Merge pull request #14 from moneromooo-monero/blockchain

Blockchain

lots of const-correctness and more proper code, bug fix with syncing.

10 files changed, 384 insertions, 487 deletions

diff --git a/src/blockchain_converter/blockchain_converter.cpp b/src/blockchain_converter/blockchain_converter.cpp
index a2b3a375f..4653cf66c 100644
--- a/src/blockchain_converter/blockchain_converter.cpp
+++ b/src/blockchain_converter/blockchain_converter.cpp
@@ -99,5 +99,6 @@ int main(int argc, char* argv[])
     }
   }
 
+  delete blockchain;
   return 0;
 }
diff --git a/src/cryptonote_core/BlockchainDB_impl/db_lmdb.cpp b/src/cryptonote_core/BlockchainDB_impl/db_lmdb.cpp
index a123a3643..278bec14f 100644
--- a/src/cryptonote_core/BlockchainDB_impl/db_lmdb.cpp
+++ b/src/cryptonote_core/BlockchainDB_impl/db_lmdb.cpp
@@ -67,6 +67,7 @@ struct lmdb_cur
     }
   }
 
+private:
   MDB_cursor* m_cur;
   bool done;
 };
@@ -79,26 +80,26 @@ auto compare_uint64 = [](const MDB_val *a, const MDB_val *b) {
   else return 1;
 };
 
-const char* LMDB_BLOCKS = "blocks";
-const char* LMDB_BLOCK_TIMESTAMPS = "block_timestamps";
-const char* LMDB_BLOCK_HEIGHTS = "block_heights";
-const char* LMDB_BLOCK_HASHES = "block_hashes";
-const char* LMDB_BLOCK_SIZES = "block_sizes";
-const char* LMDB_BLOCK_DIFFS = "block_diffs";
-const char* LMDB_BLOCK_COINS = "block_coins";
-
-const char* LMDB_TXS = "txs";
-const char* LMDB_TX_UNLOCKS = "tx_unlocks";
-const char* LMDB_TX_HEIGHTS = "tx_heights";
-const char* LMDB_TX_OUTPUTS = "tx_outputs";
-
-const char* LMDB_OUTPUT_TXS = "output_txs";
-const char* LMDB_OUTPUT_INDICES = "output_indices";
-const char* LMDB_OUTPUT_AMOUNTS = "output_amounts";
-const char* LMDB_OUTPUT_KEYS = "output_keys";
-const char* LMDB_OUTPUTS = "outputs";
-const char* LMDB_OUTPUT_GINDICES = "output_gindices";
-const char* LMDB_SPENT_KEYS = "spent_keys";
+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)
 {
@@ -628,7 +629,7 @@ blobdata BlockchainLMDB::output_to_blob(const tx_out& output)
   return b;
 }
 
-tx_out BlockchainLMDB::output_from_blob(const blobdata& blob)
+tx_out BlockchainLMDB::output_from_blob(const blobdata& blob) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   std::stringstream ss;
@@ -645,13 +646,13 @@ tx_out BlockchainLMDB::output_from_blob(const blobdata& blob)
   return o;
 }
 
-uint64_t BlockchainLMDB::get_output_global_index(const uint64_t& amount, const uint64_t& index)
+uint64_t BlockchainLMDB::get_output_global_index(const uint64_t& amount, const uint64_t& index) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   return 0;
 }
 
-void BlockchainLMDB::check_open()
+void BlockchainLMDB::check_open() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   if (!m_open)
@@ -821,7 +822,7 @@ void BlockchainLMDB::reset()
   // TODO: this
 }
 
-std::vector<std::string> BlockchainLMDB::get_filenames()
+std::vector<std::string> BlockchainLMDB::get_filenames() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   std::vector<std::string> filenames;
@@ -853,7 +854,7 @@ void BlockchainLMDB::unlock()
 }
 
 
-bool BlockchainLMDB::block_exists(const crypto::hash& h)
+bool BlockchainLMDB::block_exists(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -888,7 +889,7 @@ bool BlockchainLMDB::block_exists(const crypto::hash& h)
   return true;
 }
 
-block BlockchainLMDB::get_block(const crypto::hash& h)
+block BlockchainLMDB::get_block(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -896,7 +897,7 @@ block BlockchainLMDB::get_block(const crypto::hash& h)
   return get_block_from_height(get_block_height(h));
 }
 
-uint64_t BlockchainLMDB::get_block_height(const crypto::hash& h)
+uint64_t BlockchainLMDB::get_block_height(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -930,7 +931,7 @@ uint64_t BlockchainLMDB::get_block_height(const crypto::hash& h)
   return *(uint64_t*)result.mv_data;
 }
 
-block_header BlockchainLMDB::get_block_header(const crypto::hash& h)
+block_header BlockchainLMDB::get_block_header(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -939,7 +940,7 @@ block_header BlockchainLMDB::get_block_header(const crypto::hash& h)
   return get_block(h);
 }
 
-block BlockchainLMDB::get_block_from_height(const uint64_t& height)
+block BlockchainLMDB::get_block_from_height(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -983,7 +984,7 @@ block BlockchainLMDB::get_block_from_height(const uint64_t& height)
   return b;
 }
 
-uint64_t BlockchainLMDB::get_block_timestamp(const uint64_t& height) 
+uint64_t BlockchainLMDB::get_block_timestamp(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1016,7 +1017,7 @@ uint64_t BlockchainLMDB::get_block_timestamp(const uint64_t& height)
   return *(uint64_t*)result.mv_data;
 }
 
-uint64_t BlockchainLMDB::get_top_block_timestamp()
+uint64_t BlockchainLMDB::get_top_block_timestamp() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1030,7 +1031,7 @@ uint64_t BlockchainLMDB::get_top_block_timestamp()
   return get_block_timestamp(m_height - 1);
 }
 
-size_t BlockchainLMDB::get_block_size(const uint64_t& height)
+size_t BlockchainLMDB::get_block_size(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1063,7 +1064,7 @@ size_t BlockchainLMDB::get_block_size(const uint64_t& height)
   return *(size_t*)result.mv_data;
 }
 
-difficulty_type BlockchainLMDB::get_block_cumulative_difficulty(const uint64_t& height)
+difficulty_type BlockchainLMDB::get_block_cumulative_difficulty(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1096,7 +1097,7 @@ difficulty_type BlockchainLMDB::get_block_cumulative_difficulty(const uint64_t&
   return *(difficulty_type*)result.mv_data;
 }
 
-difficulty_type BlockchainLMDB::get_block_difficulty(const uint64_t& height)
+difficulty_type BlockchainLMDB::get_block_difficulty(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1113,7 +1114,7 @@ difficulty_type BlockchainLMDB::get_block_difficulty(const uint64_t& height)
   return diff1 - diff2;
 }
 
-uint64_t BlockchainLMDB::get_block_already_generated_coins(const uint64_t& height)
+uint64_t BlockchainLMDB::get_block_already_generated_coins(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1146,7 +1147,7 @@ uint64_t BlockchainLMDB::get_block_already_generated_coins(const uint64_t& heigh
   return *(uint64_t*)result.mv_data;
 }
 
-crypto::hash BlockchainLMDB::get_block_hash_from_height(const uint64_t& height)
+crypto::hash BlockchainLMDB::get_block_hash_from_height(const uint64_t& height) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1179,7 +1180,7 @@ crypto::hash BlockchainLMDB::get_block_hash_from_height(const uint64_t& height)
   return *(crypto::hash*)result.mv_data;
 }
 
-std::vector<block> BlockchainLMDB::get_blocks_range(const uint64_t& h1, const uint64_t& h2)
+std::vector<block> BlockchainLMDB::get_blocks_range(const uint64_t& h1, const uint64_t& h2) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1193,7 +1194,7 @@ std::vector<block> BlockchainLMDB::get_blocks_range(const uint64_t& h1, const ui
   return v;
 }
 
-std::vector<crypto::hash> BlockchainLMDB::get_hashes_range(const uint64_t& h1, const uint64_t& h2)
+std::vector<crypto::hash> BlockchainLMDB::get_hashes_range(const uint64_t& h1, const uint64_t& h2) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1207,7 +1208,7 @@ std::vector<crypto::hash> BlockchainLMDB::get_hashes_range(const uint64_t& h1, c
   return v;
 }
 
-crypto::hash BlockchainLMDB::top_block_hash()
+crypto::hash BlockchainLMDB::top_block_hash() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1219,7 +1220,7 @@ crypto::hash BlockchainLMDB::top_block_hash()
   return null_hash;
 }
 
-block BlockchainLMDB::get_top_block()
+block BlockchainLMDB::get_top_block() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1233,7 +1234,7 @@ block BlockchainLMDB::get_top_block()
   return b;
 }
 
-uint64_t BlockchainLMDB::height()
+uint64_t BlockchainLMDB::height() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1242,7 +1243,7 @@ uint64_t BlockchainLMDB::height()
 }
 
 
-bool BlockchainLMDB::tx_exists(const crypto::hash& h)
+bool BlockchainLMDB::tx_exists(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1276,7 +1277,7 @@ bool BlockchainLMDB::tx_exists(const crypto::hash& h)
   return true;
 }
 
-uint64_t BlockchainLMDB::get_tx_unlock_time(const crypto::hash& h)
+uint64_t BlockchainLMDB::get_tx_unlock_time(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1309,7 +1310,7 @@ uint64_t BlockchainLMDB::get_tx_unlock_time(const crypto::hash& h)
   return *(uint64_t*)result.mv_data;
 }
 
-transaction BlockchainLMDB::get_tx(const crypto::hash& h)
+transaction BlockchainLMDB::get_tx(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1352,7 +1353,7 @@ transaction BlockchainLMDB::get_tx(const crypto::hash& h)
   return tx;
 }
 
-uint64_t BlockchainLMDB::get_tx_count()
+uint64_t BlockchainLMDB::get_tx_count() const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1376,7 +1377,7 @@ uint64_t BlockchainLMDB::get_tx_count()
   return db_stats.ms_entries;
 }
 
-std::vector<transaction> BlockchainLMDB::get_tx_list(const std::vector<crypto::hash>& hlist)
+std::vector<transaction> BlockchainLMDB::get_tx_list(const std::vector<crypto::hash>& hlist) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1390,7 +1391,7 @@ std::vector<transaction> BlockchainLMDB::get_tx_list(const std::vector<crypto::h
   return v;
 }
 
-uint64_t BlockchainLMDB::get_tx_block_height(const crypto::hash& h)
+uint64_t BlockchainLMDB::get_tx_block_height(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1424,7 +1425,7 @@ uint64_t BlockchainLMDB::get_tx_block_height(const crypto::hash& h)
 }
 
 //FIXME: make sure the random method used here is appropriate
-uint64_t BlockchainLMDB::get_random_output(const uint64_t& amount)
+uint64_t BlockchainLMDB::get_random_output(const uint64_t& amount) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1439,7 +1440,7 @@ uint64_t BlockchainLMDB::get_random_output(const uint64_t& amount)
   return crypto::rand<uint64_t>() % num_outputs;
 }
 
-uint64_t BlockchainLMDB::get_num_outputs(const uint64_t& amount)
+uint64_t BlockchainLMDB::get_num_outputs(const uint64_t& amount) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1478,7 +1479,7 @@ uint64_t BlockchainLMDB::get_num_outputs(const uint64_t& amount)
   return num_elems;
 }
 
-crypto::public_key BlockchainLMDB::get_output_key(const uint64_t& amount, const uint64_t& index)
+crypto::public_key BlockchainLMDB::get_output_key(const uint64_t& amount, const uint64_t& index) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1512,7 +1513,7 @@ crypto::public_key BlockchainLMDB::get_output_key(const uint64_t& amount, const
   return *(crypto::public_key*)v.mv_data;
 }
 
-tx_out BlockchainLMDB::get_output(const crypto::hash& h, const uint64_t& index)
+tx_out BlockchainLMDB::get_output(const crypto::hash& h, const uint64_t& index) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1576,7 +1577,7 @@ tx_out BlockchainLMDB::get_output(const crypto::hash& h, const uint64_t& index)
 
 // 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)
+tx_out BlockchainLMDB::get_output(const uint64_t& index) const
 {
   return tx_out();
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
@@ -1612,7 +1613,7 @@ tx_out BlockchainLMDB::get_output(const uint64_t& index)
   return output_from_blob(b);
 }
 
-tx_out_index BlockchainLMDB::get_output_tx_and_index(const uint64_t& amount, const uint64_t& index)
+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();
@@ -1702,7 +1703,7 @@ tx_out_index BlockchainLMDB::get_output_tx_and_index(const uint64_t& amount, con
   return tx_out_index(tx_hash, *(uint64_t *)v.mv_data);
 }
 
-std::vector<uint64_t> BlockchainLMDB::get_tx_output_indices(const crypto::hash& h)
+std::vector<uint64_t> BlockchainLMDB::get_tx_output_indices(const crypto::hash& h) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1754,7 +1755,7 @@ std::vector<uint64_t> BlockchainLMDB::get_tx_output_indices(const crypto::hash&
   return index_vec;
 }
 
-bool BlockchainLMDB::has_key_image(const crypto::key_image& img)
+bool BlockchainLMDB::has_key_image(const crypto::key_image& img) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   check_open();
@@ -1803,12 +1804,14 @@ uint64_t BlockchainLMDB::add_block( const block& blk
   try
   {
     BlockchainDB::add_block(blk, block_size, cumulative_difficulty, coins_generated, txs);
+    m_write_txn = NULL;
 
     txn.commit();
   }
   catch (...)
   {
     m_num_outputs = num_outputs;
+    m_write_txn = NULL;
     throw;
   }
 
@@ -1829,12 +1832,14 @@ void BlockchainLMDB::pop_block(block& blk, std::vector<transaction>& txs)
   try
   {
     BlockchainDB::pop_block(blk, txs);
+    m_write_txn = NULL;
 
     txn.commit();
   }
   catch (...)
   {
     m_num_outputs = num_outputs;
+    m_write_txn = NULL;
     throw;
   }
 
diff --git a/src/cryptonote_core/BlockchainDB_impl/db_lmdb.h b/src/cryptonote_core/BlockchainDB_impl/db_lmdb.h
index e74ca4b73..3bac5d740 100644
--- a/src/cryptonote_core/BlockchainDB_impl/db_lmdb.h
+++ b/src/cryptonote_core/BlockchainDB_impl/db_lmdb.h
@@ -90,65 +90,65 @@ public:
 
   virtual void reset();
 
-  virtual std::vector<std::string> get_filenames();
+  virtual std::vector<std::string> get_filenames() const;
 
   virtual bool lock();
 
   virtual void unlock();
 
-  virtual bool block_exists(const crypto::hash& h);
+  virtual bool block_exists(const crypto::hash& h) const;
 
-  virtual block get_block(const crypto::hash& h);
+  virtual block get_block(const crypto::hash& h) const;
 
-  virtual uint64_t get_block_height(const crypto::hash& h);
+  virtual uint64_t get_block_height(const crypto::hash& h) const;
 
-  virtual block_header get_block_header(const crypto::hash& h);
+  virtual block_header get_block_header(const crypto::hash& h) const;
 
-  virtual block get_block_from_height(const uint64_t& height);
+  virtual block get_block_from_height(const uint64_t& height) const;
 
-  virtual uint64_t get_block_timestamp(const uint64_t& height) ;
+  virtual uint64_t get_block_timestamp(const uint64_t& height) const;
 
-  virtual uint64_t get_top_block_timestamp();
+  virtual uint64_t get_top_block_timestamp() const;
 
-  virtual size_t get_block_size(const uint64_t& height);
+  virtual size_t get_block_size(const uint64_t& height) const;
 
-  virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height);
+  virtual difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const;
 
-  virtual difficulty_type get_block_difficulty(const uint64_t& height);
+  virtual difficulty_type get_block_difficulty(const uint64_t& height) const;
 
-  virtual uint64_t get_block_already_generated_coins(const uint64_t& height);
+  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);
+  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);
+  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);
+  virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const;
 
-  virtual crypto::hash top_block_hash();
+  virtual crypto::hash top_block_hash() const;
 
-  virtual block get_top_block();
+  virtual block get_top_block() const;
 
-  virtual uint64_t height();
+  virtual uint64_t height() const;
 
-  virtual bool tx_exists(const crypto::hash& h);
+  virtual bool tx_exists(const crypto::hash& h) const;
 
-  virtual uint64_t get_tx_unlock_time(const crypto::hash& h);
+  virtual uint64_t get_tx_unlock_time(const crypto::hash& h) const;
 
-  virtual transaction get_tx(const crypto::hash& h);
+  virtual transaction get_tx(const crypto::hash& h) const;
 
-  virtual uint64_t get_tx_count();
+  virtual uint64_t get_tx_count() const;
 
-  virtual std::vector<transaction> get_tx_list(const std::vector<crypto::hash>& hlist);
+  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);
+  virtual uint64_t get_tx_block_height(const crypto::hash& h) const;
 
-  virtual uint64_t get_random_output(const uint64_t& amount);
+  virtual uint64_t get_random_output(const uint64_t& amount) const;
 
-  virtual uint64_t get_num_outputs(const uint64_t& amount);
+  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);
+  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);
+  virtual tx_out get_output(const crypto::hash& h, const uint64_t& index) const;
 
   /**
    * @brief get an output from its global index
@@ -159,13 +159,13 @@ public:
    * 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);
+  tx_out get_output(const uint64_t& index) const;
 
-  virtual tx_out_index get_output_tx_and_index(const uint64_t& amount, const uint64_t& index);
+  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);
+  virtual std::vector<uint64_t> get_tx_output_indices(const crypto::hash& h) const;
 
-  virtual bool has_key_image(const crypto::key_image& img);
+  virtual bool has_key_image(const crypto::key_image& img) const;
 
   virtual uint64_t add_block( const block& blk
                             , const size_t& block_size
@@ -217,7 +217,7 @@ private:
    *
    * @return the resultant tx output
    */
-  tx_out output_from_blob(const blobdata& blob);
+  tx_out output_from_blob(const blobdata& blob) const;
 
   /**
    * @brief get the global index of the index-th output of the given amount
@@ -227,9 +227,9 @@ private:
    *
    * @return the global index of the desired output
    */
-  uint64_t get_output_global_index(const uint64_t& amount, const uint64_t& index);
+  uint64_t get_output_global_index(const uint64_t& amount, const uint64_t& index) const;
 
-  void check_open();
+  void check_open() const;
 
   MDB_env* m_env;
 
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 647b9405d..b5c4f9ca4 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -129,14 +129,14 @@ void Blockchain::serialize(archive_t & ar, const unsigned int version)
       "m_current_block_cumul_sz_limit: " << m_current_block_cumul_sz_limit);
 }
 //------------------------------------------------------------------
-bool Blockchain::have_tx(const crypto::hash &id)
+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)
+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);
@@ -147,7 +147,7 @@ bool Blockchain::have_tx_keyimg_as_spent(const crypto::key_image &key_im)
 // 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)
+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);
@@ -217,7 +217,7 @@ bool Blockchain::scan_outputkeys_for_indexes(const txin_to_key& tx_in_to_key, vi
   return true;
 }
 //------------------------------------------------------------------
-uint64_t Blockchain::get_current_blockchain_height()
+uint64_t Blockchain::get_current_blockchain_height() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -465,7 +465,7 @@ bool Blockchain::purge_transaction_keyimages_from_blockchain(const transaction&
   return true;
 }
 //------------------------------------------------------------------
-crypto::hash Blockchain::get_tail_id(uint64_t& height)
+crypto::hash Blockchain::get_tail_id(uint64_t& height) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -473,7 +473,7 @@ crypto::hash Blockchain::get_tail_id(uint64_t& height)
   return get_tail_id();
 }
 //------------------------------------------------------------------
-crypto::hash Blockchain::get_tail_id()
+crypto::hash Blockchain::get_tail_id() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -492,7 +492,7 @@ crypto::hash Blockchain::get_tail_id()
  *   powers of 2 less recent from there, so 13, 17, 25, etc...
  *
  */
-bool Blockchain::get_short_chain_history(std::list<crypto::hash>& ids)
+bool Blockchain::get_short_chain_history(std::list<crypto::hash>& ids) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -533,7 +533,7 @@ bool Blockchain::get_short_chain_history(std::list<crypto::hash>& ids)
   return true;
 }
 //------------------------------------------------------------------
-crypto::hash Blockchain::get_block_id_by_height(uint64_t height)
+crypto::hash Blockchain::get_block_id_by_height(uint64_t height) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -557,7 +557,7 @@ crypto::hash Blockchain::get_block_id_by_height(uint64_t height)
   return null_hash;
 }
 //------------------------------------------------------------------
-bool Blockchain::get_block_by_hash(const crypto::hash &h, block &blk)
+bool Blockchain::get_block_by_hash(const crypto::hash &h, block &blk) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -593,7 +593,7 @@ bool Blockchain::get_block_by_hash(const crypto::hash &h, block &blk)
 //------------------------------------------------------------------
 //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)
+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);
@@ -603,10 +603,10 @@ void Blockchain::get_all_known_block_ids(std::list<crypto::hash> &main, std::lis
     main.push_back(a);
   }
 
-  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);
 }
 //------------------------------------------------------------------
@@ -614,7 +614,7 @@ void Blockchain::get_all_known_block_ids(std::list<crypto::hash> &main, std::lis
 // 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()
+difficulty_type Blockchain::get_difficulty_for_next_block() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -760,7 +760,7 @@ bool Blockchain::switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::
 //------------------------------------------------------------------
 // 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)
+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;
@@ -887,7 +887,7 @@ bool Blockchain::validate_miner_transaction(const block& b, size_t cumulative_bl
 //------------------------------------------------------------------
 // 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)
+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);
@@ -905,7 +905,7 @@ void Blockchain::get_last_n_blocks_sizes(std::vector<size_t>& sz, size_t count)
   }
 }
 //------------------------------------------------------------------
-uint64_t Blockchain::get_current_cumulative_blocksize_limit()
+uint64_t Blockchain::get_current_cumulative_blocksize_limit() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   return m_current_block_cumul_sz_limit;
@@ -922,7 +922,7 @@ uint64_t Blockchain::get_current_cumulative_blocksize_limit()
 // 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)
+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;
@@ -1250,7 +1250,7 @@ bool Blockchain::handle_alternative_block(const block& b, const crypto::hash& id
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks, std::list<transaction>& txs)
+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);
@@ -1272,7 +1272,7 @@ bool Blockchain::get_blocks(uint64_t start_offset, size_t count, std::list<block
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::get_blocks(uint64_t start_offset, size_t count, std::list<block>& blocks)
+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);
@@ -1323,7 +1323,7 @@ bool Blockchain::handle_get_objects(NOTIFY_REQUEST_GET_OBJECTS::request& arg, NO
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::get_alternative_blocks(std::list<block>& blocks)
+bool Blockchain::get_alternative_blocks(std::list<block>& blocks) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -1335,7 +1335,7 @@ bool Blockchain::get_alternative_blocks(std::list<block>& blocks)
   return true;
 }
 //------------------------------------------------------------------
-size_t Blockchain::get_alternative_blocks_count()
+size_t Blockchain::get_alternative_blocks_count() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -1344,7 +1344,7 @@ size_t Blockchain::get_alternative_blocks_count()
 //------------------------------------------------------------------
 // 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)
+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);
@@ -1358,7 +1358,7 @@ void Blockchain::add_out_to_get_random_outs(COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_A
 // 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)
+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)));
@@ -1431,7 +1431,7 @@ bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUT
 // 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)
+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);
@@ -1486,7 +1486,8 @@ bool Blockchain::find_blockchain_supplement(const std::list<crypto::hash>& qbloc
   }
 
   // if split_height remains 0, we didn't have any but the genesis block in common
-  if(split_height == 0)
+  // 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;
@@ -1497,7 +1498,7 @@ bool Blockchain::find_blockchain_supplement(const std::list<crypto::hash>& qbloc
   return true;
 }
 //------------------------------------------------------------------
-uint64_t Blockchain::block_difficulty(uint64_t i)
+uint64_t Blockchain::block_difficulty(uint64_t i) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -1513,7 +1514,7 @@ uint64_t Blockchain::block_difficulty(uint64_t i)
 }
 //------------------------------------------------------------------
 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)
+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);
@@ -1537,7 +1538,7 @@ bool Blockchain::get_blocks(const t_ids_container& block_ids, t_blocks_container
 }
 //------------------------------------------------------------------
 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)
+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);
@@ -1618,7 +1619,7 @@ void Blockchain::print_blockchain_outs(const std::string& file)
 // 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)
+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);
@@ -1642,7 +1643,7 @@ bool Blockchain::find_blockchain_supplement(const std::list<crypto::hash>& qbloc
 // 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)
+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);
@@ -1696,7 +1697,7 @@ bool Blockchain::add_block_as_invalid(const block_extended_info& bei, const cryp
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::have_block(const crypto::hash& id)
+bool Blockchain::have_block(const crypto::hash& id) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -1720,7 +1721,7 @@ bool Blockchain::handle_block_to_main_chain(const block& bl, block_verification_
   return handle_block_to_main_chain(bl, id, bvc);
 }
 //------------------------------------------------------------------
-size_t Blockchain::get_total_transactions()
+size_t Blockchain::get_total_transactions() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
@@ -1733,7 +1734,7 @@ size_t Blockchain::get_total_transactions()
 // 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)
+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);
@@ -1782,7 +1783,7 @@ bool Blockchain::check_for_double_spend(const transaction& tx, key_images_contai
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<uint64_t>& indexs)
+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);
@@ -1799,7 +1800,7 @@ bool Blockchain::get_tx_outputs_gindexs(const crypto::hash& tx_id, std::vector<u
 // 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)
+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);
@@ -1810,7 +1811,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t& max_used_block
   return true;
 }
 //------------------------------------------------------------------
-bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx)
+bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   BOOST_FOREACH(const txin_v& in, tx.vin)
@@ -1825,7 +1826,7 @@ bool Blockchain::have_tx_keyimges_as_spent(const transaction &tx)
 // 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)
+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;
@@ -1863,7 +1864,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_bloc
 //------------------------------------------------------------------
 // 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)
+bool Blockchain::is_tx_spendtime_unlocked(uint64_t unlock_time) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   if(unlock_time < CRYPTONOTE_MAX_BLOCK_NUMBER)
@@ -1888,7 +1889,7 @@ bool Blockchain::is_tx_spendtime_unlocked(uint64_t unlock_time)
 // 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)
+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);
@@ -1897,8 +1898,8 @@ bool Blockchain::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_
   {
     std::vector<const crypto::public_key *>& m_p_output_keys;
     std::vector<crypto::public_key >& m_output_keys;
-    Blockchain& m_bch;
-    outputs_visitor(std::vector<crypto::public_key >& output_keys, std::vector<const crypto::public_key *>& p_output_keys, Blockchain& bch) : m_output_keys(output_keys), m_p_output_keys(p_output_keys), m_bch(bch)
+    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)
     {
@@ -1947,7 +1948,7 @@ bool Blockchain::check_tx_input(const txin_to_key& txin, const crypto::hash& tx_
 }
 //------------------------------------------------------------------
 //TODO: Is this intended to do something else?  Need to look into the todo there.
-uint64_t Blockchain::get_adjusted_time()
+uint64_t Blockchain::get_adjusted_time() const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   //TODO: add collecting median time
@@ -1955,7 +1956,7 @@ uint64_t Blockchain::get_adjusted_time()
 }
 //------------------------------------------------------------------
 //TODO: revisit, has changed a bit on upstream
-bool Blockchain::check_block_timestamp(std::vector<uint64_t>& timestamps, const block& b)
+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);
@@ -1976,7 +1977,7 @@ bool Blockchain::check_block_timestamp(std::vector<uint64_t>& timestamps, const
 //   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)
+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)
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 75a729a09..6ab963ac7 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -87,54 +87,54 @@ 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);
+    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);
+    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_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_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_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_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, 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_cumulative_blocksize_limit();
-    bool is_storing_blockchain(){return m_is_blockchain_storing;}
-    uint64_t block_difficulty(uint64_t i);
+    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);
+    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);
+    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);
@@ -157,7 +157,7 @@ namespace cryptonote
     BlockchainDB* m_db;
 
     tx_memory_pool& m_tx_pool;
-    epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
+    mutable epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
 
     // main chain
     blocks_container m_blocks;               // height  -> block_extended_info
@@ -190,7 +190,7 @@ 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);
+    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);
@@ -198,18 +198,18 @@ namespace cryptonote
     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);
-    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);
-    bool is_tx_spendtime_unlocked(uint64_t unlock_time);
+    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);
-    bool check_block_timestamp(std::vector<uint64_t>& timestamps, const block& b);
-    uint64_t get_adjusted_time();
+    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);
+    bool check_for_double_spend(const transaction& tx, key_images_container& keys_this_block) const;
   };
 
 
diff --git a/src/cryptonote_core/blockchain_db.h b/src/cryptonote_core/blockchain_db.h
index 3418b946b..b9ea79f01 100644
--- a/src/cryptonote_core/blockchain_db.h
+++ b/src/cryptonote_core/blockchain_db.h
@@ -139,15 +139,16 @@ typedef std::pair<crypto::hash, uint64_t> tx_out_index;
 /***********************************
  * Exception Definitions
  ***********************************/
-class DB_ERROR : public std::exception
+class DB_EXCEPTION : public std::exception
 {
   private:
     std::string m;
-  public:
-    DB_ERROR() : m("Generic DB Error") { }
-    DB_ERROR(const char* s) : m(s) { }
 
-    virtual ~DB_ERROR() { }
+  protected:
+    DB_EXCEPTION(const char *s) : m(s) { }
+
+  public:
+    virtual ~DB_EXCEPTION() { }
 
     const char* what() const throw()
     {
@@ -155,196 +156,95 @@ class DB_ERROR : public std::exception
     }
 };
 
-class DB_OPEN_FAILURE : public std::exception
+class DB_ERROR : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    DB_OPEN_FAILURE() : m("Failed to open the db") { }
-    DB_OPEN_FAILURE(const char* s) : m(s) { }
-
-    virtual ~DB_OPEN_FAILURE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    DB_ERROR() : DB_EXCEPTION("Generic DB Error") { }
+    DB_ERROR(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class DB_CREATE_FAILURE : public std::exception
+class DB_OPEN_FAILURE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    DB_CREATE_FAILURE() : m("Failed to create the db") { }
-    DB_CREATE_FAILURE(const char* s) : m(s) { }
-
-    virtual ~DB_CREATE_FAILURE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    DB_OPEN_FAILURE() : DB_EXCEPTION("Failed to open the db") { }
+    DB_OPEN_FAILURE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class DB_SYNC_FAILURE : public std::exception
+class DB_CREATE_FAILURE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    DB_SYNC_FAILURE() : m("Failed to sync the db") { }
-    DB_SYNC_FAILURE(const char* s) : m(s) { }
-
-    virtual ~DB_SYNC_FAILURE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    DB_CREATE_FAILURE() : DB_EXCEPTION("Failed to create the db") { }
+    DB_CREATE_FAILURE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class BLOCK_DNE : public std::exception
+class DB_SYNC_FAILURE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    BLOCK_DNE() : m("The block requested does not exist") { }
-    BLOCK_DNE(const char* s) : m(s) { }
-
-    virtual ~BLOCK_DNE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    DB_SYNC_FAILURE() : DB_EXCEPTION("Failed to sync the db") { }
+    DB_SYNC_FAILURE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class BLOCK_PARENT_DNE : public std::exception
+class BLOCK_DNE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    BLOCK_PARENT_DNE() : m("The parent of the block does not exist") { }
-    BLOCK_PARENT_DNE(const char* s) : m(s) { }
-
-    virtual ~BLOCK_PARENT_DNE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    BLOCK_DNE() : DB_EXCEPTION("The block requested does not exist") { }
+    BLOCK_DNE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class BLOCK_EXISTS : public std::exception
+class BLOCK_PARENT_DNE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    BLOCK_EXISTS() : m("The block to be added already exists!") { }
-    BLOCK_EXISTS(const char* s) : m(s) { }
-
-    virtual ~BLOCK_EXISTS() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    BLOCK_PARENT_DNE() : DB_EXCEPTION("The parent of the block does not exist") { }
+    BLOCK_PARENT_DNE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class BLOCK_INVALID : public std::exception
+class BLOCK_EXISTS : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    BLOCK_INVALID() : m("The block to be added did not pass validation!") { }
-    BLOCK_INVALID(const char* s) : m(s) { }
-
-    virtual ~BLOCK_INVALID() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    BLOCK_EXISTS() : DB_EXCEPTION("The block to be added already exists!") { }
+    BLOCK_EXISTS(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class TX_DNE : public std::exception
+class BLOCK_INVALID : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    TX_DNE() : m("The transaction requested does not exist") { }
-    TX_DNE(const char* s) : m(s) { }
-
-    virtual ~TX_DNE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    BLOCK_INVALID() : DB_EXCEPTION("The block to be added did not pass validation!") { }
+    BLOCK_INVALID(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class TX_EXISTS : public std::exception
+class TX_DNE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    TX_EXISTS() : m("The transaction to be added already exists!") { }
-    TX_EXISTS(const char* s) : m(s) { }
-
-    virtual ~TX_EXISTS() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    TX_DNE() : DB_EXCEPTION("The transaction requested does not exist") { }
+    TX_DNE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class OUTPUT_DNE : public std::exception
+class TX_EXISTS : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    OUTPUT_DNE() : m("The output requested does not exist!") { }
-    OUTPUT_DNE(const char* s) : m(s) { }
-
-    virtual ~OUTPUT_DNE() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    TX_EXISTS() : DB_EXCEPTION("The transaction to be added already exists!") { }
+    TX_EXISTS(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class OUTPUT_EXISTS : public std::exception
+class OUTPUT_DNE : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    OUTPUT_EXISTS() : m("The output to be added already exists!") { }
-    OUTPUT_EXISTS(const char* s) : m(s) { }
-
-    virtual ~OUTPUT_EXISTS() { }
-
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+    OUTPUT_DNE() : DB_EXCEPTION("The output requested does not exist!") { }
+    OUTPUT_DNE(const char* s) : DB_EXCEPTION(s) { }
 };
 
-class KEY_IMAGE_EXISTS : public std::exception
+class OUTPUT_EXISTS : public DB_EXCEPTION
 {
-  private:
-    std::string m;
   public:
-    KEY_IMAGE_EXISTS() : m("The spent key image to be added already exists!") { }
-    KEY_IMAGE_EXISTS(const char* s) : m(s) { }
-
-    virtual ~KEY_IMAGE_EXISTS() { }
+    OUTPUT_EXISTS() : DB_EXCEPTION("The output to be added already exists!") { }
+    OUTPUT_EXISTS(const char* s) : DB_EXCEPTION(s) { }
+};
 
-    const char* what() const throw()
-    {
-      return m.c_str();
-    }
+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) { }
 };
 
 /***********************************
@@ -423,7 +323,7 @@ public:
   virtual void reset() = 0;
 
   // get all files used by this db (if any)
-  virtual std::vector<std::string> get_filenames() = 0;
+  virtual std::vector<std::string> get_filenames() const = 0;
 
 
   // FIXME: these are just for functionality mocking, need to implement
@@ -447,59 +347,59 @@ public:
                             );
 
   // return true if a block with hash <h> exists in the blockchain
-  virtual bool block_exists(const crypto::hash& h) = 0;
+  virtual bool block_exists(const crypto::hash& h) const = 0;
 
   // return block with hash <h>
-  virtual block get_block(const crypto::hash& h) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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)  = 0;
+  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() = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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() = 0;
+  virtual crypto::hash top_block_hash() const = 0;
 
   // return the block at the top of the blockchain
-  virtual block get_top_block() = 0;
+  virtual block get_top_block() const = 0;
 
   // return the index of the top block on the chain
   // NOTE: for convenience using heights as indices, this is not the total
   // size of the blockchain, but rather the index of the top block.  As the
   // chain is 0-indexed, the total size will be height() + 1.
-  virtual uint64_t height() = 0;
+  virtual uint64_t height() const = 0;
 
   // pops the top block off the blockchain.
   // Returns by reference the popped block and its associated transactions
@@ -512,48 +412,48 @@ public:
 
 
   // return true if a transaction with hash <h> exists
-  virtual bool tx_exists(const crypto::hash& h) = 0;
+  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) = 0;
+  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) = 0;
+  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() = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  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) = 0;
+  virtual tx_out get_output(const crypto::hash& h, 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) = 0;
+  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) = 0;
+  virtual std::vector<uint64_t> get_tx_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) = 0;
+  virtual bool has_key_image(const crypto::key_image& img) const = 0;
 
 };  // class BlockchainDB
 
diff --git a/src/cryptonote_core/blockchain_storage.cpp b/src/cryptonote_core/blockchain_storage.cpp
index e40eb6a0f..11bd1f2ac 100644
--- a/src/cryptonote_core/blockchain_storage.cpp
+++ b/src/cryptonote_core/blockchain_storage.cpp
@@ -55,19 +55,19 @@ 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);
@@ -77,7 +77,7 @@ 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();
@@ -113,24 +113,14 @@ 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 {
@@ -159,7 +149,7 @@ 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>();
 
@@ -173,7 +163,7 @@ 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;
 }
 //------------------------------------------------------------------
@@ -333,14 +323,14 @@ 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;
@@ -351,7 +341,7 @@ 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;
@@ -381,7 +371,7 @@ 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())
@@ -390,7 +380,7 @@ 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
@@ -410,20 +400,20 @@ 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;
@@ -535,7 +525,7 @@ 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;
@@ -580,7 +570,7 @@ 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");
@@ -603,7 +593,7 @@ 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;
@@ -630,7 +620,7 @@ 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());
@@ -642,7 +632,7 @@ 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())
@@ -650,12 +640,12 @@ 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_comulative_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;
@@ -774,7 +764,7 @@ 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)
@@ -939,7 +929,7 @@ 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())
@@ -955,7 +945,7 @@ 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())
@@ -999,7 +989,7 @@ 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);
 
@@ -1010,21 +1000,21 @@ 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
@@ -1037,7 +1027,7 @@ 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())
@@ -1046,7 +1036,7 @@ 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;
@@ -1054,7 +1044,7 @@ 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)
@@ -1067,7 +1057,7 @@ 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);
@@ -1096,7 +1086,7 @@ 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);
 
@@ -1143,7 +1133,7 @@ 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()");
@@ -1206,7 +1196,7 @@ 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))
@@ -1219,7 +1209,7 @@ 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) {
@@ -1258,7 +1248,7 @@ 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))
@@ -1296,13 +1286,13 @@ 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);
@@ -1392,7 +1382,7 @@ 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);
@@ -1407,7 +1397,7 @@ 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);
@@ -1417,7 +1407,7 @@ 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)
   {
@@ -1428,13 +1418,13 @@ 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)
@@ -1466,7 +1456,7 @@ 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)
   {
@@ -1487,15 +1477,15 @@ 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)
     {
@@ -1537,13 +1527,13 @@ 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)
   {
@@ -1559,7 +1549,7 @@ 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;
@@ -1782,7 +1772,7 @@ 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 671da40a8..e26d55b64 100644
--- a/src/cryptonote_core/blockchain_storage.h
+++ b/src/cryptonote_core/blockchain_storage.h
@@ -88,55 +88,55 @@ 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);
+    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_comulative_blocksize_limit() const;
+    bool is_storing_blockchain()const{return m_is_blockchain_storing;}
+    uint64_t block_difficulty(size_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)
+    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);
 
@@ -156,7 +156,7 @@ 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);
 
@@ -180,14 +180,14 @@ 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) { return m_blocks[height].bl; }
-    size_t get_block_size(uint64_t height) { return m_blocks[height].block_cumulative_size; }
-    difficulty_type get_block_cumulative_difficulty(uint64_t height) { return m_blocks[height].cumulative_difficulty; }
-    uint64_t get_block_coins_generated(uint64_t height) { return m_blocks[height].already_generated_coins; }
+    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;
@@ -199,7 +199,7 @@ namespace cryptonote
     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
+    mutable epee::critical_section m_blockchain_lock; // TODO: add here reader/writer lock
 
     // main chain
     blocks_container m_blocks;               // height  -> block_extended_info
@@ -233,26 +233,26 @@ 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);
     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);
   };
 
 
@@ -320,7 +320,7 @@ 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);
@@ -330,7 +330,7 @@ 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)
     {
@@ -339,7 +339,7 @@ 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..58edda7c9 100644
--- a/src/cryptonote_core/checkpoints.cpp
+++ b/src/cryptonote_core/checkpoints.cpp
@@ -99,7 +99,7 @@ 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 +108,18 @@ 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;
   };