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- /*
- This file is part of GNUnet.
- (C) 2010 Christian Grothoff (and other contributing authors)
- 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 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.
- 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.
- */
- /**
- * @file include/gnunet_bandwidth_lib.h
- * @brief functions related to bandwidth (unit)
- * @author Christian Grothoff
- */
- #ifndef GNUNET_BANDWIDTH_LIB_H
- #define GNUNET_BANDWIDTH_LIB_H
- #ifdef __cplusplus
- extern "C"
- {
- #if 0 /* keep Emacsens' auto-indent happy */
- }
- #endif
- #endif
- #include "gnunet_common.h"
- #include "gnunet_time_lib.h"
- /**
- * 32-bit bandwidth used for network exchange by GNUnet, in bytes per second.
- */
- struct GNUNET_BANDWIDTH_Value32NBO
- {
- /**
- * The actual value (bytes per second).
- */
- uint32_t value__ GNUNET_PACKED;
- };
- /**
- * Struct to track available bandwidth. Combines a time stamp with a
- * number of bytes transmitted, a quota and a maximum amount that
- * carries over. Not opaque so that it can be inlined into data
- * structures (reducing malloc-ing); however, values should not be
- * accessed directly by clients (hence the '__').
- */
- struct GNUNET_BANDWIDTH_Tracker
- {
- /**
- * Number of bytes consumed since we last updated the tracker.
- */
- int64_t consumption_since_last_update__;
- /**
- * Time when we last updated the tracker.
- */
- struct GNUNET_TIME_Absolute last_update__;
- /**
- * Bandwidth limit to enforce in bytes per s.
- */
- uint32_t available_bytes_per_s__;
- /**
- * Maximum number of seconds over which bandwidth may "accumulate".
- * Note that additionally, we also always allow at least
- * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate.
- */
- uint32_t max_carry_s__;
- };
- /**
- * Create a new bandwidth value.
- *
- * @param bytes_per_second value to create
- * @return the new bandwidth value
- */
- struct GNUNET_BANDWIDTH_Value32NBO
- GNUNET_BANDWIDTH_value_init (uint32_t bytes_per_second);
- /**
- * Maximum possible bandwidth value.
- */
- #define GNUNET_BANDWIDTH_VALUE_MAX GNUNET_BANDWIDTH_value_init(UINT32_MAX)
- /**
- * 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);
- /**
- * At the given bandwidth, calculate how long it would take for
- * '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);
- /**
- * Compute the MIN 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_min (struct GNUNET_BANDWIDTH_Value32NBO b1,
- struct GNUNET_BANDWIDTH_Value32NBO b2);
- /**
- * 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 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,
- struct GNUNET_BANDWIDTH_Value32NBO
- bytes_per_second_limit, uint32_t max_carry_s);
- /**
- * 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
- * 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
- */
- int
- GNUNET_BANDWIDTH_tracker_consume (struct GNUNET_BANDWIDTH_Tracker *av,
- ssize_t size);
- /**
- * Compute how long we should wait until consuming 'size'
- * bytes of bandwidth in order to stay within the given
- * quota.
- *
- * @param av tracker to query
- * @param size number of bytes we would like to consume
- * @return time to wait for consumption to be OK
- */
- struct GNUNET_TIME_Relative
- GNUNET_BANDWIDTH_tracker_get_delay (struct GNUNET_BANDWIDTH_Tracker *av,
- size_t size);
- /**
- * 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);
- /**
- * Update quota of bandwidth tracker.
- *
- * @param av tracker to initialize
- * @param bytes_per_second_limit new limit to assume
- */
- void
- GNUNET_BANDWIDTH_tracker_update_quota (struct GNUNET_BANDWIDTH_Tracker *av,
- struct GNUNET_BANDWIDTH_Value32NBO
- bytes_per_second_limit);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_BANDWIDTH_LIB_H */
- #endif
- /* end of gnunet_bandwidth_lib.h */
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