git / moonbite-core / src/versionbits.h · raw

// Copyright (c) 2016-2019 The Bitcoin Core developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.#ifndef BITCOIN_VERSIONBITS_H#define BITCOIN_VERSIONBITS_H#include <chain.h>#include <map>/** What block version to use for new blocks (pre versionbits) */static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION = 4;/** What bits to set in version for versionbits blocks */static const int32_t VERSIONBITS_TOP_BITS = 0x20000000UL;/** What bitmask determines whether versionbits is in use */static const int32_t VERSIONBITS_TOP_MASK = 0xE0000000UL;/** Total bits available for versionbits */static const int32_t VERSIONBITS_NUM_BITS = 29;/** BIP 9 defines a finite-state-machine to deploy a softfork in multiple stages. *  State transitions happen during retarget period if conditions are met *  In case of reorg, transitions can go backward. Without transition, state is *  inherited between periods. All blocks of a period share the same state. */enum class ThresholdState {    DEFINED,   // First state that each softfork starts out as. The genesis block is by definition in this state for each deployment.    STARTED,   // For blocks past the starttime.    LOCKED_IN, // For at least one retarget period after the first retarget period with STARTED blocks of which at least threshold have the associated bit set in nVersion, until min_activation_height is reached.    ACTIVE,    // For all blocks after the LOCKED_IN retarget period (final state)    FAILED,    // For all blocks once the first retarget period after the timeout time is hit, if LOCKED_IN wasn't already reached (final state)};// A map that gives the state for blocks whose height is a multiple of Period().// The map is indexed by the block's parent, however, so all keys in the map// will either be nullptr or a block with (height + 1) % Period() == 0.typedef std::map<const CBlockIndex*, ThresholdState> ThresholdConditionCache;/** Display status of an in-progress BIP9 softfork */struct BIP9Stats {    /** Length of blocks of the BIP9 signalling period */    int period;    /** Number of blocks with the version bit set required to activate the softfork */    int threshold;    /** Number of blocks elapsed since the beginning of the current period */    int elapsed;    /** Number of blocks with the version bit set since the beginning of the current period */    int count;    /** False if there are not enough blocks left in this period to pass activation threshold */    bool possible;};/** * Abstract class that implements BIP9-style threshold logic, and caches results. */class AbstractThresholdConditionChecker {protected:    virtual bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const =0;    virtual int64_t BeginTime(const Consensus::Params& params) const =0;    virtual int64_t EndTime(const Consensus::Params& params) const = 0;    virtual int64_t BeginHeight(const Consensus::Params& params) const = 0;    virtual int64_t EndHeight(const Consensus::Params& params) const = 0;    virtual int Period(const Consensus::Params& params) const =0;    virtual int Threshold(const Consensus::Params& params) const =0;public:    /** Returns the numerical statistics of an in-progress BIP9 softfork in the current period */    BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params) const;    /** Returns the state for pindex A based on parent pindexPrev B. Applies any state transition if conditions are present.     *  Caches state from first block of period. */    ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;    /** Returns the height since when the ThresholdState has started for pindex A based on parent pindexPrev B, all blocks of a period share the same */    int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;};/** BIP 9 allows multiple softforks to be deployed in parallel. We cache per-period state for every one of them *  keyed by the bit position used to signal support. */struct VersionBitsCache{    ThresholdConditionCache caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS];    void Clear();};ThresholdState VersionBitsState(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache);BIP9Stats VersionBitsStatistics(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos);int VersionBitsStateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache);uint32_t VersionBitsMask(const Consensus::Params& params, Consensus::DeploymentPos pos);#endif // BITCOIN_VERSIONBITS_H