2 This file is part of GNUnet.
3 (C) 2001, 2002, 2006, 2009 Christian Grothoff (and other contributing authors)
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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
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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.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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23 * @author Christian Grothoff
24 * @brief functions for handling time and time arithmetic
27 #include "gnunet_time_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
31 static long long timestamp_offset;
34 * Set the timestamp offset for this instance.
36 * @param offset the offset to skew the locale time by
39 GNUNET_TIME_set_offset (long long offset)
41 timestamp_offset = offset;
45 * Get the current time (works just as "time", just that we use the
46 * unit of time that the cron-jobs use (and is 64 bit)).
48 * @return the current time
50 struct GNUNET_TIME_Absolute
51 GNUNET_TIME_absolute_get ()
53 struct GNUNET_TIME_Absolute ret;
56 GETTIMEOFDAY (&tv, NULL);
58 (uint64_t) (((uint64_t) tv.tv_sec * 1000LL) +
59 ((uint64_t) tv.tv_usec / 1000LL)) + timestamp_offset;
65 * Return relative time of 0ms.
67 struct GNUNET_TIME_Relative
68 GNUNET_TIME_relative_get_zero ()
70 static struct GNUNET_TIME_Relative zero;
77 * Return absolute time of 0ms.
79 struct GNUNET_TIME_Absolute
80 GNUNET_TIME_absolute_get_zero ()
82 static struct GNUNET_TIME_Absolute zero;
88 * Return relative time of 1ms.
90 struct GNUNET_TIME_Relative
91 GNUNET_TIME_relative_get_unit ()
93 static struct GNUNET_TIME_Relative one = { 1 };
100 struct GNUNET_TIME_Relative
101 GNUNET_TIME_relative_get_forever ()
103 static struct GNUNET_TIME_Relative forever = { UINT64_MAX };
110 struct GNUNET_TIME_Absolute
111 GNUNET_TIME_absolute_get_forever ()
113 static struct GNUNET_TIME_Absolute forever = { UINT64_MAX };
118 * Convert relative time to an absolute time in the
121 * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow)
123 struct GNUNET_TIME_Absolute
124 GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel)
126 struct GNUNET_TIME_Absolute ret;
128 if (rel.rel_value == UINT64_MAX)
129 return GNUNET_TIME_absolute_get_forever ();
130 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
132 if (rel.rel_value + now.abs_value < rel.rel_value)
134 GNUNET_break (0); /* overflow... */
135 return GNUNET_TIME_absolute_get_forever ();
137 ret.abs_value = rel.rel_value + now.abs_value;
143 * Return the minimum of two relative time values.
145 * @param t1 first timestamp
146 * @param t2 other timestamp
147 * @return timestamp that is smaller
149 struct GNUNET_TIME_Relative
150 GNUNET_TIME_relative_min (struct GNUNET_TIME_Relative t1,
151 struct GNUNET_TIME_Relative t2)
153 return (t1.rel_value < t2.rel_value) ? t1 : t2;
158 * Return the maximum of two relative time values.
160 * @param t1 first timestamp
161 * @param t2 other timestamp
162 * @return timestamp that is larger
164 struct GNUNET_TIME_Relative
165 GNUNET_TIME_relative_max (struct GNUNET_TIME_Relative t1,
166 struct GNUNET_TIME_Relative t2)
168 return (t1.rel_value > t2.rel_value) ? t1 : t2;
174 * Return the minimum of two relative time values.
176 * @param t1 first timestamp
177 * @param t2 other timestamp
178 * @return timestamp that is smaller
180 struct GNUNET_TIME_Absolute
181 GNUNET_TIME_absolute_min (struct GNUNET_TIME_Absolute t1,
182 struct GNUNET_TIME_Absolute t2)
184 return (t1.abs_value < t2.abs_value) ? t1 : t2;
189 * Return the maximum of two relative time values.
191 * @param t1 first timestamp
192 * @param t2 other timestamp
193 * @return timestamp that is smaller
195 struct GNUNET_TIME_Absolute
196 GNUNET_TIME_absolute_max (struct GNUNET_TIME_Absolute t1,
197 struct GNUNET_TIME_Absolute t2)
199 return (t1.abs_value > t2.abs_value) ? t1 : t2;
204 * Given a timestamp in the future, how much time
205 * remains until then?
207 * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.
209 struct GNUNET_TIME_Relative
210 GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future)
212 struct GNUNET_TIME_Relative ret;
214 if (future.abs_value == UINT64_MAX)
215 return GNUNET_TIME_relative_get_forever ();
216 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
218 if (now.abs_value > future.abs_value)
219 return GNUNET_TIME_relative_get_zero ();
220 ret.rel_value = future.abs_value - now.abs_value;
225 * Compute the time difference between the given start and end times.
226 * Use this function instead of actual subtraction to ensure that
227 * "FOREVER" and overflows are handled correctly.
229 * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start
231 struct GNUNET_TIME_Relative
232 GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start,
233 struct GNUNET_TIME_Absolute end)
235 struct GNUNET_TIME_Relative ret;
237 if (end.abs_value == UINT64_MAX)
238 return GNUNET_TIME_relative_get_forever ();
239 if (end.abs_value < start.abs_value)
240 return GNUNET_TIME_relative_get_zero ();
241 ret.rel_value = end.abs_value - start.abs_value;
246 * Get the duration of an operation as the
247 * difference of the current time and the given start time "whence".
249 * @return aborts if whence==FOREVER, 0 if whence > now, otherwise now-whence.
251 struct GNUNET_TIME_Relative
252 GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence)
254 struct GNUNET_TIME_Absolute now;
255 struct GNUNET_TIME_Relative ret;
257 now = GNUNET_TIME_absolute_get ();
258 GNUNET_assert (whence.abs_value != UINT64_MAX);
259 if (whence.abs_value > now.abs_value)
260 return GNUNET_TIME_relative_get_zero ();
261 ret.rel_value = now.abs_value - whence.abs_value;
267 * Add a given relative duration to the
270 * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise
272 struct GNUNET_TIME_Absolute
273 GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start,
274 struct GNUNET_TIME_Relative duration)
276 struct GNUNET_TIME_Absolute ret;
278 if ((start.abs_value == UINT64_MAX) || (duration.rel_value == UINT64_MAX))
279 return GNUNET_TIME_absolute_get_forever ();
280 if (start.abs_value + duration.rel_value < start.abs_value)
283 return GNUNET_TIME_absolute_get_forever ();
285 ret.abs_value = start.abs_value + duration.rel_value;
291 * Subtract a given relative duration from the
294 * @param start some absolute time
295 * @param duration some relative time to subtract
296 * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise
298 struct GNUNET_TIME_Absolute
299 GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start,
300 struct GNUNET_TIME_Relative duration)
302 struct GNUNET_TIME_Absolute ret;
304 if (start.abs_value <= duration.rel_value)
305 return GNUNET_TIME_UNIT_ZERO_ABS;
306 if (start.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value)
307 return GNUNET_TIME_UNIT_FOREVER_ABS;
308 ret.abs_value = start.abs_value - duration.rel_value;
314 * Multiply relative time by a given factor.
316 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
318 struct GNUNET_TIME_Relative
319 GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel,
322 struct GNUNET_TIME_Relative ret;
325 return GNUNET_TIME_relative_get_zero ();
326 ret.rel_value = rel.rel_value * (unsigned long long) factor;
327 if (ret.rel_value / factor != rel.rel_value)
330 return GNUNET_TIME_relative_get_forever ();
337 * Divide relative time by a given factor.
339 * @param rel some duration
340 * @param factor integer to divide by
341 * @return FOREVER if rel=FOREVER or factor==0; otherwise rel/factor
343 struct GNUNET_TIME_Relative
344 GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel,
347 struct GNUNET_TIME_Relative ret;
350 (rel.rel_value == GNUNET_TIME_UNIT_FOREVER_REL.rel_value))
351 return GNUNET_TIME_UNIT_FOREVER_REL;
352 ret.rel_value = rel.rel_value / (unsigned long long) factor;
358 * Calculate the estimate time of arrival/completion
361 * @param start when did the operation start?
362 * @param finished how much has been done?
363 * @param total how much must be done overall (same unit as for "finished")
364 * @return remaining duration for the operation,
365 * assuming it continues at the same speed
367 struct GNUNET_TIME_Relative
368 GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished,
371 struct GNUNET_TIME_Relative dur;
373 struct GNUNET_TIME_Relative ret;
375 GNUNET_break (finished <= total);
376 if (finished >= total)
377 return GNUNET_TIME_UNIT_ZERO;
379 return GNUNET_TIME_UNIT_FOREVER_REL;
380 dur = GNUNET_TIME_absolute_get_duration (start);
381 exp = ((double) dur.rel_value) * ((double) total) / ((double) finished);
382 ret.rel_value = ((uint64_t) exp) - dur.rel_value;
388 * Add relative times together.
390 * @param a1 first timestamp
391 * @param a2 second timestamp
392 * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise
394 struct GNUNET_TIME_Relative
395 GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1,
396 struct GNUNET_TIME_Relative a2)
398 struct GNUNET_TIME_Relative ret;
400 if ((a1.rel_value == UINT64_MAX) || (a2.rel_value == UINT64_MAX))
401 return GNUNET_TIME_relative_get_forever ();
402 if (a1.rel_value + a2.rel_value < a1.rel_value)
405 return GNUNET_TIME_relative_get_forever ();
407 ret.rel_value = a1.rel_value + a2.rel_value;
413 * Subtract relative timestamp from the other.
415 * @param a1 first timestamp
416 * @param a2 second timestamp
417 * @return ZERO if a2>=a1 (including both FOREVER), FOREVER if a1 is FOREVER, a1-a2 otherwise
419 struct GNUNET_TIME_Relative
420 GNUNET_TIME_relative_subtract (struct GNUNET_TIME_Relative a1,
421 struct GNUNET_TIME_Relative a2)
423 struct GNUNET_TIME_Relative ret;
425 if (a2.rel_value >= a1.rel_value)
426 return GNUNET_TIME_relative_get_zero ();
427 if (a1.rel_value == UINT64_MAX)
428 return GNUNET_TIME_relative_get_forever ();
429 ret.rel_value = a1.rel_value - a2.rel_value;
435 * Convert relative time to network byte order.
437 * @param a time to convert
438 * @return time in network byte order
440 struct GNUNET_TIME_RelativeNBO
441 GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a)
443 struct GNUNET_TIME_RelativeNBO ret;
445 ret.rel_value__ = GNUNET_htonll (a.rel_value);
450 * Convert relative time from network byte order.
452 * @param a time to convert
453 * @return time in host byte order
455 struct GNUNET_TIME_Relative
456 GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a)
458 struct GNUNET_TIME_Relative ret;
460 ret.rel_value = GNUNET_ntohll (a.rel_value__);
466 * Convert absolute time to network byte order.
468 * @param a time to convert
469 * @return time in network byte order
471 struct GNUNET_TIME_AbsoluteNBO
472 GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a)
474 struct GNUNET_TIME_AbsoluteNBO ret;
476 ret.abs_value__ = GNUNET_htonll (a.abs_value);
481 * Convert absolute time from network byte order.
483 * @param a time to convert
484 * @return time in host byte order
486 struct GNUNET_TIME_Absolute
487 GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a)
489 struct GNUNET_TIME_Absolute ret;
491 ret.abs_value = GNUNET_ntohll (a.abs_value__);
497 * Convert a relative time to a string.
498 * This is one of the very few calls in the entire API that is
501 * @param time the time to print
503 * @return string form of the time (as milliseconds)
506 GNUNET_TIME_relative_to_string (struct GNUNET_TIME_Relative time)
508 static char time_string[21];
510 memset (time_string, 0, sizeof (time_string));
512 sprintf (time_string, "%llu", (unsigned long long) time.rel_value);
513 return (const char *) time_string;