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"
29 static long long timestamp_offset;
32 * Set the timestamp offset for this instance.
34 * @param offset the offset to skew the locale time by
37 GNUNET_TIME_set_offset (long long offset)
39 timestamp_offset = offset;
43 * Get the current time (works just as "time", just that we use the
44 * unit of time that the cron-jobs use (and is 64 bit)).
46 * @return the current time
48 struct GNUNET_TIME_Absolute
49 GNUNET_TIME_absolute_get ()
51 struct GNUNET_TIME_Absolute ret;
54 GETTIMEOFDAY (&tv, NULL);
56 (uint64_t) (((uint64_t) tv.tv_sec * 1000LL) +
57 ((uint64_t) tv.tv_usec / 1000LL)) + timestamp_offset;
63 * Return relative time of 0ms.
65 struct GNUNET_TIME_Relative
66 GNUNET_TIME_relative_get_zero ()
68 static struct GNUNET_TIME_Relative zero;
75 * Return absolute time of 0ms.
77 struct GNUNET_TIME_Absolute
78 GNUNET_TIME_absolute_get_zero ()
80 static struct GNUNET_TIME_Absolute zero;
86 * Return relative time of 1ms.
88 struct GNUNET_TIME_Relative
89 GNUNET_TIME_relative_get_unit ()
91 static struct GNUNET_TIME_Relative one = { 1 };
98 struct GNUNET_TIME_Relative
99 GNUNET_TIME_relative_get_forever ()
101 static struct GNUNET_TIME_Relative forever = { UINT64_MAX };
108 struct GNUNET_TIME_Absolute
109 GNUNET_TIME_absolute_get_forever ()
111 static struct GNUNET_TIME_Absolute forever = { UINT64_MAX };
116 * Convert relative time to an absolute time in the
119 * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow)
121 struct GNUNET_TIME_Absolute
122 GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel)
124 struct GNUNET_TIME_Absolute ret;
126 if (rel.rel_value == UINT64_MAX)
127 return GNUNET_TIME_absolute_get_forever ();
128 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
130 if (rel.rel_value + now.abs_value < rel.rel_value)
132 GNUNET_break (0); /* overflow... */
133 return GNUNET_TIME_absolute_get_forever ();
135 ret.abs_value = rel.rel_value + now.abs_value;
141 * Return the minimum of two relative time values.
143 * @param t1 first timestamp
144 * @param t2 other timestamp
145 * @return timestamp that is smaller
147 struct GNUNET_TIME_Relative
148 GNUNET_TIME_relative_min (struct GNUNET_TIME_Relative t1,
149 struct GNUNET_TIME_Relative t2)
151 return (t1.rel_value < t2.rel_value) ? t1 : t2;
156 * Return the maximum of two relative time values.
158 * @param t1 first timestamp
159 * @param t2 other timestamp
160 * @return timestamp that is larger
162 struct GNUNET_TIME_Relative
163 GNUNET_TIME_relative_max (struct GNUNET_TIME_Relative t1,
164 struct GNUNET_TIME_Relative t2)
166 return (t1.rel_value > t2.rel_value) ? t1 : t2;
172 * Return the minimum of two relative time values.
174 * @param t1 first timestamp
175 * @param t2 other timestamp
176 * @return timestamp that is smaller
178 struct GNUNET_TIME_Absolute
179 GNUNET_TIME_absolute_min (struct GNUNET_TIME_Absolute t1,
180 struct GNUNET_TIME_Absolute t2)
182 return (t1.abs_value < t2.abs_value) ? t1 : t2;
187 * Return the maximum of two relative time values.
189 * @param t1 first timestamp
190 * @param t2 other timestamp
191 * @return timestamp that is smaller
193 struct GNUNET_TIME_Absolute
194 GNUNET_TIME_absolute_max (struct GNUNET_TIME_Absolute t1,
195 struct GNUNET_TIME_Absolute t2)
197 return (t1.abs_value > t2.abs_value) ? t1 : t2;
202 * Given a timestamp in the future, how much time
203 * remains until then?
205 * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.
207 struct GNUNET_TIME_Relative
208 GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future)
210 struct GNUNET_TIME_Relative ret;
212 if (future.abs_value == UINT64_MAX)
213 return GNUNET_TIME_relative_get_forever ();
214 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
216 if (now.abs_value > future.abs_value)
217 return GNUNET_TIME_relative_get_zero ();
218 ret.rel_value = future.abs_value - now.abs_value;
223 * Compute the time difference between the given start and end times.
224 * Use this function instead of actual subtraction to ensure that
225 * "FOREVER" and overflows are handled correctly.
227 * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start
229 struct GNUNET_TIME_Relative
230 GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start,
231 struct GNUNET_TIME_Absolute end)
233 struct GNUNET_TIME_Relative ret;
235 if (end.abs_value == UINT64_MAX)
236 return GNUNET_TIME_relative_get_forever ();
237 if (end.abs_value < start.abs_value)
238 return GNUNET_TIME_relative_get_zero ();
239 ret.rel_value = end.abs_value - start.abs_value;
244 * Get the duration of an operation as the
245 * difference of the current time and the given start time "whence".
247 * @return aborts if whence==FOREVER, 0 if whence > now, otherwise now-whence.
249 struct GNUNET_TIME_Relative
250 GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence)
252 struct GNUNET_TIME_Absolute now;
253 struct GNUNET_TIME_Relative ret;
255 now = GNUNET_TIME_absolute_get ();
256 GNUNET_assert (whence.abs_value != UINT64_MAX);
257 if (whence.abs_value > now.abs_value)
258 return GNUNET_TIME_relative_get_zero ();
259 ret.rel_value = now.abs_value - whence.abs_value;
265 * Add a given relative duration to the
268 * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise
270 struct GNUNET_TIME_Absolute
271 GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start,
272 struct GNUNET_TIME_Relative duration)
274 struct GNUNET_TIME_Absolute ret;
276 if ((start.abs_value == UINT64_MAX) || (duration.rel_value == UINT64_MAX))
277 return GNUNET_TIME_absolute_get_forever ();
278 if (start.abs_value + duration.rel_value < start.abs_value)
281 return GNUNET_TIME_absolute_get_forever ();
283 ret.abs_value = start.abs_value + duration.rel_value;
289 * Subtract a given relative duration from the
292 * @param start some absolute time
293 * @param duration some relative time to subtract
294 * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise
296 struct GNUNET_TIME_Absolute
297 GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start,
298 struct GNUNET_TIME_Relative duration)
300 struct GNUNET_TIME_Absolute ret;
302 if (start.abs_value <= duration.rel_value)
303 return GNUNET_TIME_UNIT_ZERO_ABS;
304 if (start.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value)
305 return GNUNET_TIME_UNIT_FOREVER_ABS;
306 ret.abs_value = start.abs_value - duration.rel_value;
312 * Multiply relative time by a given factor.
314 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
316 struct GNUNET_TIME_Relative
317 GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel,
320 struct GNUNET_TIME_Relative ret;
323 return GNUNET_TIME_relative_get_zero ();
324 ret.rel_value = rel.rel_value * (unsigned long long) factor;
325 if (ret.rel_value / factor != rel.rel_value)
328 return GNUNET_TIME_relative_get_forever ();
335 * Divide relative time by a given factor.
337 * @param rel some duration
338 * @param factor integer to divide by
339 * @return FOREVER if rel=FOREVER or factor==0; otherwise rel/factor
341 struct GNUNET_TIME_Relative
342 GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel,
345 struct GNUNET_TIME_Relative ret;
348 (rel.rel_value == GNUNET_TIME_UNIT_FOREVER_REL.rel_value))
349 return GNUNET_TIME_UNIT_FOREVER_REL;
350 ret.rel_value = rel.rel_value / (unsigned long long) factor;
356 * Calculate the estimate time of arrival/completion
359 * @param start when did the operation start?
360 * @param finished how much has been done?
361 * @param total how much must be done overall (same unit as for "finished")
362 * @return remaining duration for the operation,
363 * assuming it continues at the same speed
365 struct GNUNET_TIME_Relative
366 GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished,
369 struct GNUNET_TIME_Relative dur;
371 struct GNUNET_TIME_Relative ret;
373 GNUNET_break (finished <= total);
374 if (finished >= total)
375 return GNUNET_TIME_UNIT_ZERO;
377 return GNUNET_TIME_UNIT_FOREVER_REL;
378 dur = GNUNET_TIME_absolute_get_duration (start);
379 exp = ((double) dur.rel_value) * ((double) total) / ((double) finished);
380 ret.rel_value = ((uint64_t) exp) - dur.rel_value;
386 * Add relative times together.
388 * @param a1 first timestamp
389 * @param a2 second timestamp
390 * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise
392 struct GNUNET_TIME_Relative
393 GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1,
394 struct GNUNET_TIME_Relative a2)
396 struct GNUNET_TIME_Relative ret;
398 if ((a1.rel_value == UINT64_MAX) || (a2.rel_value == UINT64_MAX))
399 return GNUNET_TIME_relative_get_forever ();
400 if (a1.rel_value + a2.rel_value < a1.rel_value)
403 return GNUNET_TIME_relative_get_forever ();
405 ret.rel_value = a1.rel_value + a2.rel_value;
411 * Subtract relative timestamp from the other.
413 * @param a1 first timestamp
414 * @param a2 second timestamp
415 * @return ZERO if a2>=a1 (including both FOREVER), FOREVER if a1 is FOREVER, a1-a2 otherwise
417 struct GNUNET_TIME_Relative
418 GNUNET_TIME_relative_subtract (struct GNUNET_TIME_Relative a1,
419 struct GNUNET_TIME_Relative a2)
421 struct GNUNET_TIME_Relative ret;
423 if (a2.rel_value >= a1.rel_value)
424 return GNUNET_TIME_relative_get_zero ();
425 if (a1.rel_value == UINT64_MAX)
426 return GNUNET_TIME_relative_get_forever ();
427 ret.rel_value = a1.rel_value - a2.rel_value;
433 * Convert relative time to network byte order.
435 * @param a time to convert
436 * @return time in network byte order
438 struct GNUNET_TIME_RelativeNBO
439 GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a)
441 struct GNUNET_TIME_RelativeNBO ret;
443 ret.rel_value__ = GNUNET_htonll (a.rel_value);
448 * Convert relative time from network byte order.
450 * @param a time to convert
451 * @return time in host byte order
453 struct GNUNET_TIME_Relative
454 GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a)
456 struct GNUNET_TIME_Relative ret;
458 ret.rel_value = GNUNET_ntohll (a.rel_value__);
464 * Convert absolute time to network byte order.
466 * @param a time to convert
467 * @return time in network byte order
469 struct GNUNET_TIME_AbsoluteNBO
470 GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a)
472 struct GNUNET_TIME_AbsoluteNBO ret;
474 ret.abs_value__ = GNUNET_htonll (a.abs_value);
479 * Convert absolute time from network byte order.
481 * @param a time to convert
482 * @return time in host byte order
484 struct GNUNET_TIME_Absolute
485 GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a)
487 struct GNUNET_TIME_Absolute ret;
489 ret.abs_value = GNUNET_ntohll (a.abs_value__);
495 * Convert a relative time to a string.
496 * This is one of the very few calls in the entire API that is
499 * @param time the time to print
501 * @return string form of the time (as milliseconds)
504 GNUNET_TIME_relative_to_string (struct GNUNET_TIME_Relative time)
506 static char time_string[21];
508 memset (time_string, 0, sizeof (time_string));
510 sprintf (time_string, "%llu", (unsigned long long) time.rel_value);
511 return (const char *) time_string;