bitcoin/src/txdb.h
James O'Beirne b223111da2 txdb: add CCoinsViewDB::ChangeCacheSize
We'll need this to dynamically update the cache size of the existing
CCoinsViewDB instance when we create a new one during snapshot activation.

This requires us to keep the CDBWrapper instance as a pointer instead of
a reference so that we're able to destruct it and create a new instance
when the cache size changes.

Also renames `db` to `m_db` since we're already modifying each usage.

Includes feedback from Russ Yanofsky.
2020-07-01 14:44:24 -04:00

112 lines
4.0 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 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_TXDB_H
#define BITCOIN_TXDB_H
#include <coins.h>
#include <dbwrapper.h>
#include <chain.h>
#include <primitives/block.h>
#include <memory>
#include <string>
#include <utility>
#include <vector>
class CBlockIndex;
class CCoinsViewDBCursor;
class uint256;
//! -dbcache default (MiB)
static const int64_t nDefaultDbCache = 450;
//! -dbbatchsize default (bytes)
static const int64_t nDefaultDbBatchSize = 16 << 20;
//! max. -dbcache (MiB)
static const int64_t nMaxDbCache = sizeof(void*) > 4 ? 16384 : 1024;
//! min. -dbcache (MiB)
static const int64_t nMinDbCache = 4;
//! Max memory allocated to block tree DB specific cache, if no -txindex (MiB)
static const int64_t nMaxBlockDBCache = 2;
//! Max memory allocated to block tree DB specific cache, if -txindex (MiB)
// Unlike for the UTXO database, for the txindex scenario the leveldb cache make
// a meaningful difference: https://github.com/bitcoin/bitcoin/pull/8273#issuecomment-229601991
static const int64_t nMaxTxIndexCache = 1024;
//! Max memory allocated to all block filter index caches combined in MiB.
static const int64_t max_filter_index_cache = 1024;
//! Max memory allocated to coin DB specific cache (MiB)
static const int64_t nMaxCoinsDBCache = 8;
// Actually declared in validation.cpp; can't include because of circular dependency.
extern RecursiveMutex cs_main;
/** CCoinsView backed by the coin database (chainstate/) */
class CCoinsViewDB final : public CCoinsView
{
protected:
std::unique_ptr<CDBWrapper> m_db;
fs::path m_ldb_path;
bool m_is_memory;
public:
/**
* @param[in] ldb_path Location in the filesystem where leveldb data will be stored.
*/
explicit CCoinsViewDB(fs::path ldb_path, size_t nCacheSize, bool fMemory, bool fWipe);
bool GetCoin(const COutPoint &outpoint, Coin &coin) const override;
bool HaveCoin(const COutPoint &outpoint) const override;
uint256 GetBestBlock() const override;
std::vector<uint256> GetHeadBlocks() const override;
bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) override;
CCoinsViewCursor *Cursor() const override;
//! Attempt to update from an older database format. Returns whether an error occurred.
bool Upgrade();
size_t EstimateSize() const override;
//! Dynamically alter the underlying leveldb cache size.
void ResizeCache(size_t new_cache_size) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
};
/** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */
class CCoinsViewDBCursor: public CCoinsViewCursor
{
public:
~CCoinsViewDBCursor() {}
bool GetKey(COutPoint &key) const override;
bool GetValue(Coin &coin) const override;
unsigned int GetValueSize() const override;
bool Valid() const override;
void Next() override;
private:
CCoinsViewDBCursor(CDBIterator* pcursorIn, const uint256 &hashBlockIn):
CCoinsViewCursor(hashBlockIn), pcursor(pcursorIn) {}
std::unique_ptr<CDBIterator> pcursor;
std::pair<char, COutPoint> keyTmp;
friend class CCoinsViewDB;
};
/** Access to the block database (blocks/index/) */
class CBlockTreeDB : public CDBWrapper
{
public:
explicit CBlockTreeDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
bool WriteBatchSync(const std::vector<std::pair<int, const CBlockFileInfo*> >& fileInfo, int nLastFile, const std::vector<const CBlockIndex*>& blockinfo);
bool ReadBlockFileInfo(int nFile, CBlockFileInfo &info);
bool ReadLastBlockFile(int &nFile);
bool WriteReindexing(bool fReindexing);
void ReadReindexing(bool &fReindexing);
bool WriteFlag(const std::string &name, bool fValue);
bool ReadFlag(const std::string &name, bool &fValue);
bool LoadBlockIndexGuts(const Consensus::Params& consensusParams, std::function<CBlockIndex*(const uint256&)> insertBlockIndex);
};
#endif // BITCOIN_TXDB_H