6f83cf2adb
Inspired by former implementations by Eric Lombrozo and Rusty Russell, and based on code by Jorge Timon.
60 lines
2.3 KiB
C++
60 lines
2.3 KiB
C++
// Copyright (c) 2016 The Bitcoin Core developers
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// Distributed under the MIT software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#ifndef BITCOIN_CONSENSUS_VERSIONBITS
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#define BITCOIN_CONSENSUS_VERSIONBITS
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#include "chain.h"
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#include <map>
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/** What block version to use for new blocks (pre versionbits) */
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static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION = 4;
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/** What bits to set in version for versionbits blocks */
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static const int32_t VERSIONBITS_TOP_BITS = 0x20000000UL;
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/** What bitmask determines whether versionbits is in use */
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static const int32_t VERSIONBITS_TOP_MASK = 0xE0000000UL;
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/** Total bits available for versionbits */
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static const int32_t VERSIONBITS_NUM_BITS = 29;
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enum ThresholdState {
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THRESHOLD_DEFINED,
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THRESHOLD_STARTED,
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THRESHOLD_LOCKED_IN,
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THRESHOLD_ACTIVE,
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THRESHOLD_FAILED,
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};
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// A map that gives the state for blocks whose height is a multiple of Period().
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// The map is indexed by the block's parent, however, so all keys in the map
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// will either be NULL or a block with (height + 1) % Period() == 0.
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typedef std::map<const CBlockIndex*, ThresholdState> ThresholdConditionCache;
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/**
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* Abstract class that implements BIP9-style threshold logic, and caches results.
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*/
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class AbstractThresholdConditionChecker {
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protected:
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virtual bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const =0;
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virtual int64_t BeginTime(const Consensus::Params& params) const =0;
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virtual int64_t EndTime(const Consensus::Params& params) const =0;
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virtual int Period(const Consensus::Params& params) const =0;
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virtual int Threshold(const Consensus::Params& params) const =0;
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public:
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// Note that the function below takes a pindexPrev as input: they compute information for block B based on its parent.
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ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
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};
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struct VersionBitsCache
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{
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ThresholdConditionCache caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS];
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void Clear();
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};
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ThresholdState VersionBitsState(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache);
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uint32_t VersionBitsMask(const Consensus::Params& params, Consensus::DeploymentPos pos);
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#endif
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