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Diffstat (limited to 'src/util/time.c')
| -rw-r--r-- | src/util/time.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/src/util/time.c b/src/util/time.c new file mode 100644 index 0000000..c57ccd1 --- /dev/null +++ b/src/util/time.c @@ -0,0 +1,521 @@ +/* + This file is part of GNUnet. + (C) 2001, 2002, 2006, 2009 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 2, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file util/time.c + * @author Christian Grothoff + * @brief functions for handling time and time arithmetic + */ +#include "platform.h" +#include "gnunet_time_lib.h" + +#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__) + +/** + * Variable used to simulate clock skew. Used for testing, never in production. + */ +static long long timestamp_offset; + +/** + * Set the timestamp offset for this instance. + * + * @param offset the offset to skew the locale time by + */ +void +GNUNET_TIME_set_offset (long long offset) +{ + timestamp_offset = offset; +} + +/** + * Get the current time (works just as "time", just that we use the + * unit of time that the cron-jobs use (and is 64 bit)). + * + * @return the current time + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_get () +{ + struct GNUNET_TIME_Absolute ret; + struct timeval tv; + + GETTIMEOFDAY (&tv, NULL); + ret.abs_value = + (uint64_t) (((uint64_t) tv.tv_sec * 1000LL) + + ((uint64_t) tv.tv_usec / 1000LL)) + timestamp_offset; + return ret; +} + + +/** + * Return relative time of 0ms. + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_get_zero () +{ + static struct GNUNET_TIME_Relative zero; + + return zero; +} + + +/** + * Return absolute time of 0ms. + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_get_zero () +{ + static struct GNUNET_TIME_Absolute zero; + + return zero; +} + +/** + * Return relative time of 1ms. + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_get_unit () +{ + static struct GNUNET_TIME_Relative one = { 1 }; + return one; +} + +/** + * Return "forever". + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_get_forever () +{ + static struct GNUNET_TIME_Relative forever = { UINT64_MAX }; + return forever; +} + +/** + * Return "forever". + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_get_forever () +{ + static struct GNUNET_TIME_Absolute forever = { UINT64_MAX }; + return forever; +} + +/** + * Convert relative time to an absolute time in the + * future. + * + * @return timestamp that is "rel" in the future, or FOREVER if rel==FOREVER (or if we would overflow) + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_relative_to_absolute (struct GNUNET_TIME_Relative rel) +{ + struct GNUNET_TIME_Absolute ret; + + if (rel.rel_value == UINT64_MAX) + return GNUNET_TIME_absolute_get_forever (); + struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get (); + + if (rel.rel_value + now.abs_value < rel.rel_value) + { + GNUNET_break (0); /* overflow... */ + return GNUNET_TIME_absolute_get_forever (); + } + ret.abs_value = rel.rel_value + now.abs_value; + return ret; +} + + +/** + * Return the minimum of two relative time values. + * + * @param t1 first timestamp + * @param t2 other timestamp + * @return timestamp that is smaller + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_min (struct GNUNET_TIME_Relative t1, + struct GNUNET_TIME_Relative t2) +{ + return (t1.rel_value < t2.rel_value) ? t1 : t2; +} + + +/** + * Return the maximum of two relative time values. + * + * @param t1 first timestamp + * @param t2 other timestamp + * @return timestamp that is larger + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_max (struct GNUNET_TIME_Relative t1, + struct GNUNET_TIME_Relative t2) +{ + return (t1.rel_value > t2.rel_value) ? t1 : t2; +} + + + +/** + * Return the minimum of two relative time values. + * + * @param t1 first timestamp + * @param t2 other timestamp + * @return timestamp that is smaller + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_min (struct GNUNET_TIME_Absolute t1, + struct GNUNET_TIME_Absolute t2) +{ + return (t1.abs_value < t2.abs_value) ? t1 : t2; +} + + +/** + * Return the maximum of two relative time values. + * + * @param t1 first timestamp + * @param t2 other timestamp + * @return timestamp that is smaller + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_max (struct GNUNET_TIME_Absolute t1, + struct GNUNET_TIME_Absolute t2) +{ + return (t1.abs_value > t2.abs_value) ? t1 : t2; +} + + +/** + * Given a timestamp in the future, how much time + * remains until then? + * + * @return future - now, or 0 if now >= future, or FOREVER if future==FOREVER. + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future) +{ + struct GNUNET_TIME_Relative ret; + + if (future.abs_value == UINT64_MAX) + return GNUNET_TIME_relative_get_forever (); + struct GNUNET_TIME_Absolute now = GNUNET_TIME_absolute_get (); + + if (now.abs_value > future.abs_value) + return GNUNET_TIME_relative_get_zero (); + ret.rel_value = future.abs_value - now.abs_value; + return ret; +} + +/** + * Compute the time difference between the given start and end times. + * Use this function instead of actual subtraction to ensure that + * "FOREVER" and overflows are handled correctly. + * + * @return 0 if start >= end; FOREVER if end==FOREVER; otherwise end - start + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start, + struct GNUNET_TIME_Absolute end) +{ + struct GNUNET_TIME_Relative ret; + + if (end.abs_value == UINT64_MAX) + return GNUNET_TIME_relative_get_forever (); + if (end.abs_value < start.abs_value) + return GNUNET_TIME_relative_get_zero (); + ret.rel_value = end.abs_value - start.abs_value; + return ret; +} + +/** + * Get the duration of an operation as the + * difference of the current time and the given start time "whence". + * + * @return aborts if whence==FOREVER, 0 if whence > now, otherwise now-whence. + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence) +{ + struct GNUNET_TIME_Absolute now; + struct GNUNET_TIME_Relative ret; + + now = GNUNET_TIME_absolute_get (); + GNUNET_assert (whence.abs_value != UINT64_MAX); + if (whence.abs_value > now.abs_value) + return GNUNET_TIME_relative_get_zero (); + ret.rel_value = now.abs_value - whence.abs_value; + return ret; +} + + +/** + * Add a given relative duration to the + * given start time. + * + * @return FOREVER if either argument is FOREVER or on overflow; start+duration otherwise + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_add (struct GNUNET_TIME_Absolute start, + struct GNUNET_TIME_Relative duration) +{ + struct GNUNET_TIME_Absolute ret; + + if ((start.abs_value == UINT64_MAX) || (duration.rel_value == UINT64_MAX)) + return GNUNET_TIME_absolute_get_forever (); + if (start.abs_value + duration.rel_value < start.abs_value) + { + GNUNET_break (0); + return GNUNET_TIME_absolute_get_forever (); + } + ret.abs_value = start.abs_value + duration.rel_value; + return ret; +} + + +/** + * Subtract a given relative duration from the + * given start time. + * + * @param start some absolute time + * @param duration some relative time to subtract + * @return ZERO if start <= duration, or FOREVER if start time is FOREVER; start-duration otherwise + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start, + struct GNUNET_TIME_Relative duration) +{ + struct GNUNET_TIME_Absolute ret; + + if (start.abs_value <= duration.rel_value) + return GNUNET_TIME_UNIT_ZERO_ABS; + if (start.abs_value == GNUNET_TIME_UNIT_FOREVER_ABS.abs_value) + return GNUNET_TIME_UNIT_FOREVER_ABS; + ret.abs_value = start.abs_value - duration.rel_value; + return ret; +} + + +/** + * Multiply relative time by a given factor. + * + * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, + unsigned int factor) +{ + struct GNUNET_TIME_Relative ret; + + if (factor == 0) + return GNUNET_TIME_relative_get_zero (); + ret.rel_value = rel.rel_value * (unsigned long long) factor; + if (ret.rel_value / factor != rel.rel_value) + { + GNUNET_break (0); + return GNUNET_TIME_relative_get_forever (); + } + return ret; +} + + +/** + * Divide relative time by a given factor. + * + * @param rel some duration + * @param factor integer to divide by + * @return FOREVER if rel=FOREVER or factor==0; otherwise rel/factor + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel, + unsigned int factor) +{ + struct GNUNET_TIME_Relative ret; + + if ((factor == 0) || + (rel.rel_value == GNUNET_TIME_UNIT_FOREVER_REL.rel_value)) + return GNUNET_TIME_UNIT_FOREVER_REL; + ret.rel_value = rel.rel_value / (unsigned long long) factor; + return ret; +} + + +/** + * Calculate the estimate time of arrival/completion + * for an operation. + * + * @param start when did the operation start? + * @param finished how much has been done? + * @param total how much must be done overall (same unit as for "finished") + * @return remaining duration for the operation, + * assuming it continues at the same speed + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished, + uint64_t total) +{ + struct GNUNET_TIME_Relative dur; + double exp; + struct GNUNET_TIME_Relative ret; + + GNUNET_break (finished <= total); + if (finished >= total) + return GNUNET_TIME_UNIT_ZERO; + if (finished == 0) + return GNUNET_TIME_UNIT_FOREVER_REL; + dur = GNUNET_TIME_absolute_get_duration (start); + exp = ((double) dur.rel_value) * ((double) total) / ((double) finished); + ret.rel_value = ((uint64_t) exp) - dur.rel_value; + return ret; +} + + +/** + * Add relative times together. + * + * @param a1 first timestamp + * @param a2 second timestamp + * @return FOREVER if either argument is FOREVER or on overflow; a1+a2 otherwise + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_add (struct GNUNET_TIME_Relative a1, + struct GNUNET_TIME_Relative a2) +{ + struct GNUNET_TIME_Relative ret; + + if ((a1.rel_value == UINT64_MAX) || (a2.rel_value == UINT64_MAX)) + return GNUNET_TIME_relative_get_forever (); + if (a1.rel_value + a2.rel_value < a1.rel_value) + { + GNUNET_break (0); + return GNUNET_TIME_relative_get_forever (); + } + ret.rel_value = a1.rel_value + a2.rel_value; + return ret; +} + + +/** + * Subtract relative timestamp from the other. + * + * @param a1 first timestamp + * @param a2 second timestamp + * @return ZERO if a2>=a1 (including both FOREVER), FOREVER if a1 is FOREVER, a1-a2 otherwise + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_subtract (struct GNUNET_TIME_Relative a1, + struct GNUNET_TIME_Relative a2) +{ + struct GNUNET_TIME_Relative ret; + + if (a2.rel_value >= a1.rel_value) + return GNUNET_TIME_relative_get_zero (); + if (a1.rel_value == UINT64_MAX) + return GNUNET_TIME_relative_get_forever (); + ret.rel_value = a1.rel_value - a2.rel_value; + return ret; +} + + +/** + * Convert relative time to network byte order. + * + * @param a time to convert + * @return time in network byte order + */ +struct GNUNET_TIME_RelativeNBO +GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a) +{ + struct GNUNET_TIME_RelativeNBO ret; + + ret.rel_value__ = GNUNET_htonll (a.rel_value); + return ret; +} + +/** + * Convert relative time from network byte order. + * + * @param a time to convert + * @return time in host byte order + */ +struct GNUNET_TIME_Relative +GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a) +{ + struct GNUNET_TIME_Relative ret; + + ret.rel_value = GNUNET_ntohll (a.rel_value__); + return ret; + +} + +/** + * Convert absolute time to network byte order. + * + * @param a time to convert + * @return time in network byte order + */ +struct GNUNET_TIME_AbsoluteNBO +GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a) +{ + struct GNUNET_TIME_AbsoluteNBO ret; + + ret.abs_value__ = GNUNET_htonll (a.abs_value); + return ret; +} + +/** + * Convert absolute time from network byte order. + * + * @param a time to convert + * @return time in host byte order + */ +struct GNUNET_TIME_Absolute +GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a) +{ + struct GNUNET_TIME_Absolute ret; + + ret.abs_value = GNUNET_ntohll (a.abs_value__); + return ret; + +} + +/** + * Convert a relative time to a string. + * This is one of the very few calls in the entire API that is + * NOT reentrant! + * + * @param time the time to print + * + * @return string form of the time (as milliseconds) + */ +const char * +GNUNET_TIME_relative_to_string (struct GNUNET_TIME_Relative time) +{ + static char time_string[21]; + + memset (time_string, 0, sizeof (time_string)); + + sprintf (time_string, "%llu", (unsigned long long) time.rel_value); + return (const char *) time_string; +} + + + +/* end of time.c */ |