src/helper/time_support.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2
   3 /***************************************************************************
   4  *   Copyright (C) 2006 by Dominic Rath                                    *
   5  *   Dominic.Rath@gmx.de                                                   *
   6  *                                                                         *
   7  *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
   8  *   oyvind.harboe@zylin.com                                               *
   9  *                                                                         *
  10  *   Copyright (C) 2008 by Spencer Oliver                                  *
  11  *   spen@spen-soft.co.uk                                                  *
  12  ***************************************************************************/
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include "config.h"
  16 #endif
  17
  18 #include "time_support.h"
  19
  20 /* calculate difference between two struct timeval values */
  21 int timeval_subtract(struct timeval *result, struct timeval *x, struct timeval *y)
  22 {
  23         if (x->tv_usec < y->tv_usec) {
  24                 int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
  25                 y->tv_usec -= 1000000 * nsec;
  26                 y->tv_sec += nsec;
  27         }
  28         if (x->tv_usec - y->tv_usec > 1000000) {
  29                 int nsec = (x->tv_usec - y->tv_usec) / 1000000;
  30                 y->tv_usec += 1000000 * nsec;
  31                 y->tv_sec -= nsec;
  32         }
  33
  34         result->tv_sec = x->tv_sec - y->tv_sec;
  35         result->tv_usec = x->tv_usec - y->tv_usec;
  36
  37         /* Return 1 if result is negative. */
  38         return x->tv_sec < y->tv_sec;
  39 }
  40
  41 int timeval_add_time(struct timeval *result, long sec, long usec)
  42 {
  43         result->tv_sec += sec;
  44         result->tv_usec += usec;
  45
  46         while (result->tv_usec > 1000000) {
  47                 result->tv_usec -= 1000000;
  48                 result->tv_sec++;
  49         }
  50
  51         return 0;
  52 }
  53
  54 /* compare two timevals and return -1/0/+1 accordingly */
  55 int timeval_compare(const struct timeval *x, const struct timeval *y)
  56 {
  57         if (x->tv_sec < y->tv_sec)
  58                 return -1;
  59         else if (x->tv_sec > y->tv_sec)
  60                 return 1;
  61         else if (x->tv_usec < y->tv_usec)
  62                 return -1;
  63         else if (x->tv_usec > y->tv_usec)
  64                 return 1;
  65         else
  66                 return 0;
  67 }
  68
  69 int duration_start(struct duration *duration)
  70 {
  71         return gettimeofday(&duration->start, NULL);
  72 }
  73
  74 int duration_measure(struct duration *duration)
  75 {
  76         struct timeval end;
  77         int retval = gettimeofday(&end, NULL);
  78         if (retval == 0)
  79                 timeval_subtract(&duration->elapsed, &end, &duration->start);
  80         return retval;
  81 }
  82
  83 float duration_elapsed(const struct duration *duration)
  84 {
  85         float t = duration->elapsed.tv_sec;
  86         t += (float)duration->elapsed.tv_usec / 1000000.0;
  87         return t;
  88 }
  89
  90 float duration_kbps(const struct duration *duration, size_t count)
  91 {
  92         return count / (1024.0 * duration_elapsed(duration));
  93 }