mirror of https://gitee.com/bigwinds/arangodb
65 lines
2.0 KiB
C++
65 lines
2.0 KiB
C++
////////////////////////////////////////////////////////////////////////////////
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/// DISCLAIMER
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///
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/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
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/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
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///
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/// Licensed under the Apache License, Version 2.0 (the "License");
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/// you may not use this file except in compliance with the License.
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/// You may obtain a copy of the License at
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///
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/// http://www.apache.org/licenses/LICENSE-2.0
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///
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/// Unless required by applicable law or agreed to in writing, software
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/// distributed under the License is distributed on an "AS IS" BASIS,
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/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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/// See the License for the specific language governing permissions and
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/// limitations under the License.
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///
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/// Copyright holder is ArangoDB GmbH, Cologne, Germany
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///
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/// @author Jan Steemann
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////////////////////////////////////////////////////////////////////////////////
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#ifndef ARANGODB_BASICS_ENCODING_H
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#define ARANGODB_BASICS_ENCODING_H 1
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#include "Basics/Common.h"
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namespace arangodb {
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namespace encoding {
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/// @brief returns the 8-byte aligned size for the value
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template <typename T, size_t alignment = 8>
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static constexpr inline T alignedSize(T value) {
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return (value + (alignment - 1)) - ((value + (alignment - 1)) & (alignment - 1));
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}
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/// @brief portably and safely reads a number from little endian storage
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template <typename T>
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static inline T readNumber(uint8_t const* source, uint32_t length) {
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T value = 0;
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uint64_t x = 0;
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uint8_t const* end = source + length;
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do {
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value += static_cast<T>(*source++) << x;
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x += 8;
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} while (source < end);
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return value;
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}
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/// @brief portably and safely stores a number in little endian format
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template <typename T>
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static inline void storeNumber(uint8_t* dest, T value, uint32_t length) {
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uint8_t* end = dest + length;
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do {
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*dest++ = static_cast<uint8_t>(value & 0xff);
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value >>= 8;
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} while (dest < end);
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}
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} // namespace encoding
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} // namespace arangodb
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#endif
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