lbrycrd/src/index/txindex.h
2018-06-04 19:22:30 -07:00

54 lines
1.7 KiB
C++

// Copyright (c) 2017-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_INDEX_TXINDEX_H
#define BITCOIN_INDEX_TXINDEX_H
#include <chain.h>
#include <index/base.h>
#include <txdb.h>
/**
* TxIndex is used to look up transactions included in the blockchain by hash.
* The index is written to a LevelDB database and records the filesystem
* location of each transaction by transaction hash.
*/
class TxIndex final : public BaseIndex
{
protected:
class DB;
private:
const std::unique_ptr<DB> m_db;
protected:
/// Override base class init to migrate from old database.
bool Init() override;
bool WriteBlock(const CBlock& block, const CBlockIndex* pindex) override;
BaseIndex::DB& GetDB() const override;
const char* GetName() const override { return "txindex"; }
public:
/// Constructs the index, which becomes available to be queried.
explicit TxIndex(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
// Destructor is declared because this class contains a unique_ptr to an incomplete type.
virtual ~TxIndex() override;
/// Look up a transaction by hash.
///
/// @param[in] tx_hash The hash of the transaction to be returned.
/// @param[out] block_hash The hash of the block the transaction is found in.
/// @param[out] tx The transaction itself.
/// @return true if transaction is found, false otherwise
bool FindTx(const uint256& tx_hash, uint256& block_hash, CTransactionRef& tx) const;
};
/// The global transaction index, used in GetTransaction. May be null.
extern std::unique_ptr<TxIndex> g_txindex;
#endif // BITCOIN_INDEX_TXINDEX_H