void CPartialMerkleTree::TraverseAndBuild(int height, unsigned int pos, const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) {
// determine whether this node is the parent of at least one matched txid
bool fParentOfMatch = false;
for (unsigned int p = pos << height; p < (pos+1) << height && p < nTransactions; p++)
fParentOfMatch |= vMatch[p];
// store as flag bit
vBits.push_back(fParentOfMatch);
if (height==0 || !fParentOfMatch) {
// if at height 0, or nothing interesting below, store hash and stop
vHash.push_back(CalcHash(height, pos, vTxid));
} else {
// otherwise, don't store any hash, but descend into the subtrees
TraverseAndBuild(height-1, pos*2, vTxid, vMatch);
if (pos*2+1 < CalcTreeWidth(height-1))
TraverseAndBuild(height-1, pos*2+1, vTxid, vMatch);
}
}
CPartialMerkleTree::CPartialMerkleTree(const std::vector<uint256> &vTxid, const std::vector<bool> &vMatch) : nTransactions(vTxid.size()), fBad(false) {
// reset state
vBits.clear();
vHash.clear();
// calculate height of tree
int nHeight = 0;
while (CalcTreeWidth(nHeight) > 1)
nHeight++;
// traverse the partial tree
TraverseAndBuild(nHeight, 0, vTxid, vMatch);
}
