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Added some comments

Some clarifications after a code review by Mike Hearn.
tags/v0.15.1
Pieter Wuille 8 years ago
parent
commit
c2ed184f98
2 changed files with 24 additions and 2 deletions
  1. 8
    1
      src/main.cpp
  2. 16
    1
      src/main.h

+ 8
- 1
src/main.cpp View File

@@ -698,6 +698,8 @@ bool CTxMemPool::accept(CTransaction &tx, bool fCheckInputs,
return false;

// do all inputs exist?
// Note that this does not check for the presence of actual outputs (see the next check for that),
// only helps filling in pfMissingInputs (to determine missing vs spent).
BOOST_FOREACH(const CTxIn txin, tx.vin) {
if (!view.HaveCoins(txin.prevout.hash)) {
if (pfMissingInputs)
@@ -706,6 +708,7 @@ bool CTxMemPool::accept(CTransaction &tx, bool fCheckInputs,
}
}

// are the actual inputs available?
if (!tx.HaveInputs(view))
return error("CTxMemPool::accept() : inputs already spent");

@@ -1956,9 +1959,13 @@ bool CBlock::CheckBlock(bool fCheckPOW, bool fCheckMerkleRoot) const
if (!tx.CheckTransaction())
return DoS(tx.nDoS, error("CheckBlock() : CheckTransaction failed"));

// Build the merkle tree already. We need it anyway later, and it makes the
// block cache the transaction hashes, which means they don't need to be
// recalculated many times during this block's validation.
BuildMerkleTree();

// Check for duplicate txids. This is caught by ConnectInputs(),
// but catching it earlier avoids a potential DoS attack:
BuildMerkleTree();
set<uint256> uniqueTx;
for (unsigned int i=0; i<vtx.size(); i++) {
uniqueTx.insert(GetTxHash(i));

+ 16
- 1
src/main.h View File

@@ -1820,7 +1820,11 @@ public:

// Modify the currently active block index
virtual bool SetBestBlock(CBlockIndex *pindex);

// Do a bulk modification (multiple SetCoins + one SetBestBlock)
virtual bool BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex);

// Calculate statistics about the unspent transaction output set
virtual bool GetStats(CCoinsStats &stats);
};

@@ -1851,14 +1855,25 @@ protected:

public:
CCoinsViewCache(CCoinsView &baseIn, bool fDummy = false);

// Standard CCoinsView methods
bool GetCoins(uint256 txid, CCoins &coins);
bool SetCoins(uint256 txid, const CCoins &coins);
bool HaveCoins(uint256 txid);
CCoins &GetCoins(uint256 txid);
CBlockIndex *GetBestBlock();
bool SetBestBlock(CBlockIndex *pindex);
bool BatchWrite(const std::map<uint256, CCoins> &mapCoins, CBlockIndex *pindex);

// Return a modifiable reference to a CCoins. Check HaveCoins first.
// Many methods explicitly require a CCoinsViewCache because of this method, to reduce
// copying.
CCoins &GetCoins(uint256 txid);

// Push the modifications applied to this cache to its base.
// Failure to call this method before destruction will cause the changes to be forgotten.
bool Flush();

// Calculate the size of the cache (in number of transactions)
unsigned int GetCacheSize();

private:

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