ArticMine's new block weight algorithm

This curbs runaway growth while still allowing substantial
spikes in block weight

Original specification from ArticMine:

here is the scaling proposal
Define: LongTermBlockWeight
Before fork:
LongTermBlockWeight = BlockWeight
At or after fork:
LongTermBlockWeight = min(BlockWeight, 1.4*LongTermEffectiveMedianBlockWeight)
Note: To avoid possible consensus issues over rounding the LongTermBlockWeight for a given block should be calculated to the nearest byte, and stored as a integer in the block itself. The stored LongTermBlockWeight is then used for future calculations of the LongTermEffectiveMedianBlockWeight and not recalculated each time.
Define:   LongTermEffectiveMedianBlockWeight
LongTermEffectiveMedianBlockWeight = max(300000, MedianOverPrevious100000Blocks(LongTermBlockWeight))
Change Definition of EffectiveMedianBlockWeight
From (current definition)
EffectiveMedianBlockWeight  = max(300000, MedianOverPrevious100Blocks(BlockWeight))
To (proposed definition)
EffectiveMedianBlockWeight  = min(max(300000, MedianOverPrevious100Blocks(BlockWeight)), 50*LongTermEffectiveMedianBlockWeight)
Notes:
1) There are no other changes to the existing penalty formula, median calculation, fees etc.
2) There is the requirement to store the LongTermBlockWeight of a block unencrypted in the block itself. This  is to avoid possible consensus issues over rounding and also to prevent the calculations from becoming unwieldy as we move away from the fork.
3) When the  EffectiveMedianBlockWeight cap is reached it is still possible to mine blocks up to 2x the EffectiveMedianBlockWeight by paying the corresponding penalty.

Note: the long term block weight is stored in the database, but not in the actual block itself,
since it requires recalculating anyway for verification.

12 files changed, 732 insertions, 176 deletions

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 20afd4203..89d77cf32 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -85,6 +85,7 @@ add_subdirectory(performance_tests)
 add_subdirectory(core_proxy)
 add_subdirectory(unit_tests)
 add_subdirectory(difficulty)
+add_subdirectory(block_weight)
 add_subdirectory(hash)
 add_subdirectory(net_load_tests)
 if (BUILD_GUI_DEPS)
@@ -115,6 +116,7 @@ add_test(
 set(enabled_tests
     core_tests
     difficulty
+    block_weight
     hash
     performance_tests
     core_proxy
diff --git a/tests/block_weight/CMakeLists.txt b/tests/block_weight/CMakeLists.txt
new file mode 100644
index 000000000..b0d716ea0
--- /dev/null
+++ b/tests/block_weight/CMakeLists.txt
@@ -0,0 +1,45 @@
+# Copyright (c) 2014-2018, The Monero Project
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this list of
+#    conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list
+#    of conditions and the following disclaimer in the documentation and/or other
+#    materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors may be
+#    used to endorse or promote products derived from this software without specific
+#    prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set(block_weight_sources
+  block_weight.cpp)
+
+set(block_weight_headers)
+
+add_executable(block_weight
+  ${block_weight_sources}
+  ${block_weight_headers})
+target_link_libraries(block_weight
+  PRIVATE
+    cryptonote_core
+    blockchain_db
+    ${EXTRA_LIBRARIES})
+
+add_test(
+  NAME    block_weight
+  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/compare.py ${CMAKE_CURRENT_SOURCE_DIR}/block_weight.py ${CMAKE_CURRENT_BINARY_DIR}/block_weight)
diff --git a/tests/block_weight/block_weight.cpp b/tests/block_weight/block_weight.cpp
new file mode 100644
index 000000000..a67f40f0f
--- /dev/null
+++ b/tests/block_weight/block_weight.cpp
@@ -0,0 +1,183 @@
+// Copyright (c) 2019, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#define IN_UNIT_TESTS
+
+#include <stdio.h>
+#include <math.h>
+#include "cryptonote_core/blockchain.h"
+#include "cryptonote_core/tx_pool.h"
+#include "cryptonote_core/cryptonote_core.h"
+#include "blockchain_db/testdb.h"
+
+#define LONG_TERM_BLOCK_WEIGHT_WINDOW 5000
+
+enum test_t
+{
+  test_max = 0,
+  test_lcg = 1,
+  test_min = 2,
+};
+
+namespace
+{
+
+class TestDB: public cryptonote::BaseTestDB
+{
+private:
+  struct block_t
+  {
+    size_t weight;
+    uint64_t long_term_weight;
+  };
+
+public:
+  TestDB() { m_open = true; }
+
+  virtual void add_block( const cryptonote::block& blk
+                        , size_t block_weight
+                        , uint64_t long_term_block_weight
+                        , const cryptonote::difficulty_type& cumulative_difficulty
+                        , const uint64_t& coins_generated
+                        , uint64_t num_rct_outs
+                        , const crypto::hash& blk_hash
+                        ) override {
+    blocks.push_back({block_weight, long_term_block_weight});
+  }
+  virtual uint64_t height() const override { return blocks.size(); }
+  virtual size_t get_block_weight(const uint64_t &h) const override { return blocks[h].weight; }
+  virtual uint64_t get_block_long_term_weight(const uint64_t &h) const override { return blocks[h].long_term_weight; }
+  virtual crypto::hash top_block_hash() const override {
+    uint64_t h = height();
+    crypto::hash top = crypto::null_hash;
+    if (h)
+      *(uint64_t*)&top = h - 1;
+    return top;
+  }
+  virtual void pop_block(cryptonote::block &blk, std::vector<cryptonote::transaction> &txs) override { blocks.pop_back(); }
+  virtual void set_hard_fork_version(uint64_t height, uint8_t version) override { if (height >= hf.size()) hf.resize(height + 1); hf[height] = version; }
+  virtual uint8_t get_hard_fork_version(uint64_t height) const override { if (height >= hf.size()) return 255; return hf[height]; }
+
+private:
+  std::vector<block_t> blocks;
+  std::vector<uint8_t> hf;
+};
+
+}
+
+#define PREFIX_WINDOW(hf_version,window) \
+  std::unique_ptr<cryptonote::Blockchain> bc; \
+  cryptonote::tx_memory_pool txpool(*bc); \
+  bc.reset(new cryptonote::Blockchain(txpool)); \
+  struct get_test_options { \
+    const std::pair<uint8_t, uint64_t> hard_forks[3]; \
+    const cryptonote::test_options test_options = { \
+      hard_forks, \
+      window, \
+    }; \
+    get_test_options(): hard_forks{std::make_pair(1, (uint64_t)0), std::make_pair((uint8_t)hf_version, (uint64_t)LONG_TERM_BLOCK_WEIGHT_WINDOW), std::make_pair((uint8_t)0, (uint64_t)0)} {} \
+  } opts; \
+  cryptonote::Blockchain *blockchain = bc.get(); \
+  bool r = blockchain->init(new TestDB(), cryptonote::FAKECHAIN, true, &opts.test_options, 0, NULL); \
+  if (!r) \
+  { \
+    fprintf(stderr, "Failed to init blockchain\n"); \
+    exit(1); \
+  }
+
+#define PREFIX(hf_version) PREFIX_WINDOW(hf_version, LONG_TERM_BLOCK_WEIGHT_WINDOW)
+
+static uint32_t lcg_seed = 0;
+
+static uint32_t lcg()
+{
+  lcg_seed = (lcg_seed * 0x100000001b3 + 0xcbf29ce484222325) & 0xffffffff;
+  return lcg_seed;
+}
+
+static void test(test_t t, uint64_t blocks)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 0; h < LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    cryptonote::block b;
+    b.major_version = 1;
+    b.minor_version = 1;
+    bc->get_db().add_block(b, 300000, 300000, bc->get_db().height(), bc->get_db().height(), {});
+    if (!bc->update_next_cumulative_weight_limit())
+    {
+      fprintf(stderr, "Failed to update cumulative weight limit 1\n");
+      exit(1);
+    }
+  }
+
+  for (uint64_t h = 0; h < blocks; ++h)
+  {
+    uint64_t w;
+    uint64_t effective_block_weight_median = bc->get_current_cumulative_block_weight_median();
+    switch (t)
+    {
+      case test_lcg:
+      {
+        uint32_t r = lcg();
+        int64_t wi = 90 + r % 500000 + 250000 + sin(h / 200.) * 350000;
+        w = wi < 90 ? 90 : wi;
+        break;
+      }
+      case test_max:
+        w = bc->get_current_cumulative_block_weight_limit();
+        break;
+      case test_min:
+        w = 90;
+        break;
+      default:
+        exit(1);
+    }
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    cryptonote::block b;
+    b.major_version = 10;
+    b.minor_version = 10;
+    bc->get_db().add_block(std::move(b), w, ltw, bc->get_db().height(), bc->get_db().height(), {});
+
+    if (!bc->update_next_cumulative_weight_limit())
+    {
+      fprintf(stderr, "Failed to update cumulative weight limit\n");
+      exit(1);
+    }
+    std::cout << "H " << h << ", BW " << w << ", EMBW " << effective_block_weight_median << ", LTBW " << ltw << std::endl;
+  }
+}
+
+int main()
+{
+  test(test_max, 2 * LONG_TERM_BLOCK_WEIGHT_WINDOW);
+  test(test_lcg, 9 * LONG_TERM_BLOCK_WEIGHT_WINDOW);
+  test(test_min, 1 * LONG_TERM_BLOCK_WEIGHT_WINDOW);
+  return 0;
+}
diff --git a/tests/block_weight/block_weight.py b/tests/block_weight/block_weight.py
new file mode 100755
index 000000000..06aaabb02
--- /dev/null
+++ b/tests/block_weight/block_weight.py
@@ -0,0 +1,74 @@
+#!/usr/bin/python
+# Simulate a maximal block attack on the Monero network
+# This uses the scheme proposed by ArticMine
+# Written by Sarang Nother
+# Copyright (c) 2019 The Monero Project
+import sys
+import math
+
+MEDIAN_WINDOW_SMALL = 100 # number of recent blocks for median computation
+MEDIAN_WINDOW_BIG = 5000
+MULTIPLIER_SMALL = 1.4 # multipliers for determining weights
+MULTIPLIER_BIG = 50.0
+MEDIAN_THRESHOLD = 300*1000 # initial value for median (scaled kB -> B)
+lcg_seed = 0
+embw = MEDIAN_THRESHOLD
+ltembw = MEDIAN_THRESHOLD
+
+weights = [MEDIAN_THRESHOLD]*MEDIAN_WINDOW_SMALL # weights of recent blocks (B), with index -1 most recent
+lt_weights = [MEDIAN_THRESHOLD]*MEDIAN_WINDOW_BIG # long-term weights
+
+# Compute the median of a list
+def get_median(vec):
+    #temp = vec
+    temp = sorted(vec)
+    if len(temp) % 2 == 1:
+        return temp[len(temp)/2]
+    else:
+        return int((temp[len(temp)/2]+temp[len(temp)/2-1])/2)
+
+def LCG():
+  global lcg_seed
+  lcg_seed = (lcg_seed * 0x100000001b3 + 0xcbf29ce484222325) & 0xffffffff
+  return lcg_seed
+
+def run(t, blocks):
+  global embw
+  global ltembw
+
+  weights = [MEDIAN_THRESHOLD]*MEDIAN_WINDOW_SMALL # weights of recent blocks (B), with index -1 most recent
+  lt_weights = [MEDIAN_THRESHOLD]*MEDIAN_WINDOW_BIG # long-term weights
+
+  for block in range(blocks):
+      # determine the long-term effective weight
+      ltmedian = get_median(lt_weights[-MEDIAN_WINDOW_BIG:])
+      ltembw = max(MEDIAN_THRESHOLD,ltmedian)
+
+      # determine the effective weight
+      stmedian = get_median(weights[-MEDIAN_WINDOW_SMALL:])
+      embw = min(max(MEDIAN_THRESHOLD,stmedian),int(MULTIPLIER_BIG*ltembw))
+
+      # drop the lowest values
+      weights = weights[1:]
+      lt_weights = lt_weights[1:]
+
+      # add a block of max weight
+      if t == 0:
+        max_weight = 2 * embw
+      elif t == 1:
+        r = LCG()
+        max_weight = int(90 + r % 500000 + 250000 + math.sin(block / 200.) * 350000)
+        if max_weight < 90: max_weight = 90
+      elif t == 2:
+        max_weight = 90
+      else:
+        sys.exit(1)
+      weights.append(max_weight)
+      lt_weights.append(min(max_weight,int(ltembw + int(ltembw * 2 / 5))))
+
+      #print "H %u, r %u, BW %u, EMBW %u, LTBW %u, LTEMBW %u, ltmedian %u" % (block, r, max_weight, embw, lt_weights[-1], ltembw, ltmedian)
+      print "H %u, BW %u, EMBW %u, LTBW %u" % (block, max_weight, embw, lt_weights[-1])
+
+run(0, 2 * MEDIAN_WINDOW_BIG)
+run(1, 9 * MEDIAN_WINDOW_BIG)
+run(2, 1 * MEDIAN_WINDOW_BIG)
diff --git a/tests/block_weight/compare.py b/tests/block_weight/compare.py
new file mode 100755
index 000000000..c6be05206
--- /dev/null
+++ b/tests/block_weight/compare.py
@@ -0,0 +1,13 @@
+#!/usr/bin/python
+
+import sys
+import subprocess
+
+print 'running: ', sys.argv[1]
+S0 = subprocess.check_output(sys.argv[1], stderr=subprocess.STDOUT)
+print 'running: ', sys.argv[2]
+S1 = subprocess.check_output(sys.argv[2], stderr=subprocess.STDOUT)
+print 'comparing'
+if S0 != S1:
+  sys.exit(1)
+sys.exit(0)
diff --git a/tests/core_tests/v2_tests.h b/tests/core_tests/v2_tests.h
index ecb23818c..cd2bcb839 100644
--- a/tests/core_tests/v2_tests.h
+++ b/tests/core_tests/v2_tests.h
@@ -81,7 +81,7 @@ template<>
 struct get_test_options<gen_v2_tx_validation_base> {
   const std::pair<uint8_t, uint64_t> hard_forks[3] = {std::make_pair(1, 0), std::make_pair(2, 1), std::make_pair(0, 0)};
   const cryptonote::test_options test_options = {
-    hard_forks
+    hard_forks, 0
   };
 };
 
diff --git a/tests/unit_tests/CMakeLists.txt b/tests/unit_tests/CMakeLists.txt
index cb421c847..aea82ede2 100644
--- a/tests/unit_tests/CMakeLists.txt
+++ b/tests/unit_tests/CMakeLists.txt
@@ -55,6 +55,7 @@ set(unit_tests_sources
   http.cpp
   keccak.cpp
   logging.cpp
+  long_term_block_weight.cpp
   main.cpp
   memwipe.cpp
   mlocker.cpp
diff --git a/tests/unit_tests/blockchain_db.cpp b/tests/unit_tests/blockchain_db.cpp
index 7e7ce9bf7..9cf8c5fbe 100644
--- a/tests/unit_tests/blockchain_db.cpp
+++ b/tests/unit_tests/blockchain_db.cpp
@@ -277,10 +277,10 @@ TYPED_TEST(BlockchainDBTest, AddBlock)
   // TODO: need at least one more block to make this reasonable, as the
   // BlockchainDB implementation should not check for parent if
   // no blocks have been added yet (because genesis has no parent).
-  //ASSERT_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]), BLOCK_PARENT_DNE);
+  //ASSERT_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]), BLOCK_PARENT_DNE);
 
-  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_diffs[0], t_coins[0], this->m_txs[0]));
-  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]));
+  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_sizes[0], t_diffs[0], t_coins[0], this->m_txs[0]));
+  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]));
 
   block b;
   ASSERT_TRUE(this->m_db->block_exists(get_block_hash(this->m_blocks[0])));
@@ -293,7 +293,7 @@ TYPED_TEST(BlockchainDBTest, AddBlock)
   ASSERT_TRUE(compare_blocks(this->m_blocks[0], b));
 
   // assert that we can't add the same block twice
-  ASSERT_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_diffs[0], t_coins[0], this->m_txs[0]), TX_EXISTS);
+  ASSERT_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_sizes[0], t_diffs[0], t_coins[0], this->m_txs[0]), TX_EXISTS);
 
   for (auto& h : this->m_blocks[0].tx_hashes)
   {
@@ -317,14 +317,14 @@ TYPED_TEST(BlockchainDBTest, RetrieveBlockData)
   this->get_filenames();
   this->init_hard_fork();
 
-  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_diffs[0], t_coins[0], this->m_txs[0]));
+  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[0], t_sizes[0], t_sizes[0],  t_diffs[0], t_coins[0], this->m_txs[0]));
 
   ASSERT_EQ(t_sizes[0], this->m_db->get_block_weight(0));
   ASSERT_EQ(t_diffs[0], this->m_db->get_block_cumulative_difficulty(0));
   ASSERT_EQ(t_diffs[0], this->m_db->get_block_difficulty(0));
   ASSERT_EQ(t_coins[0], this->m_db->get_block_already_generated_coins(0));
 
-  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]));
+  ASSERT_NO_THROW(this->m_db->add_block(this->m_blocks[1], t_sizes[1], t_sizes[1], t_diffs[1], t_coins[1], this->m_txs[1]));
   ASSERT_EQ(t_diffs[1] - t_diffs[0], this->m_db->get_block_difficulty(1));
 
   ASSERT_HASH_EQ(get_block_hash(this->m_blocks[0]), this->m_db->get_block_hash_from_height(0));
diff --git a/tests/unit_tests/hardfork.cpp b/tests/unit_tests/hardfork.cpp
index ec8d1d202..12dfde1bc 100644
--- a/tests/unit_tests/hardfork.cpp
+++ b/tests/unit_tests/hardfork.cpp
@@ -34,7 +34,7 @@
 #include "blockchain_db/blockchain_db.h"
 #include "cryptonote_basic/cryptonote_format_utils.h"
 #include "cryptonote_basic/hardfork.h"
-#include "testdb.h"
+#include "blockchain_db/testdb.h"
 
 using namespace cryptonote;
 
@@ -44,11 +44,12 @@ using namespace cryptonote;
 namespace
 {
 
-class TestDB: public BaseTestDB {
+class TestDB: public cryptonote::BaseTestDB {
 public:
   virtual uint64_t height() const { return blocks.size(); }
   virtual void add_block( const block& blk
                         , size_t block_weight
+                        , uint64_t long_term_block_weight
                         , const difficulty_type& cumulative_difficulty
                         , const uint64_t& coins_generated
                         , uint64_t num_rct_outs
@@ -106,20 +107,20 @@ TEST(major, Only)
   ASSERT_FALSE(hf.add(mkblock(0, 2), 0));
   ASSERT_FALSE(hf.add(mkblock(2, 2), 0));
   ASSERT_TRUE(hf.add(mkblock(1, 2), 0));
-  db.add_block(mkblock(1, 1), 0, 0, 0, 0, crypto::hash());
+  db.add_block(mkblock(1, 1), 0, 0, 0, 0, 0, crypto::hash());
 
   // block height 1, only version 1 is accepted
   ASSERT_FALSE(hf.add(mkblock(0, 2), 1));
   ASSERT_FALSE(hf.add(mkblock(2, 2), 1));
   ASSERT_TRUE(hf.add(mkblock(1, 2), 1));
-  db.add_block(mkblock(1, 1), 0, 0, 0, 0, crypto::hash());
+  db.add_block(mkblock(1, 1), 0, 0, 0, 0, 0, crypto::hash());
 
   // block height 2, only version 2 is accepted
   ASSERT_FALSE(hf.add(mkblock(0, 2), 2));
   ASSERT_FALSE(hf.add(mkblock(1, 2), 2));
   ASSERT_FALSE(hf.add(mkblock(3, 2), 2));
   ASSERT_TRUE(hf.add(mkblock(2, 2), 2));
-  db.add_block(mkblock(2, 1), 0, 0, 0, 0, crypto::hash());
+  db.add_block(mkblock(2, 1), 0, 0, 0, 0, 0, crypto::hash());
 }
 
 TEST(empty_hardforks, Success)
@@ -133,7 +134,7 @@ TEST(empty_hardforks, Success)
   ASSERT_TRUE(hf.get_state(time(NULL) + 3600*24*400) == HardFork::Ready);
 
   for (uint64_t h = 0; h <= 10; ++h) {
-    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
   ASSERT_EQ(hf.get(0), 1);
@@ -167,14 +168,14 @@ TEST(check_for_height, Success)
   for (uint64_t h = 0; h <= 4; ++h) {
     ASSERT_TRUE(hf.check_for_height(mkblock(1, 1), h));
     ASSERT_FALSE(hf.check_for_height(mkblock(2, 2), h));  // block version is too high
-    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 
   for (uint64_t h = 5; h <= 10; ++h) {
     ASSERT_FALSE(hf.check_for_height(mkblock(1, 1), h));  // block version is too low
     ASSERT_TRUE(hf.check_for_height(mkblock(2, 2), h));
-    db.add_block(mkblock(hf, h, 2), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 2), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 }
@@ -191,19 +192,19 @@ TEST(get, next_version)
 
   for (uint64_t h = 0; h <= 4; ++h) {
     ASSERT_EQ(2, hf.get_next_version());
-    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 1), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 
   for (uint64_t h = 5; h <= 9; ++h) {
     ASSERT_EQ(4, hf.get_next_version());
-    db.add_block(mkblock(hf, h, 2), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 2), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 
   for (uint64_t h = 10; h <= 15; ++h) {
     ASSERT_EQ(4, hf.get_next_version());
-    db.add_block(mkblock(hf, h, 4), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 4), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 }
@@ -244,7 +245,7 @@ TEST(steps_asap, Success)
   hf.init();
 
   for (uint64_t h = 0; h < 10; ++h) {
-    db.add_block(mkblock(hf, h, 9), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, 9), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 
@@ -271,7 +272,7 @@ TEST(steps_1, Success)
   hf.init();
 
   for (uint64_t h = 0 ; h < 10; ++h) {
-    db.add_block(mkblock(hf, h, h+1), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, h+1), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 
@@ -296,7 +297,7 @@ TEST(reorganize, Same)
     //                                 index  0  1  2  3  4  5  6  7  8  9
     static const uint8_t block_versions[] = { 1, 1, 4, 4, 7, 7, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 };
     for (uint64_t h = 0; h < 20; ++h) {
-      db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, crypto::hash());
+      db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, 0, crypto::hash());
       ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
     }
 
@@ -327,7 +328,7 @@ TEST(reorganize, Changed)
   static const uint8_t block_versions[] =    { 1, 1, 4, 4, 7, 7, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9 };
   static const uint8_t expected_versions[] = { 1, 1, 1, 1, 1, 1, 4, 4, 7, 7, 9, 9, 9, 9, 9, 9 };
   for (uint64_t h = 0; h < 16; ++h) {
-    db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE (hf.add(db.get_block_from_height(h), h));
   }
 
@@ -347,7 +348,7 @@ TEST(reorganize, Changed)
   ASSERT_EQ(db.height(), 3);
   hf.reorganize_from_block_height(2);
   for (uint64_t h = 3; h < 16; ++h) {
-    db.add_block(mkblock(hf, h, block_versions_new[h]), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, block_versions_new[h]), 0, 0, 0, 0, 0, crypto::hash());
     bool ret = hf.add(db.get_block_from_height(h), h);
     ASSERT_EQ (ret, h < 15);
   }
@@ -371,7 +372,7 @@ TEST(voting, threshold)
 
     for (uint64_t h = 0; h <= 8; ++h) {
       uint8_t v = 1 + !!(h % 8);
-      db.add_block(mkblock(hf, h, v), 0, 0, 0, 0, crypto::hash());
+      db.add_block(mkblock(hf, h, v), 0, 0, 0, 0, 0, crypto::hash());
       bool ret = hf.add(db.get_block_from_height(h), h);
       if (h >= 8 && threshold == 87) {
         // for threshold 87, we reach the treshold at height 7, so from height 8, hard fork to version 2, but 8 tries to add 1
@@ -405,7 +406,7 @@ TEST(voting, different_thresholds)
     static const uint8_t expected_versions[] = { 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4 };
 
     for (uint64_t h = 0; h < sizeof(block_versions) / sizeof(block_versions[0]); ++h) {
-      db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, crypto::hash());
+      db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, 0, crypto::hash());
       bool ret = hf.add(db.get_block_from_height(h), h);
       ASSERT_EQ(ret, true);
     }
@@ -459,7 +460,7 @@ TEST(voting, info)
     ASSERT_EQ(expected_thresholds[h], threshold);
     ASSERT_EQ(4, voting);
 
-    db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, crypto::hash());
+    db.add_block(mkblock(hf, h, block_versions[h]), 0, 0, 0, 0, 0, crypto::hash());
     ASSERT_TRUE(hf.add(db.get_block_from_height(h), h));
   }
 }
@@ -522,7 +523,7 @@ TEST(reorganize, changed)
 #define ADD(v, h, a) \
   do { \
     cryptonote::block b = mkblock(hf, h, v); \
-    db.add_block(b, 0, 0, 0, 0, crypto::hash()); \
+    db.add_block(b, 0, 0, 0, 0, 0, crypto::hash()); \
     ASSERT_##a(hf.add(b, h)); \
   } while(0)
 #define ADD_TRUE(v, h) ADD(v, h, TRUE)
diff --git a/tests/unit_tests/long_term_block_weight.cpp b/tests/unit_tests/long_term_block_weight.cpp
new file mode 100644
index 000000000..0ee6c5c2b
--- /dev/null
+++ b/tests/unit_tests/long_term_block_weight.cpp
@@ -0,0 +1,384 @@
+// Copyright (c) 2019, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#define IN_UNIT_TESTS
+
+#include "gtest/gtest.h"
+#include "cryptonote_core/blockchain.h"
+#include "cryptonote_core/tx_pool.h"
+#include "cryptonote_core/cryptonote_core.h"
+#include "blockchain_db/testdb.h"
+
+#define TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW 5000
+
+namespace
+{
+
+class TestDB: public cryptonote::BaseTestDB
+{
+private:
+  struct block_t
+  {
+    size_t weight;
+    uint64_t long_term_weight;
+  };
+
+public:
+  TestDB() { m_open = true; }
+
+  virtual void add_block( const cryptonote::block& blk
+                        , size_t block_weight
+                        , uint64_t long_term_block_weight
+                        , const cryptonote::difficulty_type& cumulative_difficulty
+                        , const uint64_t& coins_generated
+                        , uint64_t num_rct_outs
+                        , const crypto::hash& blk_hash
+                        ) override {
+    blocks.push_back({block_weight, long_term_block_weight});
+  }
+  virtual uint64_t height() const override { return blocks.size(); }
+  virtual size_t get_block_weight(const uint64_t &h) const override { return blocks[h].weight; }
+  virtual uint64_t get_block_long_term_weight(const uint64_t &h) const override { return blocks[h].long_term_weight; }
+  virtual crypto::hash top_block_hash() const override {
+    uint64_t h = height();
+    crypto::hash top = crypto::null_hash;
+    if (h)
+      *(uint64_t*)&top = h - 1;
+    return top;
+  }
+  virtual void pop_block(cryptonote::block &blk, std::vector<cryptonote::transaction> &txs) override { blocks.pop_back(); }
+
+private:
+  std::vector<block_t> blocks;
+};
+
+static uint32_t lcg_seed = 0;
+
+static uint32_t lcg()
+{
+  lcg_seed = (lcg_seed * 0x100000001b3 + 0xcbf29ce484222325) & 0xffffffff;
+  return lcg_seed;
+}
+
+}
+
+#define PREFIX_WINDOW(hf_version,window) \
+  std::unique_ptr<cryptonote::Blockchain> bc; \
+  cryptonote::tx_memory_pool txpool(*bc); \
+  bc.reset(new cryptonote::Blockchain(txpool)); \
+  struct get_test_options { \
+    const std::pair<uint8_t, uint64_t> hard_forks[3]; \
+    const cryptonote::test_options test_options = { \
+      hard_forks, \
+      window, \
+    }; \
+    get_test_options(): hard_forks{std::make_pair(1, (uint64_t)0), std::make_pair((uint8_t)hf_version, (uint64_t)1), std::make_pair((uint8_t)0, (uint64_t)0)} {} \
+  } opts; \
+  cryptonote::Blockchain *blockchain = bc.get(); \
+  bool r = blockchain->init(new TestDB(), cryptonote::FAKECHAIN, true, &opts.test_options, 0, NULL); \
+  ASSERT_TRUE(r)
+
+#define PREFIX(hf_version) PREFIX_WINDOW(hf_version, TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW)
+
+TEST(long_term_block_weight, empty_short)
+{
+  PREFIX(9);
+
+  ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+
+  ASSERT_EQ(bc->get_current_cumulative_block_weight_median(), CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5);
+  ASSERT_EQ(bc->get_current_cumulative_block_weight_limit(), CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 * 2);
+}
+
+TEST(long_term_block_weight, identical_before_fork)
+{
+  PREFIX(9);
+
+  for (uint64_t h = 1; h < 10 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    size_t w = h < CRYPTONOTE_REWARD_BLOCKS_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+  for (uint64_t h = 0; h < 10 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    ASSERT_EQ(bc->get_db().get_block_long_term_weight(h), bc->get_db().get_block_weight(h));
+  }
+}
+
+TEST(long_term_block_weight, identical_after_fork_before_long_term_window)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 1; h <= TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    size_t w = h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+  for (uint64_t h = 0; h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    ASSERT_EQ(bc->get_db().get_block_long_term_weight(h), bc->get_db().get_block_weight(h));
+  }
+}
+
+TEST(long_term_block_weight, ceiling_at_30000000)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 0; h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW + TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW / 2 - 1; ++h)
+  {
+    size_t w = h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+  ASSERT_EQ(bc->get_current_cumulative_block_weight_median(), 15000000);
+  ASSERT_EQ(bc->get_current_cumulative_block_weight_limit(), 30000000);
+}
+
+TEST(long_term_block_weight, multi_pop)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 1; h <= TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW + 20; ++h)
+  {
+    size_t w = h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+
+  const uint64_t effective_median = bc->get_current_cumulative_block_weight_median();
+  const uint64_t effective_limit = bc->get_current_cumulative_block_weight_limit();
+
+  for (uint64_t h = 0; h < 4; ++h)
+  {
+    size_t w = h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+
+  cryptonote::block b;
+  std::vector<cryptonote::transaction> txs;
+  bc->get_db().pop_block(b, txs);
+  bc->get_db().pop_block(b, txs);
+  bc->get_db().pop_block(b, txs);
+  bc->get_db().pop_block(b, txs);
+  ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+
+  ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+  ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+}
+
+TEST(long_term_block_weight, multiple_updates)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 1; h <= 3 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    size_t w = h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    const uint64_t effective_median = bc->get_current_cumulative_block_weight_median();
+    const uint64_t effective_limit = bc->get_current_cumulative_block_weight_limit();
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+    ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+    ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+    ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+  }
+}
+
+TEST(long_term_block_weight, pop_invariant_max)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 1; h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW - 10; ++h)
+  {
+    size_t w = bc->get_db().height() < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+
+  for (int n = 0; n < 1000; ++n)
+  {
+    // pop some blocks, then add some more
+    int remove = 1 + (n * 17) % 8;
+    int add = (n * 23) % 12;
+
+    // save long term block weights we're about to remove
+    uint64_t old_ltbw[16], h0 = bc->get_db().height() - remove - 1;
+    for (int i = -2; i < remove; ++i)
+    {
+      old_ltbw[i + 2] = bc->get_db().get_block_long_term_weight(h0 + i);
+    }
+
+    for (int i = 0; i < remove; ++i)
+    {
+      cryptonote::block b;
+      std::vector<cryptonote::transaction> txs;
+      bc->get_db().pop_block(b, txs);
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    }
+    for (int i = 0; i < add; ++i)
+    {
+      size_t w = bc->get_db().height() < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+      uint64_t ltw = bc->get_next_long_term_block_weight(w);
+      bc->get_db().add_block(cryptonote::block(), w, ltw, bc->get_db().height(), bc->get_db().height(), {});
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+    }
+
+    // check the new values are the same as the old ones
+    for (int i = -2; i < std::min(add, remove); ++i)
+    {
+      ASSERT_EQ(bc->get_db().get_block_long_term_weight(h0 + i), old_ltbw[i + 2]);
+    }
+  }
+}
+
+TEST(long_term_block_weight, pop_invariant_random)
+{
+  PREFIX(10);
+
+  for (uint64_t h = 1; h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW - 10; ++h)
+  {
+    size_t w = bc->get_db().height() < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+  }
+
+  for (int n = 0; n < 1000; ++n)
+  {
+    // pop some blocks, then add some more
+    int remove = 1 + (n * 17) % 8;
+    int add = (n * 23) % 123;
+
+    // save long term block weights we're about to remove
+    uint64_t old_ltbw[16], h0 = bc->get_db().height() - remove - 1;
+    for (int i = -2; i < remove; ++i)
+    {
+      old_ltbw[i + 2] = bc->get_db().get_block_long_term_weight(h0 + i);
+    }
+
+    for (int i = 0; i < remove; ++i)
+    {
+      cryptonote::block b;
+      std::vector<cryptonote::transaction> txs;
+      bc->get_db().pop_block(b, txs);
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+      const uint64_t effective_median = bc->get_current_cumulative_block_weight_median();
+      const uint64_t effective_limit = bc->get_current_cumulative_block_weight_limit();
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+      ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+      ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+    }
+    for (int i = 0; i < add; ++i)
+    {
+      lcg_seed = bc->get_db().height();
+      uint32_t r = lcg();
+      size_t w = bc->get_db().height() < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW ? CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5 : (r % bc->get_current_cumulative_block_weight_limit());
+      uint64_t ltw = bc->get_next_long_term_block_weight(w);
+      bc->get_db().add_block(cryptonote::block(), w, ltw, bc->get_db().height(), bc->get_db().height(), {});
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+      const uint64_t effective_median = bc->get_current_cumulative_block_weight_median();
+      const uint64_t effective_limit = bc->get_current_cumulative_block_weight_limit();
+      ASSERT_TRUE(bc->update_next_cumulative_weight_limit());
+      ASSERT_EQ(effective_median, bc->get_current_cumulative_block_weight_median());
+      ASSERT_EQ(effective_limit, bc->get_current_cumulative_block_weight_limit());
+    }
+
+    // check the new values are the same as the old ones
+    for (int i = -2; i < std::min(add, remove); ++i)
+    {
+      ASSERT_EQ(bc->get_db().get_block_long_term_weight(h0 + i), old_ltbw[i + 2]);
+    }
+  }
+}
+
+TEST(long_term_block_weight, long_growth_spike_and_drop)
+{
+  PREFIX(10);
+
+  uint64_t long_term_effective_median_block_weight;
+
+  // constant init
+  for (uint64_t h = 0; h < TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW; ++h)
+  {
+    size_t w = CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5;
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit(&long_term_effective_median_block_weight));
+  }
+  ASSERT_EQ(long_term_effective_median_block_weight, 300000);
+
+  // slow 10% yearly for a year (scaled down by 100000 / TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW) -> 8% change
+  for (uint64_t h = 0; h < 365 * 720 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW / 100000; ++h)
+  {
+    //size_t w = bc->get_current_cumulative_block_weight_median() * rate;
+    float t = h / float(365 * 720 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW / 100000);
+    size_t w = 300000 + t * 30000;
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit(&long_term_effective_median_block_weight));
+  }
+  ASSERT_GT(long_term_effective_median_block_weight, 300000 * 1.07);
+  ASSERT_LT(long_term_effective_median_block_weight, 300000 * 1.09);
+
+  // spike over three weeks - does not move much
+  for (uint64_t h = 0; h < 21 * 720 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW / 100000; ++h)
+  {
+    size_t w = bc->get_current_cumulative_block_weight_limit();
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit(&long_term_effective_median_block_weight));
+  }
+  ASSERT_GT(long_term_effective_median_block_weight, 300000 * 1.07);
+  ASSERT_LT(long_term_effective_median_block_weight, 300000 * 1.09);
+
+  // drop - does not move much
+  for (uint64_t h = 0; h < 21 * 720 * TEST_LONG_TERM_BLOCK_WEIGHT_WINDOW / 100000; ++h)
+  {
+    size_t w = bc->get_current_cumulative_block_weight_median() * .25;
+    uint64_t ltw = bc->get_next_long_term_block_weight(w);
+    bc->get_db().add_block(cryptonote::block(), w, ltw, h, h, {});
+    ASSERT_TRUE(bc->update_next_cumulative_weight_limit(&long_term_effective_median_block_weight));
+  }
+  ASSERT_GT(long_term_effective_median_block_weight, 300000 * 1.07);
+  ASSERT_LT(long_term_effective_median_block_weight, 300000 * 1.09);
+}
diff --git a/tests/unit_tests/output_distribution.cpp b/tests/unit_tests/output_distribution.cpp
index 649752ac7..45f2c135b 100644
--- a/tests/unit_tests/output_distribution.cpp
+++ b/tests/unit_tests/output_distribution.cpp
@@ -33,7 +33,7 @@
 #include "cryptonote_core/cryptonote_core.h"
 #include "cryptonote_core/tx_pool.h"
 #include "cryptonote_core/blockchain.h"
-#include "testdb.h"
+#include "blockchain_db/testdb.h"
 
 static const uint64_t test_distribution[32] = {
   0, 0, 0, 0, 0, 1, 5, 1, 4, 0, 0, 1, 0, 1, 2, 3, 1, 0, 2, 0, 1, 3, 8, 1, 3, 5, 7, 1, 5, 0, 2, 3
@@ -43,7 +43,7 @@ static const size_t test_distribution_size = sizeof(test_distribution) / sizeof(
 namespace
 {
 
-class TestDB: public BaseTestDB
+class TestDB: public cryptonote::BaseTestDB
 {
 public:
   TestDB(size_t bc_height = test_distribution_size): blockchain_height(bc_height) { m_open = true; }
diff --git a/tests/unit_tests/testdb.h b/tests/unit_tests/testdb.h
deleted file mode 100644
index 8f5cf70e8..000000000
--- a/tests/unit_tests/testdb.h
+++ /dev/null
@@ -1,147 +0,0 @@
-// Copyright (c) 2014-2018, The Monero Project
-// 
-// All rights reserved.
-// 
-// Redistribution and use in source and binary forms, with or without modification, are
-// permitted provided that the following conditions are met:
-// 
-// 1. Redistributions of source code must retain the above copyright notice, this list of
-//    conditions and the following disclaimer.
-// 
-// 2. Redistributions in binary form must reproduce the above copyright notice, this list
-//    of conditions and the following disclaimer in the documentation and/or other
-//    materials provided with the distribution.
-// 
-// 3. Neither the name of the copyright holder nor the names of its contributors may be
-//    used to endorse or promote products derived from this software without specific
-//    prior written permission.
-// 
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
-// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
-// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
-// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
-// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
-// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-// 
-// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
-
-#pragma once
-
-#include <string>
-#include <vector>
-#include <map>
-#include "gtest/gtest.h"
-
-#include "blockchain_db/blockchain_db.h"
-
-class BaseTestDB: public cryptonote::BlockchainDB {
-public:
-  BaseTestDB() {}
-  virtual void open(const std::string& filename, const int db_flags = 0) { }
-  virtual void close() {}
-  virtual void sync() {}
-  virtual void safesyncmode(const bool onoff) {}
-  virtual void reset() {}
-  virtual std::vector<std::string> get_filenames() const { return std::vector<std::string>(); }
-  virtual bool remove_data_file(const std::string& folder) const { return true; }
-  virtual std::string get_db_name() const { return std::string(); }
-  virtual bool lock() { return true; }
-  virtual void unlock() { }
-  virtual bool batch_start(uint64_t batch_num_blocks=0, uint64_t batch_bytes=0) { return true; }
-  virtual void batch_stop() {}
-  virtual void set_batch_transactions(bool) {}
-  virtual void block_txn_start(bool readonly=false) {}
-  virtual void block_txn_stop() {}
-  virtual void block_txn_abort() {}
-  virtual void drop_hard_fork_info() {}
-  virtual bool block_exists(const crypto::hash& h, uint64_t *height) const { return false; }
-  virtual cryptonote::blobdata get_block_blob_from_height(const uint64_t& height) const { return cryptonote::t_serializable_object_to_blob(get_block_from_height(height)); }
-  virtual cryptonote::blobdata get_block_blob(const crypto::hash& h) const { return cryptonote::blobdata(); }
-  virtual bool get_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const { return false; }
-  virtual bool get_pruned_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const { return false; }
-  virtual bool get_prunable_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const { return false; }
-  virtual bool get_prunable_tx_hash(const crypto::hash& tx_hash, crypto::hash &prunable_hash) const { return false; }
-  virtual uint64_t get_block_height(const crypto::hash& h) const { return 0; }
-  virtual cryptonote::block_header get_block_header(const crypto::hash& h) const { return cryptonote::block_header(); }
-  virtual uint64_t get_block_timestamp(const uint64_t& height) const { return 0; }
-  virtual std::vector<uint64_t> get_block_cumulative_rct_outputs(const std::vector<uint64_t> &heights) const { return {}; }
-  virtual uint64_t get_top_block_timestamp() const { return 0; }
-  virtual size_t get_block_weight(const uint64_t& height) const { return 128; }
-  virtual cryptonote::difficulty_type get_block_cumulative_difficulty(const uint64_t& height) const { return 10; }
-  virtual cryptonote::difficulty_type get_block_difficulty(const uint64_t& height) const { return 0; }
-  virtual uint64_t get_block_already_generated_coins(const uint64_t& height) const { return 10000000000; }
-  virtual crypto::hash get_block_hash_from_height(const uint64_t& height) const { return crypto::hash(); }
-  virtual std::vector<cryptonote::block> get_blocks_range(const uint64_t& h1, const uint64_t& h2) const { return std::vector<cryptonote::block>(); }
-  virtual std::vector<crypto::hash> get_hashes_range(const uint64_t& h1, const uint64_t& h2) const { return std::vector<crypto::hash>(); }
-  virtual crypto::hash top_block_hash() const { return crypto::hash(); }
-  virtual cryptonote::block get_top_block() const { return cryptonote::block(); }
-  virtual uint64_t height() const { return 1; }
-  virtual bool tx_exists(const crypto::hash& h) const { return false; }
-  virtual bool tx_exists(const crypto::hash& h, uint64_t& tx_index) const { return false; }
-  virtual uint64_t get_tx_unlock_time(const crypto::hash& h) const { return 0; }
-  virtual cryptonote::transaction get_tx(const crypto::hash& h) const { return cryptonote::transaction(); }
-  virtual bool get_tx(const crypto::hash& h, cryptonote::transaction &tx) const { return false; }
-  virtual uint64_t get_tx_count() const { return 0; }
-  virtual std::vector<cryptonote::transaction> get_tx_list(const std::vector<crypto::hash>& hlist) const { return std::vector<cryptonote::transaction>(); }
-  virtual uint64_t get_tx_block_height(const crypto::hash& h) const { return 0; }
-  virtual uint64_t get_num_outputs(const uint64_t& amount) const { return 1; }
-  virtual uint64_t get_indexing_base() const { return 0; }
-  virtual cryptonote::output_data_t get_output_key(const uint64_t& amount, const uint64_t& index, bool include_commitmemt) const { return cryptonote::output_data_t(); }
-  virtual cryptonote::tx_out_index get_output_tx_and_index_from_global(const uint64_t& index) const { return cryptonote::tx_out_index(); }
-  virtual cryptonote::tx_out_index get_output_tx_and_index(const uint64_t& amount, const uint64_t& index) const { return cryptonote::tx_out_index(); }
-  virtual void get_output_tx_and_index(const uint64_t& amount, const std::vector<uint64_t> &offsets, std::vector<cryptonote::tx_out_index> &indices) const {}
-  virtual void get_output_key(const epee::span<const uint64_t> &amounts, const std::vector<uint64_t> &offsets, std::vector<cryptonote::output_data_t> &outputs, bool allow_partial = false) const {}
-  virtual bool can_thread_bulk_indices() const { return false; }
-  virtual std::vector<uint64_t> get_tx_output_indices(const crypto::hash& h) const { return std::vector<uint64_t>(); }
-  virtual std::vector<std::vector<uint64_t>> get_tx_amount_output_indices(const uint64_t tx_index, size_t n_txes) const { return std::vector<std::vector<uint64_t>>(); }
-  virtual bool has_key_image(const crypto::key_image& img) const { return false; }
-  virtual void remove_block() { }
-  virtual uint64_t add_transaction_data(const crypto::hash& blk_hash, const cryptonote::transaction& tx, const crypto::hash& tx_hash, const crypto::hash& tx_prunable_hash) {return 0;}
-  virtual void remove_transaction_data(const crypto::hash& tx_hash, const cryptonote::transaction& tx) {}
-  virtual uint64_t add_output(const crypto::hash& tx_hash, const cryptonote::tx_out& tx_output, const uint64_t& local_index, const uint64_t unlock_time, const rct::key *commitment) {return 0;}
-  virtual void add_tx_amount_output_indices(const uint64_t tx_index, const std::vector<uint64_t>& amount_output_indices) {}
-  virtual void add_spent_key(const crypto::key_image& k_image) {}
-  virtual void remove_spent_key(const crypto::key_image& k_image) {}
-
-  virtual bool for_all_key_images(std::function<bool(const crypto::key_image&)>) const { return true; }
-  virtual bool for_blocks_range(const uint64_t&, const uint64_t&, std::function<bool(uint64_t, const crypto::hash&, const cryptonote::block&)>) const { return true; }
-  virtual bool for_all_transactions(std::function<bool(const crypto::hash&, const cryptonote::transaction&)>, bool pruned) const { return true; }
-  virtual bool for_all_outputs(std::function<bool(uint64_t amount, const crypto::hash &tx_hash, uint64_t height, size_t tx_idx)> f) const { return true; }
-  virtual bool for_all_outputs(uint64_t amount, const std::function<bool(uint64_t height)> &f) const { return true; }
-  virtual bool is_read_only() const { return false; }
-  virtual std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>> get_output_histogram(const std::vector<uint64_t> &amounts, bool unlocked, uint64_t recent_cutoff, uint64_t min_count) const { return std::map<uint64_t, std::tuple<uint64_t, uint64_t, uint64_t>>(); }
-  virtual bool get_output_distribution(uint64_t amount, uint64_t from_height, uint64_t to_height, std::vector<uint64_t> &distribution, uint64_t &base) const { return false; }
-
-  virtual void add_txpool_tx(const crypto::hash &txid, const cryptonote::blobdata &blob, const cryptonote::txpool_tx_meta_t& details) {}
-  virtual void update_txpool_tx(const crypto::hash &txid, const cryptonote::txpool_tx_meta_t& details) {}
-  virtual uint64_t get_txpool_tx_count(bool include_unrelayed_txes = true) const { return 0; }
-  virtual bool txpool_has_tx(const crypto::hash &txid) const { return false; }
-  virtual void remove_txpool_tx(const crypto::hash& txid) {}
-  virtual bool get_txpool_tx_meta(const crypto::hash& txid, cryptonote::txpool_tx_meta_t &meta) const { return false; }
-  virtual bool get_txpool_tx_blob(const crypto::hash& txid, cryptonote::blobdata &bd) const { return false; }
-  virtual uint64_t get_database_size() const { return 0; }
-  virtual cryptonote::blobdata get_txpool_tx_blob(const crypto::hash& txid) const { return ""; }
-  virtual bool for_all_txpool_txes(std::function<bool(const crypto::hash&, const cryptonote::txpool_tx_meta_t&, const cryptonote::blobdata*)>, bool include_blob = false, bool include_unrelayed_txes = false) const { return false; }
-
-  virtual void add_block( const cryptonote::block& blk
-                        , size_t block_weight
-                        , const cryptonote::difficulty_type& cumulative_difficulty
-                        , const uint64_t& coins_generated
-                        , uint64_t num_rct_outs
-                        , const crypto::hash& blk_hash
-                        ) { }
-  virtual cryptonote::block get_block_from_height(const uint64_t& height) const { return cryptonote::block(); }
-  virtual void set_hard_fork_version(uint64_t height, uint8_t version) {}
-  virtual uint8_t get_hard_fork_version(uint64_t height) const { return 0; }
-  virtual void check_hard_fork_info() {}
-
-  virtual uint32_t get_blockchain_pruning_seed() const { return 0; }
-  virtual bool prune_blockchain(uint32_t pruning_seed = 0) { return true; }
-  virtual bool update_pruning() { return true; }
-  virtual bool check_pruning() { return true; }
-  virtual void prune_outputs(uint64_t amount) {}
-};
-