| // 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_ |