mdw@git.distorted.org.uk Git - mLib/blob - sys/tv.c

   1 /* -*-c-*-
   2  *
   3  * Manipulation of timeval structures
   4  *
   5  * (c) 1998 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU Library General Public License as
  14  * published by the Free Software Foundation; either version 2 of the
  15  * License, or (at your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU Library General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib; if not, write to the Free
  24  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  25  * MA 02111-1307, USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include <sys/time.h>
  31 #include "tv.h"
  32
  33 /*----- Main code ---------------------------------------------------------*/
  34
  35 /* --- @tv_add@ --- *
  36  *
  37  * Arguments:   @struct timeval *dst@ = destination block
  38  *              @const struct timeval *a, *b@ = source blocks
  39  *
  40  * Returns:     ---
  41  *
  42  * Use:         Adds two timevals.
  43  */
  44
  45 void tv_add(struct timeval *dst,
  46             const struct timeval *a, const struct timeval *b)
  47 {
  48   TV_ADD(dst, a, b);
  49 }
  50
  51 /* --- @tv_addl@ --- *
  52  *
  53  * Arguments:   @struct timeval *dst@ = destination block
  54  *              @const struct timeval *a@ = source blocks
  55  *              @time_t sec@, @unsigned long usec@ = time to add
  56  *
  57  * Returns:     ---
  58  *
  59  * Use:         Adds a literal time in seconds and microseconds.
  60  */
  61
  62 void tv_addl(struct timeval *dst, const struct timeval *a,
  63              time_t sec, unsigned long usec)
  64 {
  65   TV_ADDL(dst, a, sec, usec);
  66 }
  67
  68 /* --- @tv_sub@ --- *
  69  *
  70  * Arguments:   @struct timeval *dst@ = destination block
  71  *              @const struct timeval *a, *b@ = source blocks
  72  *
  73  * Returns:     ---
  74  *
  75  * Use:         Subtracts two timevals.
  76  */
  77
  78 void tv_sub(struct timeval *dst,
  79             const struct timeval *a, const struct timeval *b)
  80 {
  81   TV_SUB(dst, a, b);
  82 }
  83
  84 /* --- @tv_subl@ --- *
  85  *
  86  * Arguments:   @struct timeval *dst@ = destination block
  87  *              @const struct timeval *a@ = source blocks
  88  *              @time_t sec@, @unsigned long usec@ = time to subtract
  89  *
  90  * Returns:     ---
  91  *
  92  * Use:         Subtracts a literal time in seconds and microseconds.
  93  */
  94
  95 void tv_subl(struct timeval *dst, const struct timeval *a,
  96                     time_t sec, unsigned long usec)
  97 {
  98   TV_SUBL(dst, a, sec, usec);
  99 }
 100
 101 /* --- @tv_cmp@ --- *
 102  *
 103  * Arguments:   @const struct timeval *a, *b@ = source blocks
 104  *
 105  * Returns:     Less than, equal to, or greater than zero.
 106  *
 107  * Use:         Compares two timevals.
 108  */
 109
 110 int tv_cmp(const struct timeval *a, const struct timeval *b)
 111 {
 112   /* --- This is more awkward than the case the macro deals with --- */
 113
 114   if (a->tv_sec > b->tv_sec)
 115     return (1);
 116   else if (a->tv_sec < b->tv_sec)
 117     return (-1);
 118   else if (a->tv_usec > b->tv_usec)
 119     return (1);
 120   else if (a->tv_usec < b->tv_usec)
 121     return (-1);
 122   else
 123     return (0);
 124 }
 125
 126 /*----- That's all, folks -------------------------------------------------*/