From dd5792a4801d906bcfeb31fd78c12328e9fafd02 Mon Sep 17 00:00:00 2001 From: MASM fan Date: Sun, 11 Jan 2015 14:17:30 -0800 Subject: [PATCH] Minor CheckBlock() optimizations. * Don't check the transaction type twice; * Use one loop to iterate all transactions. --- src/main.cpp | 99 ++++++++++++++++++++++++++++++++++----------------------- 1 files changed, 59 insertions(+), 40 deletions(-) diff --git a/src/main.cpp b/src/main.cpp index c366651..6390366 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2228,38 +2228,31 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) c // These are checks that are independent of context // that can be verified before saving an orphan block. + set uniqueTx; // tx hashes + unsigned int nSigOps = 0; // total sigops + // Size limits if (vtx.empty() || vtx.size() > MAX_BLOCK_SIZE || ::GetSerializeSize(*this, SER_NETWORK, PROTOCOL_VERSION) > MAX_BLOCK_SIZE) return DoS(100, error("CheckBlock() : size limits failed")); - // Check proof of work matches claimed amount - if (fCheckPOW && IsProofOfWork() && !CheckProofOfWork(GetHash(), nBits)) - return DoS(50, error("CheckBlock() : proof of work failed")); - - // Check timestamp - if (GetBlockTime() > FutureDrift(GetAdjustedTime())) - return error("CheckBlock() : block timestamp too far in the future"); + bool fProofOfStake = IsProofOfStake(); // First transaction must be coinbase, the rest must not be - if (vtx.empty() || !vtx[0].IsCoinBase()) + if (!vtx[0].IsCoinBase()) return DoS(100, error("CheckBlock() : first tx is not coinbase")); - // Check coinbase timestamp - if (GetBlockTime() < PastDrift((int64_t)vtx[0].nTime)) - return DoS(50, error("CheckBlock() : coinbase timestamp is too late")); - - for (unsigned int i = 1; i < vtx.size(); i++) - { - if (vtx[i].IsCoinBase()) - return DoS(100, error("CheckBlock() : more than one coinbase")); + if (!vtx[0].CheckTransaction()) + return DoS(vtx[0].nDoS, error("CheckBlock() : CheckTransaction failed on coinbase")); - // Check transaction timestamp - if (GetBlockTime() < (int64_t)vtx[i].nTime) - return DoS(50, error("CheckBlock() : block timestamp earlier than transaction timestamp")); - } + uniqueTx.insert(vtx[0].GetHash()); + nSigOps += vtx[0].GetLegacySigOpCount(); - if (IsProofOfStake()) + if (fProofOfStake) { + // Proof-of-STake related checkings. Note that we know here that 1st transactions is coinstake. We don't need + // check the type of 1st transaction because it's performed earlier by IsProofOfStake() + + // nNonce must be zero for proof-of-stake blocks if (nNonce != 0) return DoS(100, error("CheckBlock() : non-zero nonce in proof-of-stake block")); @@ -2267,13 +2260,6 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) c if (vtx[0].vout.size() != 1 || !vtx[0].vout[0].IsEmpty()) return DoS(100, error("CheckBlock() : coinbase output not empty for proof-of-stake block")); - // Second transaction must be coinstake, the rest must not be - if (vtx.empty() || !vtx[1].IsCoinStake()) - return DoS(100, error("CheckBlock() : second tx is not coinstake")); - for (unsigned int i = 2; i < vtx.size(); i++) - if (vtx[i].IsCoinStake()) - return DoS(100, error("CheckBlock() : more than one coinstake")); - // Check coinstake timestamp if (GetBlockTime() != (int64_t)vtx[1].nTime) return DoS(50, error("CheckBlock() : coinstake timestamp violation nTimeBlock=%" PRId64 " nTimeTx=%u", GetBlockTime(), vtx[1].nTime)); @@ -2281,30 +2267,63 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot, bool fCheckSig) c // NovaCoin: check proof-of-stake block signature if (fCheckSig && !CheckBlockSignature()) return DoS(100, error("CheckBlock() : bad proof-of-stake block signature")); + + if (!vtx[1].CheckTransaction()) + return DoS(vtx[1].nDoS, error("CheckBlock() : CheckTransaction failed on coinstake")); + + uniqueTx.insert(vtx[1].GetHash()); + nSigOps += vtx[1].GetLegacySigOpCount(); + } + else + { + // Check proof of work matches claimed amount + if (fCheckPOW && !CheckProofOfWork(GetHash(), nBits)) + return DoS(50, error("CheckBlock() : proof of work failed")); + + // Check timestamp + if (GetBlockTime() > FutureDrift(GetAdjustedTime())) + return error("CheckBlock() : block timestamp too far in the future"); + + // Check coinbase timestamp + if (GetBlockTime() < PastDrift((int64_t)vtx[0].nTime)) + return DoS(50, error("CheckBlock() : coinbase timestamp is too late")); } - // Check transactions - BOOST_FOREACH(const CTransaction& tx, vtx) + // Iterate all transactions starting from second for proof-of-stake block + // or first for proof-of-work block + for (unsigned int i = fProofOfStake ? 2 : 1; i < vtx.size(); i++) { + const CTransaction& tx = vtx[i]; + + // Reject coinbase transactions at non-zero index + if (tx.IsCoinBase()) + return DoS(100, error("CheckBlock() : coinbase at wrong index")); + + // Reject coinstake transactions at index != 1 + if (tx.IsCoinStake()) + return DoS(100, error("CheckBlock() : coinstake at wrong index")); + + // Check transaction timestamp + if (GetBlockTime() < (int64_t)tx.nTime) + return DoS(50, error("CheckBlock() : block timestamp earlier than transaction timestamp")); + + // Check transaction consistency if (!tx.CheckTransaction()) return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed")); + + // Add transaction hash into list of unique transaction IDs + uniqueTx.insert(tx.GetHash()); + + // Calculate sigops count + nSigOps += tx.GetLegacySigOpCount(); } // Check for duplicate txids. This is caught by ConnectInputs(), // but catching it earlier avoids a potential DoS attack: - set uniqueTx; - BOOST_FOREACH(const CTransaction& tx, vtx) - { - uniqueTx.insert(tx.GetHash()); - } if (uniqueTx.size() != vtx.size()) return DoS(100, error("CheckBlock() : duplicate transaction")); - unsigned int nSigOps = 0; - BOOST_FOREACH(const CTransaction& tx, vtx) - { - nSigOps += tx.GetLegacySigOpCount(); - } + // Reject block if validation would consume too much resources. if (nSigOps > MAX_BLOCK_SIGOPS) return DoS(100, error("CheckBlock() : out-of-bounds SigOpCount")); -- 1.7.1