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- /*
- This file is part of GNUnet.
- Copyright (C) 2001-2013 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- 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
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @author Christian Grothoff
- *
- * @file
- * Functions related to time
- *
- * @defgroup time Time library
- * Time and time calculations.
- * @{
- */
- #ifndef GNUNET_TIME_LIB_H
- #define GNUNET_TIME_LIB_H
- #ifdef __cplusplus
- extern "C"
- {
- #if 0 /* keep Emacsens' auto-indent happy */
- }
- #endif
- #endif
- #include "gnunet_common.h"
- /**
- * Time for absolute times used by GNUnet, in microseconds.
- */
- struct GNUNET_TIME_Absolute
- {
- /**
- * The actual value.
- */
- uint64_t abs_value_us;
- };
- /**
- * Time for relative time used by GNUnet, in microseconds.
- * Always positive, so we can only refer to future time.
- */
- struct GNUNET_TIME_Relative
- {
- /**
- * The actual value.
- */
- uint64_t rel_value_us;
- };
- GNUNET_NETWORK_STRUCT_BEGIN
- /**
- * Time for relative time used by GNUnet, in microseconds and in network byte order.
- */
- struct GNUNET_TIME_RelativeNBO
- {
- /**
- * The actual value (in network byte order).
- */
- uint64_t rel_value_us__ GNUNET_PACKED;
- };
- /**
- * Time for absolute time used by GNUnet, in microseconds and in network byte order.
- */
- struct GNUNET_TIME_AbsoluteNBO
- {
- /**
- * The actual value (in network byte order).
- */
- uint64_t abs_value_us__ GNUNET_PACKED;
- };
- GNUNET_NETWORK_STRUCT_END
- /**
- * Relative time zero.
- */
- #define GNUNET_TIME_UNIT_ZERO GNUNET_TIME_relative_get_zero_ ()
- /**
- * Absolute time zero.
- */
- #define GNUNET_TIME_UNIT_ZERO_ABS GNUNET_TIME_absolute_get_zero_ ()
- /**
- * One microsecond, our basic time unit.
- */
- #define GNUNET_TIME_UNIT_MICROSECONDS GNUNET_TIME_relative_get_unit_ ()
- /**
- * One millisecond.
- */
- #define GNUNET_TIME_UNIT_MILLISECONDS GNUNET_TIME_relative_get_millisecond_ ()
- /**
- * One second.
- */
- #define GNUNET_TIME_UNIT_SECONDS GNUNET_TIME_relative_get_second_ ()
- /**
- * One minute.
- */
- #define GNUNET_TIME_UNIT_MINUTES GNUNET_TIME_relative_get_minute_ ()
- /**
- * One hour.
- */
- #define GNUNET_TIME_UNIT_HOURS GNUNET_TIME_relative_get_hour_ ()
- /**
- * One day.
- */
- #define GNUNET_TIME_UNIT_DAYS GNUNET_TIME_relative_multiply ( \
- GNUNET_TIME_UNIT_HOURS, 24)
- /**
- * One week.
- */
- #define GNUNET_TIME_UNIT_WEEKS GNUNET_TIME_relative_multiply ( \
- GNUNET_TIME_UNIT_DAYS, 7)
- /**
- * One month (30 days).
- */
- #define GNUNET_TIME_UNIT_MONTHS GNUNET_TIME_relative_multiply ( \
- GNUNET_TIME_UNIT_DAYS, 30)
- /**
- * One year (365 days).
- */
- #define GNUNET_TIME_UNIT_YEARS GNUNET_TIME_relative_multiply ( \
- GNUNET_TIME_UNIT_DAYS, 365)
- /**
- * Constant used to specify "forever". This constant
- * will be treated specially in all time operations.
- */
- #define GNUNET_TIME_UNIT_FOREVER_REL GNUNET_TIME_relative_get_forever_ ()
- /**
- * Constant used to specify "forever". This constant
- * will be treated specially in all time operations.
- */
- #define GNUNET_TIME_UNIT_FOREVER_ABS GNUNET_TIME_absolute_get_forever_ ()
- /**
- * Threshold after which exponential backoff should not increase (15 m).
- */
- #define GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD \
- GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
- /**
- * Perform our standard exponential back-off calculation, starting at 1 ms
- * and then going by a factor of 2 up unto a maximum of 15 m.
- *
- * @param r current backoff time, initially zero
- */
- #define GNUNET_TIME_STD_BACKOFF(r) GNUNET_TIME_relative_min ( \
- GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD, \
- GNUNET_TIME_relative_multiply ( \
- GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_MILLISECONDS, (r)), 2));
- /**
- * Randomized exponential back-off, starting at 1 ms
- * and going up by a factor of 2+r, where 0 <= r <= 0.5, up
- * to a maximum of the given threshold.
- *
- * @param rt current backoff time, initially zero
- * @param threshold maximum value for backoff
- * @return the next backoff time
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_randomized_backoff (struct GNUNET_TIME_Relative rt, struct
- GNUNET_TIME_Relative threshold);
- /**
- * Return a random time value between 0.5*r and 1.5*r.
- *
- * @param r input time for scaling
- * @return randomized time
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_randomize (struct GNUNET_TIME_Relative r);
- /**
- * Return relative time of 0ms.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_zero_ (void);
- /**
- * Return absolute time of 0ms.
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_absolute_get_zero_ (void);
- /**
- * Return relative time of 1 microsecond.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_unit_ (void);
- /**
- * Return relative time of 1ms.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_millisecond_ (void);
- /**
- * Return relative time of 1s.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_second_ (void);
- /**
- * Return relative time of 1 minute.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_minute_ (void);
- /**
- * Return relative time of 1 hour.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_hour_ (void);
- /**
- * Return "forever".
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_get_forever_ (void);
- /**
- * Return "forever".
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_absolute_get_forever_ (void);
- /**
- * Get the current time.
- *
- * @return the current time
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_absolute_get (void);
- /**
- * Convert relative time to an absolute time in the
- * future.
- *
- * @param rel relative time to convert
- * @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);
- /**
- * Round a time value so that it is suitable for transmission
- * via JSON encodings.
- *
- * @param at time to round
- * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if
- * it was just now rounded
- */
- int
- GNUNET_TIME_round_abs (struct GNUNET_TIME_Absolute *at);
- /**
- * Round a time value so that it is suitable for transmission
- * via JSON encodings.
- *
- * @param rt time to round
- * @return #GNUNET_OK if time was already rounded, #GNUNET_NO if
- * it was just now rounded
- */
- int
- GNUNET_TIME_round_rel (struct GNUNET_TIME_Relative *rt);
- /**
- * 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 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 the minimum of two absolute 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 the maximum of two absolute 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);
- /**
- * Given a timestamp in the future, how much time
- * remains until then?
- *
- * @param future some absolute time, typically in the future
- * @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);
- /**
- * 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);
- /**
- * 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.
- *
- * @param start some absolute time
- * @param end some absolute time (typically larger or equal to start)
- * @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);
- /**
- * Get the duration of an operation as the
- * difference of the current time and the given start time "hence".
- *
- * @param whence some absolute time, typically in the past
- * @return 0 if hence > now, otherwise now-hence.
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence);
- /**
- * Add a given relative duration to the
- * given start time.
- *
- * @param start some absolute time
- * @param duration some relative time to add
- * @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);
- /**
- * 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);
- /**
- * Multiply relative time by a given factor.
- *
- * @param rel some duration
- * @param factor integer to multiply with
- * @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 long long factor);
- /**
- * Saturating multiply relative time by a given factor.
- *
- * @param rel some duration
- * @param factor integer to multiply with
- * @return FOREVER if rel=FOREVER or on overflow; otherwise rel*factor
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_saturating_multiply (struct GNUNET_TIME_Relative rel,
- unsigned long long factor);
- /**
- * 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 long long factor);
- /**
- * Add relative times together.
- *
- * @param a1 some relative time
- * @param a2 some other relative time
- * @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);
- /**
- * 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);
- /**
- * Convert relative time to network byte order.
- *
- * @param a time to convert
- * @return converted time value
- */
- struct GNUNET_TIME_RelativeNBO
- GNUNET_TIME_relative_hton (struct GNUNET_TIME_Relative a);
- /**
- * Convert relative time from network byte order.
- *
- * @param a time to convert
- * @return converted time value
- */
- struct GNUNET_TIME_Relative
- GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a);
- /**
- * Convert absolute time to network byte order.
- *
- * @param a time to convert
- * @return converted time value
- */
- struct GNUNET_TIME_AbsoluteNBO
- GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a);
- /**
- * Convert absolute time from network byte order.
- *
- * @param a time to convert
- * @return converted time value
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_absolute_ntoh (struct GNUNET_TIME_AbsoluteNBO a);
- /**
- * 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);
- /**
- * Get the timestamp offset for this instance.
- *
- * @return the offset we currently skew the locale time by
- */
- long long
- GNUNET_TIME_get_offset (void);
- /**
- * Return the current year (i.e. '2011').
- */
- unsigned int
- GNUNET_TIME_get_current_year (void);
- /**
- * Convert a year to an expiration time of January 1st of that year.
- *
- * @param year a year (after 1970, please ;-)).
- * @return absolute time for January 1st of that year.
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_year_to_time (unsigned int year);
- /**
- * Convert an expiration time to the respective year (rounds)
- *
- * @param at absolute time
- * @return year a year (after 1970), 0 on error
- */
- unsigned int
- GNUNET_TIME_time_to_year (struct GNUNET_TIME_Absolute at);
- /**
- * A configuration object.
- */
- struct GNUNET_CONFIGURATION_Handle;
- /**
- * Obtain the current time and make sure it is monotonically
- * increasing. Guards against systems without an RTC or
- * clocks running backwards and other nasty surprises. Does
- * not guarantee that the returned time is near the current
- * time returned by #GNUNET_TIME_absolute_get(). Two
- * subsequent calls (within a short time period) may return the
- * same value. Persists the last returned time on disk to
- * ensure that time never goes backwards. As a result, the
- * resulting value can be used to check if a message is the
- * "most recent" value and replays of older messages (from
- * the same origin) would be discarded.
- *
- * @param cfg configuration, used to determine where to
- * store the time; user can also insist RTC is working
- * nicely and disable the feature
- * @return monotonically increasing time
- */
- struct GNUNET_TIME_Absolute
- GNUNET_TIME_absolute_get_monotonic (const struct
- GNUNET_CONFIGURATION_Handle *cfg);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_TIME_LIB_H */
- #endif
- /** @} */ /* end of group time */
- /* end of gnunet_time_lib.h */
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