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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_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_