Disk ARchive
2.4.2
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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: int_tools.hpp,v 1.6 2011/01/09 17:25:58 edrusb Rel $ 00022 // 00023 /*********************************************************************/ 00024 00028 00029 #ifndef INT_TOOLS_HPP 00030 #define INT_TOOLS_HPP 00031 00032 #include "../my_config.h" 00033 00034 #include "integers.hpp" 00035 #include "erreurs.hpp" 00036 00037 namespace libdar 00038 { 00039 00042 00043 typedef unsigned char int_tools_bitfield[8]; 00044 00045 extern void int_tools_swap_bytes(unsigned char &a, unsigned char &b); 00046 extern void int_tools_swap_bytes(unsigned char *a, U_I size); 00047 extern void int_tools_expand_byte(unsigned char a, int_tools_bitfield &bit); 00048 extern void int_tools_contract_byte(const int_tools_bitfield &b, unsigned char & a); 00049 00050 // integer (agregates) manipulations 00051 // argument must be a regular interger (a bit field). 00052 template <class T> extern T int_tools_rotate_right_one_bit(T v) 00053 { 00054 bool retenue = (v & 1) != 0; 00055 00056 v >>= 1; 00057 if(retenue) 00058 v |= T(1) << (sizeof(v)*8 - 1); 00059 00060 return v; 00061 } 00062 00063 template <class T> extern T int_tools_maxof_agregate(T unused) { unused = 0; unused = ~unused; unused = unused > 0 ? unused : ~int_tools_rotate_right_one_bit(T(1)); return unused; } 00064 00065 template <class B> static B int_tools_higher_power_of_2(B val) 00066 { 00067 B i = 0; 00068 00069 while((val >> i) > 1) 00070 i++; 00071 00072 return i; 00073 } 00074 00076 00077 } 00078 00079 #endif