blame: source/code/Libs/include/cereal/external/rapidjson/filereadstream.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_FILEREADSTREAM_H_

#define CEREAL_RAPIDJSON_FILEREADSTREAM_H_

#include "stream.h"

#include <cstdio>

#ifdef __clang__

CEREAL_RAPIDJSON_DIAG_PUSH

CEREAL_RAPIDJSON_DIAG_OFF(padded)

CEREAL_RAPIDJSON_DIAG_OFF(unreachable-code)

CEREAL_RAPIDJSON_DIAG_OFF(missing-noreturn)

#endif

CEREAL_RAPIDJSON_NAMESPACE_BEGIN

//! File byte stream for input using fread().

/*!

    \note implements Stream concept

*/

class FileReadStream {

public:

    typedef char Ch;    //!< Character type (byte).

    //! Constructor.

    /*!

        \param fp File pointer opened for read.

        \param buffer user-supplied buffer.

        \param bufferSize size of buffer in bytes. Must >=4 bytes.

    */

    FileReadStream(std::FILE* fp, char* buffer, size_t bufferSize) : fp_(fp), buffer_(buffer), bufferSize_(bufferSize), bufferLast_(0), current_(buffer_), readCount_(0), count_(0), eof_(false) { 

        CEREAL_RAPIDJSON_ASSERT(fp_ != 0);

        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 <= bufferLast_) ? current_ : 0;

    }

private:

    void Read() {

        if (current_ < bufferLast_)

            ++current_;

        else if (!eof_) {

            count_ += readCount_;

            readCount_ = fread(buffer_, 1, bufferSize_, fp_);

            bufferLast_ = buffer_ + readCount_ - 1;

            current_ = buffer_;

            if (readCount_ < bufferSize_) {

                buffer_[readCount_] = '\0';

                ++bufferLast_;

                eof_ = true;

            }

        }

    }

    std::FILE* fp_;

    Ch *buffer_;

    size_t bufferSize_;

    Ch *bufferLast_;

    Ch *current_;

    size_t readCount_;

    size_t count_;  //!< Number of characters read

    bool eof_;

};

CEREAL_RAPIDJSON_NAMESPACE_END

#ifdef __clang__

CEREAL_RAPIDJSON_DIAG_POP

#endif

#endif // CEREAL_RAPIDJSON_FILESTREAM_H_