mirror of https://github.com/facebook/rocksdb.git
78 lines
2.2 KiB
C
78 lines
2.2 KiB
C
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// Copyright (c) 2017-present, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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// This source code is also licensed under the GPLv2 license found in the
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// COPYING file in the root directory of this source tree.
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/**
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* Helper functions which serialize and deserialize integers
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* into bytes in big endian.
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*/
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#pragma once
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namespace rocksdb {
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namespace cassandra {
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namespace {
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const int64_t kCharMask = 0xFFLL;
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const int32_t kBitsPerByte = 8;
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}
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template<typename T>
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void Serialize(T val, std::string* dest);
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template<typename T>
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T Deserialize(const char* src, std::size_t offset=0);
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// Specializations
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template<>
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inline void Serialize<int8_t>(int8_t t, std::string* dest) {
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dest->append(1, static_cast<char>(t & kCharMask));
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}
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template<>
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inline void Serialize<int32_t>(int32_t t, std::string* dest) {
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for (unsigned long i = 0; i < sizeof(int32_t); i++) {
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dest->append(1, static_cast<char>(
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(t >> (sizeof(int32_t) - 1 - i) * kBitsPerByte) & kCharMask));
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}
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}
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template<>
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inline void Serialize<int64_t>(int64_t t, std::string* dest) {
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for (unsigned long i = 0; i < sizeof(int64_t); i++) {
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dest->append(
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1, static_cast<char>(
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(t >> (sizeof(int64_t) - 1 - i) * kBitsPerByte) & kCharMask));
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}
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}
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template<>
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inline int8_t Deserialize<int8_t>(const char* src, std::size_t offset) {
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return static_cast<int8_t>(src[offset]);
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}
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template<>
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inline int32_t Deserialize<int32_t>(const char* src, std::size_t offset) {
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int32_t result = 0;
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for (unsigned long i = 0; i < sizeof(int32_t); i++) {
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result |= static_cast<int32_t>(static_cast<unsigned char>(src[offset + i]))
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<< ((sizeof(int32_t) - 1 - i) * kBitsPerByte);
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}
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return result;
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}
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template<>
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inline int64_t Deserialize<int64_t>(const char* src, std::size_t offset) {
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int64_t result = 0;
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for (unsigned long i = 0; i < sizeof(int64_t); i++) {
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result |= static_cast<int64_t>(static_cast<unsigned char>(src[offset + i]))
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<< ((sizeof(int64_t) - 1 - i) * kBitsPerByte);
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}
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return result;
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}
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} // namepsace cassandrda
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} // namespace rocksdb
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