X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Finclude%2Fgnunet_time_lib.h;h=93e6cd00f84996fa6727329ed00cf910d04d9000;hb=6e626937fd5133188d2bd06f280a1b889219eef2;hp=b5da09cd83d59940493351eb15c38ab3d794e1f5;hpb=596fe6fcff78fc66f2ed7e8bd46475feef9c6210;p=oweals%2Fgnunet.git diff --git a/src/include/gnunet_time_lib.h b/src/include/gnunet_time_lib.h index b5da09cd8..93e6cd00f 100644 --- a/src/include/gnunet_time_lib.h +++ b/src/include/gnunet_time_lib.h @@ -1,28 +1,32 @@ /* 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 . - 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 @@ -39,218 +43,558 @@ extern "C" #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 */ { @@ -261,4 +605,7 @@ struct GNUNET_TIME_Absolute GNUNET_TIME_absolute_ntoh (struct /* ifndef GNUNET_TIME_LIB_H */ #endif + +/** @} */ /* end of group time */ + /* end of gnunet_time_lib.h */