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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>
#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_