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, 3 insertions, 0 deletions

diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h
index 93db71705..d6edb23c2 100644
--- a/src/cryptonote_config.h
+++ b/src/cryptonote_config.h
@@ -59,6 +59,8 @@
 #define CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2    60000 //size of block (bytes) after which reward for block calculated using block size
 #define CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V1    20000 //size of block (bytes) after which reward for block calculated using block size - before first fork
 #define CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V5    300000 //size of block (bytes) after which reward for block calculated using block size - second change, from v5
+#define CRYPTONOTE_LONG_TERM_BLOCK_WEIGHT_WINDOW_SIZE   100000 // size in blocks of the long term block weight median window
+#define CRYPTONOTE_SHORT_TERM_BLOCK_WEIGHT_SURGE_FACTOR 50
 #define CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE          600
 #define CRYPTONOTE_DISPLAY_DECIMAL_POINT                12
 // COIN - number of smallest units in one coin
@@ -143,6 +145,7 @@
 #define HF_VERSION_ENFORCE_RCT                  6
 #define HF_VERSION_PER_BYTE_FEE                 8
 #define HF_VERSION_SMALLER_BP                   10
+#define HF_VERSION_LONG_TERM_BLOCK_WEIGHT       10
 
 #define PER_KB_FEE_QUANTIZATION_DECIMALS        8