blame: source/code/Libs/include/cereal/external/rapidjson/memorybuffer.h

// Tencent is pleased to support the open source community by making RapidJSON available.

// 

// 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 

// CONDITIONS OF ANY KIND, either express or implied. See the License for the 

// specific language governing permissions and limitations under the License.

#ifndef CEREAL_RAPIDJSON_MEMORYBUFFER_H_

#define CEREAL_RAPIDJSON_MEMORYBUFFER_H_

#include "stream.h"

#include "internal/stack.h"

CEREAL_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));

}

CEREAL_RAPIDJSON_NAMESPACE_END

#endif // CEREAL_RAPIDJSON_MEMORYBUFFER_H_