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// Copyright (c) 2012-2018 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 <consensus/consensus.h>
#include <random.h>
bool CCoinsView::GetCoin(const COutPoint &outpoint, Coin &coin) const { return false; }
uint256 CCoinsView::GetBestBlock() const { return uint256(); }
std::vector<uint256> CCoinsView::GetHeadBlocks() const { return std::vector<uint256>(); }
bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
CCoinsViewCursor *CCoinsView::Cursor() const { return nullptr; }
bool CCoinsView::HaveCoin(const COutPoint &outpoint) const
{
Coin coin;
return GetCoin(outpoint, coin);
}
CCoinsViewBacked::CCoinsViewBacked(CCoinsView *viewIn) : base(viewIn) { }
bool CCoinsViewBacked::GetCoin(const COutPoint &outpoint, Coin &coin) const { return base->GetCoin(outpoint, coin); }
bool CCoinsViewBacked::HaveCoin(const COutPoint &outpoint) const { return base->HaveCoin(outpoint); }
uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
std::vector<uint256> CCoinsViewBacked::GetHeadBlocks() const { return base->GetHeadBlocks(); }
void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
CCoinsViewCursor *CCoinsViewBacked::Cursor() const { return base->Cursor(); }
size_t CCoinsViewBacked::EstimateSize() const { return base->EstimateSize(); }
SaltedOutpointHasher::SaltedOutpointHasher() : k0(GetRand(std::numeric_limits<uint64_t>::max())), k1(GetRand(std::numeric_limits<uint64_t>::max())) {}
CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), cachedCoinsUsage(0) {}
size_t CCoinsViewCache::DynamicMemoryUsage() const {
return memusage::DynamicUsage(cacheCoins) + cachedCoinsUsage;
}
CCoinsMap::iterator CCoinsViewCache::FetchCoin(const COutPoint &outpoint) const {
CCoinsMap::iterator it = cacheCoins.find(outpoint);
if (it != cacheCoins.end())
return it;
Coin tmp;
if (!base->GetCoin(outpoint, tmp))
return cacheCoins.end();
CCoinsMap::iterator ret = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::forward_as_tuple(std::move(tmp))).first;
if (ret->second.coin.IsSpent()) {
// The parent only has an empty entry for this outpoint; we can consider our
// version as fresh.
ret->second.flags = CCoinsCacheEntry::FRESH;
}
cachedCoinsUsage += ret->second.coin.DynamicMemoryUsage();
return ret;
}
bool CCoinsViewCache::GetCoin(const COutPoint &outpoint, Coin &coin) const {
CCoinsMap::const_iterator it = FetchCoin(outpoint);
if (it != cacheCoins.end()) {
coin = it->second.coin;
return !coin.IsSpent();
}
return false;
}
void CCoinsViewCache::AddCoin(const COutPoint &outpoint, Coin&& coin, bool possible_overwrite) {
assert(!coin.IsSpent());
if (coin.out.scriptPubKey.IsUnspendable()) return;
CCoinsMap::iterator it;
bool inserted;
std::tie(it, inserted) = cacheCoins.emplace(std::piecewise_construct, std::forward_as_tuple(outpoint), std::tuple<>());
bool fresh = false;
if (!inserted) {
cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
}
if (!possible_overwrite) {
if (!it->second.coin.IsSpent()) {
throw std::logic_error("Adding new coin that replaces non-pruned entry");
}
fresh = !(it->second.flags & CCoinsCacheEntry::DIRTY);
}
it->second.coin = std::move(coin);
it->second.flags |= CCoinsCacheEntry::DIRTY | (fresh ? CCoinsCacheEntry::FRESH : 0);
cachedCoinsUsage += it->second.coin.DynamicMemoryUsage();
}
void AddCoins(CCoinsViewCache& cache, const CTransaction &tx, int nHeight, bool check) {
bool fCoinbase = tx.IsCoinBase();
const uint256& txid = tx.GetHash();
for (size_t i = 0; i < tx.vout.size(); ++i) {
bool overwrite = check ? cache.HaveCoin(COutPoint(txid, i)) : fCoinbase;
// Always set the possible_overwrite flag to AddCoin for coinbase txn, in order to correctly
// deal with the pre-BIP30 occurrences of duplicate coinbase transactions.
cache.AddCoin(COutPoint(txid, i), Coin(tx.vout[i], nHeight, fCoinbase), overwrite);
}
}
bool CCoinsViewCache::SpendCoin(const COutPoint &outpoint, Coin* moveout) {
CCoinsMap::iterator it = FetchCoin(outpoint);
if (it == cacheCoins.end()) return false;
cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
if (moveout) {
*moveout = std::move(it->second.coin);
}
if (it->second.flags & CCoinsCacheEntry::FRESH) {
cacheCoins.erase(it);
} else {
it->second.flags |= CCoinsCacheEntry::DIRTY;
it->second.coin.Clear();
}
return true;
}
static const Coin coinEmpty;
const Coin& CCoinsViewCache::AccessCoin(const COutPoint &outpoint) const {
CCoinsMap::const_iterator it = FetchCoin(outpoint);
if (it == cacheCoins.end()) {
return coinEmpty;
} else {
return it->second.coin;
}
}
bool CCoinsViewCache::HaveCoin(const COutPoint &outpoint) const {
CCoinsMap::const_iterator it = FetchCoin(outpoint);
return (it != cacheCoins.end() && !it->second.coin.IsSpent());
}
bool CCoinsViewCache::HaveCoinInCache(const COutPoint &outpoint) const {
CCoinsMap::const_iterator it = cacheCoins.find(outpoint);
return (it != cacheCoins.end() && !it->second.coin.IsSpent());
}
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) {
for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end(); it = mapCoins.erase(it)) {
// Ignore non-dirty entries (optimization).
if (!(it->second.flags & CCoinsCacheEntry::DIRTY)) {
continue;
}
CCoinsMap::iterator itUs = cacheCoins.find(it->first);
if (itUs == cacheCoins.end()) {
// The parent cache does not have an entry, while the child does
// We can ignore it if it's both FRESH and pruned in the child
if (!(it->second.flags & CCoinsCacheEntry::FRESH && it->second.coin.IsSpent())) {
// Otherwise we will need to create it in the parent
// and move the data up and mark it as dirty
CCoinsCacheEntry& entry = cacheCoins[it->first];
entry.coin = std::move(it->second.coin);
cachedCoinsUsage += entry.coin.DynamicMemoryUsage();
entry.flags = CCoinsCacheEntry::DIRTY;
// We can mark it FRESH in the parent if it was FRESH in the child
// Otherwise it might have just been flushed from the parent's cache
// and already exist in the grandparent
if (it->second.flags & CCoinsCacheEntry::FRESH) {
entry.flags |= CCoinsCacheEntry::FRESH;
}
}
} else {
// Assert that the child cache entry was not marked FRESH if the
// parent cache entry has unspent outputs. If this ever happens,
// it means the FRESH flag was misapplied and there is a logic
// error in the calling code.
if ((it->second.flags & CCoinsCacheEntry::FRESH) && !itUs->second.coin.IsSpent()) {
throw std::logic_error("FRESH flag misapplied to cache entry for base transaction with spendable outputs");
}
// Found the entry in the parent cache
if ((itUs->second.flags & CCoinsCacheEntry::FRESH) && it->second.coin.IsSpent()) {
// 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.coin.DynamicMemoryUsage();
cacheCoins.erase(itUs);
} else {
// A normal modification.
cachedCoinsUsage -= itUs->second.coin.DynamicMemoryUsage();
itUs->second.coin = std::move(it->second.coin);
cachedCoinsUsage += itUs->second.coin.DynamicMemoryUsage();
itUs->second.flags |= CCoinsCacheEntry::DIRTY;
// NOTE: It is possible the child has a FRESH flag here in
// the event the entry we found in the parent is pruned. But
// we must not copy that FRESH flag to the parent as that
// pruned state likely still needs to be communicated to the
// grandparent.
}
}
}
hashBlock = hashBlockIn;
return true;
}
bool CCoinsViewCache::Flush() {
bool fOk = base->BatchWrite(cacheCoins, hashBlock);
cacheCoins.clear();
cachedCoinsUsage = 0;
return fOk;
}
void CCoinsViewCache::Uncache(const COutPoint& hash)
{
CCoinsMap::iterator it = cacheCoins.find(hash);
if (it != cacheCoins.end() && it->second.flags == 0) {
cachedCoinsUsage -= it->second.coin.DynamicMemoryUsage();
cacheCoins.erase(it);
}
}
unsigned int CCoinsViewCache::GetCacheSize() const {
return cacheCoins.size();
}
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 += AccessCoin(tx.vin[i].prevout).out.nValue;
return nResult;
}
bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const
{
if (!tx.IsCoinBase()) {
for (unsigned int i = 0; i < tx.vin.size(); i++) {
if (!HaveCoin(tx.vin[i].prevout)) {
return false;
}
}
}
return true;
}
static const size_t MIN_TRANSACTION_OUTPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxOut(), PROTOCOL_VERSION);
static const size_t MAX_OUTPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_OUTPUT_WEIGHT;
const Coin& AccessByTxid(const CCoinsViewCache& view, const uint256& txid)
{
COutPoint iter(txid, 0);
while (iter.n < MAX_OUTPUTS_PER_BLOCK) {
const Coin& alternate = view.AccessCoin(iter);
if (!alternate.IsSpent()) return alternate;
++iter.n;
}
return coinEmpty;
}