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13 Affero General Public License for more details.
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16 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * @author Christian Grothoff
23 * Functions related to time
25 * @defgroup time Time library
26 * Time and time calculations.
30 #ifndef GNUNET_TIME_LIB_H
31 #define GNUNET_TIME_LIB_H
36 #if 0 /* keep Emacsens' auto-indent happy */
41 #include "gnunet_common.h"
44 * Time for absolute times used by GNUnet, in microseconds.
46 struct GNUNET_TIME_Absolute
51 uint64_t abs_value_us;
55 * Time for relative time used by GNUnet, in microseconds.
56 * Always positive, so we can only refer to future time.
58 struct GNUNET_TIME_Relative
63 uint64_t rel_value_us;
66 GNUNET_NETWORK_STRUCT_BEGIN
69 * Time for relative time used by GNUnet, in microseconds and in network byte order.
71 struct GNUNET_TIME_RelativeNBO
74 * The actual value (in network byte order).
76 uint64_t rel_value_us__ GNUNET_PACKED;
81 * Time for absolute time used by GNUnet, in microseconds and in network byte order.
83 struct GNUNET_TIME_AbsoluteNBO
86 * The actual value (in network byte order).
88 uint64_t abs_value_us__ GNUNET_PACKED;
90 GNUNET_NETWORK_STRUCT_END
95 #define GNUNET_TIME_UNIT_ZERO GNUNET_TIME_relative_get_zero_()
100 #define GNUNET_TIME_UNIT_ZERO_ABS GNUNET_TIME_absolute_get_zero_()
103 * One microsecond, our basic time unit.
105 #define GNUNET_TIME_UNIT_MICROSECONDS GNUNET_TIME_relative_get_unit_()
110 #define GNUNET_TIME_UNIT_MILLISECONDS GNUNET_TIME_relative_get_millisecond_()
115 #define GNUNET_TIME_UNIT_SECONDS GNUNET_TIME_relative_get_second_()
120 #define GNUNET_TIME_UNIT_MINUTES GNUNET_TIME_relative_get_minute_()
125 #define GNUNET_TIME_UNIT_HOURS GNUNET_TIME_relative_get_hour_()
130 #define GNUNET_TIME_UNIT_DAYS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 24)
135 #define GNUNET_TIME_UNIT_WEEKS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_DAYS, 7)
138 * One month (30 days).
140 #define GNUNET_TIME_UNIT_MONTHS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_DAYS, 30)
143 * One year (365 days).
145 #define GNUNET_TIME_UNIT_YEARS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_DAYS, 365)
148 * Constant used to specify "forever". This constant
149 * will be treated specially in all time operations.
151 #define GNUNET_TIME_UNIT_FOREVER_REL GNUNET_TIME_relative_get_forever_ ()
154 * Constant used to specify "forever". This constant
155 * will be treated specially in all time operations.
157 #define GNUNET_TIME_UNIT_FOREVER_ABS GNUNET_TIME_absolute_get_forever_ ()
162 * Threshold after which exponential backoff should not increase (15 m).
164 #define GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
168 * Perform our standard exponential back-off calculation, starting at 1 ms
169 * and then going by a factor of 2 up unto a maximum of 15 m.
171 * @param r current backoff time, initially zero
173 #define GNUNET_TIME_STD_BACKOFF(r) GNUNET_TIME_relative_min (GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD, \
174 GNUNET_TIME_relative_multiply (GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_MILLISECONDS, (r)), 2));
178 * Randomized exponential back-off, starting at 1 ms
179 * and going up by a factor of 2+r, where 0 <= r <= 0.5, up
180 * to a maximum of 15 m.
182 * @param r current backoff time, initially zero
183 * @return the next backoff time
185 struct GNUNET_TIME_Relative
186 GNUNET_TIME_randomized_backoff(struct GNUNET_TIME_Relative rt);
190 * Return relative time of 0ms.
192 struct GNUNET_TIME_Relative
193 GNUNET_TIME_relative_get_zero_ (void);
197 * Return absolute time of 0ms.
199 struct GNUNET_TIME_Absolute
200 GNUNET_TIME_absolute_get_zero_ (void);
204 * Return relative time of 1 microsecond.
206 struct GNUNET_TIME_Relative
207 GNUNET_TIME_relative_get_unit_ (void);
211 * Return relative time of 1ms.
213 struct GNUNET_TIME_Relative
214 GNUNET_TIME_relative_get_millisecond_ (void);
218 * Return relative time of 1s.
220 struct GNUNET_TIME_Relative
221 GNUNET_TIME_relative_get_second_ (void);
225 * Return relative time of 1 minute.
227 struct GNUNET_TIME_Relative
228 GNUNET_TIME_relative_get_minute_ (void);
232 * Return relative time of 1 hour.
234 struct GNUNET_TIME_Relative
235 GNUNET_TIME_relative_get_hour_ (void);
241 struct GNUNET_TIME_Relative
242 GNUNET_TIME_relative_get_forever_ (void);
248 struct GNUNET_TIME_Absolute
249 GNUNET_TIME_absolute_get_forever_ (void);
253 * Get the current time.
255 * @return the current time
257 struct GNUNET_TIME_Absolute
258 GNUNET_TIME_absolute_get (void);
262 * Convert relative time to an absolute time in the
265 * @param rel relative time to convert
266 * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow)
268 struct GNUNET_TIME_Absolute
269 GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel);
273 * Round a time value so that it is suitable for transmission
274 * via JSON encodings.
276 * @param at time to round
277 * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if
278 * it was just now rounded
281 GNUNET_TIME_round_abs (struct GNUNET_TIME_Absolute *at);
285 * Round a time value so that it is suitable for transmission
286 * via JSON encodings.
288 * @param rt time to round
289 * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if
290 * it was just now rounded
293 GNUNET_TIME_round_rel (struct GNUNET_TIME_Relative *rt);
297 * Return the minimum of two relative time values.
299 * @param t1 first timestamp
300 * @param t2 other timestamp
301 * @return timestamp that is smaller
303 struct GNUNET_TIME_Relative
304 GNUNET_TIME_relative_min (struct GNUNET_TIME_Relative t1,
305 struct GNUNET_TIME_Relative t2);
310 * Return the maximum of two relative time values.
312 * @param t1 first timestamp
313 * @param t2 other timestamp
314 * @return timestamp that is larger
316 struct GNUNET_TIME_Relative
317 GNUNET_TIME_relative_max (struct GNUNET_TIME_Relative t1,
318 struct GNUNET_TIME_Relative t2);
322 * Return the minimum of two absolute time values.
324 * @param t1 first timestamp
325 * @param t2 other timestamp
326 * @return timestamp that is smaller
328 struct GNUNET_TIME_Absolute
329 GNUNET_TIME_absolute_min (struct GNUNET_TIME_Absolute t1,
330 struct GNUNET_TIME_Absolute t2);
334 * Return the maximum of two absolute time values.
336 * @param t1 first timestamp
337 * @param t2 other timestamp
338 * @return timestamp that is smaller
340 struct GNUNET_TIME_Absolute
341 GNUNET_TIME_absolute_max (struct GNUNET_TIME_Absolute t1,
342 struct GNUNET_TIME_Absolute t2);
346 * Given a timestamp in the future, how much time
347 * remains until then?
349 * @param future some absolute time, typically in the future
350 * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.
352 struct GNUNET_TIME_Relative
353 GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future);
357 * Calculate the estimate time of arrival/completion
360 * @param start when did the operation start?
361 * @param finished how much has been done?
362 * @param total how much must be done overall (same unit as for "finished")
363 * @return remaining duration for the operation,
364 * assuming it continues at the same speed
366 struct GNUNET_TIME_Relative
367 GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished,
372 * Compute the time difference between the given start and end times.
373 * Use this function instead of actual subtraction to ensure that
374 * "FOREVER" and overflows are handeled correctly.
376 * @param start some absolute time
377 * @param end some absolute time (typically larger or equal to start)
378 * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start
380 struct GNUNET_TIME_Relative
381 GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start,
382 struct GNUNET_TIME_Absolute end);
386 * Get the duration of an operation as the
387 * difference of the current time and the given start time "hence".
389 * @param whence some absolute time, typically in the past
390 * @return 0 if hence > now, otherwise now-hence.
392 struct GNUNET_TIME_Relative
393 GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence);
397 * Add a given relative duration to the
400 * @param start some absolute time
401 * @param duration some relative time to add
402 * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise
404 struct GNUNET_TIME_Absolute
405 GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start,
406 struct GNUNET_TIME_Relative duration);
410 * Subtract a given relative duration from the
413 * @param start some absolute time
414 * @param duration some relative time to subtract
415 * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise
417 struct GNUNET_TIME_Absolute
418 GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start,
419 struct GNUNET_TIME_Relative duration);
423 * Multiply relative time by a given factor.
425 * @param rel some duration
426 * @param factor integer to multiply with
427 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
429 struct GNUNET_TIME_Relative
430 GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel,
431 unsigned long long factor);
435 * Saturating multiply relative time by a given factor.
437 * @param rel some duration
438 * @param factor integer to multiply with
439 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
441 struct GNUNET_TIME_Relative
442 GNUNET_TIME_relative_saturating_multiply (struct GNUNET_TIME_Relative rel,
443 unsigned long long factor);
447 * Divide relative time by a given factor.
449 * @param rel some duration
450 * @param factor integer to divide by
451 * @return FOREVER if rel=FOREVER or factor==0; otherwise rel/factor
453 struct GNUNET_TIME_Relative
454 GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel,
455 unsigned long long factor);
459 * Add relative times together.
461 * @param a1 some relative time
462 * @param a2 some other relative time
463 * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise
465 struct GNUNET_TIME_Relative
466 GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1,
467 struct GNUNET_TIME_Relative a2);
471 * Subtract relative timestamp from the other.
473 * @param a1 first timestamp
474 * @param a2 second timestamp
475 * @return ZERO if a2>=a1 (including both FOREVER), FOREVER if a1 is FOREVER, a1-a2 otherwise
477 struct GNUNET_TIME_Relative
478 GNUNET_TIME_relative_subtract (struct GNUNET_TIME_Relative a1,
479 struct GNUNET_TIME_Relative a2);
483 * Convert relative time to network byte order.
485 * @param a time to convert
486 * @return converted time value
488 struct GNUNET_TIME_RelativeNBO
489 GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a);
493 * Convert relative time from network byte order.
495 * @param a time to convert
496 * @return converted time value
498 struct GNUNET_TIME_Relative
499 GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a);
503 * Convert absolute time to network byte order.
505 * @param a time to convert
506 * @return converted time value
508 struct GNUNET_TIME_AbsoluteNBO
509 GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a);
513 * Convert absolute time from network byte order.
515 * @param a time to convert
516 * @return converted time value
518 struct GNUNET_TIME_Absolute
519 GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a);
523 * Set the timestamp offset for this instance.
525 * @param offset the offset to skew the locale time by
528 GNUNET_TIME_set_offset (long long offset);
532 * Get the timestamp offset for this instance.
534 * @return the offset we currently skew the locale time by
537 GNUNET_TIME_get_offset (void);
541 * Return the current year (i.e. '2011').
544 GNUNET_TIME_get_current_year (void);
548 * Convert a year to an expiration time of January 1st of that year.
550 * @param year a year (after 1970, please ;-)).
551 * @return absolute time for January 1st of that year.
553 struct GNUNET_TIME_Absolute
554 GNUNET_TIME_year_to_time (unsigned int year);
558 * Convert an expiration time to the respective year (rounds)
560 * @param at absolute time
561 * @return year a year (after 1970), 0 on error
564 GNUNET_TIME_time_to_year (struct GNUNET_TIME_Absolute at);
567 #if 0 /* keep Emacsens' auto-indent happy */
574 /* ifndef GNUNET_TIME_LIB_H */
577 /** @} */ /* end of group time */
579 /* end of gnunet_time_lib.h */