zlibinstream.h

realvnc是一个非常流行的远程控制程序

//
// Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
//
// This is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This software is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this software; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
// USA.

//
// ZlibInStream streams from a compressed data stream ("underlying"),
// decompressing with zlib on the fly.
//

#ifndef __RDR_ZLIBINSTREAM_H__
#define __RDR_ZLIBINSTREAM_H__

#include <rdr/InStream.h>

struct z_stream_s;

namespace rdr {

  class ZlibInStream : public InStream {

  public:

    ZlibInStream(int bufSize=0);
    virtual ~ZlibInStream();

    void setUnderlying(InStream* is, int bytesIn);
    void reset();
    int pos();

  private:

    int overrun(int itemSize, int nItems);
    void decompress();

    InStream* underlying;
    int bufSize;
    int offset;
    z_stream_s* zs;
    int bytesIn;
    U8* start;
  };

} // end of namespace rdr

#endif