diff options
Diffstat (limited to 'src/coins.h')
| -rw-r--r-- | src/coins.h | 191 |
1 files changed, 124 insertions, 67 deletions
diff --git a/src/coins.h b/src/coins.h index bf61f55aac..2be52ad171 100644 --- a/src/coins.h +++ b/src/coins.h @@ -1,12 +1,12 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto -// Copyright (c) 2009-2013 The Bitcoin developers -// Distributed under the MIT/X11 software license, see the accompanying +// Copyright (c) 2009-2014 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_COINS_H #define BITCOIN_COINS_H -#include "core.h" +#include "compressor.h" #include "serialize.h" #include "uint256.h" @@ -16,7 +16,8 @@ #include <boost/foreach.hpp> #include <boost/unordered_map.hpp> -/** pruned version of CTransaction: only retains metadata and unspent transaction outputs +/** + * Pruned version of CTransaction: only retains metadata and unspent transaction outputs * * Serialized format: * - VARINT(nVersion) @@ -70,28 +71,43 @@ class CCoins { public: - // whether transaction is a coinbase + //! whether transaction is a coinbase bool fCoinBase; - // unspent transaction outputs; spent outputs are .IsNull(); spent outputs at the end of the array are dropped + //! unspent transaction outputs; spent outputs are .IsNull(); spent outputs at the end of the array are dropped std::vector<CTxOut> vout; - // at which height this transaction was included in the active block chain + //! at which height this transaction was included in the active block chain int nHeight; - // version of the CTransaction; accesses to this value should probably check for nHeight as well, - // as new tx version will probably only be introduced at certain heights + //! version of the CTransaction; accesses to this value should probably check for nHeight as well, + //! as new tx version will probably only be introduced at certain heights int nVersion; - // construct a CCoins from a CTransaction, at a given height - CCoins(const CTransaction &tx, int nHeightIn) : fCoinBase(tx.IsCoinBase()), vout(tx.vout), nHeight(nHeightIn), nVersion(tx.nVersion) { + void FromTx(const CTransaction &tx, int nHeightIn) { + fCoinBase = tx.IsCoinBase(); + vout = tx.vout; + nHeight = nHeightIn; + nVersion = tx.nVersion; ClearUnspendable(); } - // empty constructor + //! construct a CCoins from a CTransaction, at a given height + CCoins(const CTransaction &tx, int nHeightIn) { + FromTx(tx, nHeightIn); + } + + void Clear() { + fCoinBase = false; + std::vector<CTxOut>().swap(vout); + nHeight = 0; + nVersion = 0; + } + + //! empty constructor CCoins() : fCoinBase(false), vout(0), nHeight(0), nVersion(0) { } - // remove spent outputs at the end of vout + //!remove spent outputs at the end of vout void Cleanup() { while (vout.size() > 0 && vout.back().IsNull()) vout.pop_back(); @@ -114,7 +130,7 @@ public: std::swap(to.nVersion, nVersion); } - // equality test + //! equality test friend bool operator==(const CCoins &a, const CCoins &b) { // Empty CCoins objects are always equal. if (a.IsPruned() && b.IsPruned()) @@ -220,19 +236,16 @@ public: Cleanup(); } - // mark an outpoint spent, and construct undo information - bool Spend(const COutPoint &out, CTxInUndo &undo); + //! mark a vout spent + bool Spend(uint32_t nPos); - // mark a vout spent - bool Spend(int nPos); - - // check whether a particular output is still available + //! check whether a particular output is still available bool IsAvailable(unsigned int nPos) const { return (nPos < vout.size() && !vout[nPos].IsNull()); } - // check whether the entire CCoins is spent - // note that only !IsPruned() CCoins can be serialized + //! check whether the entire CCoins is spent + //! note that only !IsPruned() CCoins can be serialized bool IsPruned() const { BOOST_FOREACH(const CTxOut &out, vout) if (!out.IsNull()) @@ -248,15 +261,31 @@ private: public: CCoinsKeyHasher(); - // This *must* return size_t. With Boost 1.46 on 32-bit systems the - // unordered_map will behave unpredictably if the custom hasher returns a - // uint64_t, resulting in failures when syncing the chain (#4634). + + /** + * This *must* return size_t. With Boost 1.46 on 32-bit systems the + * unordered_map will behave unpredictably if the custom hasher returns a + * uint64_t, resulting in failures when syncing the chain (#4634). + */ size_t operator()(const uint256& key) const { return key.GetHash(salt); } }; -typedef boost::unordered_map<uint256, CCoins, CCoinsKeyHasher> CCoinsMap; +struct CCoinsCacheEntry +{ + CCoins coins; // The actual cached data. + unsigned char flags; + + enum Flags { + DIRTY = (1 << 0), // This cache entry is potentially different from the version in the parent view. + FRESH = (1 << 1), // The parent view does not have this entry (or it is pruned). + }; + + CCoinsCacheEntry() : coins(), flags(0) {} +}; + +typedef boost::unordered_map<uint256, CCoinsCacheEntry, CCoinsKeyHasher> CCoinsMap; struct CCoinsStats { @@ -266,7 +295,7 @@ struct CCoinsStats uint64_t nTransactionOutputs; uint64_t nSerializedSize; uint256 hashSerialized; - int64_t nTotalAmount; + CAmount nTotalAmount; CCoinsStats() : nHeight(0), hashBlock(0), nTransactions(0), nTransactionOutputs(0), nSerializedSize(0), hashSerialized(0), nTotalAmount(0) {} }; @@ -276,30 +305,24 @@ struct CCoinsStats class CCoinsView { public: - // Retrieve the CCoins (unspent transaction outputs) for a given txid + //! Retrieve the CCoins (unspent transaction outputs) for a given txid virtual bool GetCoins(const uint256 &txid, CCoins &coins) const; - // Modify the CCoins for a given txid - virtual bool SetCoins(const uint256 &txid, const CCoins &coins); - - // Just check whether we have data for a given txid. - // This may (but cannot always) return true for fully spent transactions + //! Just check whether we have data for a given txid. + //! This may (but cannot always) return true for fully spent transactions virtual bool HaveCoins(const uint256 &txid) const; - // Retrieve the block hash whose state this CCoinsView currently represents + //! Retrieve the block hash whose state this CCoinsView currently represents virtual uint256 GetBestBlock() const; - // Modify the currently active block hash - virtual bool SetBestBlock(const uint256 &hashBlock); - - // Do a bulk modification (multiple SetCoins + one SetBestBlock). - // The passed mapCoins can be modified. + //! Do a bulk modification (multiple CCoins changes + BestBlock change). + //! The passed mapCoins can be modified. virtual bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock); - // Calculate statistics about the unspent transaction output set + //! Calculate statistics about the unspent transaction output set virtual bool GetStats(CCoinsStats &stats) const; - // As we use CCoinsViews polymorphically, have a virtual destructor + //! As we use CCoinsViews polymorphically, have a virtual destructor virtual ~CCoinsView() {} }; @@ -311,72 +334,106 @@ protected: CCoinsView *base; public: - CCoinsViewBacked(CCoinsView &viewIn); + CCoinsViewBacked(CCoinsView *viewIn); bool GetCoins(const uint256 &txid, CCoins &coins) const; - bool SetCoins(const uint256 &txid, const CCoins &coins); bool HaveCoins(const uint256 &txid) const; uint256 GetBestBlock() const; - bool SetBestBlock(const uint256 &hashBlock); void SetBackend(CCoinsView &viewIn); bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock); bool GetStats(CCoinsStats &stats) const; }; +class CCoinsViewCache; + +/** + * A reference to a mutable cache entry. Encapsulating it allows us to run + * cleanup code after the modification is finished, and keeping track of + * concurrent modifications. + */ +class CCoinsModifier +{ +private: + CCoinsViewCache& cache; + CCoinsMap::iterator it; + CCoinsModifier(CCoinsViewCache& cache_, CCoinsMap::iterator it_); + +public: + CCoins* operator->() { return &it->second.coins; } + CCoins& operator*() { return it->second.coins; } + ~CCoinsModifier(); + friend class CCoinsViewCache; +}; + /** CCoinsView that adds a memory cache for transactions to another CCoinsView */ class CCoinsViewCache : public CCoinsViewBacked { protected: + /* Whether this cache has an active modifier. */ + bool hasModifier; - /* Make mutable so that we can "fill the cache" even from Get-methods - declared as "const". */ + /** + * Make mutable so that we can "fill the cache" even from Get-methods + * declared as "const". + */ mutable uint256 hashBlock; mutable CCoinsMap cacheCoins; public: - CCoinsViewCache(CCoinsView &baseIn, bool fDummy = false); + CCoinsViewCache(CCoinsView *baseIn); + ~CCoinsViewCache(); // Standard CCoinsView methods bool GetCoins(const uint256 &txid, CCoins &coins) const; - bool SetCoins(const uint256 &txid, const CCoins &coins); bool HaveCoins(const uint256 &txid) const; uint256 GetBestBlock() const; - bool SetBestBlock(const uint256 &hashBlock); + void SetBestBlock(const uint256 &hashBlock); bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock); - // Return a pointer to CCoins in the cache, or NULL if not found. This is - // more efficient than GetCoins. Modifications to other cache entries are - // allowed while accessing the returned pointer. + /** + * Return a pointer to CCoins in the cache, or NULL if not found. This is + * more efficient than GetCoins. Modifications to other cache entries are + * allowed while accessing the returned pointer. + */ const CCoins* AccessCoins(const uint256 &txid) const; - // Return a modifiable reference to a CCoins. Check HaveCoins first. - CCoins &GetCoins(const uint256 &txid); + /** + * Return a modifiable reference to a CCoins. If no entry with the given + * txid exists, a new one is created. Simultaneous modifications are not + * allowed. + */ + CCoinsModifier ModifyCoins(const uint256 &txid); - // Push the modifications applied to this cache to its base. - // Failure to call this method before destruction will cause the changes to be forgotten. - // If false is returned, the state of this cache (and its backing view) will be undefined. + /** + * Push the modifications applied to this cache to its base. + * Failure to call this method before destruction will cause the changes to be forgotten. + * If false is returned, the state of this cache (and its backing view) will be undefined. + */ bool Flush(); - // Calculate the size of the cache (in number of transactions) + //! Calculate the size of the cache (in number of transactions) unsigned int GetCacheSize() const; - /** Amount of bitcoins coming in to a transaction - Note that lightweight clients may not know anything besides the hash of previous transactions, - so may not be able to calculate this. - - @param[in] tx transaction for which we are checking input total - @return Sum of value of all inputs (scriptSigs) + /** + * Amount of bitcoins coming in to a transaction + * Note that lightweight clients may not know anything besides the hash of previous transactions, + * so may not be able to calculate this. + * + * @param[in] tx transaction for which we are checking input total + * @return Sum of value of all inputs (scriptSigs) */ - int64_t GetValueIn(const CTransaction& tx) const; + CAmount GetValueIn(const CTransaction& tx) const; - // Check whether all prevouts of the transaction are present in the UTXO set represented by this view + //! Check whether all prevouts of the transaction are present in the UTXO set represented by this view bool HaveInputs(const CTransaction& tx) const; - // Return priority of tx at height nHeight + //! Return priority of tx at height nHeight double GetPriority(const CTransaction &tx, int nHeight) const; const CTxOut &GetOutputFor(const CTxIn& input) const; + friend class CCoinsModifier; + private: CCoinsMap::iterator FetchCoins(const uint256 &txid); CCoinsMap::const_iterator FetchCoins(const uint256 &txid) const; |