// 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 RAPIDJSON_FILEWRITESTREAM_H_

#define RAPIDJSON_FILEWRITESTREAM_H_

#include "rapidjson.h"

#include <cstdio>

BUTIL_RAPIDJSON_NAMESPACE_BEGIN

//! Wrapper of C file stream for input using fread().

/*!

    \note implements Stream concept

*/

class FileWriteStream {

public:

    typedef char Ch;    //!< Character type. Only support char.

    FileWriteStream(std::FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferEnd_(buffer + bufferSize), current_(buffer_) { 

        RAPIDJSON_ASSERT(fp_ != 0);

    }

    void Put(char c) { 

        if (current_ >= bufferEnd_)

            Flush();

        *current_++ = c;

    }

    void PutN(char c, size_t n) {

        size_t avail = static_cast<size_t>(bufferEnd_ - current_);

        while (n > avail) {

            std::memset(current_, c, avail);

            current_ += avail;

            Flush();

            n -= avail;

            avail = static_cast<size_t>(bufferEnd_ - current_);

        }

        if (n > 0) {

            std::memset(current_, c, n);

            current_ += n;

        }

    }

    void Flush() {

        if (current_ != buffer_) {

            fwrite(buffer_, 1, static_cast<size_t>(current_ - buffer_), fp_);

            current_ = buffer_;

        }

    }

    // Not implemented

    char Peek() const { RAPIDJSON_ASSERT(false); return 0; }

    char Take() { RAPIDJSON_ASSERT(false); return 0; }

    size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; }

    char* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }

    size_t PutEnd(char*) { RAPIDJSON_ASSERT(false); return 0; }

private:

    // Prohibit copy constructor & assignment operator.

    FileWriteStream(const FileWriteStream&);

    FileWriteStream& operator=(const FileWriteStream&);

    std::FILE* fp_;

    char *buffer_;

    char *bufferEnd_;

    char *current_;

};

//! Implement specialized version of PutN() with memset() for better performance.

template<>

inline void PutN(FileWriteStream& stream, char c, size_t n) {

    stream.PutN(c, n);

}

BUTIL_RAPIDJSON_NAMESPACE_END

#endif // RAPIDJSON_FILESTREAM_H_