You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
343 lines
10 KiB
343 lines
10 KiB
// 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: |
|
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 |
|
*/ |
|
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(); |
|
|
|
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
|
|
|