From 82dbba10d467e28e56929e2e7f3b1f04d4635da4 Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Thu, 27 Oct 2016 23:43:44 +0100 Subject: core: dynamic fee algorithm from ArticMine The fee will vary based on the base reward and the current block size limit: fee = (R/R0) * (M0/M) * F0 R: base reward R0: reference base reward (10 monero) M: block size limit M0: minimum block size limit (60000) F0: 0.002 monero Starts applying at v4 --- src/cryptonote_core/blockchain.cpp | 52 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) (limited to 'src/cryptonote_core/blockchain.cpp') diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp index 9ea023a4c..c92ee6c9b 100644 --- a/src/cryptonote_core/blockchain.cpp +++ b/src/cryptonote_core/blockchain.cpp @@ -46,6 +46,7 @@ #include "misc_language.h" #include "profile_tools.h" #include "file_io_utils.h" +#include "common/int-util.h" #include "common/boost_serialization_helper.h" #include "warnings.h" #include "crypto/hash.h" @@ -2708,6 +2709,57 @@ void Blockchain::check_ring_signature(const crypto::hash &tx_prefix_hash, const result = crypto::check_ring_signature(tx_prefix_hash, key_image, p_output_keys, sig.data()) ? 1 : 0; } +//------------------------------------------------------------------ +uint64_t Blockchain::get_dynamic_per_kb_fee(uint64_t block_reward, size_t median_block_size) +{ + if (median_block_size < CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2) + median_block_size = CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2; + + uint64_t unscaled_fee_per_kb = (DYNAMIC_FEE_PER_KB_BASE_FEE * CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 / median_block_size); + uint64_t hi, lo = mul128(unscaled_fee_per_kb, block_reward, &hi); + static_assert(DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD % 1000000 == 0, "DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD must be divisible by 1000000"); + static_assert(DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD / 1000000 <= std::numeric_limits::max(), "DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD is too large"); + // divide in two steps, since the divisor must be 32 bits, but DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD isn't + div128_32(hi, lo, DYNAMIC_FEE_PER_KB_BASE_BLOCK_REWARD / 1000000, &hi, &lo); + div128_32(hi, lo, 1000000, &hi, &lo); + assert(hi == 0); + + return lo; +} + +//------------------------------------------------------------------ +bool Blockchain::check_fee(size_t blob_size, uint64_t fee) const +{ + const uint8_t version = get_current_hard_fork_version(); + + uint64_t fee_per_kb; + if (version < HF_VERSION_DYNAMIC_FEE) + { + fee_per_kb = FEE_PER_KB; + } + else + { + uint64_t median = m_current_block_cumul_sz_limit / 2; + uint64_t already_generated_coins = m_db->height() ? m_db->get_block_already_generated_coins(m_db->height() - 1) : 0; + uint64_t base_reward; + if (!get_block_reward(median, 1, already_generated_coins, base_reward, version)) + return false; + fee_per_kb = get_dynamic_per_kb_fee(base_reward, median); + } + LOG_PRINT_L2("Using " << print_money(fee) << "/kB fee"); + + uint64_t needed_fee = blob_size / 1024; + needed_fee += (blob_size % 1024) ? 1 : 0; + needed_fee *= fee_per_kb; + + if (fee < needed_fee) + { + LOG_PRINT_L1("transaction fee is not enough: " << print_money(fee) << ", minimum fee: " << print_money(needed_fee)); + return false; + } + return true; +} + //------------------------------------------------------------------ // This function checks to see if a tx is unlocked. unlock_time is either // a block index or a unix time. -- cgit v1.2.3