Bitcoin Core  21.99.0
P2P Digital Currency
versionbits.h
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1 // Copyright (c) 2016-2019 The Bitcoin Core developers
2 // Distributed under the MIT software license, see the accompanying
3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 
5 #ifndef BITCOIN_VERSIONBITS_H
6 #define BITCOIN_VERSIONBITS_H
7 
8 #include <chain.h>
9 #include <map>
10 
12 static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION = 4;
14 static const int32_t VERSIONBITS_TOP_BITS = 0x20000000UL;
16 static const int32_t VERSIONBITS_TOP_MASK = 0xE0000000UL;
18 static const int32_t VERSIONBITS_NUM_BITS = 29;
19 
25 enum class ThresholdState {
26  DEFINED, // First state that each softfork starts out as. The genesis block is by definition in this state for each deployment.
27  STARTED, // For blocks past the starttime.
28  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.
29  ACTIVE, // For all blocks after the LOCKED_IN retarget period (final state)
30  FAILED, // For all blocks once the first retarget period after the timeout time is hit, if LOCKED_IN wasn't already reached (final state)
31 };
32 
33 // A map that gives the state for blocks whose height is a multiple of Period().
34 // The map is indexed by the block's parent, however, so all keys in the map
35 // will either be nullptr or a block with (height + 1) % Period() == 0.
36 typedef std::map<const CBlockIndex*, ThresholdState> ThresholdConditionCache;
37 
39 struct BIP9Stats {
41  int period;
43  int threshold;
45  int elapsed;
47  int count;
49  bool possible;
50 };
51 
56 protected:
57  virtual bool Condition(const CBlockIndex* pindex, const Consensus::Params& params) const =0;
58  virtual int64_t BeginTime(const Consensus::Params& params) const =0;
59  virtual int64_t EndTime(const Consensus::Params& params) const =0;
60  virtual int MinActivationHeight(const Consensus::Params& params) const { return 0; }
61  virtual int Period(const Consensus::Params& params) const =0;
62  virtual int Threshold(const Consensus::Params& params) const =0;
63 
64 public:
66  BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params) const;
69  ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
71  int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
72 };
73 
77 {
79 
80  void Clear();
81 };
82 
90 
91 #endif // BITCOIN_VERSIONBITS_H
ThresholdState::STARTED
@ STARTED
VERSIONBITS_TOP_MASK
static const int32_t VERSIONBITS_TOP_MASK
What bitmask determines whether versionbits is in use.
Definition: versionbits.h:16
ThresholdState::ACTIVE
@ ACTIVE
Consensus::DeploymentPos
DeploymentPos
Definition: params.h:14
AbstractThresholdConditionChecker::Threshold
virtual int Threshold(const Consensus::Params &params) const =0
AbstractThresholdConditionChecker::EndTime
virtual int64_t EndTime(const Consensus::Params &params) const =0
VersionBitsCache::Clear
void Clear()
Definition: versionbits.cpp:213
Consensus::MAX_VERSION_BITS_DEPLOYMENTS
@ MAX_VERSION_BITS_DEPLOYMENTS
Definition: params.h:19
AbstractThresholdConditionChecker::GetStateFor
ThresholdState GetStateFor(const CBlockIndex *pindexPrev, const Consensus::Params &params, ThresholdConditionCache &cache) const
Returns the state for pindex A based on parent pindexPrev B.
Definition: versionbits.cpp:8
VERSIONBITS_TOP_BITS
static const int32_t VERSIONBITS_TOP_BITS
What bits to set in version for versionbits blocks.
Definition: versionbits.h:14
VersionBitsCache
BIP 9 allows multiple softforks to be deployed in parallel.
Definition: versionbits.h:76
ThresholdConditionCache
std::map< const CBlockIndex *, ThresholdState > ThresholdConditionCache
Definition: versionbits.h:36
VersionBitsMask
uint32_t VersionBitsMask(const Consensus::Params &params, Consensus::DeploymentPos pos)
Definition: versionbits.cpp:208
AbstractThresholdConditionChecker::Period
virtual int Period(const Consensus::Params &params) const =0
Consensus::Params
Parameters that influence chain consensus.
Definition: params.h:56
VersionBitsStateSinceHeight
int VersionBitsStateSinceHeight(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos, VersionBitsCache &cache)
Get the block height at which the BIP9 deployment switched into the state for the block building on t...
Definition: versionbits.cpp:203
VersionBitsStatistics
BIP9Stats VersionBitsStatistics(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos)
Get the numerical statistics for the BIP9 state for a given deployment at the current tip.
Definition: versionbits.cpp:198
AbstractThresholdConditionChecker::GetStateSinceHeightFor
int GetStateSinceHeightFor(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 ...
Definition: versionbits.cpp:130
AbstractThresholdConditionChecker::BeginTime
virtual int64_t BeginTime(const Consensus::Params &params) const =0
ThresholdState::DEFINED
@ DEFINED
BIP9Stats::count
int count
Number of blocks with the version bit set since the beginning of the current period.
Definition: versionbits.h:47
BIP9Stats::threshold
int threshold
Number of blocks with the version bit set required to activate the softfork.
Definition: versionbits.h:43
AbstractThresholdConditionChecker
Abstract class that implements BIP9-style threshold logic, and caches results.
Definition: versionbits.h:55
chain.h
ThresholdState::FAILED
@ FAILED
AbstractThresholdConditionChecker::MinActivationHeight
virtual int MinActivationHeight(const Consensus::Params &params) const
Definition: versionbits.h:60
AbstractThresholdConditionChecker::GetStateStatisticsFor
BIP9Stats GetStateStatisticsFor(const CBlockIndex *pindex, const Consensus::Params &params) const
Returns the numerical statistics of an in-progress BIP9 softfork in the current period.
Definition: versionbits.cpp:101
BIP9Stats
Display status of an in-progress BIP9 softfork.
Definition: versionbits.h:39
AbstractThresholdConditionChecker::Condition
virtual bool Condition(const CBlockIndex *pindex, const Consensus::Params &params) const =0
VERSIONBITS_NUM_BITS
static const int32_t VERSIONBITS_NUM_BITS
Total bits available for versionbits.
Definition: versionbits.h:18
BIP9Stats::elapsed
int elapsed
Number of blocks elapsed since the beginning of the current period.
Definition: versionbits.h:45
ThresholdState::LOCKED_IN
@ LOCKED_IN
BIP9Stats::possible
bool possible
False if there are not enough blocks left in this period to pass activation threshold.
Definition: versionbits.h:49
VersionBitsState
ThresholdState VersionBitsState(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos, VersionBitsCache &cache)
Get the BIP9 state for a given deployment at the current tip.
Definition: versionbits.cpp:193
VERSIONBITS_LAST_OLD_BLOCK_VERSION
static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION
What block version to use for new blocks (pre versionbits)
Definition: versionbits.h:12
BIP9Stats::period
int period
Length of blocks of the BIP9 signalling period.
Definition: versionbits.h:41
ThresholdState
ThresholdState
BIP 9 defines a finite-state-machine to deploy a softfork in multiple stages.
Definition: versionbits.h:25
CBlockIndex
The block chain is a tree shaped structure starting with the genesis block at the root,...
Definition: chain.h:137
VersionBitsCache::caches
ThresholdConditionCache caches[Consensus::MAX_VERSION_BITS_DEPLOYMENTS]
Definition: versionbits.h:78