src/consensus/params.h

   1 // Copyright (c) 2009-2010 Satoshi Nakamoto
   2 // Copyright (c) 2009-2016 The Bitcoin Core developers
   3 // Distributed under the MIT software license, see the accompanying
   4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   5
   6 #ifndef BITCOIN_CONSENSUS_PARAMS_H
   7 #define BITCOIN_CONSENSUS_PARAMS_H
   8
   9 #include "uint256.h"
  10 #include <limits>
  11 #include <map>
  12 #include <string>
  13
  14 namespace Consensus {
  15
  16 enum DeploymentPos
  17 {
  18     DEPLOYMENT_TESTDUMMY,
  19     DEPLOYMENT_CSV, // Deployment of BIP68, BIP112, and BIP113.
  20     DEPLOYMENT_SEGWIT, // Deployment of BIP141, BIP143, and BIP147.
  21     // NOTE: Also add new deployments to VersionBitsDeploymentInfo in versionbits.cpp
  22     MAX_VERSION_BITS_DEPLOYMENTS
  23 };
  24
  25 /**
  26  * Struct for each individual consensus rule change using BIP9.
  27  */
  28 struct BIP9Deployment {
  29     /** Bit position to select the particular bit in nVersion. */
  30     int bit;
  31     /** Start MedianTime for version bits miner confirmation. Can be a date in the past */
  32     int64_t nStartTime;
  33     /** Timeout/expiry MedianTime for the deployment attempt. */
  34     int64_t nTimeout;
  35
  36     /** Constant for nTimeout very far in the future. */
  37     static constexpr int64_t NO_TIMEOUT = std::numeric_limits<int64_t>::max();
  38
  39     /** Special value for nStartTime indicating that the deployment is always active.
  40      *  This is useful for testing, as it means tests don't need to deal with the activation
  41      *  process (which takes at least 3 BIP9 intervals). Only tests that specifically test the
  42      *  behaviour during activation cannot use this. */
  43     static constexpr int64_t ALWAYS_ACTIVE = -1;
  44 };
  45
  46 /**
  47  * Parameters that influence chain consensus.
  48  */
  49 struct Params {
  50     uint256 hashGenesisBlock;
  51     int nSubsidyHalvingInterval;
  52     /** Block height at which BIP16 becomes active */
  53     int BIP16Height;
  54     /** Block height and hash at which BIP34 becomes active */
  55     int BIP34Height;
  56     uint256 BIP34Hash;
  57     /** Block height at which BIP65 becomes active */
  58     int BIP65Height;
  59     /** Block height at which BIP66 becomes active */
  60     int BIP66Height;
  61     /**
  62      * Minimum blocks including miner confirmation of the total of 2016 blocks in a retargeting period,
  63      * (nPowTargetTimespan / nPowTargetSpacing) which is also used for BIP9 deployments.
  64      * Examples: 1916 for 95%, 1512 for testchains.
  65      */
  66     uint32_t nRuleChangeActivationThreshold;
  67     uint32_t nMinerConfirmationWindow;
  68     BIP9Deployment vDeployments[MAX_VERSION_BITS_DEPLOYMENTS];
  69     /** Proof of work parameters */
  70     uint256 powLimit;
  71     bool fPowAllowMinDifficultyBlocks;
  72     bool fPowNoRetargeting;
  73     int64_t nPowTargetSpacing;
  74     int64_t nPowTargetTimespan;
  75     int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; }
  76     uint256 nMinimumChainWork;
  77     uint256 defaultAssumeValid;
  78 };
  79 } // namespace Consensus
  80
  81 #endif // BITCOIN_CONSENSUS_PARAMS_H