60 lines
1.7 KiB
C++
60 lines
1.7 KiB
C++
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// Copyright (c) 2009-2010 Satoshi Nakamoto
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// Copyright (c) 2009-2014 The Bitcoin developers
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// Distributed under the MIT/X11 software license, see the accompanying
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// file COPYING or http://www.opensource.org/licenses/mit-license.php.
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#include "chain.h"
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using namespace std;
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// CChain implementation
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CBlockIndex *CChain::SetTip(CBlockIndex *pindex) {
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if (pindex == NULL) {
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vChain.clear();
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return NULL;
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}
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vChain.resize(pindex->nHeight + 1);
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while (pindex && vChain[pindex->nHeight] != pindex) {
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vChain[pindex->nHeight] = pindex;
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pindex = pindex->pprev;
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}
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return pindex;
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}
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CBlockLocator CChain::GetLocator(const CBlockIndex *pindex) const {
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int nStep = 1;
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std::vector<uint256> vHave;
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vHave.reserve(32);
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if (!pindex)
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pindex = Tip();
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while (pindex) {
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vHave.push_back(pindex->GetBlockHash());
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// Stop when we have added the genesis block.
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if (pindex->nHeight == 0)
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break;
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// Exponentially larger steps back, plus the genesis block.
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int nHeight = std::max(pindex->nHeight - nStep, 0);
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if (Contains(pindex)) {
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// Use O(1) CChain index if possible.
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pindex = (*this)[nHeight];
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} else {
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// Otherwise, use O(log n) skiplist.
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pindex = pindex->GetAncestor(nHeight);
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}
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if (vHave.size() > 10)
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nStep *= 2;
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}
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return CBlockLocator(vHave);
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}
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const CBlockIndex *CChain::FindFork(const CBlockIndex *pindex) const {
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if (pindex->nHeight > Height())
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pindex = pindex->GetAncestor(Height());
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while (pindex && !Contains(pindex))
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pindex = pindex->pprev;
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return pindex;
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}
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