Application: gvSIG desktop

/* $Id$ */

/* //////////////////////////////////////////////////////////////////////////

//                                                                         //

// This code is Copyright (c) 2004 LizardTech, Inc, 1008 Western Avenue,   //

// Suite 200, Seattle, WA 98104.  Unauthorized use or distribution         //

// prohibited.  Access to and use of this code is permitted only under     //

// license from LizardTech, Inc.  Portions of the code are protected by    //

// US and foreign patents and other filings. All Rights Reserved.          //

//                                                                         //

////////////////////////////////////////////////////////////////////////// */

/* PUBLIC */

#ifndef LT_IO_BUFFERED_STREAM_H

#define LT_IO_BUFFERED_STREAM_H

#include "lt_ioStreamInf.h"

LT_BEGIN_NAMESPACE( LizardTech )

class LTIOBufPage;

class LTIOBufPageCache;

/**

 * Stream which wraps an array of bytes in memory.

 *

 * The buffer is of a fixed size and does not grow or shrink.

 */

class LTIOBufferedStream : public LTIOStreamInf

{

public:

   LTIOBufferedStream();

   virtual ~LTIOBufferedStream();

   /**

    * Initializes the stream

    *

    * @param   src                 source stream; this instance takes ownership of it

    * @param   pageSize size of each page in bytes

    * @param   numPages number of pages to keep cached in memory

         *        @param        tempDir        temp directory to store unused pages; this instance

         *                                                        does not clean them up

    */

   virtual LT_STATUS initialize(        LTIOStreamInf* src,

                                                                                        lt_uint32 pageSize=1024,

                                                                                        lt_uint32 numPages = 10,

                                                                                        const char* tempDir = 0L);

        virtual bool isEOF();

        virtual bool isOpen();

        virtual LT_STATUS open();

        virtual LT_STATUS close();

   virtual lt_uint32 read( lt_uint8 *pDest, lt_uint32 numBytes );

   virtual lt_uint32 write( const lt_uint8 *pSrc, lt_uint32 numBytes );

   virtual LT_STATUS seek( lt_int64 offset, LTIOSeekDir origin );

   virtual lt_int64 tell();

        virtual LTIOStreamInf* duplicate();

        virtual LT_STATUS getLastError() const;

        virtual const char* getID() const;

private:

        const LTIOBufPage* getPage( lt_uint64 pageIndex );

protected:

   lt_uint32                m_pageSize;

        lt_uint32                m_numPages;

        LTIOBufPageCache*                m_buffer;

        LTIOStreamInf*        m_src;

        lt_uint64                m_cur;

        bool                                 m_eof;

        char*                                m_tempDir;

};

LT_END_NAMESPACE( LizardTech )

#endif        // LT_IO_BUFFERED_STREAM_H