blame: source/code/Libs/include/cereal/external/rapidjson/istreamwrapper.h

// 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 CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_

#define CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_

#include "stream.h"

#include <iosfwd>

#include <ios>

#ifdef __clang__

CEREAL_RAPIDJSON_DIAG_PUSH

CEREAL_RAPIDJSON_DIAG_OFF(padded)

#elif defined(_MSC_VER)

CEREAL_RAPIDJSON_DIAG_PUSH

CEREAL_RAPIDJSON_DIAG_OFF(4351) // new behavior: elements of array 'array' will be default initialized

#endif

CEREAL_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) { 

        CEREAL_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) { CEREAL_RAPIDJSON_ASSERT(false); }

    void Flush() { CEREAL_RAPIDJSON_ASSERT(false); } 

    Ch* PutBegin() { CEREAL_RAPIDJSON_ASSERT(false); return 0; }

    size_t PutEnd(Ch*) { CEREAL_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)

CEREAL_RAPIDJSON_DIAG_POP

#endif

CEREAL_RAPIDJSON_NAMESPACE_END

#endif // CEREAL_RAPIDJSON_ISTREAMWRAPPER_H_