/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009 Christian Grothoff (and other contributing authors)
+ 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 General Public License as published
- by the Free Software Foundation; either version 2, or (at your
- option) any later version.
+ 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
- General Public License for more details.
+ 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/>.
- 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.
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
- * @file include/gnunet_time_lib.h
- * @brief functions related to time
- *
* @author Christian Grothoff
+ *
+ * @file
+ * Functions related to time
+ *
+ * @defgroup time Time library
+ * Time and time calculations.
+ * @{
*/
#ifndef GNUNET_TIME_LIB_H
#include "gnunet_common.h"
/**
- * Time for absolute times used by GNUnet, in milliseconds.
+ * Time for absolute times used by GNUnet, in microseconds.
*/
struct GNUNET_TIME_Absolute
{
- uint64_t value;
+ /**
+ * The actual value.
+ */
+ uint64_t abs_value_us;
};
/**
- * Time for relative time used by GNUnet, in milliseconds.
+ * Time for relative time used by GNUnet, in microseconds.
* Always positive, so we can only refer to future time.
*/
struct GNUNET_TIME_Relative
{
- uint64_t value;
+ /**
+ * The actual value.
+ */
+ uint64_t rel_value_us;
};
+GNUNET_NETWORK_STRUCT_BEGIN
/**
- * Time for relative time used by GNUnet, in milliseconds and in network byte order.
+ * Time for relative time used by GNUnet, in microseconds and in network byte order.
*/
struct GNUNET_TIME_RelativeNBO
{
- uint64_t value__ GNUNET_PACKED;
+ /**
+ * The actual value (in network byte order).
+ */
+ uint64_t rel_value_us__ GNUNET_PACKED;
};
/**
- * Time for absolute time used by GNUnet, in milliseconds and in network byte order.
+ * Time for absolute time used by GNUnet, in microseconds and in network byte order.
*/
struct GNUNET_TIME_AbsoluteNBO
{
- uint64_t value__ GNUNET_PACKED;
+ /**
+ * 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_()
/**
- * @brief constants to specify time
+ * One hour.
+ */
+#define GNUNET_TIME_UNIT_HOURS GNUNET_TIME_relative_get_hour_()
+
+/**
+ * One day.
*/
-#define GNUNET_TIME_UNIT_ZERO GNUNET_TIME_relative_get_zero()
-#define GNUNET_TIME_UNIT_ZERO_ABS GNUNET_TIME_absolute_get_zero()
-#define GNUNET_TIME_UNIT_MILLISECONDS GNUNET_TIME_relative_get_unit()
-#define GNUNET_TIME_UNIT_SECONDS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 1000)
-#define GNUNET_TIME_UNIT_MINUTES GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 60)
-#define GNUNET_TIME_UNIT_HOURS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MINUTES, 60)
#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 ()
+#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 ()
+#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 relative time of 0ms.
*/
-struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_zero (void);
+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);
+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_unit (void);
+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);
+struct GNUNET_TIME_Relative
+GNUNET_TIME_relative_get_forever_ (void);
+
/**
* Return "forever".
*/
-struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_get_forever (void);
+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);
+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);
+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_Relative GNUNET_TIME_relative_min (struct
- GNUNET_TIME_Relative
- t1,
- struct
- GNUNET_TIME_Relative t2);
+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);
+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 handeled 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);
+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".
*
- * @return aborts if hence==FOREVER, 0 if hence > now, otherwise now-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
- 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);
+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_multiply (struct
- GNUNET_TIME_Relative
- rel,
- unsigned int
- 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);
+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);
+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);
+struct GNUNET_TIME_Relative
+GNUNET_TIME_relative_ntoh (struct GNUNET_TIME_RelativeNBO a);
+
/**
- * Convert relative time to network byte order.
+ * 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);
+struct GNUNET_TIME_AbsoluteNBO
+GNUNET_TIME_absolute_hton (struct GNUNET_TIME_Absolute a);
+
/**
- * Convert relative time from network byte order.
+ * 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
*/
-struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh (struct
- GNUNET_TIME_AbsoluteNBO
- a);
+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 */
{
/* ifndef GNUNET_TIME_LIB_H */
#endif
+
+/** @} */ /* end of group time */
+
/* end of gnunet_time_lib.h */
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