Disk ARchive  2.5.2
Full featured and portable backup and archiving tool
memory_file.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 : http://dar.linux.free.fr/email.html
00020 /*********************************************************************/
00021 
00025 
00026 #ifndef MEMORY_FILE_HPP
00027 #define MEMORY_FILE_HPP
00028 
00029 #include "generic_file.hpp"
00030 #include "storage.hpp"
00031 
00032 namespace libdar
00033 {
00034 
00037 
00038     class memory_file : public generic_file
00039     {
00040     public:
00041 
00043     memory_file() : generic_file(gf_read_write), data(0) { position = 0; };
00044 
00045         // memory_storage specific methods
00046 
00047     void reset() { if(is_terminated()) throw SRC_BUG; position = 0; data = storage(0); };
00048     infinint size() const { return data.size(); };
00049 
00050 
00051         // virtual method inherited from generic_file
00052     bool skippable(skippability direction, const infinint & amount) { return true; };
00053     bool skip(const infinint & pos);
00054     bool skip_to_eof();
00055     bool skip_relative(S_I x);
00056     infinint get_position() const { if(is_terminated()) throw SRC_BUG; return position; };
00057 
00058 
00059     protected:
00060 
00061         // virtual method inherited from generic_file
00062     void inherited_read_ahead(const infinint & amount) {}; // no optimization can be done here, we rely on the OS here
00063     U_I inherited_read(char *a, U_I size);
00064     void inherited_write(const char *a, U_I size);
00065     void inherited_sync_write() {};
00066     void inherited_flush_read() {};
00067     void inherited_terminate() {};
00068 
00069     private:
00070     storage data;
00071     infinint position;
00072     };
00073 
00075 
00076 } // end of namespace
00077 
00078 #endif
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