Bitcoin Core  0.20.99
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 one retarget period after the first retarget period with STARTED blocks of which at least threshold have the associated bit set in nVersion.
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 Period(const Consensus::Params& params) const =0;
61  virtual int Threshold(const Consensus::Params& params) const =0;
62 
63 public:
65  BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, const Consensus::Params& params) const;
68  ThresholdState GetStateFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
70  int GetStateSinceHeightFor(const CBlockIndex* pindexPrev, const Consensus::Params& params, ThresholdConditionCache& cache) const;
71 };
72 
76 {
78 
79  void Clear();
80 };
81 
86 
87 #endif // BITCOIN_VERSIONBITS_H
Display status of an in-progress BIP9 softfork.
Definition: versionbits.h:39
static const int32_t VERSIONBITS_TOP_MASK
What bitmask determines whether versionbits is in use.
Definition: versionbits.h:16
ThresholdState
BIP 9 defines a finite-state-machine to deploy a softfork in multiple stages.
Definition: versionbits.h:25
int threshold
Number of blocks with the version bit set required to activate the softfork.
Definition: versionbits.h:43
BIP9Stats VersionBitsStatistics(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos)
BIP 9 allows multiple softforks to be deployed in parallel.
Definition: versionbits.h:75
DeploymentPos
Definition: params.h:14
int period
Length of blocks of the BIP9 signalling period.
Definition: versionbits.h:41
ThresholdState VersionBitsState(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos, VersionBitsCache &cache)
Abstract class that implements BIP9-style threshold logic, and caches results.
Definition: versionbits.h:55
int count
Number of blocks with the version bit set since the beginning of the current period.
Definition: versionbits.h:47
Parameters that influence chain consensus.
Definition: params.h:45
std::map< const CBlockIndex *, ThresholdState > ThresholdConditionCache
Definition: versionbits.h:36
int VersionBitsStateSinceHeight(const CBlockIndex *pindexPrev, const Consensus::Params &params, Consensus::DeploymentPos pos, VersionBitsCache &cache)
The block chain is a tree shaped structure starting with the genesis block at the root...
Definition: chain.h:137
static const int32_t VERSIONBITS_LAST_OLD_BLOCK_VERSION
What block version to use for new blocks (pre versionbits)
Definition: versionbits.h:12
static const int32_t VERSIONBITS_TOP_BITS
What bits to set in version for versionbits blocks.
Definition: versionbits.h:14
int elapsed
Number of blocks elapsed since the beginning of the current period.
Definition: versionbits.h:45
bool possible
False if there are not enough blocks left in this period to pass activation threshold.
Definition: versionbits.h:49
uint32_t VersionBitsMask(const Consensus::Params &params, Consensus::DeploymentPos pos)
static const int32_t VERSIONBITS_NUM_BITS
Total bits available for versionbits.
Definition: versionbits.h:18