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
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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__)
32 * Variable used to simulate clock skew. Used for testing, never in production.
34 static long long timestamp_offset;
37 * Set the timestamp offset for this instance.
39 * @param offset the offset to skew the locale time by
42 GNUNET_TIME_set_offset (long long offset)
44 timestamp_offset = offset;
48 * Get the current time (works just as "time", just that we use the
49 * unit of time that the cron-jobs use (and is 64 bit)).
51 * @return the current time
53 struct GNUNET_TIME_Absolute
54 GNUNET_TIME_absolute_get ()
56 struct GNUNET_TIME_Absolute ret;
59 GETTIMEOFDAY (&tv, NULL);
61 (uint64_t) (((uint64_t) tv.tv_sec * 1000LL) +
62 ((uint64_t) tv.tv_usec / 1000LL)) + timestamp_offset;
68 * Return relative time of 0ms.
70 struct GNUNET_TIME_Relative
71 GNUNET_TIME_relative_get_zero ()
73 static struct GNUNET_TIME_Relative zero;
80 * Return absolute time of 0ms.
82 struct GNUNET_TIME_Absolute
83 GNUNET_TIME_absolute_get_zero ()
85 static struct GNUNET_TIME_Absolute zero;
91 * Return relative time of 1ms.
93 struct GNUNET_TIME_Relative
94 GNUNET_TIME_relative_get_unit ()
96 static struct GNUNET_TIME_Relative one = { 1 };
103 struct GNUNET_TIME_Relative
104 GNUNET_TIME_relative_get_forever ()
106 static struct GNUNET_TIME_Relative forever = { UINT64_MAX };
113 struct GNUNET_TIME_Absolute
114 GNUNET_TIME_absolute_get_forever ()
116 static struct GNUNET_TIME_Absolute forever = { UINT64_MAX };
121 * Convert relative time to an absolute time in the
124 * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow)
126 struct GNUNET_TIME_Absolute
127 GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel)
129 struct GNUNET_TIME_Absolute ret;
131 if (rel.rel_value == UINT64_MAX)
132 return GNUNET_TIME_absolute_get_forever ();
133 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
135 if (rel.rel_value + now.abs_value < rel.rel_value)
137 GNUNET_break (0); /* overflow... */
138 return GNUNET_TIME_absolute_get_forever ();
140 ret.abs_value = rel.rel_value + now.abs_value;
146 * Return the minimum of two relative time values.
148 * @param t1 first timestamp
149 * @param t2 other timestamp
150 * @return timestamp that is smaller
152 struct GNUNET_TIME_Relative
153 GNUNET_TIME_relative_min (struct GNUNET_TIME_Relative t1,
154 struct GNUNET_TIME_Relative t2)
156 return (t1.rel_value < t2.rel_value) ? t1 : t2;
161 * Return the maximum of two relative time values.
163 * @param t1 first timestamp
164 * @param t2 other timestamp
165 * @return timestamp that is larger
167 struct GNUNET_TIME_Relative
168 GNUNET_TIME_relative_max (struct GNUNET_TIME_Relative t1,
169 struct GNUNET_TIME_Relative t2)
171 return (t1.rel_value > t2.rel_value) ? t1 : t2;
177 * Return the minimum of two relative time values.
179 * @param t1 first timestamp
180 * @param t2 other timestamp
181 * @return timestamp that is smaller
183 struct GNUNET_TIME_Absolute
184 GNUNET_TIME_absolute_min (struct GNUNET_TIME_Absolute t1,
185 struct GNUNET_TIME_Absolute t2)
187 return (t1.abs_value < t2.abs_value) ? t1 : t2;
192 * Return the maximum of two relative time values.
194 * @param t1 first timestamp
195 * @param t2 other timestamp
196 * @return timestamp that is smaller
198 struct GNUNET_TIME_Absolute
199 GNUNET_TIME_absolute_max (struct GNUNET_TIME_Absolute t1,
200 struct GNUNET_TIME_Absolute t2)
202 return (t1.abs_value > t2.abs_value) ? t1 : t2;
207 * Given a timestamp in the future, how much time
208 * remains until then?
210 * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER.
212 struct GNUNET_TIME_Relative
213 GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future)
215 struct GNUNET_TIME_Relative ret;
217 if (future.abs_value == UINT64_MAX)
218 return GNUNET_TIME_relative_get_forever ();
219 struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get ();
221 if (now.abs_value > future.abs_value)
222 return GNUNET_TIME_relative_get_zero ();
223 ret.rel_value = future.abs_value - now.abs_value;
228 * Compute the time difference between the given start and end times.
229 * Use this function instead of actual subtraction to ensure that
230 * "FOREVER" and overflows are handled correctly.
232 * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start
234 struct GNUNET_TIME_Relative
235 GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start,
236 struct GNUNET_TIME_Absolute end)
238 struct GNUNET_TIME_Relative ret;
240 if (end.abs_value == UINT64_MAX)
241 return GNUNET_TIME_relative_get_forever ();
242 if (end.abs_value < start.abs_value)
243 return GNUNET_TIME_relative_get_zero ();
244 ret.rel_value = end.abs_value - start.abs_value;
249 * Get the duration of an operation as the
250 * difference of the current time and the given start time "whence".
252 * @return aborts if whence==FOREVER, 0 if whence > now, otherwise now-whence.
254 struct GNUNET_TIME_Relative
255 GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence)
257 struct GNUNET_TIME_Absolute now;
258 struct GNUNET_TIME_Relative ret;
260 now = GNUNET_TIME_absolute_get ();
261 GNUNET_assert (whence.abs_value != UINT64_MAX);
262 if (whence.abs_value > now.abs_value)
263 return GNUNET_TIME_relative_get_zero ();
264 ret.rel_value = now.abs_value - whence.abs_value;
270 * Add a given relative duration to the
273 * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise
275 struct GNUNET_TIME_Absolute
276 GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start,
277 struct GNUNET_TIME_Relative duration)
279 struct GNUNET_TIME_Absolute ret;
281 if ((start.abs_value == UINT64_MAX) || (duration.rel_value == UINT64_MAX))
282 return GNUNET_TIME_absolute_get_forever ();
283 if (start.abs_value + duration.rel_value < start.abs_value)
286 return GNUNET_TIME_absolute_get_forever ();
288 ret.abs_value = start.abs_value + duration.rel_value;
294 * Subtract a given relative duration from the
297 * @param start some absolute time
298 * @param duration some relative time to subtract
299 * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise
301 struct GNUNET_TIME_Absolute
302 GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start,
303 struct GNUNET_TIME_Relative duration)
305 struct GNUNET_TIME_Absolute ret;
307 if (start.abs_value <= duration.rel_value)
308 return GNUNET_TIME_UNIT_ZERO_ABS;
309 if (start.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value)
310 return GNUNET_TIME_UNIT_FOREVER_ABS;
311 ret.abs_value = start.abs_value - duration.rel_value;
317 * Multiply relative time by a given factor.
319 * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
321 struct GNUNET_TIME_Relative
322 GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel,
325 struct GNUNET_TIME_Relative ret;
328 return GNUNET_TIME_relative_get_zero ();
329 ret.rel_value = rel.rel_value * (unsigned long long) factor;
330 if (ret.rel_value / factor != rel.rel_value)
333 return GNUNET_TIME_relative_get_forever ();
340 * Divide relative time by a given factor.
342 * @param rel some duration
343 * @param factor integer to divide by
344 * @return FOREVER if rel=FOREVER or factor==0; otherwise rel/factor
346 struct GNUNET_TIME_Relative
347 GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel,
350 struct GNUNET_TIME_Relative ret;
353 (rel.rel_value == GNUNET_TIME_UNIT_FOREVER_REL.rel_value))
354 return GNUNET_TIME_UNIT_FOREVER_REL;
355 ret.rel_value = rel.rel_value / (unsigned long long) factor;
361 * Calculate the estimate time of arrival/completion
364 * @param start when did the operation start?
365 * @param finished how much has been done?
366 * @param total how much must be done overall (same unit as for "finished")
367 * @return remaining duration for the operation,
368 * assuming it continues at the same speed
370 struct GNUNET_TIME_Relative
371 GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished,
374 struct GNUNET_TIME_Relative dur;
376 struct GNUNET_TIME_Relative ret;
378 GNUNET_break (finished <= total);
379 if (finished >= total)
380 return GNUNET_TIME_UNIT_ZERO;
382 return GNUNET_TIME_UNIT_FOREVER_REL;
383 dur = GNUNET_TIME_absolute_get_duration (start);
384 exp = ((double) dur.rel_value) * ((double) total) / ((double) finished);
385 ret.rel_value = ((uint64_t) exp) - dur.rel_value;
391 * Add relative times together.
393 * @param a1 first timestamp
394 * @param a2 second timestamp
395 * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise
397 struct GNUNET_TIME_Relative
398 GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1,
399 struct GNUNET_TIME_Relative a2)
401 struct GNUNET_TIME_Relative ret;
403 if ((a1.rel_value == UINT64_MAX) || (a2.rel_value == UINT64_MAX))
404 return GNUNET_TIME_relative_get_forever ();
405 if (a1.rel_value + a2.rel_value < a1.rel_value)
408 return GNUNET_TIME_relative_get_forever ();
410 ret.rel_value = a1.rel_value + a2.rel_value;
416 * Subtract relative timestamp from the other.
418 * @param a1 first timestamp
419 * @param a2 second timestamp
420 * @return ZERO if a2>=a1 (including both FOREVER), FOREVER if a1 is FOREVER, a1-a2 otherwise
422 struct GNUNET_TIME_Relative
423 GNUNET_TIME_relative_subtract (struct GNUNET_TIME_Relative a1,
424 struct GNUNET_TIME_Relative a2)
426 struct GNUNET_TIME_Relative ret;
428 if (a2.rel_value >= a1.rel_value)
429 return GNUNET_TIME_relative_get_zero ();
430 if (a1.rel_value == UINT64_MAX)
431 return GNUNET_TIME_relative_get_forever ();
432 ret.rel_value = a1.rel_value - a2.rel_value;
438 * Convert relative time to network byte order.
440 * @param a time to convert
441 * @return time in network byte order
443 struct GNUNET_TIME_RelativeNBO
444 GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a)
446 struct GNUNET_TIME_RelativeNBO ret;
448 ret.rel_value__ = GNUNET_htonll (a.rel_value);
453 * Convert relative time from network byte order.
455 * @param a time to convert
456 * @return time in host byte order
458 struct GNUNET_TIME_Relative
459 GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a)
461 struct GNUNET_TIME_Relative ret;
463 ret.rel_value = GNUNET_ntohll (a.rel_value__);
469 * Convert absolute time to network byte order.
471 * @param a time to convert
472 * @return time in network byte order
474 struct GNUNET_TIME_AbsoluteNBO
475 GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a)
477 struct GNUNET_TIME_AbsoluteNBO ret;
479 ret.abs_value__ = GNUNET_htonll (a.abs_value);
484 * Convert absolute time from network byte order.
486 * @param a time to convert
487 * @return time in host byte order
489 struct GNUNET_TIME_Absolute
490 GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a)
492 struct GNUNET_TIME_Absolute ret;
494 ret.abs_value = GNUNET_ntohll (a.abs_value__);
500 * Convert a relative time to a string.
501 * This is one of the very few calls in the entire API that is
504 * @param time the time to print
506 * @return string form of the time (as milliseconds)
509 GNUNET_TIME_relative_to_string (struct GNUNET_TIME_Relative time)
511 static char time_string[21];
513 memset (time_string, 0, sizeof (time_string));
515 sprintf (time_string, "%llu", (unsigned long long) time.rel_value);
516 return (const char *) time_string;