# compressor.hpp

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    00001 /*********************************************************************/
    00002 // dar - disk archive - a backup/restoration program
    00003 // Copyright (C) 2002-2052 Denis Corbin
    00004 //
    00005 // This program is free software; you can redistribute it and/or
    00006 // modify it under the terms of the GNU General Public License
    00007 // as published by the Free Software Foundation; either version 2
    00008 // of the License, or (at your option) any later version.
    00009 //
    00010 // This program is distributed in the hope that it will be useful,
    00011 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00012 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00013 // GNU General Public License for more details.
    00014 //
    00015 // You should have received a copy of the GNU General Public License
    00016 // along with this program; if not, write to the Free Software
    00017 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
    00018 //
    00019 // to contact the author : dar.linux@free.fr
    00020 /*********************************************************************/
    00021 // $Id: compressor.hpp,v 1.12.4.3 2009/05/14 17:33:39 edrusb Rel $
    00022 //
    00023 /*********************************************************************/
    00026
    00027 #ifndef COMPRESSOR_HPP
    00028 #define COMPRESSOR_HPP
    00029
    00030 #include "../my_config.h"
    00031
    00032 #include "infinint.hpp"
    00033 #include "generic_file.hpp"
    00034 #include "integers.hpp"
    00035 #include "wrapperlib.hpp"
    00036
    00037 namespace libdar
    00038 {
    00039
    00041
    00044     enum compression
    00045     {
    00046         none = 'n',
    00047         zip = 'p',
    00048         gzip = 'z',
    00049         bzip2 = 'y'
    00050     };
    00051
    00052     extern compression char2compression(char a);
    00053     extern char compression2char(compression c);
    00054     extern std::string compression2string(compression c);
    00055
    00057     class compressor : public generic_file
    00058     {
    00059     public :
    00060         compressor(user_interaction & dialog, compression algo, generic_file & compressed_side, U_I compression_level = 9);
    00061             // compressed_side is not owned by the object and will remains
    00062             // after the objet destruction
    00063
    00064         compressor(user_interaction & dialog, compression algo, generic_file *compressed_side, U_I compression_level = 9);
    00065             // compressed_side is owned by the object and will be
    00066             // deleted a destructor time
    00067
    00068         ~compressor();
    00069
    00070         void flush_write(); // flush all data to compressed_side, and reset the compressor
    00071             // for that additional write can be uncompresssed starting at this point.
    00072         void flush_read(); // reset decompression engine to be able to read the next block of compressed data
    00073             // if not called, furthur read return EOF
    00074         void clean_read(); // discard any byte buffered and not yet returned by read()
    00075         void clean_write(); // discard any byte buffered and not yet wrote to compressed_side;
    00076
    00077         compression get_algo() const { return current_algo; };
    00078
    00080
    00085         void change_algo(compression new_algo, U_I new_compression_level);
    00086
    00087
    00089
    00090         void change_algo(compression new_algo)
    00091         {
    00092             change_algo(new_algo, current_level);
    00093         };
    00094
    00095             // inherited from generic file
    00096         bool skip(const infinint & position) { flush_write(); flush_read(); clean_read(); return compressed->skip(position); };
    00097         bool skip_to_eof()  { flush_write(); flush_read(); clean_read(); return compressed->skip_to_eof(); };
    00098         bool skip_relative(S_I x) { flush_write(); flush_read(); clean_read(); return compressed->skip_relative(x); };
    00099         infinint get_position() { return compressed->get_position(); };
    00100
    00101     protected :
    00102         S_I inherited_read(char *a, size_t size) { return (this->*read_ptr)(a, size); };
    00103         S_I inherited_write(const char *a, size_t size) { return (this->*write_ptr)(a, size); };
    00104
    00105     private :
    00106         struct xfer
    00107         {
    00108             wrapperlib wrap;
    00109             char *buffer;
    00110             U_I size;
    00111
    00112             xfer(U_I sz, wrapperlib_mode mode);
    00113             ~xfer();
    00114         };
    00115
    00116         xfer *compr, *decompr;
    00117         generic_file *compressed;
    00118         bool compressed_owner;
    00119         compression current_algo;
    00120         U_I current_level;
    00121
    00122         void init(compression algo, generic_file *compressed_side, U_I compression_level);
    00123         void terminate();
    00124         S_I (compressor::*read_ptr) (char *a, size_t size);
    00125         S_I none_read(char *a, size_t size);
    00126         S_I gzip_read(char *a, size_t size);
    00127             // S_I zip_read(char *a, size_t size);
    00128             // S_I bzip2_read(char *a, size_t size); // using gzip_read, same code thanks to wrapperlib
    00129
    00130         S_I (compressor::*write_ptr) (const char *a, size_t size);
    00131         S_I none_write(const char *a, size_t size);
    00132         S_I gzip_write(const char *a, size_t size);
    00133             // S_I zip_write(char *a, size_t size);
    00134             // S_I bzip2_write(char *a, size_t size); // using gzip_write, same code thanks to wrapperlib
    00135     };
    00136
    00137 } // end of namespace
    00138
    00139 #endif