blame: source/code/Libs/include/cereal/external/rapidjson/stream.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.

#include "rapidjson.h"

#ifndef CEREAL_RAPIDJSON_STREAM_H_

#define CEREAL_RAPIDJSON_STREAM_H_

#include "encodings.h"

CEREAL_RAPIDJSON_NAMESPACE_BEGIN

///////////////////////////////////////////////////////////////////////////////

//  Stream

/*! \class rapidjson::Stream

    \brief Concept for reading and writing characters.

    For read-only stream, no need to implement PutBegin(), Put(), Flush() and PutEnd().

    For write-only stream, only need to implement Put() and Flush().

\code

concept Stream {

    typename Ch;    //!< Character type of the stream.

    //! Read the current character from stream without moving the read cursor.

    Ch Peek() const;

    //! Read the current character from stream and moving the read cursor to next character.

    Ch Take();

    //! Get the current read cursor.

    //! \return Number of characters read from start.

    size_t Tell();

    //! Begin writing operation at the current read pointer.

    //! \return The begin writer pointer.

    Ch* PutBegin();

    //! Write a character.

    void Put(Ch c);

    //! Flush the buffer.

    void Flush();

    //! End the writing operation.

    //! \param begin The begin write pointer returned by PutBegin().

    //! \return Number of characters written.

    size_t PutEnd(Ch* begin);

}

\endcode

*/

//! Provides additional information for stream.

/*!

    By using traits pattern, this type provides a default configuration for stream.

    For custom stream, this type can be specialized for other configuration.

    See TEST(Reader, CustomStringStream) in readertest.cpp for example.

*/

template<typename Stream>

struct StreamTraits {

    //! Whether to make local copy of stream for optimization during parsing.

    /*!

        By default, for safety, streams do not use local copy optimization.

        Stream that can be copied fast should specialize this, like StreamTraits<StringStream>.

    */

    enum { copyOptimization = 0 };

};

//! Reserve n characters for writing to a stream.

template<typename Stream>

inline void PutReserve(Stream& stream, size_t count) {

    (void)stream;

    (void)count;

}

//! Write character to a stream, presuming buffer is reserved.

template<typename Stream>

inline void PutUnsafe(Stream& stream, typename Stream::Ch c) {

    stream.Put(c);

}

//! Put N copies of a character to a stream.

template<typename Stream, typename Ch>

inline void PutN(Stream& stream, Ch c, size_t n) {

    PutReserve(stream, n);

    for (size_t i = 0; i < n; i++)

        PutUnsafe(stream, c);

}

///////////////////////////////////////////////////////////////////////////////

// StringStream

//! Read-only string stream.

/*! \note implements Stream concept

*/

template <typename Encoding>

struct GenericStringStream {

    typedef typename Encoding::Ch Ch;

    GenericStringStream(const Ch *src) : src_(src), head_(src) {}

    Ch Peek() const { return *src_; }

    Ch Take() { return *src_++; }

    size_t Tell() const { return static_cast<size_t>(src_ - head_); }

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

    void Put(Ch) { CEREAL_RAPIDJSON_ASSERT(false); }

    void Flush() { CEREAL_RAPIDJSON_ASSERT(false); }

    size_t PutEnd(Ch*) { CEREAL_RAPIDJSON_ASSERT(false); return 0; }

    const Ch* src_;     //!< Current read position.

    const Ch* head_;    //!< Original head of the string.

};

template <typename Encoding>

struct StreamTraits<GenericStringStream<Encoding> > {

    enum { copyOptimization = 1 };

};

//! String stream with UTF8 encoding.

typedef GenericStringStream<UTF8<> > StringStream;

///////////////////////////////////////////////////////////////////////////////

// InsituStringStream

//! A read-write string stream.

/*! This string stream is particularly designed for in-situ parsing.

    \note implements Stream concept

*/

template <typename Encoding>

struct GenericInsituStringStream {

    typedef typename Encoding::Ch Ch;

    GenericInsituStringStream(Ch *src) : src_(src), dst_(0), head_(src) {}

    // Read

    Ch Peek() { return *src_; }

    Ch Take() { return *src_++; }

    size_t Tell() { return static_cast<size_t>(src_ - head_); }

    // Write

    void Put(Ch c) { CEREAL_RAPIDJSON_ASSERT(dst_ != 0); *dst_++ = c; }

    Ch* PutBegin() { return dst_ = src_; }

    size_t PutEnd(Ch* begin) { return static_cast<size_t>(dst_ - begin); }

    void Flush() {}

    Ch* Push(size_t count) { Ch* begin = dst_; dst_ += count; return begin; }

    void Pop(size_t count) { dst_ -= count; }

    Ch* src_;

    Ch* dst_;

    Ch* head_;

};

template <typename Encoding>

struct StreamTraits<GenericInsituStringStream<Encoding> > {

    enum { copyOptimization = 1 };

};

//! Insitu string stream with UTF8 encoding.

typedef GenericInsituStringStream<UTF8<> > InsituStringStream;

CEREAL_RAPIDJSON_NAMESPACE_END

#endif // CEREAL_RAPIDJSON_STREAM_H_