CFileGZInputStream.h

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/* +---------------------------------------------------------------------------+
   |          The Mobile Robot Programming Toolkit (MRPT) C++ library          |
   |                                                                           |
   |                       http://www.mrpt.org/                                |
   |                                                                           |
   |   Copyright (C) 2005-2012  University of Malaga                           |
   |                                                                           |
   |    This software was written by the Machine Perception and Intelligent    |
   |      Robotics Lab, University of Malaga (Spain).                          |
   |    Contact: Jose-Luis Blanco  <jlblanco@ctima.uma.es>                     |
   |                                                                           |
   |  This file is part of the MRPT project.                                   |
   |                                                                           |
   |     MRPT 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 3 of the License, or     |
   |     (at your option) any later version.                                   |
   |                                                                           |
   |   MRPT 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 MRPT.  If not, see <http://www.gnu.org/licenses/>.         |
   |                                                                           |
   +---------------------------------------------------------------------------+ */
#ifndef  CFileGZInputStream_H
#define  CFileGZInputStream_H

#include <mrpt/utils/CStream.h>

#include <iostream>


/*---------------------------------------------------------------
        Class
  ---------------------------------------------------------------*/
namespace mrpt
{
        namespace utils
        {
                /** Transparently opens a compressed "gz" file and reads uncompressed data from it.
                 *   If the file is not a .gz file, it silently reads data from the file.
                 *  This class requires compiling MRPT with wxWidgets. If wxWidgets is not available then the class is actually mapped to the standard CFileInputStream
                 *
                 * \sa CFileInputStream
                 * \ingroup mrpt_base_grp
                 */
                class BASE_IMPEXP CFileGZInputStream : public CStream, public CUncopiable
                {
                protected:
                         /** Method responsible for reading from the stream.
                         */
                        size_t  Read(void *Buffer, size_t Count);

                        /** Method responsible for writing to the stream.
                         *  Write attempts to write up to Count bytes to Buffer, and returns the number of bytes actually written.
                         */
                        size_t  Write(const void *Buffer, size_t Count);

                        // DECLARE_UNCOPIABLE( CFileGZInputStream )

                private:
                        void            *m_f;
                        uint64_t        m_file_size;    //!< Compressed file size

                public:
                         /** Constructor without open
                          */
                        CFileGZInputStream();

                         /** Constructor and open
                          * \param fileName The file to be open in this stream
                          * \exception std::exception If there's an error opening the file.
                          */
                        CFileGZInputStream(const std::string &fileName );

                         /** Destructor
                         */
                         virtual ~CFileGZInputStream();

                         /** Opens the file for read.
                          * \param fileName The file to be open in this stream
                          * \return false if there's an error opening the file, true otherwise
                          */
                         bool open(const std::string &fileName );

                         /** Closes the file */
                         void close();

                         /** Says if file was open successfully or not.
                          */
                         bool  fileOpenCorrectly();

                         /** Will be true if EOF has been already reached.
                           */
                         bool checkEOF();

                        /** Method for getting the total number of <b>compressed</b> bytes of in the file (the physical size of the compressed file).
                         */
                        uint64_t getTotalBytesCount();

                        /** Method for getting the current cursor position in the <b>compressed</b>, where 0 is the first byte and TotalBytesCount-1 the last one.
                         */
                        uint64_t getPosition();

                        /** This method is not implemented in this class */
                        uint64_t Seek(long Offset, CStream::TSeekOrigin Origin = sFromBeginning)
                        {
                                THROW_EXCEPTION("Seek is not implemented in this class");
                        }

                }; // End of class def.

        } // End of namespace
} // end of namespace
#endif