X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Finclude%2Fgnunet_time_lib.h;h=93e6cd00f84996fa6727329ed00cf910d04d9000;hb=6e626937fd5133188d2bd06f280a1b889219eef2;hp=da22ab31eb1d2f6792014d213e3abe330b271e0a;hpb=f9e6c67a3f1bf54c892cafa5aae454d9d0883d6e;p=oweals%2Fgnunet.git diff --git a/src/include/gnunet_time_lib.h b/src/include/gnunet_time_lib.h index da22ab31e..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 @@ -39,18 +43,18 @@ 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 { /** * The actual value. */ - uint64_t abs_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 @@ -58,32 +62,32 @@ struct GNUNET_TIME_Relative /** * The actual value. */ - uint64_t rel_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 { /** * The actual value (in network byte order). */ - uint64_t rel_value__ GNUNET_PACKED; + 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 { /** * The actual value (in network byte order). */ - uint64_t abs_value__ GNUNET_PACKED; + uint64_t abs_value_us__ GNUNET_PACKED; }; GNUNET_NETWORK_STRUCT_END @@ -98,9 +102,14 @@ GNUNET_NETWORK_STRUCT_END #define GNUNET_TIME_UNIT_ZERO_ABS GNUNET_TIME_absolute_get_zero_() /** - * One millisecond, our basic time unit. + * 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_unit_() +#define GNUNET_TIME_UNIT_MILLISECONDS GNUNET_TIME_relative_get_millisecond_() /** * One second. @@ -150,6 +159,36 @@ GNUNET_NETWORK_STRUCT_END #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. */ @@ -165,12 +204,19 @@ GNUNET_TIME_absolute_get_zero_ (void); /** - * Return relative time of 1ms. + * 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. */ @@ -226,6 +272,30 @@ 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. * @@ -297,7 +367,8 @@ GNUNET_TIME_absolute_get_remaining (struct GNUNET_TIME_Absolute future); * assuming it continues at the same speed */ struct GNUNET_TIME_Relative -GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, uint64_t finished, +GNUNET_TIME_calculate_eta (struct GNUNET_TIME_Absolute start, + uint64_t finished, uint64_t total); @@ -320,7 +391,7 @@ GNUNET_TIME_absolute_get_difference (struct GNUNET_TIME_Absolute start, * difference of the current time and the given start time "hence". * * @param whence some absolute time, typically in the past - * @return aborts if hence==FOREVER, 0 if hence > now, otherwise now-hence. + * @return 0 if hence > now, otherwise now-hence. */ struct GNUNET_TIME_Relative GNUNET_TIME_absolute_get_duration (struct GNUNET_TIME_Absolute whence); @@ -361,7 +432,19 @@ GNUNET_TIME_absolute_subtract (struct GNUNET_TIME_Absolute start, */ struct GNUNET_TIME_Relative GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, - unsigned int factor); + 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); /** @@ -373,7 +456,7 @@ GNUNET_TIME_relative_multiply (struct GNUNET_TIME_Relative rel, */ struct GNUNET_TIME_Relative GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel, - unsigned int factor); + unsigned long long factor); /** @@ -421,7 +504,7 @@ 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 @@ -431,7 +514,7 @@ 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 @@ -449,6 +532,70 @@ 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 @@ -458,4 +605,7 @@ GNUNET_TIME_set_offset (long long offset); /* ifndef GNUNET_TIME_LIB_H */ #endif + +/** @} */ /* end of group time */ + /* end of gnunet_time_lib.h */