# int_tools.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: int_tools.hpp,v 1.3 2004/11/07 18:21:38 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     typedef unsigned char int_tools_bitfield[8];
    00040
    00041     extern void int_tools_swap_bytes(unsigned char &a, unsigned char &b);
    00042     extern void int_tools_swap_bytes(unsigned char *a, U_I size);
    00043     extern void int_tools_expand_byte(unsigned char a, int_tools_bitfield &bit);
    00044     extern void int_tools_contract_byte(const int_tools_bitfield &b, unsigned char & a);
    00045
    00046         // integer (agregates) manipulations
    00047         // argument must be a regular interger (a bit field).
    00048     template <class T> extern T int_tools_rotate_right_one_bit(T v)
    00049     {
    00050         bool retenue = (v & 1) != 0;
    00051
    00052         v >>= 1;
    00053         if(retenue)
    00054             v |= T(1) << (sizeof(v)*8 - 1);
    00055
    00056         return v;
    00057     }
    00058
    00059     template <class T> extern T int_tools_maxof_agregate(T unused) { return ~T(0) > 0 ? ~T(0) : ~int_tools_rotate_right_one_bit(T(1)); }
    00060
    00061     template <class B> static B int_tools_higher_power_of_2(B val)
    00062     {
    00063         B i = 0;
    00064
    00065         while((val >> i) > 1)
    00066             i++;
    00067
    00068         return i;
    00069     }
    00070
    00071 }
    00072
    00073 #endif