    std::list<blocks_ext_by_hash::iterator> alt_chain;
+    std::vector<uint64_t> timestamps;
+    while(alt_it != m_alternative_chains.end())
+    {
+      alt_chain.push_front(alt_it);
+      timestamps.push_back(alt_it->second.bl.timestamp);
+      alt_it = m_alternative_chains.find(alt_it->second.bl.prev_id);
+    }
+
+    // if block to be added connects to known blocks that aren't part of the
+    // main chain -- that is, if we're adding on to an alternate chain
+    if(alt_chain.size())
+    {
+      // make sure alt chain doesn't somehow start past the end of the main chain
+      CHECK_AND_ASSERT_MES(m_db->height() > alt_chain.front()->second.height, false, "main blockchain wrong height");
+
+      // make sure that the blockchain contains the block that should connect
+      // this alternate chain with it.
+      if (!m_db->block_exists(alt_chain.front()->second.bl.prev_id))
+      {
+        LOG_PRINT_L1("alternate chain does not appear to connect to main chain...");
+        return false;
+      }
+
+      // make sure block connects correctly to the main chain
+      auto h = m_db->get_block_hash_from_height(alt_chain.front()->second.height - 1);
+      CHECK_AND_ASSERT_MES(h == alt_chain.front()->second.bl.prev_id, false, "alternative chain has wrong connection to main chain");
+      complete_timestamps_vector(m_db->get_block_height(alt_chain.front()->second.bl.prev_id), timestamps);
+    }
+    // if block not associated with known alternate chain
+    else
+    {
+      // if block parent is not part of main chain or an alternate chain,
+      // we ignore it
+      CHECK_AND_ASSERT_MES(parent_in_main, false, "internal error: broken imperative condition it_main_prev != m_blocks_index.end()");
+
+      complete_timestamps_vector(m_db->get_block_height(b.prev_id), timestamps);
+    }
+
+    // verify that the block's timestamp is within the acceptable range
+    // (not earlier than the median of the last X blocks)
+    if(!check_block_timestamp(timestamps, b))
+    {
+      LOG_PRINT_RED_L1("Block with id: " << id
+        << std::endl << " for alternative chain, has invalid timestamp: " << b.timestamp);
+      bvc.m_verifivation_failed = true;
+      return false;
+    }
+
+    // FIXME: consider moving away from block_extended_info at some point
+    block_extended_info bei = boost::value_initialized<block_extended_info>();
+    bei.bl = b;
+    bei.height = alt_chain.size() ? it_prev->second.height + 1 : m_db->get_block_height(b.prev_id) + 1;
+
+    bool is_a_checkpoint;
+    if(!m_checkpoints.check_block(bei.height, id, is_a_checkpoint))
+    {
+      LOG_ERROR("CHECKPOINT VALIDATION FAILED");
+      bvc.m_verifivation_failed = true;
+      return false;
+    }
+
+    // Check the block's hash against the difficulty target for its alt chain
+    m_is_in_checkpoint_zone = false;
+    difficulty_type current_diff = get_next_difficulty_for_alternative_chain(alt_chain, bei);
+    CHECK_AND_ASSERT_MES(current_diff, false, "!!!!!!! DIFFICULTY OVERHEAD !!!!!!!");
+    crypto::hash proof_of_work = null_hash;
+    get_block_longhash(bei.bl, proof_of_work, bei.height);
+    if(!check_hash(proof_of_work, current_diff))
+    {
+      LOG_PRINT_RED_L1("Block with id: " << id
+        << std::endl << " for alternative chain, does not have enough proof of work: " << proof_of_work
+        << std::endl << " expected difficulty: " << current_diff);
+      bvc.m_verifivation_failed = true;
+      return false;
+    }
+
+    if(!prevalidate_miner_transaction(b, bei.height))
+    {
+      LOG_PRINT_RED_L1("Block with id: " << epee::string_tools::pod_to_hex(id)
+        << " (as alternative) has incorrect miner transaction.");
+      bvc.m_verifivation_failed = true;
+      return false;
+
+    }
+
+    // FIXME:
+    // this brings up an interesting point: consider allowing to get block
+    // difficulty both by height OR by hash, not just height.
+    difficulty_type main_chain_cumulative_difficulty = m_db->get_block_cumulative_difficulty(m_db->height() - 1);
+    if (alt_chain.size())
+    {
+      bei.cumulative_difficulty = it_prev->second.cumulative_difficulty;
+    }
+    else
+    {
+      // passed-in block's previous block's cumulative difficulty, found on the main chain
+      bei.cumulative_difficulty = m_db->get_block_cumulative_difficulty(m_db->get_block_height(b.prev_id));
+    }
+    bei.cumulative_difficulty += current_diff;
+
+    // add block to alternate blocks storage,
+    // as well as the current "alt chain" container
+    auto i_res = m_alternative_chains.insert(blocks_ext_by_hash::value_type(id, bei));
+    CHECK_AND_ASSERT_MES(i_res.second, false, "insertion of new alternative block returned as it already exist");
+    alt_chain.push_back(i_res.first);
+
+    // FIXME: is it even possible for a checkpoint to show up not on the main chain?
+    if(is_a_checkpoint)
+    {
+      //do reorganize!
+      LOG_PRINT_GREEN("###### REORGANIZE on height: " << alt_chain.front()->second.height << " of " << m_db->height() - 1 <<
+        ", checkpoint is found in alternative chain on height " << bei.height, LOG_LEVEL_0);
+
+      bool r = switch_to_alternative_blockchain(alt_chain, true);
+
+      bvc.m_added_to_main_chain = r;
+      bvc.m_verifivation_failed = !r;
+
+      return r;
+    }
+    else if(main_chain_cumulative_difficulty < bei.cumulative_difficulty) //check if difficulty bigger then in main chain
+    {
+      //do reorganize!
+      LOG_PRINT_GREEN("###### REORGANIZE on height: "
+          << alt_chain.front()->second.height << " of " << m_db->height() - 1
+          << " with cum_difficulty " << m_db->get_block_cumulative_difficulty(m_db->height() - 1)
+          << std::endl << " alternative blockchain size: " << alt_chain.size()
+          << " with cum_difficulty " << bei.cumulative_difficulty, LOG_LEVEL_0
+      );
+
+      bool r = switch_to_alternative_blockchain(alt_chain, false);
+      if(r) bvc.m_added_to_main_chain = true;
+      else bvc.m_verifivation_failed = true;
+      return r;
+    }
+    else
+    {
+      LOG_PRINT_BLUE("----- BLOCK ADDED AS ALTERNATIVE ON HEIGHT " << bei.height
+        << std::endl << "id:\t" << id
+        << std::endl << "PoW:\t" << proof_of_work
+        << std::endl << "difficulty:\t" << current_diff, LOG_LEVEL_0);
+      return true;
+    }
+  }
+  else
+  {
+    //block orphaned
+    bvc.m_marked_as_orphaned = true;
+    LOG_PRINT_RED_L1("Block recognized as orphaned and rejected, id = " << id);
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  if(start_offset > m_db->height())
+    return false;
+
+  if (!get_blocks(start_offset, count, blocks))
+  {
+    return false;
+  }
+
+  for(const block& blk : blocks)
+  {
+    std::list<crypto::hash> missed_ids;
+    get_transactions(blk.tx_hashes, txs, missed_ids);
+    CHECK_AND_ASSERT_MES(!missed_ids.size(), false, "has missed transactions in own block in main blockchain");
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  if(start_offset > m_db->height())
+    return false;
+
+  for(size_t i = start_offset; i < start_offset + count && i <= m_db->height();i++)
+  {
+    blocks.push_back(m_db->get_block_from_height(i));
+  }
+  return true;
+}
+//------------------------------------------------------------------
+//TODO: This function *looks* like it won't need to be rewritten
+//      to use BlockchainDB, as it calls other functions that were,
+//      but it warrants some looking into later.
+bool Blockchain::handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request& arg, NOTIFY_RESPONSE_GET_OBJECTS::request& rsp)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  rsp.current_blockchain_height = get_current_blockchain_height();
+  std::list<block> blocks;
+  get_blocks(arg.blocks, blocks, rsp.missed_ids);
+
+  BOOST_FOREACH(const auto& bl, blocks)
+  {
+    std::list<crypto::hash> missed_tx_id;
+    std::list<transaction> txs;
+    get_transactions(bl.tx_hashes, txs, rsp.missed_ids);
+    CHECK_AND_ASSERT_MES(!missed_tx_id.size(), false, "Internal error: has missed missed_tx_id.size()=" << missed_tx_id.size()
+      << std::endl << "for block id = " << get_block_hash(bl));
+   rsp.blocks.push_back(block_complete_entry());
+   block_complete_entry& e = rsp.blocks.back();
+   //pack block
+   e.block = t_serializable_object_to_blob(bl);
+   //pack transactions
+   BOOST_FOREACH(transaction& tx, txs)
+     e.txs.push_back(t_serializable_object_to_blob(tx));
+
+  }
+  //get another transactions, if need
+  std::list<transaction> txs;
+  get_transactions(arg.txs, txs, rsp.missed_ids);
+  //pack aside transactions
+  BOOST_FOREACH(const auto& tx, txs)
+    rsp.txs.push_back(t_serializable_object_to_blob(tx));
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::get_alternative_blocks(std::list<block>& blocks) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  BOOST_FOREACH(const auto& alt_bl, m_alternative_chains)
+  {
+    blocks.push_back(alt_bl.second.bl);
+  }
+  return true;
+}
+//------------------------------------------------------------------
+size_t Blockchain::get_alternative_blocks_count() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return m_alternative_chains.size();
+}
+//------------------------------------------------------------------
+// This function adds the output specified by <amount, i> to the result_outs container
+// unlocked and other such checks should be done by here.
+void Blockchain::add_out_to_get_random_outs(COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::out_entry& oen = *result_outs.outs.insert(result_outs.outs.end(), COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::out_entry());
+  oen.global_amount_index = i;
+  oen.out_key = m_db->get_output_key(amount, i);
+}
+//------------------------------------------------------------------
+// This function takes an RPC request for mixins and creates an RPC response
+// with the requested mixins.
+// TODO: figure out why this returns boolean / if we should be returning false
+// in some cases
+bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  srand(static_cast<unsigned int>(time(NULL)));
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // for each amount that we need to get mixins for, get <n> random outputs
+  // from BlockchainDB where <n> is req.outs_count (number of mixins).
+  for (uint64_t amount : req.amounts)
+  {
+    // create outs_for_amount struct and populate amount field
+    COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs = *res.outs.insert(res.outs.end(), COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount());
+    result_outs.amount = amount;
+
+    std::unordered_set<uint64_t> seen_indices;
+
+    // if there aren't enough outputs to mix with (or just enough),
+    // use all of them.  Eventually this should become impossible.
+    if (m_db->get_num_outputs(amount) <= req.outs_count)
+    {
+      for (uint64_t i = 0; i < m_db->get_num_outputs(amount); i++)
+      {
+        // get tx_hash, tx_out_index from DB
+        tx_out_index toi = m_db->get_output_tx_and_index(amount, i);
+
+        // if tx is unlocked, add output to result_outs
+        if (is_tx_spendtime_unlocked(m_db->get_tx_unlock_time(toi.first)))
+        {
+          add_out_to_get_random_outs(result_outs, amount, i);
+        }
+
+      }
+    }
+    else
+    {
+      // while we still need more mixins
+      auto num_outs = m_db->get_num_outputs(amount);
+      while (result_outs.outs.size() < req.outs_count)
+      {
+        // if we've gone through every possible output, we've gotten all we can
+        if (seen_indices.size() == num_outs)
+        {
+          break;
+        }
+
+        // get a random output index from the DB.  If we've already seen it,
+        // return to the top of the loop and try again, otherwise add it to the
+        // list of output indices we've seen.
+        uint64_t i = m_db->get_random_output(amount);
+        if (seen_indices.count(i))
+        {
+          continue;
+        }
+        seen_indices.emplace(i);
+
+        // get tx_hash, tx_out_index from DB
+        tx_out_index toi = m_db->get_output_tx_and_index(amount, i);
+
+        // if the output's transaction is unlocked, add the output's index to
+        // our list.
+        if (is_tx_spendtime_unlocked(m_db->get_tx_unlock_time(toi.first)))
+        {
+          add_out_to_get_random_outs(result_outs, amount, i);
+        }
+      }
+    }
+  }
+  return true;
+}
+//------------------------------------------------------------------
+// This function takes a list of block hashes from another node
+// on the network to find where the split point is between us and them.
+// This is used to see what to send another node that needs to sync.
+bool Blockchain::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // make sure the request includes at least the genesis block, otherwise
+  // how can we expect to sync from the client that the block list came from?
+  if(!qblock_ids.size() /*|| !req.m_total_height*/)
+  {
+    LOG_PRINT_L1("Client sent wrong NOTIFY_REQUEST_CHAIN: m_block_ids.size()=" << qblock_ids.size() << /*", m_height=" << req.m_total_height <<*/ ", dropping connection");
+    return false;
+  }
+
+  // make sure that the last block in the request's block list matches
+  // the genesis block
+  auto gen_hash = m_db->get_block_hash_from_height(0);
+  if(qblock_ids.back() != gen_hash)
+  {
+    LOG_PRINT_L1("Client sent wrong NOTIFY_REQUEST_CHAIN: genesis block missmatch: " << std::endl << "id: "
+      << qblock_ids.back() << ", " << std::endl << "expected: " << gen_hash
+      << "," << std::endl << " dropping connection");
+    return false;
+  }
+
+  // Find the first block the foreign chain has that we also have.
+  // Assume qblock_ids is in reverse-chronological order.
+  auto bl_it = qblock_ids.begin();
+  uint64_t split_height = 0;
+  for(; bl_it != qblock_ids.end(); bl_it++)
+  {
+    try
+    {
+      split_height = m_db->get_block_height(*bl_it);
+      break;
+    }
+    catch (const BLOCK_DNE& e)
+    {
+      continue;
+    }
+    catch (const std::exception& e)
+    {
+      LOG_PRINT_L1("Non-critical error trying to find block by hash in BlockchainDB, hash: " << *bl_it);
+      return false;
+    }
+  }
+
+  // this should be impossible, as we checked that we share the genesis block,
+  // but just in case...
+  if(bl_it == qblock_ids.end())
+  {
+    LOG_PRINT_L1("Internal error handling connection, can't find split point");
+    return false;
+  }
+
+  // if split_height remains 0, we didn't have any but the genesis block in common
+  // which is only fine if the blocks just have the genesis block
+  if(split_height == 0 && qblock_ids.size() > 1)
+  {
+    LOG_ERROR("Ours and foreign blockchain have only genesis block in common... o.O");
+    return false;
+  }
+
+  //we start to put block ids INCLUDING last known id, just to make other side be sure
+  starter_offset = split_height;
+  return true;
+}
+//------------------------------------------------------------------
+uint64_t Blockchain::block_difficulty(uint64_t i) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  try
+  {
+    return m_db->get_block_difficulty(i);
+  }
+  catch (const BLOCK_DNE& e)
+  {
+    LOG_PRINT_L0("Attempted to get block difficulty for height above blockchain height");
+  }
+  return 0;
+}
+//------------------------------------------------------------------
+template<class t_ids_container, class t_blocks_container, class t_missed_container>
+bool Blockchain::get_blocks(const t_ids_container& block_ids, t_blocks_container& blocks, t_missed_container& missed_bs) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  for (const auto& block_hash : block_ids)
+  {
+    try
+    {
+      blocks.push_back(m_db->get_block(block_hash));
+    }
+    catch (const BLOCK_DNE& e)
+    {
+      missed_bs.push_back(block_hash);
+    }
+    catch (const std::exception& e)
+    {
+      return false;
+    }
+  }
+  return true;
+}
+//------------------------------------------------------------------
+template<class t_ids_container, class t_tx_container, class t_missed_container>
+bool Blockchain::get_transactions(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  for (const auto& tx_hash : txs_ids)
+  {
+    try
+    {
+      txs.push_back(m_db->get_tx(tx_hash));
+    }
+    catch (const TX_DNE& e)
+    {
+      missed_txs.push_back(tx_hash);
+    }
+    //FIXME: is this the correct way to handle this?
+    catch (const std::exception& e)
+    {
+      return false;
+    }
+  }
+  return true;
+}
+//------------------------------------------------------------------
+void Blockchain::print_blockchain(uint64_t start_index, uint64_t end_index)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  std::stringstream ss;
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  auto h = m_db->height();
+  if(start_index > h)
+  {
+    LOG_PRINT_L1("Wrong starter index set: " << start_index << ", expected max index " << h);
+    return;
+  }
+
+  for(size_t i = start_index; i <= h && i != end_index; i++)
+  {
+    ss << "height " << i
+       << ", timestamp " << m_db->get_block_timestamp(i)
+       << ", cumul_dif " << m_db->get_block_cumulative_difficulty(i)
+       << ", size " << m_db->get_block_size(i)
+       << "\nid\t\t" <<  m_db->get_block_hash_from_height(i)
+       << "\ndifficulty\t\t" << m_db->get_block_difficulty(i)
+       << ", nonce " << m_db->get_block_from_height(i).nonce
+       << ", tx_count " << m_db->get_block_from_height(i).tx_hashes.size()
+       << std::endl;
+  }
+  LOG_PRINT_L1("Current blockchain:" << std::endl << ss.str());
+  LOG_PRINT_L0("Blockchain printed with log level 1");
+}
+//------------------------------------------------------------------
+void Blockchain::print_blockchain_index()
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  std::stringstream ss;
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  auto height = m_db->height();
+  if (height != 0)
+  {
+    for(uint64_t i = 0; i <= height; i++)
+    {
+      ss << "height: " << i << ", hash: " << m_db->get_block_hash_from_height(i);
+    }
+  }
+
+  LOG_PRINT_L0("Current blockchain index:" << std::endl
+               << ss.str()
+              );
+}
+//------------------------------------------------------------------
+//TODO: remove this function and references to it
+void Blockchain::print_blockchain_outs(const std::string& file)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  return;
+}
+//------------------------------------------------------------------
+// Find the split point between us and foreign blockchain and return
+// (by reference) the most recent common block hash along with up to
+// BLOCKS_IDS_SYNCHRONIZING_DEFAULT_COUNT additional (more recent) hashes.
+bool Blockchain::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // if we can't find the split point, return false
+  if(!find_blockchain_supplement(qblock_ids, resp.start_height))
+  {
+    return false;
+  }
+
+  resp.total_height = get_current_blockchain_height();
+  size_t count = 0;
+  for(size_t i = resp.start_height; i < resp.total_height && count < BLOCKS_IDS_SYNCHRONIZING_DEFAULT_COUNT; i++, count++)
+  {
+    resp.m_block_ids.push_back(m_db->get_block_hash_from_height(i));
+  }
+  return true;
+}
+//------------------------------------------------------------------
+//FIXME: change argument to std::vector, low priority
+// find split point between ours and foreign blockchain (or start at
+// blockchain height <req_start_block>), and return up to max_count FULL
+// blocks by reference.
+bool Blockchain::find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  // if a specific start height has been requested
+  if(req_start_block > 0)
+  {
+    // if requested height is higher than our chain, return false -- we can't help
+    if (req_start_block >= m_db->height())
+    {
+      return false;
+    }
+    start_height = req_start_block; 
+  }
+  else
+  {
+    if(!find_blockchain_supplement(qblock_ids, start_height))
+    {
+      return false;
+    }
+  }
+
+  total_height = get_current_blockchain_height();
+  size_t count = 0;
+  for(size_t i = start_height; i < total_height && count < max_count; i++, count++)
+  {
+    blocks.resize(blocks.size()+1);
+    blocks.back().first = m_db->get_block_from_height(i);
+    std::list<crypto::hash> mis;
+    get_transactions(blocks.back().first.tx_hashes, blocks.back().second, mis);
+    CHECK_AND_ASSERT_MES(!mis.size(), false, "internal error, transaction from block not found");
+  }
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::add_block_as_invalid(const block& bl, const crypto::hash& h)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  block_extended_info bei = AUTO_VAL_INIT(bei);
+  bei.bl = bl;
+  return add_block_as_invalid(bei, h);
+}
+//------------------------------------------------------------------
+bool Blockchain::add_block_as_invalid(const block_extended_info& bei, const crypto::hash& h)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  auto i_res = m_invalid_blocks.insert(std::map<crypto::hash, block_extended_info>::value_type(h, bei));
+  CHECK_AND_ASSERT_MES(i_res.second, false, "at insertion invalid by tx returned status existed");
+  LOG_PRINT_L1("BLOCK ADDED AS INVALID: " << h << std::endl << ", prev_id=" << bei.bl.prev_id << ", m_invalid_blocks count=" << m_invalid_blocks.size());
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::have_block(const crypto::hash& id) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  if(m_db->block_exists(id))
+  {
+    LOG_PRINT_L3("block exists in main chain");
+    return true;
+  }
+
+  if(m_alternative_chains.count(id))
+  {
+    LOG_PRINT_L3("block found in m_alternative_chains");
+    return true;
+  }
+
+  if(m_invalid_blocks.count(id))
+  {
+    LOG_PRINT_L3("block found in m_invalid_blocks");
+    return true;
+  }
+
+  return false;
+}
+//------------------------------------------------------------------
+bool Blockchain::handle_block_to_main_chain(const block& bl, block_verification_context& bvc)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  crypto::hash id = get_block_hash(bl);
+  return handle_block_to_main_chain(bl, id, bvc);
+}
+//------------------------------------------------------------------
+size_t Blockchain::get_total_transactions() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return m_db->get_tx_count();
+}
+//------------------------------------------------------------------
+// This function checks each input in the transaction <tx> to make sure it
+// has not been used already, and adds its key to the container <keys_this_block>.
+//
+// This container should be managed by the code that validates blocks so we don't
+// have to store the used keys in a given block in the permanent storage only to
+// remove them later if the block fails validation.
+bool Blockchain::check_for_double_spend(const transaction& tx, key_images_container& keys_this_block) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  struct add_transaction_input_visitor: public boost::static_visitor<bool>
+  {
+    key_images_container& m_spent_keys;
+    BlockchainDB* m_db;
+    add_transaction_input_visitor(key_images_container& spent_keys, BlockchainDB* db):m_spent_keys(spent_keys), m_db(db)
+    {}
+    bool operator()(const txin_to_key& in) const
+    {
+      const crypto::key_image& ki = in.k_image;
+
+      // attempt to insert the newly-spent key into the container of
+      // keys spent this block.  If this fails, the key was spent already
+      // in this block, return false to flag that a double spend was detected.
+      //
+      // if the insert into the block-wide spent keys container succeeds,
+      // check the blockchain-wide spent keys container and make sure the
+      // key wasn't used in another block already.
+      auto r = m_spent_keys.insert(ki);
+      if(!r.second || m_db->has_key_image(ki))
+      {
+        //double spend detected
+        return false;
+      }
+
+      // if no double-spend detected, return true
+      return true;
+    }
+
+    bool operator()(const txin_gen& tx) const{return true;}
+    bool operator()(const txin_to_script& tx) const{return false;}
+    bool operator()(const txin_to_scripthash& tx) const{return false;}
+  };
+
+  for (const txin_v& in : tx.vin)
+  {
+    if(!boost::apply_visitor(add_transaction_input_visitor(keys_this_block, m_db), in))
+    {
+      LOG_ERROR("Double spend detected!");
+      return false;
+    }
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  if (!m_db->tx_exists(tx_id))
+  {
+    LOG_PRINT_RED_L1("warning: get_tx_outputs_gindexs failed to find transaction with id = " << tx_id);
+    return false;
+  }
+
+  // get amount output indexes, currently referred to in parts as "output global indices", but they are actually specific to amounts
+  indexs = m_db->get_tx_amount_output_indices(tx_id);
+  CHECK_AND_ASSERT_MES(indexs.size(), false, "internal error: global indexes for transaction " << tx_id << " is empty");
+
+  return true;
+}
+//------------------------------------------------------------------
+// This function overloads its sister function with
+// an extra value (hash of highest block that holds an output used as input)
+// as a return-by-reference.
+bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t& max_used_block_height, crypto::hash& max_used_block_id) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  bool res = check_tx_inputs(tx, &max_used_block_height);
+  if(!res) return false;
+  CHECK_AND_ASSERT_MES(max_used_block_height < m_db->height(), false,  "internal error: max used block index=" << max_used_block_height << " is not less then blockchain size = " << m_db->height());
+  max_used_block_id = m_db->get_block_hash_from_height(max_used_block_height);
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  BOOST_FOREACH(const txin_v& in, tx.vin)
+  {
+    CHECKED_GET_SPECIFIC_VARIANT(in, const txin_to_key, in_to_key, true);
+    if(have_tx_keyimg_as_spent(in_to_key.k_image))
+      return true;
+  }
+  return false;
+}
+//------------------------------------------------------------------
+// This function validates transaction inputs and their keys.  Previously
+// it also performed double spend checking, but that has been moved to its
+// own function.
+bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  size_t sig_index = 0;
+  if(pmax_used_block_height)
+    *pmax_used_block_height = 0;
+
+  crypto::hash tx_prefix_hash = get_transaction_prefix_hash(tx);
+
+  for (const auto& txin : tx.vin)
+  {
+    // make sure output being spent is of type txin_to_key, rather than
+    // e.g. txin_gen, which is only used for miner transactions
+    CHECK_AND_ASSERT_MES(txin.type() == typeid(txin_to_key), false, "wrong type id in tx input at Blockchain::check_tx_inputs");
+    const txin_to_key& in_to_key = boost::get<txin_to_key>(txin);
+
+    // make sure tx output has key offset(s) (is signed to be used)
+    CHECK_AND_ASSERT_MES(in_to_key.key_offsets.size(), false, "empty in_to_key.key_offsets in transaction with id " << get_transaction_hash(tx));
+
+    // basically, make sure number of inputs == number of signatures
+    CHECK_AND_ASSERT_MES(sig_index < tx.signatures.size(), false, "wrong transaction: not signature entry for input with index= " << sig_index);
+
+    // make sure that output being spent matches up correctly with the
+    // signature spending it.
+    if(!check_tx_input(in_to_key, tx_prefix_hash, tx.signatures[sig_index], pmax_used_block_height))
+    {
+      LOG_PRINT_L1("Failed to check ring signature for tx " << get_transaction_hash(tx) << "  vin key with k_image: " << in_to_key.k_image << "  sig_index: " << sig_index);
+      if (pmax_used_block_height) // a default value of NULL is used when called from Blockchain::handle_block_to_main_chain()
+      {
+        LOG_PRINT_L1("  *pmax_used_block_height: " << *pmax_used_block_height);
+      }
+      return false;
+    }
+
+    sig_index++;
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+// This function checks to see if a tx is unlocked.  unlock_time is either
+// a block index or a unix time.
+bool Blockchain::is_tx_spendtime_unlocked(uint64_t unlock_time) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  if(unlock_time < CRYPTONOTE_MAX_BLOCK_NUMBER)
+  {
+    //interpret as block index
+    if(get_current_blockchain_height() + CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_BLOCKS >= unlock_time)
+      return true;
+    else
+      return false;
+  }else
+  {
+    //interpret as time
+    uint64_t current_time = static_cast<uint64_t>(time(NULL));
+    if(current_time + CRYPTONOTE_LOCKED_TX_ALLOWED_DELTA_SECONDS >= unlock_time)
+      return true;
+    else
+      return false;
+  }
+  return false;
+}
+//------------------------------------------------------------------
+// This function locates all outputs associated with a given input (mixins)
+// and validates that they exist and are usable.  It also checks the ring
+// signature for each input.
+bool Blockchain::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
+  struct outputs_visitor
+  {
+    std::vector<const crypto::public_key *>& m_p_output_keys;
+    std::vector<crypto::public_key >& m_output_keys;
+    const Blockchain& m_bch;
+    outputs_visitor(std::vector<crypto::public_key >& output_keys, std::vector<const crypto::public_key *>& p_output_keys, const Blockchain& bch) : m_output_keys(output_keys), m_p_output_keys(p_output_keys), m_bch(bch)
+    {}
+    bool handle_output(const transaction& tx, const tx_out& out)
+    {
+      //check tx unlock time
+      if(!m_bch.is_tx_spendtime_unlocked(tx.unlock_time))
+      {
+        LOG_PRINT_L1("One of outputs for one of inputs has wrong tx.unlock_time = " << tx.unlock_time);
+        return false;
+      }
+
+      if(out.target.type() != typeid(txout_to_key))
+      {
+        LOG_PRINT_L1("Output has wrong type id, which=" << out.target.which());
+        return false;
+      }
+
+      m_output_keys.push_back(boost::get<txout_to_key>(out.target).key);
+      return true;
+    }
+  };
+
+  //check ring signature
+  std::vector<crypto::public_key> output_keys;
+  std::vector<const crypto::public_key *> p_output_keys;
+  outputs_visitor vi(output_keys, p_output_keys, *this);
+  if(!scan_outputkeys_for_indexes(txin, vi, pmax_related_block_height))
+  {
+    LOG_PRINT_L1("Failed to get output keys for tx with amount = " << print_money(txin.amount) << " and count indexes " << txin.key_offsets.size());
+    return false;
+  }
+
+  for (auto& k : output_keys)
+  {
+    p_output_keys.push_back(&k);
+  }
+
+  if(txin.key_offsets.size() != output_keys.size())
+  {
+    LOG_PRINT_L1("Output keys for tx with amount = " << txin.amount << " and count indexes " << txin.key_offsets.size() << " returned wrong keys count " << output_keys.size());
+    return false;
+  }
+  CHECK_AND_ASSERT_MES(sig.size() == output_keys.size(), false, "internal error: tx signatures count=" << sig.size() << " mismatch with outputs keys count for inputs=" << output_keys.size());
+  if(m_is_in_checkpoint_zone)
+    return true;
+  return crypto::check_ring_signature(tx_prefix_hash, txin.k_image, p_output_keys, sig.data());
+}
+//------------------------------------------------------------------
+//TODO: Is this intended to do something else?  Need to look into the todo there.
+uint64_t Blockchain::get_adjusted_time() const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  //TODO: add collecting median time
+  return time(NULL);
+}
+//------------------------------------------------------------------
+//TODO: revisit, has changed a bit on upstream
+bool Blockchain::check_block_timestamp(std::vector<uint64_t>& timestamps, const block& b) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  uint64_t median_ts = epee::misc_utils::median(timestamps);
+
+  if(b.timestamp < median_ts)
+  {
+    LOG_PRINT_L1("Timestamp of block with id: " << get_block_hash(b) << ", " << b.timestamp << ", less than median of last " << BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW << " blocks, " << median_ts);
+    return false;
+  }
+
+  return true;
+}
+//------------------------------------------------------------------
+// This function grabs the timestamps from the most recent <n> blocks,
+// where n = BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW.  If there are not those many
+// blocks in the blockchain, the timestap is assumed to be valid.  If there
+// are, this function returns:
+//   true if the block's timestamp is not less than the timestamp of the
+//       median of the selected blocks
+//   false otherwise
+bool Blockchain::check_block_timestamp(const block& b) const
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  if(b.timestamp > get_adjusted_time() + CRYPTONOTE_BLOCK_FUTURE_TIME_LIMIT)
+  {
+    LOG_PRINT_L1("Timestamp of block with id: " << get_block_hash(b) << ", " << b.timestamp << ", bigger than adjusted time + 2 hours");
+    return false;
+  }
+
+  // if not enough blocks, no proper median yet, return true
+  if(m_db->height() < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW + 1)
+  {
+    return true;
+  }
+
+  std::vector<uint64_t> timestamps;
+  auto h = m_db->height();
+
+  // need most recent 60 blocks, get index of first of those
+  // using +1 because BlockchainDB::height() returns the index of the top block,
+  // not the size of the blockchain (0-indexed)
+  size_t offset = h - BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW - 1;
+  for(;offset < h; ++offset)
+  {
+    timestamps.push_back(m_db->get_block_timestamp(offset));
+  }
+
+  return check_block_timestamp(timestamps, b);
+}
+//------------------------------------------------------------------
+//      Needs to validate the block and acquire each transaction from the
+//      transaction mem_pool, then pass the block and transactions to
+//      m_db->add_block()
+bool Blockchain::handle_block_to_main_chain(const block& bl, const crypto::hash& id, block_verification_context& bvc)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+
+  TIME_MEASURE_START(block_processing_time);
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  if(bl.prev_id != get_tail_id())
+  {
+    LOG_PRINT_L1("Block with id: " << id << std::endl
+      << "has wrong prev_id: " << bl.prev_id << std::endl
+      << "expected: " << get_tail_id());
+    return false;
+  }
+
+  // make sure block timestamp is not less than the median timestamp
+  // of a set number of the most recent blocks.
+  if(!check_block_timestamp(bl))
+  {
+    LOG_PRINT_L1("Block with id: " << id << std::endl
+      << "has invalid timestamp: " << bl.timestamp);
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+
+  //check proof of work
+  TIME_MEASURE_START(target_calculating_time);
+
+  // get the target difficulty for the block.
+  // the calculation can overflow, among other failure cases,
+  // so we need to check the return type.
+  // FIXME: get_difficulty_for_next_block can also assert, look into
+  // changing this to throwing exceptions instead so we can clean up.
+  difficulty_type current_diffic = get_difficulty_for_next_block();
+  CHECK_AND_ASSERT_MES(current_diffic, false, "!!!!!!!!! difficulty overhead !!!!!!!!!");
+
+  TIME_MEASURE_FINISH(target_calculating_time);
+
+  TIME_MEASURE_START(longhash_calculating_time);
+
+  crypto::hash proof_of_work = null_hash;
+
+  // Formerly the code below contained an if loop with the following condition
+  // !m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height())
+  // however, this caused the daemon to not bother checking PoW for blocks
+  // before checkpoints, which is very dangerous behaviour. We moved the PoW
+  // validation out of the next chunk of code to make sure that we correctly
+  // check PoW now.
+  // FIXME: height parameter is not used...should it be used or should it not
+  // be a parameter?
+  proof_of_work = get_block_longhash(bl, m_db->height());
+
+  // validate proof_of_work versus difficulty target
+  if(!check_hash(proof_of_work, current_diffic))
+  {
+    LOG_PRINT_L1("Block with id: " << id << std::endl
+      << "does not have enough proof of work: " << proof_of_work << std::endl
+      << "unexpected difficulty: " << current_diffic );
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+
+  // If we're at a checkpoint, ensure that our hardcoded checkpoint hash
+  // is correct.
+  if(m_checkpoints.is_in_checkpoint_zone(get_current_blockchain_height()))
+  {
+    if(!m_checkpoints.check_block(get_current_blockchain_height(), id))
+    {
+      LOG_ERROR("CHECKPOINT VALIDATION FAILED");
+      bvc.m_verifivation_failed = true;
+      return false;
+    }
+  }
+
+  TIME_MEASURE_FINISH(longhash_calculating_time);
+
+  // sanity check basic miner tx properties
+  if(!prevalidate_miner_transaction(bl, m_db->height()))
+  {
+    LOG_PRINT_L1("Block with id: " << id
+      << " failed to pass prevalidation");
+    bvc.m_verifivation_failed = true;
+    return false;
+  }
+
+  size_t coinbase_blob_size = get_object_blobsize(bl.miner_tx);
+  size_t cumulative_block_size = coinbase_blob_size;
+
+  std::vector<transaction> txs;
+  key_images_container keys;
+
+  uint64_t fee_summary = 0;
+
+  // Iterate over the block's transaction hashes, grabbing each
+  // from the tx_pool and validating them.  Each is then added
+  // to txs.  Keys spent in each are added to <keys> by the double spend check.
+  for (const crypto::hash& tx_id : bl.tx_hashes)
+  {
+    transaction tx;
+    size_t blob_size = 0;
+    uint64_t fee = 0;
+
+    if (m_db->tx_exists(tx_id))
+    {
+      LOG_PRINT_L1("Block with id: " << id << " attempting to add transaction already in blockchain with id: " << tx_id);
+      bvc.m_verifivation_failed = true;
+      break;
+    }
+
+    // get transaction with hash <tx_id> from tx_pool
+    if(!m_tx_pool.take_tx(tx_id, tx, blob_size, fee))
+    {
+      LOG_PRINT_L1("Block with id: " << id  << " has at least one unknown transaction with id: " << tx_id);
+      bvc.m_verifivation_failed = true;
+      break;
+    }
+
+    // add the transaction to the temp list of transactions, so we can either
+    // store the list of transactions all at once or return the ones we've
+    // taken from the tx_pool back to it if the block fails verification.
+    txs.push_back(tx);
+
+    // validate that transaction inputs and the keys spending them are correct.
+    if(!check_tx_inputs(tx))
+    {
+      LOG_PRINT_L1("Block with id: " << id  << " has at least one transaction (id: " << tx_id << ") with wrong inputs.");
+
+      //TODO: why is this done?  make sure that keeping invalid blocks makes sense.
+      add_block_as_invalid(bl, id);
+      LOG_PRINT_L1("Block with id " << id << " added as invalid becouse of wrong inputs in transactions");
+      bvc.m_verifivation_failed = true;
+      break;
+    }
+
+    if (!check_for_double_spend(tx, keys))
+    {
+      LOG_PRINT_L0("Double spend detected in transaction (id: " << tx_id);
+      bvc.m_verifivation_failed = true;
+      break;
+    }
+
+    fee_summary += fee;
+    cumulative_block_size += blob_size;
+  }
+
+  uint64_t base_reward = 0;
+  uint64_t already_generated_coins = m_db->height() ? m_db->get_block_already_generated_coins(m_db->height() - 1) : 0;
+  if(!validate_miner_transaction(bl, cumulative_block_size, fee_summary, base_reward, already_generated_coins))
+  {
+    LOG_PRINT_L1("Block with id: " << id
+      << " has incorrect miner transaction");
+    bvc.m_verifivation_failed = true;
+  }
+
+
+  block_extended_info bei = boost::value_initialized<block_extended_info>();
+  size_t block_size;
+  difficulty_type cumulative_difficulty;
+
+  // populate various metadata about the block to be stored alongside it.
+  block_size = cumulative_block_size;
+  cumulative_difficulty = current_diffic;
+  already_generated_coins = already_generated_coins + base_reward;
+  if(m_db->height())
+    cumulative_difficulty += m_db->get_block_cumulative_difficulty(m_db->height() - 1);
+
+  update_next_cumulative_size_limit();
+
+  TIME_MEASURE_FINISH(block_processing_time);
+
+  uint64_t new_height = 0;
+  bool add_success = true;
+  if (!bvc.m_verifivation_failed)
+  {
+    try
+    {
+      new_height = m_db->add_block(bl, block_size, cumulative_difficulty, already_generated_coins, txs);
+    }
+    catch (const std::exception& e)
+    {
+      //TODO: figure out the best way to deal with this failure
+      LOG_ERROR("Error adding block with hash: " << id << " to blockchain, what = " << e.what());
+      add_success = false;
+    }
+  }
+
+  // if we failed for any reason to verify the block, return taken
+  // transactions to the tx_pool.
+  if (bvc.m_verifivation_failed || !add_success)
+  {
+    // return taken transactions to transaction pool
+    for (auto& tx : txs)
+    {
+      cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
+      if (!m_tx_pool.add_tx(tx, tvc, true))
+      {
+        LOG_PRINT_L0("Failed to return taken transaction with hash: " << get_transaction_hash(tx) << " to tx_pool");
+      }
+    }
+    return false;
+  }
+
+  LOG_PRINT_L1("+++++ BLOCK SUCCESSFULLY ADDED" << std::endl << "id:\t" << id
+    << std::endl << "PoW:\t" << proof_of_work
+    << std::endl << "HEIGHT " << new_height << ", difficulty:\t" << current_diffic
+    << std::endl << "block reward: " << print_money(fee_summary + base_reward) << "(" << print_money(base_reward) << " + " << print_money(fee_summary)
+    << "), coinbase_blob_size: " << coinbase_blob_size << ", cumulative size: " << cumulative_block_size
+    << ", " << block_processing_time << "("<< target_calculating_time << "/" << longhash_calculating_time << ")ms");
+
+  bvc.m_added_to_main_chain = true;
+
+  // appears to be a NOP *and* is called elsewhere.  wat?
+  m_tx_pool.on_blockchain_inc(new_height, id);
+
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::update_next_cumulative_size_limit()
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  std::vector<size_t> sz;
+  get_last_n_blocks_sizes(sz, CRYPTONOTE_REWARD_BLOCKS_WINDOW);
+
+  uint64_t median = epee::misc_utils::median(sz);
+  if(median <= CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE)
+    median = CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE;
+
+  m_current_block_cumul_sz_limit = median*2;
+  return true;
+}
+//------------------------------------------------------------------
+bool Blockchain::add_new_block(const block& bl_, block_verification_context& bvc)
+{
+  LOG_PRINT_L3("Blockchain::" << __func__);
+  //copy block here to let modify block.target
+  block bl = bl_;
+  crypto::hash id = get_block_hash(bl);
+  CRITICAL_REGION_LOCAL(m_tx_pool);//to avoid deadlock lets lock tx_pool for whole add/reorganize process
+  CRITICAL_REGION_LOCAL1(m_blockchain_lock);
+  if(have_block(id))
+  {
+    LOG_PRINT_L3("block with id = " << id << " already exists");
+    bvc.m_already_exists = true;
+    return false;
+  }
+
+  //check that block refers to chain tail
+  if(!(bl.prev_id == get_tail_id()))
+  {
+    //chain switching or wrong block
+    bvc.m_added_to_main_chain = false;
+    return handle_alternative_block(bl, id, bvc);
+    //never relay alternative blocks
+  }
+
+  return handle_block_to_main_chain(bl, id, bvc);
+}
+//------------------------------------------------------------------
+void Blockchain::check_against_checkpoints(const checkpoints& points, bool enforce)
+{
+  const auto& pts = points.get_points();
+
+  for (const auto& pt : pts)
+  {
+    // if the checkpoint is for a block we don't have yet, move on
+    if (pt.first >= m_db->height())
+    {
+      continue;
+    }
+
+    if (!points.check_block(pt.first, m_db->get_block_hash_from_height(pt.first)))
+    {
+      // if asked to enforce checkpoints, roll back to a couple of blocks before the checkpoint
+      if (enforce)
+      {
+        LOG_ERROR("Local blockchain failed to pass a checkpoint, rolling back!");
+        std::list<block> empty;
+        rollback_blockchain_switching(empty, pt.first - 2);
+      }
+      else
+      {
+        LOG_ERROR("WARNING: local blockchain failed to pass a MoneroPulse checkpoint, and you could be on a fork. You should either sync up from scratch, OR download a fresh blockchain bootstrap, OR enable checkpoint enforcing with the --enforce-dns-checkpointing command-line option");
+      }
+    }
+  }
+}
+//------------------------------------------------------------------
+// returns false if any of the checkpoints loading returns false.
+// That should happen only if a checkpoint is added that conflicts
+// with an existing checkpoint.
+bool Blockchain::update_checkpoints(const std::string& file_path, bool check_dns)
+{
+  if (!cryptonote::load_checkpoints_from_json(m_checkpoints, file_path))
+  {
+    return false;
+  }
+
+  // if we're checking both dns and json, load checkpoints from dns.
+  // if we're not hard-enforcing dns checkpoints, handle accordingly
+  if (m_enforce_dns_checkpoints && check_dns)
+  {
+    if (!cryptonote::load_checkpoints_from_dns(m_checkpoints))
+    {
+      return false;
+    }
+  }
+  else if (check_dns)
+  {
+    checkpoints dns_points;
+    cryptonote::load_checkpoints_from_dns(dns_points);
+    if (m_checkpoints.check_for_conflicts(dns_points))
+    {
+      check_against_checkpoints(dns_points, false);
+    }
+    else
+    {
+      LOG_PRINT_L0("One or more checkpoints fetched from DNS conflicted with existing checkpoints!");
+    }
+  }
+
+  check_against_checkpoints(m_checkpoints, true);
+
+  return true;
+}
+//------------------------------------------------------------------
+void Blockchain::set_enforce_dns_checkpoints(bool enforce_checkpoints)
+{
+  m_enforce_dns_checkpoints = enforce_checkpoints;
+}
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
new file mode 100644
index 000000000..bc13901d2
--- /dev/null
+++ b/src/cryptonote_core/blockchain.h
@@ -0,0 +1,229 @@
+// Copyright (c) 2014, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// 
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+#pragma once
+#include <boost/serialization/serialization.hpp>
+#include <boost/serialization/version.hpp>
+#include <boost/serialization/list.hpp>
+#include <boost/multi_index_container.hpp>
+#include <boost/multi_index/global_fun.hpp>
+#include <boost/multi_index/hashed_index.hpp>
+#include <boost/multi_index/member.hpp>
+#include <boost/foreach.hpp>
+#include <atomic>
+
+#include "syncobj.h"
+#include "string_tools.h"
+#include "cryptonote_basic.h"
+#include "common/util.h"
+#include "cryptonote_protocol/cryptonote_protocol_defs.h"
+#include "rpc/core_rpc_server_commands_defs.h"
+#include "difficulty.h"
+#include "cryptonote_core/cryptonote_format_utils.h"
+#include "verification_context.h"
+#include "crypto/hash.h"
+#include "checkpoints.h"
+#include "blockchain_db/blockchain_db.h"
+
+namespace cryptonote
+{
+  class tx_memory_pool;
+
+  /************************************************************************/
+  /*                                                                      */
+  /************************************************************************/
+  class Blockchain
+  {
+  public:
+    struct transaction_chain_entry
+    {
+      transaction tx;
+      uint64_t m_keeper_block_height;
+      size_t m_blob_size;
+      std::vector<uint64_t> m_global_output_indexes;
+    };
+
+    struct block_extended_info
+    {
+      block   bl;
+      uint64_t height;
+      size_t block_cumulative_size;
+      difficulty_type cumulative_difficulty;
+      uint64_t already_generated_coins;
+    };
+
+    Blockchain(tx_memory_pool& tx_pool);
+
+    bool init(BlockchainDB* db, const bool testnet = false);
+    bool deinit();
+
+    void set_checkpoints(checkpoints&& chk_pts) { m_checkpoints = chk_pts; }
+
+    //bool push_new_block();
+    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs) const;
+    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks) const;
+    bool get_alternative_blocks(std::list<block>& blocks) const;
+    size_t get_alternative_blocks_count() const;
+    crypto::hash get_block_id_by_height(uint64_t height) const;
+    bool get_block_by_hash(const crypto::hash &h, block &blk) const;
+    void get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) const;
+
+    template<class archive_t>
+    void serialize(archive_t & ar, const unsigned int version);
+
+    bool have_tx(const crypto::hash &id) const;
+    bool have_tx_keyimges_as_spent(const transaction &tx) const;
+    bool have_tx_keyimg_as_spent(const crypto::key_image &key_im) const;
+
+    template<class visitor_t>
+    bool scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height = NULL) const;
+
+    uint64_t get_current_blockchain_height() const;
+    crypto::hash get_tail_id() const;
+    crypto::hash get_tail_id(uint64_t& height) const;
+    difficulty_type get_difficulty_for_next_block() const;
+    bool add_new_block(const block& bl_, block_verification_context& bvc);
+    bool reset_and_set_genesis_block(const block& b);
+    bool create_block_template(block& b, const account_public_address& miner_address, difficulty_type& di, uint64_t& height, const blobdata& ex_nonce) const;
+    bool have_block(const crypto::hash& id) const;
+    size_t get_total_transactions() const;
+    bool get_short_chain_history(std::list<crypto::hash>& ids) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset) const;
+    bool find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count) const;
+    bool handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request& arg, NOTIFY_RESPONSE_GET_OBJECTS::request& rsp);
+    bool handle_get_objects(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res);
+    bool get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res) const;
+    bool get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs) const;
+    bool store_blockchain();
+    bool check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height = NULL) const;
+    bool check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height = NULL) const;
+    bool check_tx_inputs(const transaction& tx, uint64_t& pmax_used_block_height, crypto::hash& max_used_block_id) const;
+    uint64_t get_current_cumulative_blocksize_limit() const;
+    bool is_storing_blockchain()const{return m_is_blockchain_storing;}
+    uint64_t block_difficulty(uint64_t i) const;
+
+    template<class t_ids_container, class t_blocks_container, class t_missed_container>
+    bool get_blocks(const t_ids_container& block_ids, t_blocks_container& blocks, t_missed_container& missed_bs) const;
+
+    template<class t_ids_container, class t_tx_container, class t_missed_container>
+    bool get_transactions(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs) const;
+
+    //debug functions
+    void print_blockchain(uint64_t start_index, uint64_t end_index);
+    void print_blockchain_index();
+    void print_blockchain_outs(const std::string& file);
+
+    void check_against_checkpoints(const checkpoints& points, bool enforce);
+    void set_enforce_dns_checkpoints(bool enforce);
+    bool update_checkpoints(const std::string& file_path, bool check_dns);
+
+    BlockchainDB& get_db()
+    {
+      return *m_db;
+    }
+
+  private:
+    typedef std::unordered_map<crypto::hash, size_t> blocks_by_id_index;
+    typedef std::unordered_map<crypto::hash, transaction_chain_entry> transactions_container;
+    typedef std::unordered_set<crypto::key_image> key_images_container;
+    typedef std::vector<block_extended_info> blocks_container;
+    typedef std::unordered_map<crypto::hash, block_extended_info> blocks_ext_by_hash;
+    typedef std::unordered_map<crypto::hash, block> blocks_by_hash;
+    typedef std::map<uint64_t, std::vector<std::pair<crypto::hash, size_t>>> outputs_container; //crypto::hash - tx hash, size_t - index of out in transaction
+
+    BlockchainDB* m_db;
+
+    tx_memory_pool& m_tx_pool;
+    mutable epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
+
+    // main chain
+    blocks_container m_blocks;               // height  -> block_extended_info
+    blocks_by_id_index m_blocks_index;       // crypto::hash -> height
+    transactions_container m_transactions;
+    key_images_container m_spent_keys;
+    size_t m_current_block_cumul_sz_limit;
+
+
+    // all alternative chains
+    blocks_ext_by_hash m_alternative_chains; // crypto::hash -> block_extended_info
+
+    // some invalid blocks
+    blocks_ext_by_hash m_invalid_blocks;     // crypto::hash -> block_extended_info
+    outputs_container m_outputs;
+
+
+    checkpoints m_checkpoints;
+    std::atomic<bool> m_is_in_checkpoint_zone;
+    std::atomic<bool> m_is_blockchain_storing;
+    bool m_enforce_dns_checkpoints;
+
+    bool switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain);
+    block pop_block_from_blockchain();
+    bool purge_transaction_from_blockchain(const crypto::hash& tx_id);
+    bool purge_transaction_keyimages_from_blockchain(const transaction& tx, bool strict_check);
+
+    bool handle_block_to_main_chain(const block& bl, block_verification_context& bvc);
+    bool handle_block_to_main_chain(const block& bl, const crypto::hash& id, block_verification_context& bvc);
+    bool handle_alternative_block(const block& b, const crypto::hash& id, block_verification_context& bvc);
+    difficulty_type get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei) const;
+    bool prevalidate_miner_transaction(const block& b, uint64_t height);
+    bool validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins);
+    bool validate_transaction(const block& b, uint64_t height, const transaction& tx);
+    bool rollback_blockchain_switching(std::list<block>& original_chain, uint64_t rollback_height);
+    bool add_transaction_from_block(const transaction& tx, const crypto::hash& tx_id, const crypto::hash& bl_id, uint64_t bl_height);
+    bool push_transaction_to_global_outs_index(const transaction& tx, const crypto::hash& tx_id, std::vector<uint64_t>& global_indexes);
+    bool pop_transaction_from_global_index(const transaction& tx, const crypto::hash& tx_id);
+    void get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count) const;
+    void add_out_to_get_random_outs(COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i) const;
+    bool is_tx_spendtime_unlocked(uint64_t unlock_time) const;
+    bool add_block_as_invalid(const block& bl, const crypto::hash& h);
+    bool add_block_as_invalid(const block_extended_info& bei, const crypto::hash& h);
+    bool check_block_timestamp(const block& b) const;
+    bool check_block_timestamp(std::vector<uint64_t>& timestamps, const block& b) const;
+    uint64_t get_adjusted_time() const;
+    bool complete_timestamps_vector(uint64_t start_height, std::vector<uint64_t>& timestamps);
+    bool update_next_cumulative_size_limit();
+
+    bool check_for_double_spend(const transaction& tx, key_images_container& keys_this_block) const;
+  };
+
+
+  /************************************************************************/
+  /*                                                                      */
+  /************************************************************************/
+
+  #define CURRENT_BLOCKCHAIN_STORAGE_ARCHIVE_VER    12
+
+  //------------------------------------------------------------------
+
+}  // namespace cryptonote
+
+BOOST_CLASS_VERSION(cryptonote::Blockchain, CURRENT_BLOCKCHAIN_STORAGE_ARCHIVE_VER)
diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp
index d59fc7a58..ee4263687 100644
--- a/src/cryptonote_core/blockchain_storage.cpp
+++ b/src/cryptonote_core/blockchain_storage.cpp
@@ -58,19 +58,19 @@ using namespace cryptonote;
 DISABLE_VS_WARNINGS(4267)
 
 //------------------------------------------------------------------
-bool blockchain_storage::have_tx(const crypto::hash &id)
+bool blockchain_storage::have_tx(const crypto::hash &id) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   return m_transactions.find(id) != m_transactions.end();
 }
 //------------------------------------------------------------------
-bool blockchain_storage::have_tx_keyimg_as_spent(const crypto::key_image &key_im)
+bool blockchain_storage::have_tx_keyimg_as_spent(const crypto::key_image &key_im) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   return  m_spent_keys.find(key_im) != m_spent_keys.end();
 }
 //------------------------------------------------------------------
-transaction *blockchain_storage::get_tx(const crypto::hash &id)
+const transaction *blockchain_storage::get_tx(const crypto::hash &id) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   auto it = m_transactions.find(id);
@@ -80,7 +80,7 @@ transaction *blockchain_storage::get_tx(const crypto::hash &id)
   return &it->second.tx;
 }
 //------------------------------------------------------------------
-uint64_t blockchain_storage::get_current_blockchain_height()
+uint64_t blockchain_storage::get_current_blockchain_height() const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   return m_blocks.size();
@@ -117,24 +117,14 @@ bool blockchain_storage::init(const std::string& config_folder, bool testnet)
   else
   {
       LOG_PRINT_L0("Can't load blockchain storage from file, generating genesis block.");
-      block bl = boost::value_initialized<block>();
-      block_verification_context bvc = boost::value_initialized<block_verification_context>();
-      if (testnet)
-      {
-        generate_genesis_block(bl, config::testnet::GENESIS_TX, config::testnet::GENESIS_NONCE);
-      }
-      else
-      {
-        generate_genesis_block(bl, config::GENESIS_TX, config::GENESIS_NONCE);
-      }
-      add_new_block(bl, bvc);
-      CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed && bvc.m_added_to_main_chain, false, "Failed to add genesis block to blockchain");
+      if (!store_genesis_block(testnet, true))
+        return false;
   }
   if(!m_blocks.size())
   {
     LOG_PRINT_L0("Blockchain not loaded, generating genesis block.");
 
-    if (!store_genesis_block(testnet)) {
+    if (!store_genesis_block(testnet, false)) {
       return false;
     }
   } else {
@@ -163,7 +153,7 @@ bool blockchain_storage::init(const std::string& config_folder, bool testnet)
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::store_genesis_block(bool testnet) {
+bool blockchain_storage::store_genesis_block(bool testnet, bool check_added) {
   block bl = ::boost::value_initialized<block>();
   block_verification_context bvc = boost::value_initialized<block_verification_context>();
 
@@ -177,7 +167,7 @@ bool blockchain_storage::store_genesis_block(bool testnet) {
   }
 
   add_new_block(bl, bvc);
-  CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed, false, "Failed to add genesis block to blockchain");
+  CHECK_AND_ASSERT_MES(!bvc.m_verifivation_failed && (bvc.m_added_to_main_chain || !check_added), false, "Failed to add genesis block to blockchain");
   return true;
 }
 //------------------------------------------------------------------
@@ -235,7 +225,7 @@ bool blockchain_storage::pop_block_from_blockchain()
   m_blocks_index.erase(bl_ind);
   //pop block from core
   m_blocks.pop_back();
-  m_tx_pool.on_blockchain_dec(m_blocks.size()-1, get_tail_id());
+  m_tx_pool->on_blockchain_dec(m_blocks.size()-1, get_tail_id());
   return true;
 }
 //------------------------------------------------------------------
@@ -311,7 +301,7 @@ bool blockchain_storage::purge_transaction_from_blockchain(const crypto::hash& t
   if(!is_coinbase(tx))
   {
     cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
-    bool r = m_tx_pool.add_tx(tx, tvc, true);
+    bool r = m_tx_pool->add_tx(tx, tvc, true);
     CHECK_AND_ASSERT_MES(r, false, "purge_block_data_from_blockchain: failed to add transaction to transaction pool");
   }
 
@@ -337,14 +327,14 @@ bool blockchain_storage::purge_block_data_from_blockchain(const block& bl, size_
   return res;
 }
 //------------------------------------------------------------------
-crypto::hash blockchain_storage::get_tail_id(uint64_t& height)
+crypto::hash blockchain_storage::get_tail_id(uint64_t& height) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   height = get_current_blockchain_height()-1;
   return get_tail_id();
 }
 //------------------------------------------------------------------
-crypto::hash blockchain_storage::get_tail_id()
+crypto::hash blockchain_storage::get_tail_id() const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   crypto::hash id = null_hash;
@@ -355,7 +345,7 @@ crypto::hash blockchain_storage::get_tail_id()
   return id;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_short_chain_history(std::list<crypto::hash>& ids)
+bool blockchain_storage::get_short_chain_history(std::list<crypto::hash>& ids) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   size_t i = 0;
@@ -385,7 +375,7 @@ bool blockchain_storage::get_short_chain_history(std::list<crypto::hash>& ids)
   return true;
 }
 //------------------------------------------------------------------
-crypto::hash blockchain_storage::get_block_id_by_height(uint64_t height)
+crypto::hash blockchain_storage::get_block_id_by_height(uint64_t height) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(height >= m_blocks.size())
@@ -394,7 +384,7 @@ crypto::hash blockchain_storage::get_block_id_by_height(uint64_t height)
   return get_block_hash(m_blocks[height].bl);
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_block_by_hash(const crypto::hash &h, block &blk) {
+bool blockchain_storage::get_block_by_hash(const crypto::hash &h, block &blk) const {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
   // try to find block in main chain
@@ -414,20 +404,20 @@ bool blockchain_storage::get_block_by_hash(const crypto::hash &h, block &blk) {
   return false;
 }
 //------------------------------------------------------------------
-void blockchain_storage::get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) {
+void blockchain_storage::get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) const {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
-  BOOST_FOREACH(blocks_by_id_index::value_type &v, m_blocks_index)
+  BOOST_FOREACH(const blocks_by_id_index::value_type &v, m_blocks_index)
     main.push_back(v.first);
 
-  BOOST_FOREACH(blocks_ext_by_hash::value_type &v, m_alternative_chains)
+  BOOST_FOREACH(const blocks_ext_by_hash::value_type &v, m_alternative_chains)
     alt.push_back(v.first);
 
-  BOOST_FOREACH(blocks_ext_by_hash::value_type &v, m_invalid_blocks)
+  BOOST_FOREACH(const blocks_ext_by_hash::value_type &v, m_invalid_blocks)
     invalid.push_back(v.first);
 }
 //------------------------------------------------------------------
-difficulty_type blockchain_storage::get_difficulty_for_next_block()
+difficulty_type blockchain_storage::get_difficulty_for_next_block() const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   std::vector<uint64_t> timestamps;
@@ -539,7 +529,7 @@ bool blockchain_storage::switch_to_alternative_blockchain(std::list<blocks_ext_b
   return true;
 }
 //------------------------------------------------------------------
-difficulty_type blockchain_storage::get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei)
+difficulty_type blockchain_storage::get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei) const
 {
   std::vector<uint64_t> timestamps;
   std::vector<difficulty_type> commulative_difficulties;
@@ -584,7 +574,7 @@ difficulty_type blockchain_storage::get_next_difficulty_for_alternative_chain(co
   return next_difficulty(timestamps, commulative_difficulties);
 }
 //------------------------------------------------------------------
-bool blockchain_storage::prevalidate_miner_transaction(const block& b, uint64_t height)
+bool blockchain_storage::prevalidate_miner_transaction(const block& b, uint64_t height) const
 {
   CHECK_AND_ASSERT_MES(b.miner_tx.vin.size() == 1, false, "coinbase transaction in the block has no inputs");
   CHECK_AND_ASSERT_MES(b.miner_tx.vin[0].type() == typeid(txin_gen), false, "coinbase transaction in the block has the wrong type");
@@ -607,7 +597,7 @@ bool blockchain_storage::prevalidate_miner_transaction(const block& b, uint64_t
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins)
+bool blockchain_storage::validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins) const
 {
   //validate reward
   uint64_t money_in_use = 0;
@@ -634,7 +624,7 @@ bool blockchain_storage::validate_miner_transaction(const block& b, size_t cumul
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_backward_blocks_sizes(size_t from_height, std::vector<size_t>& sz, size_t count)
+bool blockchain_storage::get_backward_blocks_sizes(size_t from_height, std::vector<size_t>& sz, size_t count) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   CHECK_AND_ASSERT_MES(from_height < m_blocks.size(), false, "Internal error: get_backward_blocks_sizes called with from_height=" << from_height << ", blockchain height = " << m_blocks.size());
@@ -646,7 +636,7 @@ bool blockchain_storage::get_backward_blocks_sizes(size_t from_height, std::vect
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count)
+bool blockchain_storage::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(!m_blocks.size())
@@ -654,12 +644,12 @@ bool blockchain_storage::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t
   return get_backward_blocks_sizes(m_blocks.size() -1, sz, count);
 }
 //------------------------------------------------------------------
-uint64_t blockchain_storage::get_current_comulative_blocksize_limit()
+uint64_t blockchain_storage::get_current_cumulative_blocksize_limit() const
 {
   return m_current_block_cumul_sz_limit;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::create_block_template(block& b, const account_public_address& miner_address, difficulty_type& diffic, uint64_t& height, const blobdata& ex_nonce)
+bool blockchain_storage::create_block_template(block& b, const account_public_address& miner_address, difficulty_type& diffic, uint64_t& height, const blobdata& ex_nonce) const
 {
   size_t median_size;
   uint64_t already_generated_coins;
@@ -680,16 +670,16 @@ bool blockchain_storage::create_block_template(block& b, const account_public_ad
 
   size_t txs_size;
   uint64_t fee;
-  if (!m_tx_pool.fill_block_template(b, median_size, already_generated_coins, txs_size, fee)) {
+  if (!m_tx_pool->fill_block_template(b, median_size, already_generated_coins, txs_size, fee)) {
     return false;
   }
 #if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
   size_t real_txs_size = 0;
   uint64_t real_fee = 0;
-  CRITICAL_REGION_BEGIN(m_tx_pool.m_transactions_lock);
+  CRITICAL_REGION_BEGIN(m_tx_pool->m_transactions_lock);
   BOOST_FOREACH(crypto::hash &cur_hash, b.tx_hashes) {
-    auto cur_res = m_tx_pool.m_transactions.find(cur_hash);
-    if (cur_res == m_tx_pool.m_transactions.end()) {
+    auto cur_res = m_tx_pool->m_transactions.find(cur_hash);
+    if (cur_res == m_tx_pool->m_transactions.end()) {
       LOG_ERROR("Creating block template: error: transaction not found");
       continue;
     }
@@ -778,7 +768,7 @@ bool blockchain_storage::create_block_template(block& b, const account_public_ad
   return false;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::complete_timestamps_vector(uint64_t start_top_height, std::vector<uint64_t>& timestamps)
+bool blockchain_storage::complete_timestamps_vector(uint64_t start_top_height, std::vector<uint64_t>& timestamps) const
 {
 
   if(timestamps.size() >= BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW)
@@ -943,7 +933,7 @@ bool blockchain_storage::handle_alternative_block(const block& b, const crypto::
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs)
+bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(start_offset >= m_blocks.size())
@@ -959,7 +949,7 @@ bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::li
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks)
+bool blockchain_storage::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(start_offset >= m_blocks.size())
@@ -1003,7 +993,7 @@ bool blockchain_storage::handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request&
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_alternative_blocks(std::list<block>& blocks)
+bool blockchain_storage::get_alternative_blocks(std::list<block>& blocks) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
@@ -1014,21 +1004,21 @@ bool blockchain_storage::get_alternative_blocks(std::list<block>& blocks)
   return true;
 }
 //------------------------------------------------------------------
-size_t blockchain_storage::get_alternative_blocks_count()
+size_t blockchain_storage::get_alternative_blocks_count() const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   return m_alternative_chains.size();
 }
 //------------------------------------------------------------------
-bool blockchain_storage::add_out_to_get_random_outs(std::vector<std::pair<crypto::hash, size_t> >& amount_outs, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i)
+bool blockchain_storage::add_out_to_get_random_outs(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
-  transactions_container::iterator tx_it = m_transactions.find(amount_outs[i].first);
+  transactions_container::const_iterator tx_it = m_transactions.find(amount_outs[i].first);
   CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "internal error: transaction with id " << amount_outs[i].first << ENDL <<
     ", used in mounts global index for amount=" << amount << ": i=" << i << "not found in transactions index");
   CHECK_AND_ASSERT_MES(tx_it->second.tx.vout.size() > amount_outs[i].second, false, "internal error: in global outs index, transaction out index="
     << amount_outs[i].second << " more than transaction outputs = " << tx_it->second.tx.vout.size() << ", for tx id = " << amount_outs[i].first);
-  transaction& tx = tx_it->second.tx;
+  const transaction& tx = tx_it->second.tx;
   CHECK_AND_ASSERT_MES(tx.vout[amount_outs[i].second].target.type() == typeid(txout_to_key), false, "unknown tx out type");
 
   //check if transaction is unlocked
@@ -1041,7 +1031,7 @@ bool blockchain_storage::add_out_to_get_random_outs(std::vector<std::pair<crypto
   return true;
 }
 //------------------------------------------------------------------
-size_t blockchain_storage::find_end_of_allowed_index(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs)
+size_t blockchain_storage::find_end_of_allowed_index(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(!amount_outs.size())
@@ -1050,7 +1040,7 @@ size_t blockchain_storage::find_end_of_allowed_index(const std::vector<std::pair
   do
   {
     --i;
-    transactions_container::iterator it = m_transactions.find(amount_outs[i].first);
+    transactions_container::const_iterator it = m_transactions.find(amount_outs[i].first);
     CHECK_AND_ASSERT_MES(it != m_transactions.end(), 0, "internal error: failed to find transaction from outputs index with tx_id=" << amount_outs[i].first);
     if(it->second.m_keeper_block_height + CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW <= get_current_blockchain_height() )
       return i+1;
@@ -1058,7 +1048,7 @@ size_t blockchain_storage::find_end_of_allowed_index(const std::vector<std::pair
   return 0;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res)
+bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   BOOST_FOREACH(uint64_t amount, req.amounts)
@@ -1071,7 +1061,7 @@ bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDO
       LOG_PRINT_L1("COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS: not outs for amount " << amount << ", wallet should use some real outs when it lookup for some mix, so, at least one out for this amount should exist");
       continue;//actually this is strange situation, wallet should use some real outs when it lookup for some mix, so, at least one out for this amount should exist
     }
-    std::vector<std::pair<crypto::hash, size_t> >& amount_outs  = it->second;
+    const std::vector<std::pair<crypto::hash, size_t> >& amount_outs  = it->second;
     //it is not good idea to use top fresh outs, because it increases possibility of transaction canceling on split
     //lets find upper bound of not fresh outs
     size_t up_index_limit = find_end_of_allowed_index(amount_outs);
@@ -1106,7 +1096,7 @@ bool blockchain_storage::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDO
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset)
+bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
@@ -1153,7 +1143,7 @@ bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash
   return true;
 }
 //------------------------------------------------------------------
-uint64_t blockchain_storage::block_difficulty(size_t i)
+uint64_t blockchain_storage::block_difficulty(size_t i) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   CHECK_AND_ASSERT_MES(i < m_blocks.size(), false, "wrong block index i = " << i << " at blockchain_storage::block_difficulty()");
@@ -1163,7 +1153,7 @@ uint64_t blockchain_storage::block_difficulty(size_t i)
   return m_blocks[i].cumulative_difficulty - m_blocks[i-1].cumulative_difficulty;
 }
 //------------------------------------------------------------------
-double blockchain_storage::get_avg_block_size( size_t count)
+double blockchain_storage::get_avg_block_size( size_t count) const
 {
 		if (count > get_current_blockchain_height()) return 500;
 
@@ -1241,7 +1231,7 @@ void blockchain_storage::print_blockchain_outs(const std::string& file)
   }
 }
 //------------------------------------------------------------------
-bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp)
+bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(!find_blockchain_supplement(qblock_ids, resp.start_height))
@@ -1254,7 +1244,7 @@ bool blockchain_storage::find_blockchain_supplement(const std::list<crypto::hash
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count)
+bool blockchain_storage::find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(req_start_block > 0) {
@@ -1293,7 +1283,7 @@ bool blockchain_storage::add_block_as_invalid(const block_extended_info& bei, co
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::have_block(const crypto::hash& id)
+bool blockchain_storage::have_block(const crypto::hash& id) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   if(m_blocks_index.count(id))
@@ -1331,13 +1321,13 @@ bool blockchain_storage::push_transaction_to_global_outs_index(const transaction
   return true;
 }
 //------------------------------------------------------------------
-size_t blockchain_storage::get_total_transactions()
+size_t blockchain_storage::get_total_transactions() const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   return m_transactions.size();
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_outs(uint64_t amount, std::list<crypto::public_key>& pkeys)
+bool blockchain_storage::get_outs(uint64_t amount, std::list<crypto::public_key>& pkeys) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   auto it = m_outputs.find(amount);
@@ -1428,7 +1418,7 @@ bool blockchain_storage::add_transaction_from_block(const transaction& tx, const
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs)
+bool blockchain_storage::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   auto it = m_transactions.find(tx_id);
@@ -1443,7 +1433,7 @@ bool blockchain_storage::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t& max_used_block_height, crypto::hash& max_used_block_id)
+bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t& max_used_block_height, crypto::hash& max_used_block_id) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
   bool res = check_tx_inputs(tx, &max_used_block_height);
@@ -1453,7 +1443,7 @@ bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t& max_us
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::have_tx_keyimges_as_spent(const transaction &tx)
+bool blockchain_storage::have_tx_keyimges_as_spent(const transaction &tx) const
 {
   BOOST_FOREACH(const txin_v& in, tx.vin)
   {
@@ -1464,13 +1454,13 @@ bool blockchain_storage::have_tx_keyimges_as_spent(const transaction &tx)
   return false;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height)
+bool blockchain_storage::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height) const
 {
   crypto::hash tx_prefix_hash = get_transaction_prefix_hash(tx);
   return check_tx_inputs(tx, tx_prefix_hash, pmax_used_block_height);
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_tx_inputs(const transaction& tx, const crypto::hash& tx_prefix_hash, uint64_t* pmax_used_block_height)
+bool blockchain_storage::check_tx_inputs(const transaction& tx, const crypto::hash& tx_prefix_hash, uint64_t* pmax_used_block_height) const
 {
   size_t sig_index = 0;
   if(pmax_used_block_height)
@@ -1502,7 +1492,7 @@ bool blockchain_storage::check_tx_inputs(const transaction& tx, const crypto::ha
   return true;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::is_tx_spendtime_unlocked(uint64_t unlock_time)
+bool blockchain_storage::is_tx_spendtime_unlocked(uint64_t unlock_time) const
 {
   if(unlock_time < CRYPTONOTE_MAX_BLOCK_NUMBER)
   {
@@ -1523,15 +1513,15 @@ bool blockchain_storage::is_tx_spendtime_unlocked(uint64_t unlock_time)
   return false;
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height)
+bool blockchain_storage::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height) const
 {
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
   struct outputs_visitor
   {
     std::vector<const crypto::public_key *>& m_results_collector;
-    blockchain_storage& m_bch;
-    outputs_visitor(std::vector<const crypto::public_key *>& results_collector, blockchain_storage& bch):m_results_collector(results_collector), m_bch(bch)
+    const blockchain_storage& m_bch;
+    outputs_visitor(std::vector<const crypto::public_key *>& results_collector, const blockchain_storage& bch):m_results_collector(results_collector), m_bch(bch)
     {}
     bool handle_output(const transaction& tx, const tx_out& out)
     {
@@ -1573,13 +1563,13 @@ bool blockchain_storage::check_tx_input(const txin_to_key& txin, const crypto::h
   return crypto::check_ring_signature(tx_prefix_hash, txin.k_image, output_keys, sig.data());
 }
 //------------------------------------------------------------------
-uint64_t blockchain_storage::get_adjusted_time()
+uint64_t blockchain_storage::get_adjusted_time() const
 {
   //TODO: add collecting median time
   return time(NULL);
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_block_timestamp_main(const block& b)
+bool blockchain_storage::check_block_timestamp_main(const block& b) const
 {
   if(b.timestamp > get_adjusted_time() + CRYPTONOTE_BLOCK_FUTURE_TIME_LIMIT)
   {
@@ -1595,7 +1585,7 @@ bool blockchain_storage::check_block_timestamp_main(const block& b)
   return check_block_timestamp(std::move(timestamps), b);
 }
 //------------------------------------------------------------------
-bool blockchain_storage::check_block_timestamp(std::vector<uint64_t> timestamps, const block& b)
+bool blockchain_storage::check_block_timestamp(std::vector<uint64_t> timestamps, const block& b) const
 {
   if(timestamps.size() < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW)
     return true;
@@ -1696,7 +1686,7 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
     transaction tx;
     size_t blob_size = 0;
     uint64_t fee = 0;
-    if(!m_tx_pool.take_tx(tx_id, tx, blob_size, fee))
+    if(!m_tx_pool->take_tx(tx_id, tx, blob_size, fee))
     {
       LOG_PRINT_L1("Block with id: " << id  << "has at least one unknown transaction with id: " << tx_id);
       purge_block_data_from_blockchain(bl, tx_processed_count);
@@ -1708,7 +1698,7 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
     {
       LOG_PRINT_L1("Block with id: " << id  << "has at least one transaction (id: " << tx_id << ") with wrong inputs.");
       cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
-      bool add_res = m_tx_pool.add_tx(tx, tvc, true);
+      bool add_res = m_tx_pool->add_tx(tx, tvc, true);
       CHECK_AND_ASSERT_MES2(add_res, "handle_block_to_main_chain: failed to add transaction back to transaction pool");
       purge_block_data_from_blockchain(bl, tx_processed_count);
       add_block_as_invalid(bl, id);
@@ -1721,7 +1711,7 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
     {
        LOG_PRINT_L1("Block with id: " << id << " failed to add transaction to blockchain storage");
        cryptonote::tx_verification_context tvc = AUTO_VAL_INIT(tvc);
-       bool add_res = m_tx_pool.add_tx(tx, tvc, true);
+       bool add_res = m_tx_pool->add_tx(tx, tvc, true);
        CHECK_AND_ASSERT_MES2(add_res, "handle_block_to_main_chain: failed to add transaction back to transaction pool");
        purge_block_data_from_blockchain(bl, tx_processed_count);
        bvc.m_verifivation_failed = true;
@@ -1785,7 +1775,7 @@ bool blockchain_storage::handle_block_to_main_chain(const block& bl, const crypt
   /*if(!m_orphanes_reorganize_in_work)
     review_orphaned_blocks_with_new_block_id(id, true);*/
 
-  m_tx_pool.on_blockchain_inc(bei.height, id);
+  m_tx_pool->on_blockchain_inc(bei.height, id);
   //LOG_PRINT_L0("BLOCK: " << ENDL << "" << dump_obj_as_json(bei.bl));
   return true;
 }
@@ -1808,7 +1798,7 @@ bool blockchain_storage::add_new_block(const block& bl_, block_verification_cont
   //copy block here to let modify block.target
   block bl = bl_;
   crypto::hash id = get_block_hash(bl);
-  CRITICAL_REGION_LOCAL(m_tx_pool);//to avoid deadlock lets lock tx_pool for whole add/reorganize process
+  CRITICAL_REGION_LOCAL(*m_tx_pool);//to avoid deadlock lets lock tx_pool for whole add/reorganize process
   CRITICAL_REGION_LOCAL1(m_blockchain_lock);
   if(have_block(id))
   {
@@ -1829,7 +1819,7 @@ bool blockchain_storage::add_new_block(const block& bl_, block_verification_cont
   return handle_block_to_main_chain(bl, id, bvc);
 }
 //------------------------------------------------------------------
-void blockchain_storage::check_against_checkpoints(checkpoints& points, bool enforce)
+void blockchain_storage::check_against_checkpoints(const checkpoints& points, bool enforce)
 {
   const auto& pts = points.get_points();
 
diff --git a/src/cryptonote_core/blockchain_storage.h b/src/cryptonote_core/blockchain_storage.h
index 505ed4574..50a62a428 100644
--- a/src/cryptonote_core/blockchain_storage.h
+++ b/src/cryptonote_core/blockchain_storage.h
@@ -78,7 +78,7 @@ namespace cryptonote
       uint64_t already_generated_coins;
     };
 
-    blockchain_storage(tx_memory_pool& tx_pool):m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false), m_enforce_dns_checkpoints(false)
+    blockchain_storage(tx_memory_pool* tx_pool):m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false), m_enforce_dns_checkpoints(false)
     {};
 
     bool init() { return init(tools::get_default_data_dir(), true); }
@@ -88,56 +88,56 @@ namespace cryptonote
     void set_checkpoints(checkpoints&& chk_pts) { m_checkpoints = chk_pts; }
 
     //bool push_new_block();
-    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs);
-    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks);
-    bool get_alternative_blocks(std::list<block>& blocks);
-    size_t get_alternative_blocks_count();
-    crypto::hash get_block_id_by_height(uint64_t height);
-    bool get_block_by_hash(const crypto::hash &h, block &blk);
-    void get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid);
+    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs) const;
+    bool get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks) const;
+    bool get_alternative_blocks(std::list<block>& blocks) const;
+    size_t get_alternative_blocks_count() const;
+    crypto::hash get_block_id_by_height(uint64_t height) const;
+    bool get_block_by_hash(const crypto::hash &h, block &blk) const;
+    void get_all_known_block_ids(std::list<crypto::hash> &main, std::list<crypto::hash> &alt, std::list<crypto::hash> &invalid) const;
 
     template<class archive_t>
     void serialize(archive_t & ar, const unsigned int version);
 
-    bool have_tx(const crypto::hash &id);
-    bool have_tx_keyimges_as_spent(const transaction &tx);
-    bool have_tx_keyimg_as_spent(const crypto::key_image &key_im);
-    transaction *get_tx(const crypto::hash &id);
+    bool have_tx(const crypto::hash &id) const;
+    bool have_tx_keyimges_as_spent(const transaction &tx) const;
+    bool have_tx_keyimg_as_spent(const crypto::key_image &key_im) const;
+    const transaction *get_tx(const crypto::hash &id) const;
 
     template<class visitor_t>
-    bool scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height = NULL);
+    bool scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height = NULL) const;
 
-    uint64_t get_current_blockchain_height();
-    crypto::hash get_tail_id();
-    crypto::hash get_tail_id(uint64_t& height);
-    difficulty_type get_difficulty_for_next_block();
+    uint64_t get_current_blockchain_height() const;
+    crypto::hash get_tail_id() const;
+    crypto::hash get_tail_id(uint64_t& height) const;
+    difficulty_type get_difficulty_for_next_block() const;
     bool add_new_block(const block& bl_, block_verification_context& bvc);
     bool reset_and_set_genesis_block(const block& b);
-    bool create_block_template(block& b, const account_public_address& miner_address, difficulty_type& di, uint64_t& height, const blobdata& ex_nonce);
-    bool have_block(const crypto::hash& id);
-    size_t get_total_transactions();
-    bool get_outs(uint64_t amount, std::list<crypto::public_key>& pkeys);
-    bool get_short_chain_history(std::list<crypto::hash>& ids);
-    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp);
-    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset);
-    bool find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count);
+    bool create_block_template(block& b, const account_public_address& miner_address, difficulty_type& di, uint64_t& height, const blobdata& ex_nonce) const;
+    bool have_block(const crypto::hash& id) const;
+    size_t get_total_transactions() const;
+    bool get_outs(uint64_t amount, std::list<crypto::public_key>& pkeys) const;
+    bool get_short_chain_history(std::list<crypto::hash>& ids) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, NOTIFY_RESPONSE_CHAIN_ENTRY::request& resp) const;
+    bool find_blockchain_supplement(const std::list<crypto::hash>& qblock_ids, uint64_t& starter_offset) const;
+    bool find_blockchain_supplement(const uint64_t req_start_block, const std::list<crypto::hash>& qblock_ids, std::list<std::pair<block, std::list<transaction> > >& blocks, uint64_t& total_height, uint64_t& start_height, size_t max_count) const;
     bool handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request& arg, NOTIFY_RESPONSE_GET_OBJECTS::request& rsp);
     bool handle_get_objects(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res);
-    bool get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res);
-    bool get_backward_blocks_sizes(size_t from_height, std::vector<size_t>& sz, size_t count);
-    bool get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs);
+    bool get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res) const;
+    bool get_backward_blocks_sizes(size_t from_height, std::vector<size_t>& sz, size_t count) const;
+    bool get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs) const;
     bool store_blockchain();
-    bool check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height = NULL);
-    bool check_tx_inputs(const transaction& tx, const crypto::hash& tx_prefix_hash, uint64_t* pmax_used_block_height = NULL);
-    bool check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height = NULL);
-    bool check_tx_inputs(const transaction& tx, uint64_t& pmax_used_block_height, crypto::hash& max_used_block_id);
-    uint64_t get_current_comulative_blocksize_limit();
-    bool is_storing_blockchain(){return m_is_blockchain_storing;}
-    uint64_t block_difficulty(size_t i);
-    double get_avg_block_size( size_t count);
+    bool check_tx_input(const txin_to_key& txin, const crypto::hash& tx_prefix_hash, const std::vector<crypto::signature>& sig, uint64_t* pmax_related_block_height = NULL) const;
+    bool check_tx_inputs(const transaction& tx, const crypto::hash& tx_prefix_hash, uint64_t* pmax_used_block_height = NULL) const;
+    bool check_tx_inputs(const transaction& tx, uint64_t* pmax_used_block_height = NULL) const;
+    bool check_tx_inputs(const transaction& tx, uint64_t& pmax_used_block_height, crypto::hash& max_used_block_id) const;
+    uint64_t get_current_cumulative_blocksize_limit() const;
+    bool is_storing_blockchain()const{return m_is_blockchain_storing;}
+    uint64_t block_difficulty(size_t i) const;
+    double get_avg_block_size( size_t count) const;
 
     template<class t_ids_container, class t_blocks_container, class t_missed_container>
-    bool get_blocks(const t_ids_container& block_ids, t_blocks_container& blocks, t_missed_container& missed_bs)
+    bool get_blocks(const t_ids_container& block_ids, t_blocks_container& blocks, t_missed_container& missed_bs) const
     {
       CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
@@ -157,7 +157,7 @@ namespace cryptonote
     }
 
     template<class t_ids_container, class t_tx_container, class t_missed_container>
-    bool get_transactions(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs)
+    bool get_transactions(const t_ids_container& txs_ids, t_tx_container& txs, t_missed_container& missed_txs) const
     {
       CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
@@ -167,7 +167,7 @@ namespace cryptonote
         if(it == m_transactions.end())
         {
           transaction tx;
-          if(!m_tx_pool.get_transaction(tx_id, tx))
+          if(!m_tx_pool->get_transaction(tx_id, tx))
             missed_txs.push_back(tx_id);
           else
             txs.push_back(tx);
@@ -181,10 +181,15 @@ namespace cryptonote
     void print_blockchain(uint64_t start_index, uint64_t end_index);
     void print_blockchain_index();
     void print_blockchain_outs(const std::string& file);
-    void check_against_checkpoints(checkpoints& points, bool enforce);
+    void check_against_checkpoints(const checkpoints& points, bool enforce);
     bool update_checkpoints(const std::string& file_path, bool check_dns);
     void set_enforce_dns_checkpoints(bool enforce_checkpoints);
 
+    block get_block(uint64_t height) const { return m_blocks[height].bl; }
+    size_t get_block_size(uint64_t height) const { return m_blocks[height].block_cumulative_size; }
+    difficulty_type get_block_cumulative_difficulty(uint64_t height) const { return m_blocks[height].cumulative_difficulty; }
+    uint64_t get_block_coins_generated(uint64_t height) const { return m_blocks[height].already_generated_coins; }
+
   private:
     typedef std::unordered_map<crypto::hash, size_t> blocks_by_id_index;
     typedef std::unordered_map<crypto::hash, transaction_chain_entry> transactions_container;
@@ -194,8 +199,8 @@ namespace cryptonote
     typedef std::unordered_map<crypto::hash, block> blocks_by_hash;
     typedef std::map<uint64_t, std::vector<std::pair<crypto::hash, size_t>>> outputs_container; //crypto::hash - tx hash, size_t - index of out in transaction
 
-    tx_memory_pool& m_tx_pool;
-    epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
+    tx_memory_pool* m_tx_pool;
+    mutable epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
 
     // main chain
     blocks_container m_blocks;               // height  -> block_extended_info
@@ -230,26 +235,26 @@ namespace cryptonote
     bool handle_block_to_main_chain(const block& bl, block_verification_context& bvc);
     bool handle_block_to_main_chain(const block& bl, const crypto::hash& id, block_verification_context& bvc);
     bool handle_alternative_block(const block& b, const crypto::hash& id, block_verification_context& bvc);
-    difficulty_type get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei);
-    bool prevalidate_miner_transaction(const block& b, uint64_t height);
-    bool validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins);
-    bool validate_transaction(const block& b, uint64_t height, const transaction& tx);
+    difficulty_type get_next_difficulty_for_alternative_chain(const std::list<blocks_ext_by_hash::iterator>& alt_chain, block_extended_info& bei) const;
+    bool prevalidate_miner_transaction(const block& b, uint64_t height) const;
+    bool validate_miner_transaction(const block& b, size_t cumulative_block_size, uint64_t fee, uint64_t& base_reward, uint64_t already_generated_coins) const;
+    bool validate_transaction(const block& b, uint64_t height, const transaction& tx) const;
     bool rollback_blockchain_switching(std::list<block>& original_chain, size_t rollback_height);
     bool add_transaction_from_block(const transaction& tx, const crypto::hash& tx_id, const crypto::hash& bl_id, uint64_t bl_height, size_t blob_size);
     bool push_transaction_to_global_outs_index(const transaction& tx, const crypto::hash& tx_id, std::vector<uint64_t>& global_indexes);
     bool pop_transaction_from_global_index(const transaction& tx, const crypto::hash& tx_id);
-    bool get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count);
-    bool add_out_to_get_random_outs(std::vector<std::pair<crypto::hash, size_t> >& amount_outs, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i);
-    bool is_tx_spendtime_unlocked(uint64_t unlock_time);
+    bool get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count) const;
+    bool add_out_to_get_random_outs(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs, uint64_t amount, size_t i) const;
+    bool is_tx_spendtime_unlocked(uint64_t unlock_time) const;
     bool add_block_as_invalid(const block& bl, const crypto::hash& h);
     bool add_block_as_invalid(const block_extended_info& bei, const crypto::hash& h);
-    size_t find_end_of_allowed_index(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs);
-    bool check_block_timestamp_main(const block& b);
-    bool check_block_timestamp(std::vector<uint64_t> timestamps, const block& b);
-    uint64_t get_adjusted_time();
-    bool complete_timestamps_vector(uint64_t start_height, std::vector<uint64_t>& timestamps);
+    size_t find_end_of_allowed_index(const std::vector<std::pair<crypto::hash, size_t> >& amount_outs) const;
+    bool check_block_timestamp_main(const block& b) const;
+    bool check_block_timestamp(std::vector<uint64_t> timestamps, const block& b) const;
+    uint64_t get_adjusted_time() const;
+    bool complete_timestamps_vector(uint64_t start_height, std::vector<uint64_t>& timestamps) const;
     bool update_next_comulative_size_limit();
-    bool store_genesis_block(bool testnet);
+    bool store_genesis_block(bool testnet, bool check_added = false);
   };
 
 
@@ -317,7 +322,7 @@ namespace cryptonote
 
   //------------------------------------------------------------------
   template<class visitor_t>
-  bool blockchain_storage::scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height)
+  bool blockchain_storage::scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, visitor_t& vis, uint64_t* pmax_related_block_height) const
   {
     CRITICAL_REGION_LOCAL(m_blockchain_lock);
     auto it = m_outputs.find(tx_in_to_key.amount);
@@ -327,7 +332,7 @@ namespace cryptonote
     std::vector<uint64_t> absolute_offsets = relative_output_offsets_to_absolute(tx_in_to_key.key_offsets);
 
 
-    std::vector<std::pair<crypto::hash, size_t> >& amount_outs_vec = it->second;
+    const std::vector<std::pair<crypto::hash, size_t> >& amount_outs_vec = it->second;
     size_t count = 0;
     BOOST_FOREACH(uint64_t i, absolute_offsets)
     {
@@ -336,7 +341,7 @@ namespace cryptonote
         LOG_PRINT_L0("Wrong index in transaction inputs: " << i << ", expected maximum " << amount_outs_vec.size() - 1);
         return false;
       }
-      transactions_container::iterator tx_it = m_transactions.find(amount_outs_vec[i].first);
+      transactions_container::const_iterator tx_it = m_transactions.find(amount_outs_vec[i].first);
       CHECK_AND_ASSERT_MES(tx_it != m_transactions.end(), false, "Wrong transaction id in output indexes: " << epee::string_tools::pod_to_hex(amount_outs_vec[i].first));
       CHECK_AND_ASSERT_MES(amount_outs_vec[i].second < tx_it->second.tx.vout.size(), false,
         "Wrong index in transaction outputs: " << amount_outs_vec[i].second << ", expected less then " << tx_it->second.tx.vout.size());
diff --git a/src/cryptonote_core/checkpoints.cpp b/src/cryptonote_core/checkpoints.cpp
index 73668ab36..e4223afb5 100644
--- a/src/cryptonote_core/checkpoints.cpp
+++ b/src/cryptonote_core/checkpoints.cpp
@@ -84,6 +84,10 @@ namespace cryptonote
     return check_block(height, h, ignored);
   }
   //---------------------------------------------------------------------------
+  // this basically says if the blockchain is smaller than the first
+  // checkpoint then alternate blocks are allowed.  Alternatively, if the
+  // last checkpoint *before* the end of the current chain is also before
+  // the block to be added, then this is fine.
   bool checkpoints::is_alternative_block_allowed(uint64_t blockchain_height, uint64_t block_height) const
   {
     if (0 == block_height)
@@ -99,7 +103,7 @@ namespace cryptonote
     return checkpoint_height < block_height;
   }
   //---------------------------------------------------------------------------
-  uint64_t checkpoints::get_max_height()
+  uint64_t checkpoints::get_max_height() const
   {
     std::map< uint64_t, crypto::hash >::const_iterator highest = 
         std::max_element( m_points.begin(), m_points.end(),
@@ -108,18 +112,18 @@ namespace cryptonote
     return highest->first;
   }
   //---------------------------------------------------------------------------
-  const std::map<uint64_t, crypto::hash>& checkpoints::get_points()
+  const std::map<uint64_t, crypto::hash>& checkpoints::get_points() const
   {
     return m_points;
   }
 
-  bool checkpoints::check_for_conflicts(checkpoints& other)
+  bool checkpoints::check_for_conflicts(const checkpoints& other) const
   {
     for (auto& pt : other.get_points())
     {
       if (m_points.count(pt.first))
       {
-        CHECK_AND_ASSERT_MES(pt.second == m_points[pt.first], false, "Checkpoint at given height already exists, and hash for new checkpoint was different!");
+        CHECK_AND_ASSERT_MES(pt.second == m_points.at(pt.first), false, "Checkpoint at given height already exists, and hash for new checkpoint was different!");
       }
     }
     return true;
diff --git a/src/cryptonote_core/checkpoints.h b/src/cryptonote_core/checkpoints.h
index a39ce1964..55d765b71 100644
--- a/src/cryptonote_core/checkpoints.h
+++ b/src/cryptonote_core/checkpoints.h
@@ -45,9 +45,9 @@ namespace cryptonote
     bool check_block(uint64_t height, const crypto::hash& h) const;
     bool check_block(uint64_t height, const crypto::hash& h, bool& is_a_checkpoint) const;
     bool is_alternative_block_allowed(uint64_t blockchain_height, uint64_t block_height) const;
-    uint64_t get_max_height();
-    const std::map<uint64_t, crypto::hash>& get_points();
-    bool check_for_conflicts(checkpoints& other);
+    uint64_t get_max_height() const;
+    const std::map<uint64_t, crypto::hash>& get_points() const;
+    bool check_for_conflicts(const checkpoints& other) const;
   private:
     std::map<uint64_t, crypto::hash> m_points;
   };
diff --git a/src/cryptonote_core/cryptonote_basic.h b/src/cryptonote_core/cryptonote_basic.h
index f50a19f9e..2be76c0de 100644
--- a/src/cryptonote_core/cryptonote_basic.h
+++ b/src/cryptonote_core/cryptonote_basic.h
@@ -50,6 +50,8 @@
 #include "misc_language.h"
 #include "tx_extra.h"
 
+#define DB_MEMORY 1
+#define DB_LMDB   2
 
 namespace cryptonote
 {
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index 9be5eca9b..4754be43c 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -44,6 +44,11 @@ using namespace epee;
 #include <csignal>
 #include "daemon/command_line_args.h"
 #include "cryptonote_core/checkpoints_create.h"
+#include "blockchain_db/blockchain_db.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+#ifndef STATICLIB
+#include "blockchain_db/berkeleydb/db_bdb.h"
+#endif
 
 DISABLE_VS_WARNINGS(4355)
 
@@ -53,7 +58,11 @@ namespace cryptonote
   //-----------------------------------------------------------------------------------------------
   core::core(i_cryptonote_protocol* pprotocol):
               m_mempool(m_blockchain_storage),
+#if BLOCKCHAIN_DB == DB_LMDB
               m_blockchain_storage(m_mempool),
+#else
+              m_blockchain_storage(&m_mempool),
+#endif
               m_miner(this),
               m_miner_address(boost::value_initialized<account_public_address>()), 
               m_starter_message_showed(false),
@@ -195,7 +204,50 @@ namespace cryptonote
     r = m_mempool.init(m_config_folder);
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize memory pool");
 
+#if BLOCKCHAIN_DB == DB_LMDB
+    std::string db_type = command_line::get_arg(vm, daemon_args::arg_db_type);
+
+    BlockchainDB* db = nullptr;
+    if (db_type == "lmdb")
+    {
+      db = new BlockchainLMDB();
+    }
+    else if (db_type == "berkeley")
+    {
+#ifndef STATICLIB
+      db = new BlockchainBDB();
+#else
+      LOG_ERROR("BlockchainBDB not supported on STATIC builds");
+      return false;
+#endif
+    }
+    else
+    {
+      LOG_ERROR("Attempted to use non-existant database type");
+      return false;
+    }
+
+    boost::filesystem::path folder(m_config_folder);
+
+    folder /= db->get_db_name();
+
+    LOG_PRINT_L0("Loading blockchain from folder " << folder.c_str() << " ...");
+
+    const std::string filename = folder.string();
+    try
+    {
+      db->open(filename);
+    }
+    catch (const DB_ERROR& e)
+    {
+      LOG_PRINT_L0("Error opening database: " << e.what());
+      return false;
+    }
+
+    r = m_blockchain_storage.init(db, m_testnet);
+#else
     r = m_blockchain_storage.init(m_config_folder, m_testnet);
+#endif
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize blockchain storage");
 
     // load json & DNS checkpoints, and verify them
@@ -363,9 +415,9 @@ namespace cryptonote
       return false;
     }
 
-    if(!keeped_by_block && get_object_blobsize(tx) >= m_blockchain_storage.get_current_comulative_blocksize_limit() - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE)
+    if(!keeped_by_block && get_object_blobsize(tx) >= m_blockchain_storage.get_current_cumulative_blocksize_limit() - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE)
     {
-      LOG_PRINT_RED_L1("tx is too large " << get_object_blobsize(tx) << ", expected not bigger than " << m_blockchain_storage.get_current_comulative_blocksize_limit() - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE);
+      LOG_PRINT_RED_L1("tx is too large " << get_object_blobsize(tx) << ", expected not bigger than " << m_blockchain_storage.get_current_cumulative_blocksize_limit() - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE);
       return false;
     }
 
@@ -650,7 +702,11 @@ namespace cryptonote
       m_starter_message_showed = true;
     }
 
+#if BLOCKCHAIN_DB == DB_LMDB
+    m_store_blockchain_interval.do_call(boost::bind(&Blockchain::store_blockchain, &m_blockchain_storage));
+#else
     m_store_blockchain_interval.do_call(boost::bind(&blockchain_storage::store_blockchain, &m_blockchain_storage));
+#endif
     m_miner.on_idle();
     m_mempool.on_idle();
     return true;
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index bb53ecb81..973f01272 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -39,7 +39,11 @@
 #include "cryptonote_protocol/cryptonote_protocol_handler_common.h"
 #include "storages/portable_storage_template_helper.h"
 #include "tx_pool.h"
+#if BLOCKCHAIN_DB == DB_LMDB
+#include "blockchain.h"
+#else
 #include "blockchain_storage.h"
+#endif
 #include "miner.h"
 #include "connection_context.h"
 #include "cryptonote_core/cryptonote_stat_info.h"
@@ -118,7 +122,11 @@ namespace cryptonote
      bool get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::request& req, COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::response& res);
      void pause_mine();
      void resume_mine();
+#if BLOCKCHAIN_DB == DB_LMDB
+     Blockchain& get_blockchain_storage(){return m_blockchain_storage;}
+#else
      blockchain_storage& get_blockchain_storage(){return m_blockchain_storage;}
+#endif
      //debug functions
      void print_blockchain(uint64_t start_index, uint64_t end_index);
      void print_blockchain_index();
@@ -159,7 +167,11 @@ namespace cryptonote
 	 uint64_t m_test_drop_download_height = 0;
 
      tx_memory_pool m_mempool;
+#if BLOCKCHAIN_DB == DB_LMDB
+     Blockchain m_blockchain_storage;
+#else
      blockchain_storage m_blockchain_storage;
+#endif
      i_cryptonote_protocol* m_pprotocol;
      epee::critical_section m_incoming_tx_lock;
      //m_miner and m_miner_addres are probably temporary here
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index 691d16492..03ced2c2e 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -37,7 +37,11 @@
 #include "cryptonote_format_utils.h"
 #include "cryptonote_boost_serialization.h"
 #include "cryptonote_config.h"
+#if BLOCKCHAIN_DB == DB_LMDB
+#include "blockchain.h"
+#else
 #include "blockchain_storage.h"
+#endif
 #include "common/boost_serialization_helper.h"
 #include "common/int-util.h"
 #include "misc_language.h"
@@ -52,12 +56,19 @@ namespace cryptonote
   {
     size_t const TRANSACTION_SIZE_LIMIT = (((CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE * 125) / 100) - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE);
   }
-
   //---------------------------------------------------------------------------------
+#if BLOCKCHAIN_DB == DB_LMDB
+  //---------------------------------------------------------------------------------
+  tx_memory_pool::tx_memory_pool(Blockchain& bchs): m_blockchain(bchs)
+  {
+
+  }
+#else
   tx_memory_pool::tx_memory_pool(blockchain_storage& bchs): m_blockchain(bchs)
   {
 
   }
+#endif
   //---------------------------------------------------------------------------------
   bool tx_memory_pool::add_tx(const transaction &tx, /*const crypto::hash& tx_prefix_hash,*/ const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool kept_by_block)
   {
diff --git a/src/cryptonote_core/tx_pool.h b/src/cryptonote_core/tx_pool.h
index 9c1c2b1aa..b867a1a7d 100644
--- a/src/cryptonote_core/tx_pool.h
+++ b/src/cryptonote_core/tx_pool.h
@@ -44,10 +44,13 @@
 #include "verification_context.h"
 #include "crypto/hash.h"
 
-
 namespace cryptonote
 {
+#if BLOCKCHAIN_DB == DB_LMDB
+  class Blockchain;
+#else
   class blockchain_storage;
+#endif
   /************************************************************************/
   /*                                                                      */
   /************************************************************************/
@@ -55,7 +58,11 @@ namespace cryptonote
   class tx_memory_pool: boost::noncopyable
   {
   public:
+#if BLOCKCHAIN_DB == DB_LMDB
+    tx_memory_pool(Blockchain& bchs);
+#else
     tx_memory_pool(blockchain_storage& bchs);
+#endif
     bool add_tx(const transaction &tx, const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool keeped_by_block);
     bool add_tx(const transaction &tx, tx_verification_context& tvc, bool keeped_by_block);
     //gets tx and remove it from pool
@@ -127,7 +134,11 @@ namespace cryptonote
     //transactions_container m_alternative_transactions;
 
     std::string m_config_folder;
+#if BLOCKCHAIN_DB == DB_LMDB
+    Blockchain& m_blockchain;
+#else
     blockchain_storage& m_blockchain;
+#endif
     /************************************************************************/
     /*                                                                      */
     /************************************************************************/
@@ -170,9 +181,12 @@ namespace cryptonote
       uint64_t operator()(const txin_to_scripthash& tx) const {return 0;}
     };
 
+#if BLOCKCHAIN_DB == DB_LMDB
+#else
 #if defined(DEBUG_CREATE_BLOCK_TEMPLATE)
     friend class blockchain_storage;
 #endif
+#endif
   };
 }
 
diff --git a/src/daemon/CMakeLists.txt b/src/daemon/CMakeLists.txt
index f9c2af32a..bf25bbca9 100644
--- a/src/daemon/CMakeLists.txt
+++ b/src/daemon/CMakeLists.txt
@@ -74,6 +74,7 @@ bitmonero_add_executable(daemon
 target_link_libraries(daemon
   LINK_PRIVATE
     rpc
+    blockchain_db
     cryptonote_core
     crypto
     common
diff --git a/src/daemon/command_line_args.h b/src/daemon/command_line_args.h
index bcf599128..2bd918478 100644
--- a/src/daemon/command_line_args.h
+++ b/src/daemon/command_line_args.h
@@ -70,6 +70,11 @@ namespace daemon_args
   , "checkpoints from DNS server will be enforced"
   , false
   };
+  const command_line::arg_descriptor<std::string> arg_db_type = {
+    "db-type"
+  , "Specify database type"
+  , "lmdb"
+  };
 
 }  // namespace daemon_args
 
diff --git a/src/daemon/main.cpp b/src/daemon/main.cpp
index d1e0cf671..71df34950 100644
--- a/src/daemon/main.cpp
+++ b/src/daemon/main.cpp
@@ -42,6 +42,7 @@
 #include "rpc/core_rpc_server.h"
 #include <boost/program_options.hpp>
 #include "daemon/command_line_args.h"
+#include "blockchain_db/db_types.h"
 
 namespace po = boost::program_options;
 namespace bf = boost::filesystem;
@@ -84,6 +85,7 @@ int main(int argc, char const * argv[])
       command_line::add_arg(core_settings, daemon_args::arg_log_level);
       command_line::add_arg(core_settings, daemon_args::arg_testnet_on);
       command_line::add_arg(core_settings, daemon_args::arg_dns_checkpoints);
+      command_line::add_arg(core_settings, daemon_args::arg_db_type);
       daemonizer::init_options(hidden_options, visible_options);
       daemonize::t_executor::init_options(core_settings);
 
@@ -136,6 +138,19 @@ int main(int argc, char const * argv[])
     
     epee::g_test_dbg_lock_sleep = command_line::get_arg(vm, command_line::arg_test_dbg_lock_sleep);
 
+    std::string db_type = command_line::get_arg(vm, daemon_args::arg_db_type);
+
+    // verify that blockchaindb type is valid
+    if(cryptonote::blockchain_db_types.count(db_type) == 0)
+    {
+      std::cout << "Invalid database type (" << db_type << "), available types are:" << std::endl;
+      for (const auto& type : cryptonote::blockchain_db_types)
+      {
+        std::cout << "\t" << type << std::endl;
+      }
+      return 0;
+    }
+
     bool testnet_mode = command_line::get_arg(vm, daemon_args::arg_testnet_on);
 
     auto data_dir_arg = testnet_mode ? command_line::arg_testnet_data_dir : command_line::arg_data_dir;