filewritestream.h

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// 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>

RAPIDJSON_NAMESPACE_BEGIN


class FileWriteStream {
public:
 typedef char Ch; 

 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_;
};

template<>
inline void PutN(FileWriteStream& stream, char c, size_t n) {
 stream.PutN(c, n);
}

RAPIDJSON_NAMESPACE_END

#endif // RAPIDJSON_FILESTREAM_H_