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59 lines
1.6 KiB
59 lines
1.6 KiB
// 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 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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/** |
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* CChain implementation |
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*/ |
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void CChain::SetTip(CBlockIndex *pindex) { |
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if (pindex == NULL) { |
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vChain.clear(); |
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return; |
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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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} |
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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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