lbrycrd/src/txdb.h
MarcoFalke 0277173b1d
Merge #10498: Use static_cast instead of C-style casts for non-fundamental types
9ad6746ccd Use static_cast instead of C-style casts for non-fundamental types (practicalswift)

Pull request description:

  A C-style cast is equivalent to try casting in the following order:

  1. `const_cast(...)`
  2. `static_cast(...)`
  3. `const_cast(static_cast(...))`
  4. `reinterpret_cast(...)`
  5. `const_cast(reinterpret_cast(...))`

  By using `static_cast<T>(...)` explicitly we avoid the possibility of an unintentional and dangerous `reinterpret_cast`. Furthermore `static_cast<T>(...)` allows for easier grepping of casts.

  For a more thorough discussion, see ["ES.49: If you must use a cast, use a named cast"](https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#es49-if-you-must-use-a-cast-use-a-named-cast) in the C++ Core Guidelines (Stroustrup & Sutter).

Tree-SHA512: bd6349b7ea157da93a47b8cf238932af5dff84731374ccfd69b9f732fabdad1f9b1cdfca67497040f14eaa85346391404f4c0495e22c467f26ca883cd2de4d3c
2018-02-07 16:15:28 -05:00

129 lines
4.4 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2017 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 <map>
#include <string>
#include <utility>
#include <vector>
class CBlockIndex;
class CCoinsViewDBCursor;
class uint256;
//! No need to periodic flush if at least this much space still available.
static constexpr int MAX_BLOCK_COINSDB_USAGE = 10;
//! -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 nMaxBlockDBAndTxIndexCache = 1024;
//! Max memory allocated to coin DB specific cache (MiB)
static const int64_t nMaxCoinsDBCache = 8;
struct CDiskTxPos : public CDiskBlockPos
{
unsigned int nTxOffset; // after header
ADD_SERIALIZE_METHODS;
template <typename Stream, typename Operation>
inline void SerializationOp(Stream& s, Operation ser_action) {
READWRITE(*static_cast<CDiskBlockPos*>(this));
READWRITE(VARINT(nTxOffset));
}
CDiskTxPos(const CDiskBlockPos &blockIn, unsigned int nTxOffsetIn) : CDiskBlockPos(blockIn.nFile, blockIn.nPos), nTxOffset(nTxOffsetIn) {
}
CDiskTxPos() {
SetNull();
}
void SetNull() {
CDiskBlockPos::SetNull();
nTxOffset = 0;
}
};
/** CCoinsView backed by the coin database (chainstate/) */
class CCoinsViewDB final : public CCoinsView
{
protected:
CDBWrapper db;
public:
explicit CCoinsViewDB(size_t nCacheSize, bool fMemory = false, bool fWipe = false);
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;
};
/** 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);
CBlockTreeDB(const CBlockTreeDB&) = delete;
CBlockTreeDB& operator=(const CBlockTreeDB&) = delete;
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);
bool ReadReindexing(bool &fReindexing);
bool ReadTxIndex(const uint256 &txid, CDiskTxPos &pos);
bool WriteTxIndex(const std::vector<std::pair<uint256, CDiskTxPos> > &vect);
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