// 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. // // 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_ISTREAMWRAPPER_H_ #define RAPIDJSON_ISTREAMWRAPPER_H_ #include "stream.h" #include <iosfwd> #include <ios> #ifdef __clang__ RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_OFF(padded) #elif defined(_MSC_VER) RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_OFF(4351) // new behavior: elements of array 'array' will be default initialized #endif RAPIDJSON_NAMESPACE_BEGIN //! Wrapper of \c std::basic_istream into RapidJSON's Stream concept. /*! The classes can be wrapped including but not limited to: - \c std::istringstream - \c std::stringstream - \c std::wistringstream - \c std::wstringstream - \c std::ifstream - \c std::fstream - \c std::wifstream - \c std::wfstream \tparam StreamType Class derived from \c std::basic_istream. */ template <typename StreamType> class BasicIStreamWrapper { public: typedef typename StreamType::char_type Ch; //! Constructor. /*! \param stream stream opened for read. */ BasicIStreamWrapper(StreamType &stream) : stream_(stream), buffer_(peekBuffer_), bufferSize_(4), bufferLast_(0), current_(buffer_), readCount_(0), count_(0), eof_(false) { Read(); } //! Constructor. /*! \param stream stream opened for read. \param buffer user-supplied buffer. \param bufferSize size of buffer in bytes. Must >=4 bytes. */ BasicIStreamWrapper(StreamType &stream, char* buffer, size_t bufferSize) : stream_(stream), buffer_(buffer), bufferSize_(bufferSize), bufferLast_(0), current_(buffer_), readCount_(0), count_(0), eof_(false) { RAPIDJSON_ASSERT(bufferSize >= 4); Read(); } Ch Peek() const { return *current_; } Ch Take() { Ch c = *current_; Read(); return c; } size_t Tell() const { return count_ + static_cast<size_t>(current_ - buffer_); } // Not implemented void Put(Ch) { RAPIDJSON_ASSERT(false); } void Flush() { RAPIDJSON_ASSERT(false); } Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; } size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; } // For encoding detection only. const Ch* Peek4() const { return (current_ + 4 - !eof_ <= bufferLast_) ? current_ : 0; } private: BasicIStreamWrapper(); BasicIStreamWrapper(const BasicIStreamWrapper&); BasicIStreamWrapper& operator=(const BasicIStreamWrapper&); void Read() { if (current_ < bufferLast_) ++current_; else if (!eof_) { count_ += readCount_; readCount_ = bufferSize_; bufferLast_ = buffer_ + readCount_ - 1; current_ = buffer_; if (!stream_.read(buffer_, static_cast<std::streamsize>(bufferSize_))) { readCount_ = static_cast<size_t>(stream_.gcount()); *(bufferLast_ = buffer_ + readCount_) = '\0'; eof_ = true; } } } StreamType &stream_; Ch peekBuffer_[4], *buffer_; size_t bufferSize_; Ch *bufferLast_; Ch *current_; size_t readCount_; size_t count_; //!< Number of characters read bool eof_; }; typedef BasicIStreamWrapper<std::istream> IStreamWrapper; typedef BasicIStreamWrapper<std::wistream> WIStreamWrapper; #if defined(__clang__) || defined(_MSC_VER) RAPIDJSON_DIAG_POP #endif RAPIDJSON_NAMESPACE_END #endif // RAPIDJSON_ISTREAMWRAPPER_H_