code.delx.au - pulseaudio/blob - src/pulse/timeval.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   PulseAudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU Lesser General Public License as
   8   published by the Free Software Foundation; either version 2.1 of the
   9   License, or (at your option) any later version.
  10
  11   PulseAudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with PulseAudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <assert.h>
  27 #include <stddef.h>
  28 #include <sys/time.h>
  29
  30 #ifdef HAVE_WINDOWS_H
  31 #include <windows.h>
  32 #endif
  33
  34 #include "../pulsecore/winsock.h"
  35
  36 #include "timeval.h"
  37
  38 struct timeval *pa_gettimeofday(struct timeval *tv) {
  39 #ifdef HAVE_GETTIMEOFDAY
  40     assert(tv);
  41
  42     return gettimeofday(tv, NULL) < 0 ? NULL : tv;
  43 #elif defined(OS_IS_WIN32)
  44     /*
  45      * Copied from implementation by Steven Edwards (LGPL).
  46      * Found on wine mailing list.
  47      */
  48
  49 #if defined(_MSC_VER) || defined(__BORLANDC__)
  50 #define EPOCHFILETIME (116444736000000000i64)
  51 #else
  52 #define EPOCHFILETIME (116444736000000000LL)
  53 #endif
  54
  55     FILETIME        ft;
  56     LARGE_INTEGER   li;
  57     __int64         t;
  58
  59     assert(tv);
  60
  61     GetSystemTimeAsFileTime(&ft);
  62     li.LowPart  = ft.dwLowDateTime;
  63     li.HighPart = ft.dwHighDateTime;
  64     t  = li.QuadPart;       /* In 100-nanosecond intervals */
  65     t -= EPOCHFILETIME;     /* Offset to the Epoch time */
  66     t /= 10;                /* In microseconds */
  67     tv->tv_sec  = (long)(t / 1000000);
  68     tv->tv_usec = (long)(t % 1000000);
  69
  70     return tv;
  71 #else
  72 #error "Platform lacks gettimeofday() or equivalent function."
  73 #endif
  74 }
  75
  76 pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) {
  77     pa_usec_t r;
  78     assert(a && b);
  79
  80     /* Check which whan is the earlier time and swap the two arguments if reuqired. */
  81     if (pa_timeval_cmp(a, b) < 0) {
  82         const struct timeval *c;
  83         c = a;
  84         a = b;
  85         b = c;
  86     }
  87
  88     /* Calculate the second difference*/
  89     r = ((pa_usec_t) a->tv_sec - b->tv_sec)* 1000000;
  90
  91     /* Calculate the microsecond difference */
  92     if (a->tv_usec > b->tv_usec)
  93         r += ((pa_usec_t) a->tv_usec - b->tv_usec);
  94     else if (a->tv_usec < b->tv_usec)
  95         r -= ((pa_usec_t) b->tv_usec - a->tv_usec);
  96
  97     return r;
  98 }
  99
 100 int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) {
 101     assert(a && b);
 102
 103     if (a->tv_sec < b->tv_sec)
 104         return -1;
 105
 106     if (a->tv_sec > b->tv_sec)
 107         return 1;
 108
 109     if (a->tv_usec < b->tv_usec)
 110         return -1;
 111
 112     if (a->tv_usec > b->tv_usec)
 113         return 1;
 114
 115     return 0;
 116 }
 117
 118 pa_usec_t pa_timeval_age(const struct timeval *tv) {
 119     struct timeval now;
 120     assert(tv);
 121
 122     return pa_timeval_diff(pa_gettimeofday(&now), tv);
 123 }
 124
 125 struct timeval* pa_timeval_add(struct timeval *tv, pa_usec_t v) {
 126     unsigned long secs;
 127     assert(tv);
 128
 129     secs = (v/1000000);
 130     tv->tv_sec += (unsigned long) secs;
 131     v -= secs*1000000;
 132
 133     tv->tv_usec += v;
 134
 135     /* Normalize */
 136     while (tv->tv_usec >= 1000000) {
 137         tv->tv_sec++;
 138         tv->tv_usec -= 1000000;
 139     }
 140
 141     return tv;
 142 }