// Copyright (c) 2017-present, Facebook, Inc. All rights reserved. // This source code is licensed under both the GPLv2 (found in the // COPYING file in the root directory) and Apache 2.0 License // (found in the LICENSE.Apache file in the root directory). /** * Helper functions which serialize and deserialize integers * into bytes in big endian. */ #pragma once namespace rocksdb { namespace cassandra { namespace { const int64_t kCharMask = 0xFFLL; const int32_t kBitsPerByte = 8; } template<typename T> void Serialize(T val, std::string* dest); template<typename T> T Deserialize(const char* src, std::size_t offset=0); // Specializations template<> inline void Serialize<int8_t>(int8_t t, std::string* dest) { dest->append(1, static_cast<char>(t & kCharMask)); } template<> inline void Serialize<int32_t>(int32_t t, std::string* dest) { for (unsigned long i = 0; i < sizeof(int32_t); i++) { dest->append(1, static_cast<char>( (t >> (sizeof(int32_t) - 1 - i) * kBitsPerByte) & kCharMask)); } } template<> inline void Serialize<int64_t>(int64_t t, std::string* dest) { for (unsigned long i = 0; i < sizeof(int64_t); i++) { dest->append( 1, static_cast<char>( (t >> (sizeof(int64_t) - 1 - i) * kBitsPerByte) & kCharMask)); } } template<> inline int8_t Deserialize<int8_t>(const char* src, std::size_t offset) { return static_cast<int8_t>(src[offset]); } template<> inline int32_t Deserialize<int32_t>(const char* src, std::size_t offset) { int32_t result = 0; for (unsigned long i = 0; i < sizeof(int32_t); i++) { result |= static_cast<int32_t>(static_cast<unsigned char>(src[offset + i])) << ((sizeof(int32_t) - 1 - i) * kBitsPerByte); } return result; } template<> inline int64_t Deserialize<int64_t>(const char* src, std::size_t offset) { int64_t result = 0; for (unsigned long i = 0; i < sizeof(int64_t); i++) { result |= static_cast<int64_t>(static_cast<unsigned char>(src[offset + i])) << ((sizeof(int64_t) - 1 - i) * kBitsPerByte); } return result; } } // namepsace cassandrda } // namespace rocksdb