1 files changed, 277 insertions, 0 deletions
diff --git a/src/coins.cpp b/src/coins.cpp
new file mode 100644
index 0000000000..b71362c6a0
--- /dev/null
+++ b/src/coins.cpp
@@ -0,0 +1,277 @@
+// Copyright (c) 2012-2019 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 <logging.h>
+#include <random.h>
+#include <version.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;
+}
+
+bool CCoinsViewErrorCatcher::GetCoin(const COutPoint &outpoint, Coin &coin) const {
+    try {
+        return CCoinsViewBacked::GetCoin(outpoint, coin);
+    } catch(const std::runtime_error& e) {
+        for (auto f : m_err_callbacks) {
+            f();
+        }
+        LogPrintf("Error reading from database: %s\n", e.what());
+        // Starting the shutdown sequence and returning false to the caller would be
+        // interpreted as 'entry not found' (as opposed to unable to read data), and
+        // could lead to invalid interpretation. Just exit immediately, as we can't
+        // continue anyway, and all writes should be atomic.
+        std::abort();
+    }
+}