/*
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
{
/**
* 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
/**
* 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
#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.
#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.
*/
/**
- * 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.
*/
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.
*
* 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);
* 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);
*/
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);
/**
*/
struct GNUNET_TIME_Relative
GNUNET_TIME_relative_divide (struct GNUNET_TIME_Relative rel,
- unsigned int factor);
+ unsigned long long factor);
/**
/**
- * Convert relative time to network byte order.
+ * Convert absolute time to network byte order.
*
* @param a time to convert
* @return converted time value
/**
- * Convert relative time from network byte order.
+ * Convert absolute time from network byte order.
*
* @param a time to convert
* @return converted time value
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
/* ifndef GNUNET_TIME_LIB_H */
#endif
+
+/** @} */ /* end of group time */
+
/* end of gnunet_time_lib.h */
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