neobytes/src/db.h
Pieter Wuille 83743ed681 Make lsn_reset ("detach databases") optional and off by default.
Add an option -detachdb (and entry in OptionDialog), without which no
lsn_reset is called on addr.dat and blkindex.dat. That means these
files cannot be moved to a new environment, but shutdown can be
significantly faster. The wallet file is always lsn_reset'ed.

-detachdb corresponds to the old behaviour, though it is off by
default now to speed up shutdowns.
2012-04-26 00:31:54 +02:00

316 lines
8.2 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2012 The Bitcoin developers
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_DB_H
#define BITCOIN_DB_H
#include "main.h"
#include <map>
#include <string>
#include <vector>
#include <db_cxx.h>
class CAddress;
class CAddrMan;
class CBlockLocator;
class CDiskBlockIndex;
class CDiskTxPos;
class CMasterKey;
class COutPoint;
class CTxIndex;
class CWallet;
class CWalletTx;
extern unsigned int nWalletDBUpdated;
extern bool fDetachDB;
extern DbEnv dbenv;
extern void DBFlush(bool fShutdown);
void ThreadFlushWalletDB(void* parg);
bool BackupWallet(const CWallet& wallet, const std::string& strDest);
/** RAII class that provides access to a Berkeley database */
class CDB
{
protected:
Db* pdb;
std::string strFile;
std::vector<DbTxn*> vTxn;
bool fReadOnly;
explicit CDB(const char* pszFile, const char* pszMode="r+");
~CDB() { Close(); }
public:
void Close();
private:
CDB(const CDB&);
void operator=(const CDB&);
protected:
template<typename K, typename T>
bool Read(const K& key, T& value)
{
if (!pdb)
return false;
// Key
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(1000);
ssKey << key;
Dbt datKey(&ssKey[0], ssKey.size());
// Read
Dbt datValue;
datValue.set_flags(DB_DBT_MALLOC);
int ret = pdb->get(GetTxn(), &datKey, &datValue, 0);
memset(datKey.get_data(), 0, datKey.get_size());
if (datValue.get_data() == NULL)
return false;
// Unserialize value
CDataStream ssValue((char*)datValue.get_data(), (char*)datValue.get_data() + datValue.get_size(), SER_DISK, CLIENT_VERSION);
ssValue >> value;
// Clear and free memory
memset(datValue.get_data(), 0, datValue.get_size());
free(datValue.get_data());
return (ret == 0);
}
template<typename K, typename T>
bool Write(const K& key, const T& value, bool fOverwrite=true)
{
if (!pdb)
return false;
if (fReadOnly)
assert(!"Write called on database in read-only mode");
// Key
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(1000);
ssKey << key;
Dbt datKey(&ssKey[0], ssKey.size());
// Value
CDataStream ssValue(SER_DISK, CLIENT_VERSION);
ssValue.reserve(10000);
ssValue << value;
Dbt datValue(&ssValue[0], ssValue.size());
// Write
int ret = pdb->put(GetTxn(), &datKey, &datValue, (fOverwrite ? 0 : DB_NOOVERWRITE));
// Clear memory in case it was a private key
memset(datKey.get_data(), 0, datKey.get_size());
memset(datValue.get_data(), 0, datValue.get_size());
return (ret == 0);
}
template<typename K>
bool Erase(const K& key)
{
if (!pdb)
return false;
if (fReadOnly)
assert(!"Erase called on database in read-only mode");
// Key
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(1000);
ssKey << key;
Dbt datKey(&ssKey[0], ssKey.size());
// Erase
int ret = pdb->del(GetTxn(), &datKey, 0);
// Clear memory
memset(datKey.get_data(), 0, datKey.get_size());
return (ret == 0 || ret == DB_NOTFOUND);
}
template<typename K>
bool Exists(const K& key)
{
if (!pdb)
return false;
// Key
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
ssKey.reserve(1000);
ssKey << key;
Dbt datKey(&ssKey[0], ssKey.size());
// Exists
int ret = pdb->exists(GetTxn(), &datKey, 0);
// Clear memory
memset(datKey.get_data(), 0, datKey.get_size());
return (ret == 0);
}
Dbc* GetCursor()
{
if (!pdb)
return NULL;
Dbc* pcursor = NULL;
int ret = pdb->cursor(NULL, &pcursor, 0);
if (ret != 0)
return NULL;
return pcursor;
}
int ReadAtCursor(Dbc* pcursor, CDataStream& ssKey, CDataStream& ssValue, unsigned int fFlags=DB_NEXT)
{
// Read at cursor
Dbt datKey;
if (fFlags == DB_SET || fFlags == DB_SET_RANGE || fFlags == DB_GET_BOTH || fFlags == DB_GET_BOTH_RANGE)
{
datKey.set_data(&ssKey[0]);
datKey.set_size(ssKey.size());
}
Dbt datValue;
if (fFlags == DB_GET_BOTH || fFlags == DB_GET_BOTH_RANGE)
{
datValue.set_data(&ssValue[0]);
datValue.set_size(ssValue.size());
}
datKey.set_flags(DB_DBT_MALLOC);
datValue.set_flags(DB_DBT_MALLOC);
int ret = pcursor->get(&datKey, &datValue, fFlags);
if (ret != 0)
return ret;
else if (datKey.get_data() == NULL || datValue.get_data() == NULL)
return 99999;
// Convert to streams
ssKey.SetType(SER_DISK);
ssKey.clear();
ssKey.write((char*)datKey.get_data(), datKey.get_size());
ssValue.SetType(SER_DISK);
ssValue.clear();
ssValue.write((char*)datValue.get_data(), datValue.get_size());
// Clear and free memory
memset(datKey.get_data(), 0, datKey.get_size());
memset(datValue.get_data(), 0, datValue.get_size());
free(datKey.get_data());
free(datValue.get_data());
return 0;
}
DbTxn* GetTxn()
{
if (!vTxn.empty())
return vTxn.back();
else
return NULL;
}
public:
bool TxnBegin()
{
if (!pdb)
return false;
DbTxn* ptxn = NULL;
int ret = dbenv.txn_begin(GetTxn(), &ptxn, DB_TXN_NOSYNC);
if (!ptxn || ret != 0)
return false;
vTxn.push_back(ptxn);
return true;
}
bool TxnCommit()
{
if (!pdb)
return false;
if (vTxn.empty())
return false;
int ret = vTxn.back()->commit(0);
vTxn.pop_back();
return (ret == 0);
}
bool TxnAbort()
{
if (!pdb)
return false;
if (vTxn.empty())
return false;
int ret = vTxn.back()->abort();
vTxn.pop_back();
return (ret == 0);
}
bool ReadVersion(int& nVersion)
{
nVersion = 0;
return Read(std::string("version"), nVersion);
}
bool WriteVersion(int nVersion)
{
return Write(std::string("version"), nVersion);
}
bool static Rewrite(const std::string& strFile, const char* pszSkip = NULL);
};
/** Access to the transaction database (blkindex.dat) */
class CTxDB : public CDB
{
public:
CTxDB(const char* pszMode="r+") : CDB("blkindex.dat", pszMode) { }
private:
CTxDB(const CTxDB&);
void operator=(const CTxDB&);
public:
bool ReadTxIndex(uint256 hash, CTxIndex& txindex);
bool UpdateTxIndex(uint256 hash, const CTxIndex& txindex);
bool AddTxIndex(const CTransaction& tx, const CDiskTxPos& pos, int nHeight);
bool EraseTxIndex(const CTransaction& tx);
bool ContainsTx(uint256 hash);
bool ReadOwnerTxes(uint160 hash160, int nHeight, std::vector<CTransaction>& vtx);
bool ReadDiskTx(uint256 hash, CTransaction& tx, CTxIndex& txindex);
bool ReadDiskTx(uint256 hash, CTransaction& tx);
bool ReadDiskTx(COutPoint outpoint, CTransaction& tx, CTxIndex& txindex);
bool ReadDiskTx(COutPoint outpoint, CTransaction& tx);
bool WriteBlockIndex(const CDiskBlockIndex& blockindex);
bool EraseBlockIndex(uint256 hash);
bool ReadHashBestChain(uint256& hashBestChain);
bool WriteHashBestChain(uint256 hashBestChain);
bool ReadBestInvalidWork(CBigNum& bnBestInvalidWork);
bool WriteBestInvalidWork(CBigNum bnBestInvalidWork);
bool LoadBlockIndex();
};
/** Access to the (IP) address database (addr.dat) */
class CAddrDB : public CDB
{
public:
CAddrDB(const char* pszMode="r+") : CDB("addr.dat", pszMode) { }
private:
CAddrDB(const CAddrDB&);
void operator=(const CAddrDB&);
public:
bool WriteAddrman(const CAddrMan& addr);
bool LoadAddresses();
};
bool LoadAddresses();
#endif // BITCOIN_DB_H