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Diffstat (limited to 'include/rapidjson/filewritestream.h')
-rw-r--r-- | include/rapidjson/filewritestream.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/include/rapidjson/filewritestream.h b/include/rapidjson/filewritestream.h new file mode 100644 index 0000000..8b48fee --- /dev/null +++ b/include/rapidjson/filewritestream.h @@ -0,0 +1,104 @@ +// 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 "stream.h" +#include <cstdio> + +#ifdef __clang__ +RAPIDJSON_DIAG_PUSH +RAPIDJSON_DIAG_OFF(unreachable-code) +#endif + +RAPIDJSON_NAMESPACE_BEGIN + +//! Wrapper of C file stream for output using fwrite(). +/*! + \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_) { + size_t result = std::fwrite(buffer_, 1, static_cast<size_t>(current_ - buffer_), fp_); + if (result < static_cast<size_t>(current_ - buffer_)) { + // failure deliberately ignored at this time + // added to avoid warn_unused_result build errors + } + 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); +} + +RAPIDJSON_NAMESPACE_END + +#ifdef __clang__ +RAPIDJSON_DIAG_POP +#endif + +#endif // RAPIDJSON_FILESTREAM_H_ |