mirror of
https://github.com/dashpay/dash.git
synced 2024-12-30 22:35:51 +01:00
344 lines
10 KiB
C++
344 lines
10 KiB
C++
// Copyright (c) 2012-2016 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_DBWRAPPER_H
|
|
#define BITCOIN_DBWRAPPER_H
|
|
|
|
#include "clientversion.h"
|
|
#include "fs.h"
|
|
#include "serialize.h"
|
|
#include "streams.h"
|
|
#include "util.h"
|
|
#include "utilstrencodings.h"
|
|
#include "version.h"
|
|
|
|
#include <leveldb/db.h>
|
|
#include <leveldb/write_batch.h>
|
|
|
|
static const size_t DBWRAPPER_PREALLOC_KEY_SIZE = 64;
|
|
static const size_t DBWRAPPER_PREALLOC_VALUE_SIZE = 1024;
|
|
|
|
class dbwrapper_error : public std::runtime_error
|
|
{
|
|
public:
|
|
explicit dbwrapper_error(const std::string& msg) : std::runtime_error(msg) {}
|
|
};
|
|
|
|
class CDBWrapper;
|
|
|
|
/** These should be considered an implementation detail of the specific database.
|
|
*/
|
|
namespace dbwrapper_private {
|
|
|
|
/** Handle database error by throwing dbwrapper_error exception.
|
|
*/
|
|
void HandleError(const leveldb::Status& status);
|
|
|
|
/** Work around circular dependency, as well as for testing in dbwrapper_tests.
|
|
* Database obfuscation should be considered an implementation detail of the
|
|
* specific database.
|
|
*/
|
|
const std::vector<unsigned char>& GetObfuscateKey(const CDBWrapper &w);
|
|
|
|
};
|
|
|
|
/** Batch of changes queued to be written to a CDBWrapper */
|
|
class CDBBatch
|
|
{
|
|
friend class CDBWrapper;
|
|
|
|
private:
|
|
const CDBWrapper &parent;
|
|
leveldb::WriteBatch batch;
|
|
|
|
CDataStream ssKey;
|
|
CDataStream ssValue;
|
|
|
|
size_t size_estimate;
|
|
|
|
public:
|
|
/**
|
|
* @param[in] _parent CDBWrapper that this batch is to be submitted to
|
|
*/
|
|
explicit CDBBatch(const CDBWrapper &_parent) : parent(_parent), ssKey(SER_DISK, CLIENT_VERSION), ssValue(SER_DISK, CLIENT_VERSION), size_estimate(0) { };
|
|
|
|
void Clear()
|
|
{
|
|
batch.Clear();
|
|
size_estimate = 0;
|
|
}
|
|
|
|
template <typename K, typename V>
|
|
void Write(const K& key, const V& value)
|
|
{
|
|
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey << key;
|
|
leveldb::Slice slKey(ssKey.data(), ssKey.size());
|
|
|
|
ssValue.reserve(DBWRAPPER_PREALLOC_VALUE_SIZE);
|
|
ssValue << value;
|
|
ssValue.Xor(dbwrapper_private::GetObfuscateKey(parent));
|
|
leveldb::Slice slValue(ssValue.data(), ssValue.size());
|
|
|
|
batch.Put(slKey, slValue);
|
|
// LevelDB serializes writes as:
|
|
// - byte: header
|
|
// - varint: key length (1 byte up to 127B, 2 bytes up to 16383B, ...)
|
|
// - byte[]: key
|
|
// - varint: value length
|
|
// - byte[]: value
|
|
// The formula below assumes the key and value are both less than 16k.
|
|
size_estimate += 3 + (slKey.size() > 127) + slKey.size() + (slValue.size() > 127) + slValue.size();
|
|
ssKey.clear();
|
|
ssValue.clear();
|
|
}
|
|
|
|
template <typename K>
|
|
void Erase(const K& key)
|
|
{
|
|
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey << key;
|
|
leveldb::Slice slKey(ssKey.data(), ssKey.size());
|
|
|
|
batch.Delete(slKey);
|
|
// LevelDB serializes erases as:
|
|
// - byte: header
|
|
// - varint: key length
|
|
// - byte[]: key
|
|
// The formula below assumes the key is less than 16kB.
|
|
size_estimate += 2 + (slKey.size() > 127) + slKey.size();
|
|
ssKey.clear();
|
|
}
|
|
|
|
size_t SizeEstimate() const { return size_estimate; }
|
|
};
|
|
|
|
class CDBIterator
|
|
{
|
|
private:
|
|
const CDBWrapper &parent;
|
|
leveldb::Iterator *piter;
|
|
|
|
public:
|
|
|
|
/**
|
|
* @param[in] _parent Parent CDBWrapper instance.
|
|
* @param[in] _piter The original leveldb iterator.
|
|
*/
|
|
CDBIterator(const CDBWrapper &_parent, leveldb::Iterator *_piter) :
|
|
parent(_parent), piter(_piter) { };
|
|
~CDBIterator();
|
|
|
|
bool Valid() const;
|
|
|
|
void SeekToFirst();
|
|
|
|
template<typename K> void Seek(const K& key) {
|
|
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
|
|
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey << key;
|
|
leveldb::Slice slKey(ssKey.data(), ssKey.size());
|
|
piter->Seek(slKey);
|
|
}
|
|
|
|
void Next();
|
|
|
|
template<typename K> bool GetKey(K& key) {
|
|
leveldb::Slice slKey = piter->key();
|
|
try {
|
|
CDataStream ssKey(slKey.data(), slKey.data() + slKey.size(), SER_DISK, CLIENT_VERSION);
|
|
ssKey >> key;
|
|
} catch (const std::exception&) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
template<typename V> bool GetValue(V& value) {
|
|
leveldb::Slice slValue = piter->value();
|
|
try {
|
|
CDataStream ssValue(slValue.data(), slValue.data() + slValue.size(), SER_DISK, CLIENT_VERSION);
|
|
ssValue.Xor(dbwrapper_private::GetObfuscateKey(parent));
|
|
ssValue >> value;
|
|
} catch (const std::exception&) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
unsigned int GetValueSize() {
|
|
return piter->value().size();
|
|
}
|
|
|
|
};
|
|
|
|
class CDBWrapper
|
|
{
|
|
friend const std::vector<unsigned char>& dbwrapper_private::GetObfuscateKey(const CDBWrapper &w);
|
|
private:
|
|
//! custom environment this database is using (may be nullptr in case of default environment)
|
|
leveldb::Env* penv;
|
|
|
|
//! database options used
|
|
leveldb::Options options;
|
|
|
|
//! options used when reading from the database
|
|
leveldb::ReadOptions readoptions;
|
|
|
|
//! options used when iterating over values of the database
|
|
leveldb::ReadOptions iteroptions;
|
|
|
|
//! options used when writing to the database
|
|
leveldb::WriteOptions writeoptions;
|
|
|
|
//! options used when sync writing to the database
|
|
leveldb::WriteOptions syncoptions;
|
|
|
|
//! the database itself
|
|
leveldb::DB* pdb;
|
|
|
|
//! a key used for optional XOR-obfuscation of the database
|
|
std::vector<unsigned char> obfuscate_key;
|
|
|
|
//! the key under which the obfuscation key is stored
|
|
static const std::string OBFUSCATE_KEY_KEY;
|
|
|
|
//! the length of the obfuscate key in number of bytes
|
|
static const unsigned int OBFUSCATE_KEY_NUM_BYTES;
|
|
|
|
std::vector<unsigned char> CreateObfuscateKey() const;
|
|
|
|
public:
|
|
/**
|
|
* @param[in] path Location in the filesystem where leveldb data will be stored.
|
|
* @param[in] nCacheSize Configures various leveldb cache settings.
|
|
* @param[in] fMemory If true, use leveldb's memory environment.
|
|
* @param[in] fWipe If true, remove all existing data.
|
|
* @param[in] obfuscate If true, store data obfuscated via simple XOR. If false, XOR
|
|
* with a zero'd byte array.
|
|
*/
|
|
CDBWrapper(const fs::path& path, size_t nCacheSize, bool fMemory = false, bool fWipe = false, bool obfuscate = false);
|
|
~CDBWrapper();
|
|
|
|
template <typename K, typename V>
|
|
bool Read(const K& key, V& value) const
|
|
{
|
|
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
|
|
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey << key;
|
|
leveldb::Slice slKey(ssKey.data(), ssKey.size());
|
|
|
|
std::string strValue;
|
|
leveldb::Status status = pdb->Get(readoptions, slKey, &strValue);
|
|
if (!status.ok()) {
|
|
if (status.IsNotFound())
|
|
return false;
|
|
LogPrintf("LevelDB read failure: %s\n", status.ToString());
|
|
dbwrapper_private::HandleError(status);
|
|
}
|
|
try {
|
|
CDataStream ssValue(strValue.data(), strValue.data() + strValue.size(), SER_DISK, CLIENT_VERSION);
|
|
ssValue.Xor(obfuscate_key);
|
|
ssValue >> value;
|
|
} catch (const std::exception&) {
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
template <typename K, typename V>
|
|
bool Write(const K& key, const V& value, bool fSync = false)
|
|
{
|
|
CDBBatch batch(*this);
|
|
batch.Write(key, value);
|
|
return WriteBatch(batch, fSync);
|
|
}
|
|
|
|
template <typename K>
|
|
bool Exists(const K& key) const
|
|
{
|
|
CDataStream ssKey(SER_DISK, CLIENT_VERSION);
|
|
ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey << key;
|
|
leveldb::Slice slKey(ssKey.data(), ssKey.size());
|
|
|
|
std::string strValue;
|
|
leveldb::Status status = pdb->Get(readoptions, slKey, &strValue);
|
|
if (!status.ok()) {
|
|
if (status.IsNotFound())
|
|
return false;
|
|
LogPrintf("LevelDB read failure: %s\n", status.ToString());
|
|
dbwrapper_private::HandleError(status);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
template <typename K>
|
|
bool Erase(const K& key, bool fSync = false)
|
|
{
|
|
CDBBatch batch(*this);
|
|
batch.Erase(key);
|
|
return WriteBatch(batch, fSync);
|
|
}
|
|
|
|
bool WriteBatch(CDBBatch& batch, bool fSync = false);
|
|
|
|
// not available for LevelDB; provide for compatibility with BDB
|
|
bool Flush()
|
|
{
|
|
return true;
|
|
}
|
|
|
|
bool Sync()
|
|
{
|
|
CDBBatch batch(*this);
|
|
return WriteBatch(batch, true);
|
|
}
|
|
|
|
CDBIterator *NewIterator()
|
|
{
|
|
return new CDBIterator(*this, pdb->NewIterator(iteroptions));
|
|
}
|
|
|
|
/**
|
|
* Return true if the database managed by this class contains no entries.
|
|
*/
|
|
bool IsEmpty();
|
|
|
|
template<typename K>
|
|
size_t EstimateSize(const K& key_begin, const K& key_end) const
|
|
{
|
|
CDataStream ssKey1(SER_DISK, CLIENT_VERSION), ssKey2(SER_DISK, CLIENT_VERSION);
|
|
ssKey1.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey2.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey1 << key_begin;
|
|
ssKey2 << key_end;
|
|
leveldb::Slice slKey1(ssKey1.data(), ssKey1.size());
|
|
leveldb::Slice slKey2(ssKey2.data(), ssKey2.size());
|
|
uint64_t size = 0;
|
|
leveldb::Range range(slKey1, slKey2);
|
|
pdb->GetApproximateSizes(&range, 1, &size);
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* Compact a certain range of keys in the database.
|
|
*/
|
|
template<typename K>
|
|
void CompactRange(const K& key_begin, const K& key_end) const
|
|
{
|
|
CDataStream ssKey1(SER_DISK, CLIENT_VERSION), ssKey2(SER_DISK, CLIENT_VERSION);
|
|
ssKey1.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey2.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
|
|
ssKey1 << key_begin;
|
|
ssKey2 << key_end;
|
|
leveldb::Slice slKey1(ssKey1.data(), ssKey1.size());
|
|
leveldb::Slice slKey2(ssKey2.data(), ssKey2.size());
|
|
pdb->CompactRange(&slKey1, &slKey2);
|
|
}
|
|
|
|
};
|
|
|
|
#endif // BITCOIN_DBWRAPPER_H
|