common.h

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/*! \file xstream/common.h
 *
 * \brief common objects
 */

#ifndef XSTREAM_COMMON_H
#define XSTREAM_COMMON_H

#include <xstream/config.h>

#include <streambuf>

namespace xstream{


/*!
 * \internal
 * \brief common base for ostreambufs
 *
 */
class ostreambuf: public std::streambuf
{
    protected:
        /*!
         * \brief remaining characters in the buffer
         *
         */
        std::streamsize inline available() const {
            return (epptr() - pptr());
        }

        /*!
         * \brief number of characters in the buffer
         *
         */
        std::streamsize inline taken() const {
            return (pptr() - pbase());
        }        
};

/*!
 * \brief buffer management
 *
 */

class buffer
{
    public:
        char* buf; /*!< buffer where data is kept */
        size_t size; /*!< size of buffer */

        /*
         * \brief allocates a buffer of size \c size
         *
         * \param size length of buffer
         *
         */
        buffer(size_t size);

        /*!
         * \brief increases the size of buffer
         *
         * \param factor size is updated according to \f$ size'=size*factor \f$ 
         * \note old data is copied to the new buffer
         * 
         */
        void grow(unsigned int factor=2);

        /*!
         * \brief resets the size of the buffer
         *
         * \param size new length of the buffer 
         *
         * \note no copying of data is done
         *
         */
        void resize(size_t size);

        /*!
         * \brief deallocates buffer
         *
         */
        ~buffer();
};

/*!
 * \brief common base for objects that manage input and output buffers
 * to use with zlib and bzlib
 *
 */
class common_buffer
{
    protected:
        std::streambuf *_sb; /*!< streambuf to read/write from/to */
        buffer in; /*!< input buffer */
        buffer out; /*!< output buffer */

    public:
        /*!
         * \brief construct using a streambuf
         */
        common_buffer(std::streambuf* sb);

        ~common_buffer();

};

}//namespace xstream

#endif