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Refactor proof of work related functions out of main

tags/v0.15.1
jtimon 7 years ago
parent
commit
df852d2bcc
9 changed files with 155 additions and 124 deletions
  1. 2
    0
      src/Makefile.am
  2. 1
    112
      src/main.cpp
  3. 0
    10
      src/main.h
  4. 1
    0
      src/miner.cpp
  5. 123
    0
      src/pow.cpp
  6. 23
    0
      src/pow.h
  7. 1
    0
      src/rpcmining.cpp
  8. 1
    0
      src/test/DoS_tests.cpp
  9. 3
    2
      src/txdb.cpp

+ 2
- 0
src/Makefile.am View File

@@ -71,6 +71,7 @@ BITCOIN_CORE_H = \
netbase.h \
net.h \
noui.h \
pow.h \
protocol.h \
rpcclient.h \
rpcprotocol.h \
@@ -121,6 +122,7 @@ libbitcoin_server_a_SOURCES = \
miner.cpp \
net.cpp \
noui.cpp \
pow.cpp \
rpcblockchain.cpp \
rpcmining.cpp \
rpcmisc.cpp \

+ 1
- 112
src/main.cpp View File

@@ -12,6 +12,7 @@
#include "checkqueue.h"
#include "init.h"
#include "net.h"
#include "pow.h"
#include "txdb.h"
#include "txmempool.h"
#include "ui_interface.h"
@@ -1194,118 +1195,6 @@ int64_t GetBlockValue(int nHeight, int64_t nFees)
return nSubsidy + nFees;
}

static const int64_t nTargetTimespan = 14 * 24 * 60 * 60; // two weeks
static const int64_t nTargetSpacing = 10 * 60;
static const int64_t nInterval = nTargetTimespan / nTargetSpacing;

//
// minimum amount of work that could possibly be required nTime after
// minimum work required was nBase
//
unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime)
{
const uint256 &bnLimit = Params().ProofOfWorkLimit();
// Testnet has min-difficulty blocks
// after nTargetSpacing*2 time between blocks:
if (Params().AllowMinDifficultyBlocks() && nTime > nTargetSpacing*2)
return bnLimit.GetCompact();

uint256 bnResult;
bnResult.SetCompact(nBase);
while (nTime > 0 && bnResult < bnLimit)
{
// Maximum 400% adjustment...
bnResult *= 4;
// ... in best-case exactly 4-times-normal target time
nTime -= nTargetTimespan*4;
}
if (bnResult > bnLimit)
bnResult = bnLimit;
return bnResult.GetCompact();
}

unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock)
{
unsigned int nProofOfWorkLimit = Params().ProofOfWorkLimit().GetCompact();

// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;

// Only change once per interval
if ((pindexLast->nHeight+1) % nInterval != 0)
{
if (Params().AllowMinDifficultyBlocks())
{
// Special difficulty rule for testnet:
// If the new block's timestamp is more than 2* 10 minutes
// then allow mining of a min-difficulty block.
if (pblock->nTime > pindexLast->nTime + nTargetSpacing*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % nInterval != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}
return pindexLast->nBits;
}

// Go back by what we want to be 14 days worth of blocks
const CBlockIndex* pindexFirst = pindexLast;
for (int i = 0; pindexFirst && i < nInterval-1; i++)
pindexFirst = pindexFirst->pprev;
assert(pindexFirst);

// Limit adjustment step
int64_t nActualTimespan = pindexLast->GetBlockTime() - pindexFirst->GetBlockTime();
LogPrintf(" nActualTimespan = %d before bounds\n", nActualTimespan);
if (nActualTimespan < nTargetTimespan/4)
nActualTimespan = nTargetTimespan/4;
if (nActualTimespan > nTargetTimespan*4)
nActualTimespan = nTargetTimespan*4;

// Retarget
uint256 bnNew;
uint256 bnOld;
bnNew.SetCompact(pindexLast->nBits);
bnOld = bnNew;
bnNew *= nActualTimespan;
bnNew /= nTargetTimespan;

if (bnNew > Params().ProofOfWorkLimit())
bnNew = Params().ProofOfWorkLimit();

/// debug print
LogPrintf("GetNextWorkRequired RETARGET\n");
LogPrintf("nTargetTimespan = %d nActualTimespan = %d\n", nTargetTimespan, nActualTimespan);
LogPrintf("Before: %08x %s\n", pindexLast->nBits, bnOld.ToString());
LogPrintf("After: %08x %s\n", bnNew.GetCompact(), bnNew.ToString());

return bnNew.GetCompact();
}

bool CheckProofOfWork(uint256 hash, unsigned int nBits)
{
bool fNegative;
bool fOverflow;
uint256 bnTarget;
bnTarget.SetCompact(nBits, &fNegative, &fOverflow);

// Check range
if (fNegative || bnTarget == 0 || fOverflow || bnTarget > Params().ProofOfWorkLimit())
return error("CheckProofOfWork() : nBits below minimum work");

// Check proof of work matches claimed amount
if (hash > bnTarget)
return error("CheckProofOfWork() : hash doesn't match nBits");

return true;
}

bool IsInitialBlockDownload()
{
LOCK(cs_main);

+ 0
- 10
src/main.h View File

@@ -146,10 +146,6 @@ bool ProcessMessages(CNode* pfrom);
bool SendMessages(CNode* pto, bool fSendTrickle);
/** Run an instance of the script checking thread */
void ThreadScriptCheck();
/** Check whether a block hash satisfies the proof-of-work requirement specified by nBits */
bool CheckProofOfWork(uint256 hash, unsigned int nBits);
/** Calculate the minimum amount of work a received block needs, without knowing its direct parent */
unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime);
/** Check whether we are doing an initial block download (synchronizing from disk or network) */
bool IsInitialBlockDownload();
/** Format a string that describes several potential problems detected by the core */
@@ -159,7 +155,6 @@ bool GetTransaction(const uint256 &hash, CTransaction &tx, uint256 &hashBlock, b
/** Find the best known block, and make it the tip of the block chain */
bool ActivateBestChain(CValidationState &state);
int64_t GetBlockValue(int nHeight, int64_t nFees);
unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock);

void UpdateTime(CBlockHeader& block, const CBlockIndex* pindexPrev);

@@ -812,11 +807,6 @@ public:
return (~bnTarget / (bnTarget + 1)) + 1;
}

bool CheckIndex() const
{
return CheckProofOfWork(GetBlockHash(), nBits);
}

enum { nMedianTimeSpan=11 };

int64_t GetMedianTimePast() const

+ 1
- 0
src/miner.cpp View File

@@ -9,6 +9,7 @@
#include "hash.h"
#include "main.h"
#include "net.h"
#include "pow.h"
#ifdef ENABLE_WALLET
#include "wallet.h"
#endif

+ 123
- 0
src/pow.cpp View File

@@ -0,0 +1,123 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "pow.h"

#include "chainparams.h"
#include "core.h"
#include "main.h"
#include "uint256.h"

static const int64_t nTargetTimespan = 14 * 24 * 60 * 60; // two weeks
static const int64_t nTargetSpacing = 10 * 60;
static const int64_t nInterval = nTargetTimespan / nTargetSpacing;

unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock)
{
unsigned int nProofOfWorkLimit = Params().ProofOfWorkLimit().GetCompact();

// Genesis block
if (pindexLast == NULL)
return nProofOfWorkLimit;

// Only change once per interval
if ((pindexLast->nHeight+1) % nInterval != 0)
{
if (Params().AllowMinDifficultyBlocks())
{
// Special difficulty rule for testnet:
// If the new block's timestamp is more than 2* 10 minutes
// then allow mining of a min-difficulty block.
if (pblock->nTime > pindexLast->nTime + nTargetSpacing*2)
return nProofOfWorkLimit;
else
{
// Return the last non-special-min-difficulty-rules-block
const CBlockIndex* pindex = pindexLast;
while (pindex->pprev && pindex->nHeight % nInterval != 0 && pindex->nBits == nProofOfWorkLimit)
pindex = pindex->pprev;
return pindex->nBits;
}
}
return pindexLast->nBits;
}

// Go back by what we want to be 14 days worth of blocks
const CBlockIndex* pindexFirst = pindexLast;
for (int i = 0; pindexFirst && i < nInterval-1; i++)
pindexFirst = pindexFirst->pprev;
assert(pindexFirst);

// Limit adjustment step
int64_t nActualTimespan = pindexLast->GetBlockTime() - pindexFirst->GetBlockTime();
LogPrintf(" nActualTimespan = %d before bounds\n", nActualTimespan);
if (nActualTimespan < nTargetTimespan/4)
nActualTimespan = nTargetTimespan/4;
if (nActualTimespan > nTargetTimespan*4)
nActualTimespan = nTargetTimespan*4;

// Retarget
uint256 bnNew;
uint256 bnOld;
bnNew.SetCompact(pindexLast->nBits);
bnOld = bnNew;
bnNew *= nActualTimespan;
bnNew /= nTargetTimespan;

if (bnNew > Params().ProofOfWorkLimit())
bnNew = Params().ProofOfWorkLimit();

/// debug print
LogPrintf("GetNextWorkRequired RETARGET\n");
LogPrintf("nTargetTimespan = %d nActualTimespan = %d\n", nTargetTimespan, nActualTimespan);
LogPrintf("Before: %08x %s\n", pindexLast->nBits, bnOld.ToString());
LogPrintf("After: %08x %s\n", bnNew.GetCompact(), bnNew.ToString());

return bnNew.GetCompact();
}

bool CheckProofOfWork(uint256 hash, unsigned int nBits)
{
bool fNegative;
bool fOverflow;
uint256 bnTarget;
bnTarget.SetCompact(nBits, &fNegative, &fOverflow);

// Check range
if (fNegative || bnTarget == 0 || fOverflow || bnTarget > Params().ProofOfWorkLimit())
return error("CheckProofOfWork() : nBits below minimum work");

// Check proof of work matches claimed amount
if (hash > bnTarget)
return error("CheckProofOfWork() : hash doesn't match nBits");

return true;
}

//
// minimum amount of work that could possibly be required nTime after
// minimum work required was nBase
//
unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime)
{
const uint256 &bnLimit = Params().ProofOfWorkLimit();
// Testnet has min-difficulty blocks
// after nTargetSpacing*2 time between blocks:
if (Params().AllowMinDifficultyBlocks() && nTime > nTargetSpacing*2)
return bnLimit.GetCompact();

uint256 bnResult;
bnResult.SetCompact(nBase);
while (nTime > 0 && bnResult < bnLimit)
{
// Maximum 400% adjustment...
bnResult *= 4;
// ... in best-case exactly 4-times-normal target time
nTime -= nTargetTimespan*4;
}
if (bnResult > bnLimit)
bnResult = bnLimit;
return bnResult.GetCompact();
}

+ 23
- 0
src/pow.h View File

@@ -0,0 +1,23 @@

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2014 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#ifndef BITCOIN_POW_H
#define BITCOIN_POW_H

#include <stdint.h>

class CBlockIndex;
class CBlockHeader;
class uint256;

unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHeader *pblock);

/** Check whether a block hash satisfies the proof-of-work requirement specified by nBits */
bool CheckProofOfWork(uint256 hash, unsigned int nBits);
/** Calculate the minimum amount of work a received block needs, without knowing its direct parent */
unsigned int ComputeMinWork(unsigned int nBase, int64_t nTime);

#endif

+ 1
- 0
src/rpcmining.cpp View File

@@ -9,6 +9,7 @@
#include "net.h"
#include "main.h"
#include "miner.h"
#include "pow.h"
#ifdef ENABLE_WALLET
#include "db.h"
#include "wallet.h"

+ 1
- 0
src/test/DoS_tests.cpp View File

@@ -11,6 +11,7 @@
#include "keystore.h"
#include "main.h"
#include "net.h"
#include "pow.h"
#include "script.h"
#include "serialize.h"


+ 3
- 2
src/txdb.cpp View File

@@ -6,6 +6,7 @@
#include "txdb.h"

#include "core.h"
#include "pow.h"
#include "uint256.h"

#include <stdint.h>
@@ -212,8 +213,8 @@ bool CBlockTreeDB::LoadBlockIndexGuts()
pindexNew->nStatus = diskindex.nStatus;
pindexNew->nTx = diskindex.nTx;

if (!pindexNew->CheckIndex())
return error("LoadBlockIndex() : CheckIndex failed: %s", pindexNew->ToString());
if (!CheckProofOfWork(pindexNew->GetBlockHash(), pindexNew->nBits))
return error("LoadBlockIndex() : CheckProofOfWork failed: %s", pindexNew->ToString());

pcursor->Next();
} else {

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