util_math.c

著名的入侵检测系统snort的最新版本的源码

/****************************************************************************
 *
 * Copyright (C) 2003-2007 Sourcefire, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License Version 2 as
 * published by the Free Software Foundation.  You may not use, modify or
 * distribute this program under any other version of the GNU General
 * Public License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 ****************************************************************************/
 
/**
 * @file   util_math.c
 * @author Chris Green <[e-mail]>
 * @date   Fri Jun 27 10:12:57 2003
 * 
 * @brief  math related util functions
 * 
 * Place simple math functions that are useful all over the place
 * here.
 */

#include "util_math.h"
#include "sf_types.h"

/** 
 * Calculate the percentage of something.
 *
 * If the total is <= 0, we return 0.
 * 
 * @param amt amount to that you have
 * @param total amount there is
 * 
 * @return a/b * 100
 */
double calc_percent(double amt, double total)
{
    if(total <= 0.0)
        return 0.0;    
    
    return (amt/total) * 100.0;
}

double calc_percent64(UINT64 amt, UINT64 total)
{
    if (total <= 0)
        return 0.0;

    return ((double)amt/total) * 100.0;
}