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// 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 {
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_NAMESPACE
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