/*
This file is part of GNUnet.
- (C) 2010 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2010, 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
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
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.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
* @file util/bandwidth.c
- * @brief functions related to bandwidth (unit)
+ * @brief functions related to bandwidth (unit)
* @author Christian Grothoff
*/
#include "platform.h"
-#include "gnunet_bandwidth_lib.h"
-#include "gnunet_server_lib.h"
+#include "gnunet_util_lib.h"
+
+
+#define LOG(kind,...) GNUNET_log_from (kind, "util-bandwidth", __VA_ARGS__)
/**
* Create a new bandwidth value.
*/
struct GNUNET_BANDWIDTH_Value32NBO
GNUNET_BANDWIDTH_value_min (struct GNUNET_BANDWIDTH_Value32NBO b1,
- struct GNUNET_BANDWIDTH_Value32NBO b2)
+ struct GNUNET_BANDWIDTH_Value32NBO b2)
+{
+ return
+ GNUNET_BANDWIDTH_value_init (GNUNET_MIN
+ (ntohl (b1.value__),
+ ntohl (b2.value__)));
+}
+
+
+/**
+ * Compute the MAX of two bandwidth values.
+ *
+ * @param b1 first value
+ * @param b2 second value
+ * @return the min of b1 and b2
+ */
+struct GNUNET_BANDWIDTH_Value32NBO
+GNUNET_BANDWIDTH_value_max (struct GNUNET_BANDWIDTH_Value32NBO b1,
+ struct GNUNET_BANDWIDTH_Value32NBO b2)
+{
+ return
+ GNUNET_BANDWIDTH_value_init (GNUNET_MAX
+ (ntohl (b1.value__),
+ ntohl (b2.value__)));
+}
+
+
+/**
+ * At the given bandwidth, calculate how much traffic will be
+ * available until the given deadline.
+ *
+ * @param bps bandwidth
+ * @param deadline when is the deadline
+ * @return number of bytes available at bps until deadline
+ */
+uint64_t
+GNUNET_BANDWIDTH_value_get_available_until (struct GNUNET_BANDWIDTH_Value32NBO bps,
+ struct GNUNET_TIME_Relative deadline)
+{
+ uint64_t b;
+
+ b = ntohl (bps.value__);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Bandwidth has %llu bytes available until deadline in %s\n",
+ (unsigned long long) ((b * deadline.rel_value_us + 500000LL) / 1000000LL),
+ GNUNET_STRINGS_relative_time_to_string (deadline, GNUNET_YES));
+ return (b * deadline.rel_value_us + 500000LL) / 1000000LL;
+}
+
+
+/**
+ * At the given bandwidth, calculate how long it would take for
+ * @a size bytes to be transmitted.
+ *
+ * @param bps bandwidth
+ * @param size number of bytes we want to have available
+ * @return how long it would take
+ */
+struct GNUNET_TIME_Relative
+GNUNET_BANDWIDTH_value_get_delay_for (struct GNUNET_BANDWIDTH_Value32NBO bps,
+ uint64_t size)
+{
+ uint64_t b;
+ struct GNUNET_TIME_Relative ret;
+
+ b = ntohl (bps.value__);
+ if (0 == b)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Bandwidth suggests delay of infinity (zero bandwidth)\n");
+ return GNUNET_TIME_UNIT_FOREVER_REL;
+ }
+ ret.rel_value_us = size * 1000LL * 1000LL / b;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Bandwidth suggests delay of %s for %llu bytes of traffic\n",
+ GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES),
+ (unsigned long long) size);
+ return ret;
+}
+
+
+/**
+ * Task run whenever we hit the bandwidth limit for a tracker.
+ *
+ * @param cls the `struct GNUNET_BANDWIDTH_Tracker`
+ */
+static void
+excess_trigger (void *cls)
+{
+ struct GNUNET_BANDWIDTH_Tracker *av = cls;
+
+ av->excess_task = NULL;
+ if (NULL != av->excess_cb)
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Notifying application about excess bandwidth\n");
+ av->excess_cb (av->excess_cb_cls);
+ }
+}
+
+
+/**
+ * Recalculate when we might need to call the excess callback.
+ */
+static void
+update_excess (struct GNUNET_BANDWIDTH_Tracker *av)
{
- return GNUNET_BANDWIDTH_value_init (GNUNET_MIN (ntohl (b1.value__),
- ntohl (b2.value__)));
+ struct GNUNET_TIME_Relative delay;
+ struct GNUNET_TIME_Absolute now;
+ uint64_t delta_time;
+ uint64_t delta_avail;
+ int64_t left_bytes;
+ uint64_t max_carry;
+ int64_t current_consumption;
+
+ if (NULL == av->excess_cb)
+ return; /* nothing to do */
+ now = GNUNET_TIME_absolute_get ();
+ delta_time = now.abs_value_us - av->last_update__.abs_value_us;
+ delta_avail =
+ (delta_time * ((unsigned long long) av->available_bytes_per_s__) +
+ 500000LL) / 1000000LL;
+ current_consumption = av->consumption_since_last_update__ - delta_avail;
+ if (current_consumption > av->consumption_since_last_update__)
+ {
+ /* integer underflow, cap! */
+ current_consumption = INT64_MIN;
+ }
+ /* negative current_consumption means that we have savings */
+ max_carry = ((uint64_t) av->available_bytes_per_s__) * av->max_carry_s__;
+ if (max_carry < GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ max_carry = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+ if (max_carry > INT64_MAX)
+ max_carry = INT64_MAX;
+ left_bytes = current_consumption + max_carry;
+ if (left_bytes < current_consumption)
+ {
+ /* integer overflow, cap! */
+ left_bytes = INT64_MAX;
+ }
+ /* left_bytes now contains the number of bytes needed until
+ we have more savings than allowed */
+ if (left_bytes < 0)
+ {
+ /* having excess already */
+ delay = GNUNET_TIME_UNIT_ZERO;
+ }
+ else
+ {
+ double factor = 1.0 * left_bytes / (double) av->available_bytes_per_s__;
+ delay = GNUNET_TIME_relative_saturating_multiply (GNUNET_TIME_UNIT_SECONDS,
+ (unsigned long long) factor);
+ }
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "At %llu bps it will take us %s for %lld bytes to reach excess threshold\n",
+ (unsigned long long) av->available_bytes_per_s__,
+ GNUNET_STRINGS_relative_time_to_string (delay,
+ GNUNET_NO),
+ (long long) left_bytes);
+ if (NULL != av->excess_task)
+ GNUNET_SCHEDULER_cancel (av->excess_task);
+ av->excess_task = GNUNET_SCHEDULER_add_delayed (delay,
+ &excess_trigger,
+ av);
}
/**
* Initialize bandwidth tracker. Note that in addition to the
* 'max_carry_s' limit, we also always allow at least
- * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
+ * #GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
* bytes-per-second limit is so small that within 'max_carry_s' not
- * even GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
- * ignored and replaced by GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
+ * even #GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
+ * ignored and replaced by #GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
* bytes).
*
+ * To stop notifications about updates and excess callbacks use
+ * #GNUNET_BANDWIDTH_tracker_notification_stop().
+ *
* @param av tracker to initialize
+ * @param update_cb callback to notify a client about the tracker being updated
+ * @param update_cb_cls cls for the callback
* @param bytes_per_second_limit initial limit to assume
* @param max_carry_s maximum number of seconds unused bandwidth
* may accumulate before it expires
+ * @param excess_cb callback to notify if we have excess bandwidth
+ * @param excess_cb_cls closure for @a excess_cb
*/
void
-GNUNET_BANDWIDTH_tracker_init (struct GNUNET_BANDWIDTH_Tracker *av,
- struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit,
- uint32_t max_carry_s)
+GNUNET_BANDWIDTH_tracker_init2 (struct GNUNET_BANDWIDTH_Tracker *av,
+ GNUNET_BANDWIDTH_TrackerUpdateCallback update_cb,
+ void *update_cb_cls,
+ struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit,
+ uint32_t max_carry_s,
+ GNUNET_BANDWIDTH_ExcessNotificationCallback excess_cb,
+ void *excess_cb_cls)
{
+ av->update_cb = update_cb;
+ av->update_cb_cls = update_cb_cls;
av->consumption_since_last_update__ = 0;
av->last_update__ = GNUNET_TIME_absolute_get ();
av->available_bytes_per_s__ = ntohl (bytes_per_second_limit.value__);
av->max_carry_s__ = max_carry_s;
+ av->excess_cb = excess_cb;
+ av->excess_cb_cls = excess_cb_cls;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p initialized with %u Bps and max carry %u\n",
+ av,
+ (unsigned int) av->available_bytes_per_s__,
+ (unsigned int) max_carry_s);
+ update_excess (av);
+}
+
+
+/**
+ * Initialize bandwidth tracker. Note that in addition to the
+ * 'max_carry_s' limit, we also always allow at least
+ * #GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
+ * bytes-per-second limit is so small that within 'max_carry_s' not
+ * even #GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
+ * ignored and replaced by #GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
+ * bytes).
+ *
+ * @param av tracker to initialize
+ * @param update_cb callback to notify a client about the tracker being updated
+ * @param update_cb_cls cls for the callback
+ * @param bytes_per_second_limit initial limit to assume
+ * @param max_carry_s maximum number of seconds unused bandwidth
+ * may accumulate before it expires
+ */
+void
+GNUNET_BANDWIDTH_tracker_init (struct GNUNET_BANDWIDTH_Tracker *av,
+ GNUNET_BANDWIDTH_TrackerUpdateCallback update_cb,
+ void *update_cb_cls,
+ struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit,
+ uint32_t max_carry_s)
+{
+ GNUNET_BANDWIDTH_tracker_init2 (av, update_cb,
+ update_cb_cls,
+ bytes_per_second_limit,
+ max_carry_s,
+ NULL, NULL);
+}
+
+
+/**
+ * Stop notifying about tracker updates and excess notifications
+ *
+ * @param av the respective trackers
+ */
+void
+GNUNET_BANDWIDTH_tracker_notification_stop (struct GNUNET_BANDWIDTH_Tracker *av)
+{
+ if (NULL != av->excess_task)
+ GNUNET_SCHEDULER_cancel (av->excess_task);
+ av->excess_task = NULL;
+ av->excess_cb = NULL;
+ av->excess_cb_cls = NULL;
+ av->update_cb = NULL;
+ av->update_cb_cls = NULL;
}
update_tracker (struct GNUNET_BANDWIDTH_Tracker *av)
{
struct GNUNET_TIME_Absolute now;
- uint64_t avail_per_ms;
+ struct GNUNET_TIME_Relative delta;
uint64_t delta_time;
uint64_t delta_avail;
uint64_t left_bytes;
- uint64_t left_time_ms;
+ uint64_t max_carry;
now = GNUNET_TIME_absolute_get ();
- delta_time = now.value - av->last_update__.value;
- delta_avail = (delta_time * ((unsigned long long) av->available_bytes_per_s__)) / 1000LL;
- if (av->consumption_since_last_update__ >= delta_avail)
- {
- av->consumption_since_last_update__ -= delta_avail;
- av->last_update__ = now;
- }
- else
- {
- left_bytes = delta_avail - av->consumption_since_last_update__;
- avail_per_ms = ((unsigned long long) av->available_bytes_per_s__) / 1000LL;
- if (avail_per_ms > 0)
- left_time_ms = left_bytes / avail_per_ms;
- else
- left_time_ms = 0;
- if (left_time_ms > ((unsigned long long) av->max_carry_s__) * 1000LL)
- {
- /* need to limit accumulation of unused bandwidth */
- left_time_ms = ((unsigned long long) av->max_carry_s__) * 1000LL;
- if (left_time_ms * avail_per_ms < GNUNET_SERVER_MAX_MESSAGE_SIZE)
- {
- /* need to still allow GNUNET_SERVER_MAX_MESSAGE_SIZE accumulation */
- if (left_bytes > GNUNET_SERVER_MAX_MESSAGE_SIZE)
- left_bytes = GNUNET_SERVER_MAX_MESSAGE_SIZE;
- left_time_ms = left_bytes / avail_per_ms;
- }
- }
- av->consumption_since_last_update__ = 0;
- av->last_update__.value = now.value - left_time_ms;
- }
+ delta_time = now.abs_value_us - av->last_update__.abs_value_us;
+ delta_avail =
+ (delta_time * ((unsigned long long) av->available_bytes_per_s__) +
+ 500000LL) / 1000000LL;
+ av->consumption_since_last_update__ -= delta_avail;
+ av->last_update__ = now;
+ if (av->consumption_since_last_update__ < 0)
+ {
+ left_bytes = - av->consumption_since_last_update__;
+ max_carry = ((unsigned long long) av->available_bytes_per_s__) *
+ av->max_carry_s__;
+ if (max_carry < GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ max_carry = GNUNET_SERVER_MAX_MESSAGE_SIZE;
+ if (max_carry > INT64_MAX)
+ max_carry = INT64_MAX;
+ if (max_carry > left_bytes)
+ av->consumption_since_last_update__ = - left_bytes;
+ else
+ av->consumption_since_last_update__ = - max_carry;
+ }
+ delta.rel_value_us = delta_time;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p updated, consumption at %lld at %u Bps, last update was %s ago\n",
+ av,
+ (long long) av->consumption_since_last_update__,
+ (unsigned int) av->available_bytes_per_s__,
+ GNUNET_STRINGS_relative_time_to_string (delta,
+ GNUNET_YES));
}
-
/**
* Notify the tracker that a certain number of bytes of bandwidth have
* been consumed. Note that it is legal to consume bytes even if not
* enough bandwidth is available (in that case,
- * GNUNET_BANDWIDTH_tracker_get_delay may return non-zero delay values
+ * #GNUNET_BANDWIDTH_tracker_get_delay may return non-zero delay values
* even for a size of zero for a while).
*
* @param av tracker to update
* @param size number of bytes consumed
+ * @return #GNUNET_YES if this consumption is above the limit
*/
-void
+int
GNUNET_BANDWIDTH_tracker_consume (struct GNUNET_BANDWIDTH_Tracker *av,
- size_t size)
+ ssize_t size)
{
- uint64_t nc;
+ int64_t nc;
- nc = av->consumption_since_last_update__ + size;
- if (nc < av->consumption_since_last_update__)
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p consumes %d bytes\n",
+ av,
+ (int) size);
+ if (size > 0)
+ {
+ nc = av->consumption_since_last_update__ + size;
+ if (nc < av->consumption_since_last_update__)
{
+ /* integer overflow, very bad */
GNUNET_break (0);
- return;
+ return GNUNET_SYSERR;
}
- av->consumption_since_last_update__ += size;
- update_tracker (av);
+ av->consumption_since_last_update__ = nc;
+ update_tracker (av);
+ update_excess (av);
+ if (av->consumption_since_last_update__ > 0)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p consumption %llu bytes above limit\n",
+ av,
+ (unsigned long long) av->consumption_since_last_update__);
+ return GNUNET_YES;
+ }
+ }
+ else
+ {
+ nc = av->consumption_since_last_update__ + size;
+ if (nc > av->consumption_since_last_update__)
+ {
+ /* integer underflow, very bad */
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ av->consumption_since_last_update__ = nc;
+ update_excess (av);
+ }
+ return GNUNET_NO;
}
*
* @param av tracker to query
* @param size number of bytes we would like to consume
- * @return time to wait for consumption to be OK
+ * @return time in ms to wait for consumption to be OK
*/
struct GNUNET_TIME_Relative
GNUNET_BANDWIDTH_tracker_get_delay (struct GNUNET_BANDWIDTH_Tracker *av,
- size_t size)
+ size_t size)
{
struct GNUNET_TIME_Relative ret;
- struct GNUNET_TIME_Absolute now;
- uint64_t delta_avail;
- uint64_t delta_time;
- uint64_t bytes_needed;
+ int64_t bytes_needed;
- if (av->available_bytes_per_s__ == 0)
+ if (0 == av->available_bytes_per_s__)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p delay is infinity\n", av);
return GNUNET_TIME_UNIT_FOREVER_REL;
+ }
update_tracker (av);
- now = GNUNET_TIME_absolute_get ();
- delta_time = now.value - av->last_update__.value;
- delta_avail = (delta_time * ((unsigned long long) av->available_bytes_per_s__)) / 1000LL;
- if (delta_avail >= size)
+ bytes_needed = size + av->consumption_since_last_update__;
+ if (bytes_needed <= 0)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p delay for %u bytes is zero\n", av,
+ (unsigned int) size);
return GNUNET_TIME_UNIT_ZERO;
- bytes_needed = size - delta_avail;
- ret.value = 1000LL * bytes_needed / (unsigned long long) av->available_bytes_per_s__;
+ }
+ ret.rel_value_us =
+ (1000LL * 1000LL * bytes_needed) /
+ (unsigned long long) av->available_bytes_per_s__;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p delay for %u bytes is %s\n",
+ av,
+ (unsigned int) size,
+ GNUNET_STRINGS_relative_time_to_string (ret, GNUNET_YES));
return ret;
}
+/**
+ * Compute how many bytes are available for consumption right now.
+ * quota.
+ *
+ * @param av tracker to query
+ * @return number of bytes available for consumption right now
+ */
+int64_t
+GNUNET_BANDWIDTH_tracker_get_available (struct GNUNET_BANDWIDTH_Tracker *av)
+{
+ struct GNUNET_BANDWIDTH_Value32NBO bps;
+ uint64_t avail;
+ int64_t used;
+
+ update_tracker (av);
+ bps = GNUNET_BANDWIDTH_value_init (av->available_bytes_per_s__);
+ avail =
+ GNUNET_BANDWIDTH_value_get_available_until (bps,
+ GNUNET_TIME_absolute_get_duration
+ (av->last_update__));
+ used = av->consumption_since_last_update__;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p available bandwidth is %lld bytes\n", av,
+ (long long) (int64_t) (avail - used));
+ return (int64_t) (avail - used);
+}
+
+
/**
* Update quota of bandwidth tracker.
*
*/
void
GNUNET_BANDWIDTH_tracker_update_quota (struct GNUNET_BANDWIDTH_Tracker *av,
- struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit)
+ struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit)
{
uint32_t old_limit;
uint32_t new_limit;
new_limit = ntohl (bytes_per_second_limit.value__);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Tracker %p bandwidth changed to %u Bps\n", av,
+ (unsigned int) new_limit);
update_tracker (av);
old_limit = av->available_bytes_per_s__;
av->available_bytes_per_s__ = new_limit;
+ if (NULL != av->update_cb)
+ av->update_cb (av->update_cb_cls);
if (old_limit > new_limit)
- update_tracker (av); /* maximum excess might be less now */
+ update_tracker (av); /* maximum excess might be less now */
+ update_excess (av);
}