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arangodb/arangod/RocksDBEngine/RocksDBFormat.h

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2.9 KiB
C++

////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2018 ArangoDB GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Simon Grätzer
////////////////////////////////////////////////////////////////////////////////
#ifndef ARANGO_ROCKSDB_ROCKSDB_FORMAT_H
#define ARANGO_ROCKSDB_ROCKSDB_FORMAT_H 1
#include "Basics/Common.h"
#include "Basics/Endian.h"
#include "RocksDBEngine/RocksDBTypes.h"
namespace arangodb {
namespace rocksutils {
extern RocksDBEndianness rocksDBEndianness;
/* function pointers to serialization implementation */
extern uint16_t (*uint16FromPersistent)(char const* p);
extern uint32_t (*uint32FromPersistent)(char const* p);
extern uint64_t (*uint64FromPersistent)(char const* p);
extern void (*uint16ToPersistent)(std::string& p, uint16_t value);
extern void (*uint32ToPersistent)(std::string& p, uint32_t value);
extern void (*uint64ToPersistent)(std::string& p, uint64_t value);
/// Enable litte endian or big-endian key formats
void setRocksDBKeyFormatEndianess(RocksDBEndianness);
inline uint64_t doubleToInt(double d) {
uint64_t i;
std::memcpy(&i, &d, sizeof(i));
return i;
}
inline double intToDouble(uint64_t i) {
double d;
std::memcpy(&d, &i, sizeof(i));
return d;
}
template <typename T>
inline T uintFromPersistentLittleEndian(char const* p) {
static_assert(std::is_unsigned<T>::value, "type must be unsigned");
T value;
memcpy(&value, p, sizeof(T));
return basics::littleToHost<T>(value);
}
template <typename T>
inline T uintFromPersistentBigEndian(char const* p) {
static_assert(std::is_unsigned<T>::value, "type must be unsigned");
T value;
memcpy(&value, p, sizeof(T));
return basics::bigToHost<T>(value);
}
template <typename T>
inline void uintToPersistentLittleEndian(std::string& p, T value) {
static_assert(std::is_unsigned<T>::value, "type must be unsigned");
value = basics::hostToLittle(value);
p.append(reinterpret_cast<const char*>(&value), sizeof(T));
}
template <typename T>
inline void uintToPersistentBigEndian(std::string& p, T value) {
// uintToPersistentLittleEndian<T>(p, basics::hostToBig(value));
static_assert(std::is_unsigned<T>::value, "type must be unsigned");
value = basics::hostToBig(value);
p.append(reinterpret_cast<const char*>(&value), sizeof(T));
}
} // namespace rocksutils
} // namespace arangodb
#endif