/* interface/dataprovider.h - Interface for data sources
   Copyright (C) 2003 Klarälvdalens Datakonsult AB

   This file is part of GPGME++.
 
   GPGME++ 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.
 
   GPGME++ 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 GPGME; if not, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#ifndef __GPGMEPP_INTERFACES_DATAPROVIDER_H__
#define __GPGMEPP_INTERFACES_DATAPROVIDER_H__

#include <sys/types.h>

#include <tdemacros.h>

namespace GpgME {

  class TDE_EXPORT DataProvider {
  public:
    virtual ~DataProvider() {}

    enum Operation {
      Read, Write, Seek, Release
    };
    virtual bool isSupported( Operation op ) const = 0;


    virtual ssize_t read( void  * buffer, size_t bufSize ) = 0;
    virtual ssize_t write( const void * buffer, size_t bufSize ) = 0;
    virtual off_t seek( off_t offset, int whence ) = 0;
    virtual void release() = 0;
  };

} // namespace GpgME

#endif // __GPGMEPP_INTERFACES_DATAPROVIDER_H__
