memorybuffer.h
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//
// Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
//
// Licensed under the MIT License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// http://opensource.org/licenses/MIT
//
// 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
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#ifndef RAPIDJSON_MEMORYBUFFER_H_
#define RAPIDJSON_MEMORYBUFFER_H_
#include "stream.h"
#include "internal/stack.h"
RAPIDJSON_NAMESPACE_BEGIN
//! Represents an in-memory output byte stream.
/*!
This class is mainly for being wrapped by EncodedOutputStream or AutoUTFOutputStream.
It is similar to FileWriteBuffer but the destination is an in-memory buffer instead of a file.
Differences between MemoryBuffer and StringBuffer:
1. StringBuffer has Encoding but MemoryBuffer is only a byte buffer.
2. StringBuffer::GetString() returns a null-terminated string. MemoryBuffer::GetBuffer() returns a buffer without terminator.
\tparam Allocator type for allocating memory buffer.
\note implements Stream concept
*/
template <typename Allocator = CrtAllocator>
struct GenericMemoryBuffer {
typedef char Ch; // byte
GenericMemoryBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {}
void Put(Ch c) { *stack_.template Push<Ch>() = c; }
void Flush() {}
void Clear() { stack_.Clear(); }
void ShrinkToFit() { stack_.ShrinkToFit(); }
Ch* Push(size_t count) { return stack_.template Push<Ch>(count); }
void Pop(size_t count) { stack_.template Pop<Ch>(count); }
const Ch* GetBuffer() const {
return stack_.template Bottom<Ch>();
}
size_t GetSize() const { return stack_.GetSize(); }
static const size_t kDefaultCapacity = 256;
mutable internal::Stack<Allocator> stack_;
};
typedef GenericMemoryBuffer<> MemoryBuffer;
//! Implement specialized version of PutN() with memset() for better performance.
template<>
inline void PutN(MemoryBuffer& memoryBuffer, char c, size_t n) {
std::memset(memoryBuffer.stack_.Push<char>(n), c, n * sizeof(c));
}
RAPIDJSON_NAMESPACE_END
#endif // RAPIDJSON_MEMORYBUFFER_H_
rapidjson::PutN
void PutN(FileWriteStream &stream, char c, size_t n)
Implement specialized version of PutN() with memset() for better performance.
Definition: filewritestream.h:94