diff --git a/src/chain.cpp b/src/chain.cpp index e13c0478..3dbaf5a3 100644 --- a/src/chain.cpp +++ b/src/chain.cpp @@ -57,3 +57,52 @@ const CBlockIndex *CChain::FindFork(const CBlockIndex *pindex) const { pindex = pindex->pprev; return pindex; } + +/** Turn the lowest '1' bit in the binary representation of a number into a '0'. */ +int static inline InvertLowestOne(int n) { return n & (n - 1); } + +/** Compute what height to jump back to with the CBlockIndex::pskip pointer. */ +int static inline GetSkipHeight(int height) { + if (height < 2) + return 0; + + // Determine which height to jump back to. Any number strictly lower than height is acceptable, + // but the following expression seems to perform well in simulations (max 110 steps to go back + // up to 2**18 blocks). + return (height & 1) ? InvertLowestOne(InvertLowestOne(height - 1)) + 1 : InvertLowestOne(height); +} + +CBlockIndex* CBlockIndex::GetAncestor(int height) +{ + if (height > nHeight || height < 0) + return NULL; + + CBlockIndex* pindexWalk = this; + int heightWalk = nHeight; + while (heightWalk > height) { + int heightSkip = GetSkipHeight(heightWalk); + int heightSkipPrev = GetSkipHeight(heightWalk - 1); + if (heightSkip == height || + (heightSkip > height && !(heightSkipPrev < heightSkip - 2 && + heightSkipPrev >= height))) { + // Only follow pskip if pprev->pskip isn't better than pskip->pprev. + pindexWalk = pindexWalk->pskip; + heightWalk = heightSkip; + } else { + pindexWalk = pindexWalk->pprev; + heightWalk--; + } + } + return pindexWalk; +} + +const CBlockIndex* CBlockIndex::GetAncestor(int height) const +{ + return const_cast(this)->GetAncestor(height); +} + +void CBlockIndex::BuildSkip() +{ + if (pprev) + pskip = pprev->GetAncestor(GetSkipHeight(nHeight)); +} diff --git a/src/chain.h b/src/chain.h index 1c2d8993..a8a6b4dd 100644 --- a/src/chain.h +++ b/src/chain.h @@ -236,14 +236,6 @@ public: return pbegin[(pend - pbegin)/2]; } - /** - * Returns true if there are nRequired or more blocks of minVersion or above - * in the last Params().ToCheckBlockUpgradeMajority() blocks, starting at pstart - * and going backwards. - */ - static bool IsSuperMajority(int minVersion, const CBlockIndex* pstart, - unsigned int nRequired); - std::string ToString() const { return strprintf("CBlockIndex(pprev=%p, nHeight=%d, merkle=%s, hashBlock=%s)", diff --git a/src/main.cpp b/src/main.cpp index 50e63e93..7533c326 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -67,6 +67,13 @@ map mapOrphanTransactions; map > mapOrphanTransactionsByPrev; void EraseOrphansFor(NodeId peer); +/** + * Returns true if there are nRequired or more blocks of minVersion or above + * in the last Params().ToCheckBlockUpgradeMajority() blocks, starting at pstart + * and going backwards. + */ +static bool IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired); + /** Constant stuff for coinbase transactions we create: */ CScript COINBASE_FLAGS; @@ -2479,8 +2486,7 @@ bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationState& sta return state.DoS(100, error("%s : forked chain older than last checkpoint (height %d)", __func__, nHeight)); // Reject block.nVersion=1 blocks when 95% (75% on testnet) of the network has upgraded: - if (block.nVersion < 2 && - CBlockIndex::IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority())) + if (block.nVersion < 2 && IsSuperMajority(2, pindexPrev, Params().RejectBlockOutdatedMajority())) { return state.Invalid(error("%s : rejected nVersion=1 block", __func__), REJECT_OBSOLETE, "bad-version"); @@ -2501,8 +2507,7 @@ bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIn // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet): - if (block.nVersion >= 2 && - CBlockIndex::IsSuperMajority(2, pindexPrev, Params().EnforceBlockUpgradeMajority())) + if (block.nVersion >= 2 && IsSuperMajority(2, pindexPrev, Params().EnforceBlockUpgradeMajority())) { CScript expect = CScript() << nHeight; if (block.vtx[0].vin[0].scriptSig.size() < expect.size() || @@ -2600,7 +2605,7 @@ bool AcceptBlock(CBlock& block, CValidationState& state, CBlockIndex** ppindex, return true; } -bool CBlockIndex::IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired) +static bool IsSuperMajority(int minVersion, const CBlockIndex* pstart, unsigned int nRequired) { unsigned int nToCheck = Params().ToCheckBlockUpgradeMajority(); unsigned int nFound = 0; @@ -2613,54 +2618,6 @@ bool CBlockIndex::IsSuperMajority(int minVersion, const CBlockIndex* pstart, uns return (nFound >= nRequired); } -/** Turn the lowest '1' bit in the binary representation of a number into a '0'. */ -int static inline InvertLowestOne(int n) { return n & (n - 1); } - -/** Compute what height to jump back to with the CBlockIndex::pskip pointer. */ -int static inline GetSkipHeight(int height) { - if (height < 2) - return 0; - - // Determine which height to jump back to. Any number strictly lower than height is acceptable, - // but the following expression seems to perform well in simulations (max 110 steps to go back - // up to 2**18 blocks). - return (height & 1) ? InvertLowestOne(InvertLowestOne(height - 1)) + 1 : InvertLowestOne(height); -} - -CBlockIndex* CBlockIndex::GetAncestor(int height) -{ - if (height > nHeight || height < 0) - return NULL; - - CBlockIndex* pindexWalk = this; - int heightWalk = nHeight; - while (heightWalk > height) { - int heightSkip = GetSkipHeight(heightWalk); - int heightSkipPrev = GetSkipHeight(heightWalk - 1); - if (heightSkip == height || - (heightSkip > height && !(heightSkipPrev < heightSkip - 2 && - heightSkipPrev >= height))) { - // Only follow pskip if pprev->pskip isn't better than pskip->pprev. - pindexWalk = pindexWalk->pskip; - heightWalk = heightSkip; - } else { - pindexWalk = pindexWalk->pprev; - heightWalk--; - } - } - return pindexWalk; -} - -const CBlockIndex* CBlockIndex::GetAncestor(int height) const -{ - return const_cast(this)->GetAncestor(height); -} - -void CBlockIndex::BuildSkip() -{ - if (pprev) - pskip = pprev->GetAncestor(GetSkipHeight(nHeight)); -} bool ProcessNewBlock(CValidationState &state, CNode* pfrom, CBlock* pblock, CDiskBlockPos *dbp) {