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.

1 files changed, 6 insertions, 6 deletions

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));