Disk ARchive
2.4.5
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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 // $Id$ 00022 // 00023 /*********************************************************************/ 00024 00030 00031 #ifndef NULL_FILE_HPP 00032 #define NULL_FILE_HPP 00033 00034 #include "../my_config.h" 00035 #include "generic_file.hpp" 00036 #include "thread_cancellation.hpp" 00037 00038 namespace libdar 00039 { 00040 00043 00045 00052 00053 class null_file : public generic_file, public thread_cancellation 00054 { 00055 public : 00056 null_file(gf_mode m) : generic_file(m) {}; 00057 bool skip(const infinint &pos) { return true; }; 00058 bool skip_to_eof() { return true; }; 00059 bool skip_relative(signed int x) { return false; }; 00060 infinint get_position() { return 0; }; 00061 00062 #ifdef LIBDAR_SPECIAL_ALLOC 00063 USE_SPECIAL_ALLOC(null_file); 00064 #endif 00065 protected : 00066 U_I inherited_read(char *a, U_I size) 00067 { 00068 #ifdef MUTEX_WORKS 00069 check_self_cancellation(); 00070 #endif 00071 return 0; 00072 }; 00073 00074 void inherited_write(const char *a, U_I size) 00075 { 00076 #ifdef MUTEX_WORKS 00077 check_self_cancellation(); 00078 #endif 00079 }; 00080 00081 void inherited_sync_write() {}; 00082 00083 void inherited_terminate() {}; 00084 }; 00085 00087 00088 } // end of namespace 00089 00090 #endif