diff options
Diffstat (limited to 'src/coins.cpp')
-rw-r--r-- | src/coins.cpp | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/src/coins.cpp b/src/coins.cpp new file mode 100644 index 0000000000..f02949de53 --- /dev/null +++ b/src/coins.cpp @@ -0,0 +1,266 @@ +// Copyright (c) 2012-2014 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "coins.h" + +#include "memusage.h" +#include "random.h" + +#include <assert.h> + +/** + * calculate number of bytes for the bitmask, and its number of non-zero bytes + * each bit in the bitmask represents the availability of one output, but the + * availabilities of the first two outputs are encoded separately + */ +void CCoins::CalcMaskSize(unsigned int &nBytes, unsigned int &nNonzeroBytes) const { + unsigned int nLastUsedByte = 0; + for (unsigned int b = 0; 2+b*8 < vout.size(); b++) { + bool fZero = true; + for (unsigned int i = 0; i < 8 && 2+b*8+i < vout.size(); i++) { + if (!vout[2+b*8+i].IsNull()) { + fZero = false; + continue; + } + } + if (!fZero) { + nLastUsedByte = b + 1; + nNonzeroBytes++; + } + } + nBytes += nLastUsedByte; +} + +bool CCoins::Spend(uint32_t nPos) +{ + if (nPos >= vout.size() || vout[nPos].IsNull()) + return false; + vout[nPos].SetNull(); + Cleanup(); + return true; +} + +bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) const { return false; } +bool CCoinsView::HaveCoins(const uint256 &txid) const { return false; } +uint256 CCoinsView::GetBestBlock() const { return uint256(); } +bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; } +bool CCoinsView::GetStats(CCoinsStats &stats) const { return false; } + + +CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { } +bool CCoinsViewBacked::GetCoins(const uint256 &txid, CCoins &coins) const { return base->GetCoins(txid, coins); } +bool CCoinsViewBacked::HaveCoins(const uint256 &txid) const { return base->HaveCoins(txid); } +uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); } +void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; } +bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); } +bool CCoinsViewBacked::GetStats(CCoinsStats &stats) const { return base->GetStats(stats); } + +CCoinsKeyHasher::CCoinsKeyHasher() : salt(GetRandHash()) {} + +CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), hasModifier(false), cachedCoinsUsage(0) { } + +CCoinsViewCache::~CCoinsViewCache() +{ + assert(!hasModifier); +} + +size_t CCoinsViewCache::DynamicMemoryUsage() const { + return memusage::DynamicUsage(cacheCoins) + cachedCoinsUsage; +} + +CCoinsMap::const_iterator CCoinsViewCache::FetchCoins(const uint256 &txid) const { + CCoinsMap::iterator it = cacheCoins.find(txid); + if (it != cacheCoins.end()) + return it; + CCoins tmp; + if (!base->GetCoins(txid, tmp)) + return cacheCoins.end(); + CCoinsMap::iterator ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry())).first; + tmp.swap(ret->second.coins); + if (ret->second.coins.IsPruned()) { + // The parent only has an empty entry for this txid; we can consider our + // version as fresh. + ret->second.flags = CCoinsCacheEntry::FRESH; + } + cachedCoinsUsage += ret->second.coins.DynamicMemoryUsage(); + return ret; +} + +bool CCoinsViewCache::GetCoins(const uint256 &txid, CCoins &coins) const { + CCoinsMap::const_iterator it = FetchCoins(txid); + if (it != cacheCoins.end()) { + coins = it->second.coins; + return true; + } + return false; +} + +CCoinsModifier CCoinsViewCache::ModifyCoins(const uint256 &txid) { + assert(!hasModifier); + std::pair<CCoinsMap::iterator, bool> ret = cacheCoins.insert(std::make_pair(txid, CCoinsCacheEntry())); + size_t cachedCoinUsage = 0; + if (ret.second) { + if (!base->GetCoins(txid, ret.first->second.coins)) { + // The parent view does not have this entry; mark it as fresh. + ret.first->second.coins.Clear(); + ret.first->second.flags = CCoinsCacheEntry::FRESH; + } else if (ret.first->second.coins.IsPruned()) { + // The parent view only has a pruned entry for this; mark it as fresh. + ret.first->second.flags = CCoinsCacheEntry::FRESH; + } + } else { + cachedCoinUsage = ret.first->second.coins.DynamicMemoryUsage(); + } + // Assume that whenever ModifyCoins is called, the entry will be modified. + ret.first->second.flags |= CCoinsCacheEntry::DIRTY; + return CCoinsModifier(*this, ret.first, cachedCoinUsage); +} + +const CCoins* CCoinsViewCache::AccessCoins(const uint256 &txid) const { + CCoinsMap::const_iterator it = FetchCoins(txid); + if (it == cacheCoins.end()) { + return NULL; + } else { + return &it->second.coins; + } +} + +bool CCoinsViewCache::HaveCoins(const uint256 &txid) const { + CCoinsMap::const_iterator it = FetchCoins(txid); + // We're using vtx.empty() instead of IsPruned here for performance reasons, + // as we only care about the case where a transaction was replaced entirely + // in a reorganization (which wipes vout entirely, as opposed to spending + // which just cleans individual outputs). + return (it != cacheCoins.end() && !it->second.coins.vout.empty()); +} + +uint256 CCoinsViewCache::GetBestBlock() const { + if (hashBlock.IsNull()) + hashBlock = base->GetBestBlock(); + return hashBlock; +} + +void CCoinsViewCache::SetBestBlock(const uint256 &hashBlockIn) { + hashBlock = hashBlockIn; +} + +bool CCoinsViewCache::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlockIn) { + assert(!hasModifier); + for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) { + if (it->second.flags & CCoinsCacheEntry::DIRTY) { // Ignore non-dirty entries (optimization). + CCoinsMap::iterator itUs = cacheCoins.find(it->first); + if (itUs == cacheCoins.end()) { + if (!it->second.coins.IsPruned()) { + // The parent cache does not have an entry, while the child + // cache does have (a non-pruned) one. Move the data up, and + // mark it as fresh (if the grandparent did have it, we + // would have pulled it in at first GetCoins). + assert(it->second.flags & CCoinsCacheEntry::FRESH); + CCoinsCacheEntry& entry = cacheCoins[it->first]; + entry.coins.swap(it->second.coins); + cachedCoinsUsage += entry.coins.DynamicMemoryUsage(); + entry.flags = CCoinsCacheEntry::DIRTY | CCoinsCacheEntry::FRESH; + } + } else { + if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coins.IsPruned()) { + // The grandparent does not have an entry, and the child is + // modified and being pruned. This means we can just delete + // it from the parent. + cachedCoinsUsage -= itUs->second.coins.DynamicMemoryUsage(); + cacheCoins.erase(itUs); + } else { + // A normal modification. + cachedCoinsUsage -= itUs->second.coins.DynamicMemoryUsage(); + itUs->second.coins.swap(it->second.coins); + cachedCoinsUsage += itUs->second.coins.DynamicMemoryUsage(); + itUs->second.flags |= CCoinsCacheEntry::DIRTY; + } + } + } + CCoinsMap::iterator itOld = it++; + mapCoins.erase(itOld); + } + hashBlock = hashBlockIn; + return true; +} + +bool CCoinsViewCache::Flush() { + bool fOk = base->BatchWrite(cacheCoins, hashBlock); + cacheCoins.clear(); + cachedCoinsUsage = 0; + return fOk; +} + +unsigned int CCoinsViewCache::GetCacheSize() const { + return cacheCoins.size(); +} + +const CTxOut &CCoinsViewCache::GetOutputFor(const CTxIn& input) const +{ + const CCoins* coins = AccessCoins(input.prevout.hash); + assert(coins && coins->IsAvailable(input.prevout.n)); + return coins->vout[input.prevout.n]; +} + +CAmount CCoinsViewCache::GetValueIn(const CTransaction& tx) const +{ + if (tx.IsCoinBase()) + return 0; + + CAmount nResult = 0; + for (unsigned int i = 0; i < tx.vin.size(); i++) + nResult += GetOutputFor(tx.vin[i]).nValue; + + return nResult; +} + +bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const +{ + if (!tx.IsCoinBase()) { + for (unsigned int i = 0; i < tx.vin.size(); i++) { + const COutPoint &prevout = tx.vin[i].prevout; + const CCoins* coins = AccessCoins(prevout.hash); + if (!coins || !coins->IsAvailable(prevout.n)) { + return false; + } + } + } + return true; +} + +double CCoinsViewCache::GetPriority(const CTransaction &tx, int nHeight) const +{ + if (tx.IsCoinBase()) + return 0.0; + double dResult = 0.0; + BOOST_FOREACH(const CTxIn& txin, tx.vin) + { + const CCoins* coins = AccessCoins(txin.prevout.hash); + assert(coins); + if (!coins->IsAvailable(txin.prevout.n)) continue; + if (coins->nHeight < nHeight) { + dResult += coins->vout[txin.prevout.n].nValue * (nHeight-coins->nHeight); + } + } + return tx.ComputePriority(dResult); +} + +CCoinsModifier::CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_, size_t usage) : cache(cache_), it(it_), cachedCoinUsage(usage) { + assert(!cache.hasModifier); + cache.hasModifier = true; +} + +CCoinsModifier::~CCoinsModifier() +{ + assert(cache.hasModifier); + cache.hasModifier = false; + it->second.coins.Cleanup(); + cache.cachedCoinsUsage -= cachedCoinUsage; // Subtract the old usage + if ((it->second.flags & CCoinsCacheEntry::FRESH) && it->second.coins.IsPruned()) { + cache.cacheCoins.erase(it); + } else { + // If the coin still exists after the modification, add the new usage + cache.cachedCoinsUsage += it->second.coins.DynamicMemoryUsage(); + } +} |