2 This file is part of GNUnet.
3 (C) 2001, 2002, 2006, 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
23 * @author Christian Grothoff
24 * @brief functions for handling time and time arithmetic
27 #include "gnunet_time_lib.h"
31 * Get the current time (works just as "time", just that we use the
32 * unit of time that the cron-jobs use (and is 64 bit)).
34 * @return the current time
36 struct GNUNET_TIME_Absolute
37 GNUNET_TIME_absolute_get ()
39 struct GNUNET_TIME_Absolute ret;
42 GETTIMEOFDAY (&tv, NULL);
43 ret.value = (uint64_t) (((uint64_t) tv.tv_sec * 1000LL) + ((uint64_t) tv.tv_usec / 1000LL));
49 * Return relative time of 0ms.
51 struct GNUNET_TIME_Relative
52 GNUNET_TIME_relative_get_zero ()
54 static struct GNUNET_TIME_Relative zero;
60 * Return absolute time of 0ms.
62 struct GNUNET_TIME_Absolute
63 GNUNET_TIME_absolute_get_zero ()
65 static struct GNUNET_TIME_Absolute zero;
70 * Return relative time of 1ms.
72 struct GNUNET_TIME_Relative
73 GNUNET_TIME_relative_get_unit ()
75 static struct GNUNET_TIME_Relative one = { 1 };
82 struct GNUNET_TIME_Relative
83 GNUNET_TIME_relative_get_forever ()
85 static struct GNUNET_TIME_Relative forever = { (uint64_t) - 1LL };
92 struct GNUNET_TIME_Absolute
93 GNUNET_TIME_absolute_get_forever ()
95 static struct GNUNET_TIME_Absolute forever = { (uint64_t) - 1LL };
100 * Convert relative time to an absolute time in the
103 * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow)
105 struct GNUNET_TIME_Absolute
106 GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel)
108 struct GNUNET_TIME_Absolute ret;
109 if (rel.value == (uint64_t) -1LL)
110 return GNUNET_TIME_absolute_get_forever ();
111 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
112 if (rel.value + now.value < rel.value)
114 GNUNET_break (0); /* overflow... */
115 return GNUNET_TIME_absolute_get_forever ();
117 ret.value = rel.value + now.value;
123 * Return the minimum of two relative time values.
125 * @return timestamp that is smaller
127 struct GNUNET_TIME_Relative GNUNET_TIME_relative_min (struct
131 GNUNET_TIME_Relative t2)
133 return (t1.value < t2.value) ? t1 : t2;
137 * Given a timestamp in the future, how much time
138 * remains until then?
140 * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.
142 struct GNUNET_TIME_Relative
143 GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future)
145 struct GNUNET_TIME_Relative ret;
146 if (future.value == (uint64_t) - 1LL)
147 return GNUNET_TIME_relative_get_forever ();
148 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
149 if (now.value > future.value)
150 return GNUNET_TIME_relative_get_zero ();
151 ret.value = future.value - now.value;
156 * Compute the time difference between the given start and end times.
157 * Use this function instead of actual subtraction to ensure that
158 * "FOREVER" and overflows are handeled correctly.
160 * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start
162 struct GNUNET_TIME_Relative
163 GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start,
164 struct GNUNET_TIME_Absolute end)
166 struct GNUNET_TIME_Relative ret;
167 if (end.value == (uint64_t) - 1LL)
168 return GNUNET_TIME_relative_get_forever ();
169 if (end.value < start.value)
170 return GNUNET_TIME_relative_get_zero ();
171 ret.value = end.value - start.value;
176 * Get the duration of an operation as the
177 * difference of the current time and the given start time "hence".
179 * @return aborts if hence==FOREVER, 0 if hence > now, otherwise now-hence.
181 struct GNUNET_TIME_Relative
182 GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute hence)
184 struct GNUNET_TIME_Absolute now;
185 struct GNUNET_TIME_Relative ret;
187 now = GNUNET_TIME_absolute_get ();
188 GNUNET_assert (hence.value != (uint64_t) - 1LL);
189 if (hence.value > now.value)
190 return GNUNET_TIME_relative_get_zero ();
191 ret.value = now.value - hence.value;
197 * Add a given relative duration to the
200 * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise
202 struct GNUNET_TIME_Absolute
203 GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start,
204 struct GNUNET_TIME_Relative duration)
206 struct GNUNET_TIME_Absolute ret;
208 if ((start.value == (uint64_t) - 1LL) ||
209 (duration.value == (uint64_t) - 1LL))
210 return GNUNET_TIME_absolute_get_forever ();
211 if (start.value + duration.value < start.value)
214 return GNUNET_TIME_absolute_get_forever ();
216 ret.value = start.value + duration.value;
221 * Multiply relative time by a given factor.
223 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
225 struct GNUNET_TIME_Relative
226 GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel,
229 struct GNUNET_TIME_Relative ret;
231 return GNUNET_TIME_relative_get_zero ();
232 ret.value = rel.value * (unsigned long long) factor;
233 if (ret.value / factor != rel.value)
236 return GNUNET_TIME_relative_get_forever ();
243 * Calculate the estimate time of arrival/completion
246 * @param start when did the operation start?
247 * @param finished how much has been done?
248 * @param total how much must be done overall (same unit as for "finished")
249 * @return remaining duration for the operation,
250 * assuming it continues at the same speed
252 struct GNUNET_TIME_Relative GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start,
256 struct GNUNET_TIME_Relative dur;
258 struct GNUNET_TIME_Relative ret;
260 GNUNET_break (finished > total);
261 if (finished >= total)
262 return GNUNET_TIME_UNIT_ZERO;
264 return GNUNET_TIME_UNIT_FOREVER_REL;
265 dur = GNUNET_TIME_absolute_get_duration (start);
266 exp = ((double)dur.value) * ((double) total) / ((double)finished);
267 ret.value = ((uint64_t) exp) - dur.value;
273 * Add relative times together.
275 * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise
277 struct GNUNET_TIME_Relative
278 GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1,
279 struct GNUNET_TIME_Relative a2)
281 struct GNUNET_TIME_Relative ret;
283 if ((a1.value == (uint64_t) - 1LL) || (a2.value == (uint64_t) - 1LL))
284 return GNUNET_TIME_relative_get_forever ();
285 if (a1.value + a2.value < a1.value)
288 return GNUNET_TIME_relative_get_forever ();
290 ret.value = a1.value + a2.value;
296 * Convert relative time to network byte order.
298 struct GNUNET_TIME_RelativeNBO
299 GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a)
301 struct GNUNET_TIME_RelativeNBO ret;
302 ret.value__ = GNUNET_htonll (a.value);
307 * Convert relative time from network byte order.
309 struct GNUNET_TIME_Relative
310 GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a)
312 struct GNUNET_TIME_Relative ret;
313 ret.value = GNUNET_ntohll (a.value__);
319 * Convert absolute time to network byte order.
321 struct GNUNET_TIME_AbsoluteNBO
322 GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a)
324 struct GNUNET_TIME_AbsoluteNBO ret;
325 ret.value__ = GNUNET_htonll (a.value);
330 * Convert absolute time from network byte order.
332 struct GNUNET_TIME_Absolute
333 GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a)
335 struct GNUNET_TIME_Absolute ret;
336 ret.value = GNUNET_ntohll (a.value__);