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3 (C) 2010 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_bandwidth_lib.h
23 * @brief functions related to bandwidth (unit)
24 * @author Christian Grothoff
27 #ifndef GNUNET_BANDWIDTH_LIB_H
28 #define GNUNET_BANDWIDTH_LIB_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_common.h"
39 #include "gnunet_time_lib.h"
41 GNUNET_NETWORK_STRUCT_BEGIN
44 * 32-bit bandwidth used for network exchange by GNUnet, in bytes per second.
46 struct GNUNET_BANDWIDTH_Value32NBO
49 * The actual value (bytes per second).
51 uint32_t value__ GNUNET_PACKED;
53 GNUNET_NETWORK_STRUCT_END
57 * Callback to be called by the bandwidth tracker if the tracker
58 * was updated and the client should update it's delay values
60 * @param cls a closure to pass
63 typedef (*GNUNET_BANDWIDTH_tracker_update_cb) (void *cls);
67 * Struct to track available bandwidth. Combines a time stamp with a
68 * number of bytes transmitted, a quota and a maximum amount that
69 * carries over. Not opaque so that it can be inlined into data
70 * structures (reducing malloc-ing); however, values should not be
71 * accessed directly by clients (hence the '__').
73 struct GNUNET_BANDWIDTH_Tracker
77 GNUNET_BANDWIDTH_tracker_update_cb update_cb;
80 * Number of bytes consumed since we last updated the tracker.
82 int64_t consumption_since_last_update__;
85 * Time when we last updated the tracker.
87 struct GNUNET_TIME_Absolute last_update__;
90 * Bandwidth limit to enforce in bytes per s.
92 uint32_t available_bytes_per_s__;
95 * Maximum number of seconds over which bandwidth may "accumulate".
96 * Note that additionally, we also always allow at least
97 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate.
99 uint32_t max_carry_s__;
104 * Create a new bandwidth value.
106 * @param bytes_per_second value to create
107 * @return the new bandwidth value
109 struct GNUNET_BANDWIDTH_Value32NBO
110 GNUNET_BANDWIDTH_value_init (uint32_t bytes_per_second);
114 * Maximum possible bandwidth value.
116 #define GNUNET_BANDWIDTH_VALUE_MAX GNUNET_BANDWIDTH_value_init(UINT32_MAX)
120 * At the given bandwidth, calculate how much traffic will be
121 * available until the given deadline.
123 * @param bps bandwidth
124 * @param deadline when is the deadline
125 * @return number of bytes available at bps until deadline
128 GNUNET_BANDWIDTH_value_get_available_until (struct GNUNET_BANDWIDTH_Value32NBO
130 struct GNUNET_TIME_Relative
135 * At the given bandwidth, calculate how long it would take for
136 * 'size' bytes to be transmitted.
138 * @param bps bandwidth
139 * @param size number of bytes we want to have available
140 * @return how long it would take
142 struct GNUNET_TIME_Relative
143 GNUNET_BANDWIDTH_value_get_delay_for (struct GNUNET_BANDWIDTH_Value32NBO bps,
148 * Compute the MIN of two bandwidth values.
150 * @param b1 first value
151 * @param b2 second value
152 * @return the min of b1 and b2
154 struct GNUNET_BANDWIDTH_Value32NBO
155 GNUNET_BANDWIDTH_value_min (struct GNUNET_BANDWIDTH_Value32NBO b1,
156 struct GNUNET_BANDWIDTH_Value32NBO b2);
160 * Initialize bandwidth tracker. Note that in addition to the
161 * 'max_carry_s' limit, we also always allow at least
162 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
163 * bytes-per-second limit is so small that within 'max_carry_s' not
164 * even GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
165 * ignored and replaced by GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
168 * @param av tracker to initialize
169 * @param update_cb callback to notify a client about the tracker being updated
170 * @param update_cb_cls cls for the callback
171 * @param bytes_per_second_limit initial limit to assume
172 * @param max_carry_s maximum number of seconds unused bandwidth
173 * may accumulate before it expires
176 GNUNET_BANDWIDTH_tracker_init (struct GNUNET_BANDWIDTH_Tracker *av,
177 GNUNET_BANDWIDTH_tracker_update_cb update_cb,
179 struct GNUNET_BANDWIDTH_Value32NBO
180 bytes_per_second_limit,
181 uint32_t max_carry_s);
185 * Notify the tracker that a certain number of bytes of bandwidth have
186 * been consumed. Note that it is legal to consume bytes even if not
187 * enough bandwidth is available (in that case,
188 * GNUNET_BANDWIDTH_tracker_get_delay may return non-zero delay values
189 * even for a size of zero for a while).
191 * @param av tracker to update
192 * @param size number of bytes consumed
193 * @return GNUNET_YES if this consumption is above the limit
196 GNUNET_BANDWIDTH_tracker_consume (struct GNUNET_BANDWIDTH_Tracker *av,
201 * Compute how long we should wait until consuming 'size'
202 * bytes of bandwidth in order to stay within the given
205 * @param av tracker to query
206 * @param size number of bytes we would like to consume
207 * @return time to wait for consumption to be OK
209 struct GNUNET_TIME_Relative
210 GNUNET_BANDWIDTH_tracker_get_delay (struct GNUNET_BANDWIDTH_Tracker *av,
215 * Compute how many bytes are available for consumption right now.
218 * @param av tracker to query
219 * @return number of bytes available for consumption right now
222 GNUNET_BANDWIDTH_tracker_get_available (struct GNUNET_BANDWIDTH_Tracker *av);
226 * Update quota of bandwidth tracker.
228 * @param av tracker to initialize
229 * @param bytes_per_second_limit new limit to assume
232 GNUNET_BANDWIDTH_tracker_update_quota (struct GNUNET_BANDWIDTH_Tracker *av,
233 struct GNUNET_BANDWIDTH_Value32NBO
234 bytes_per_second_limit);
237 #if 0 /* keep Emacsens' auto-indent happy */
244 /* ifndef GNUNET_BANDWIDTH_LIB_H */
246 /* end of gnunet_bandwidth_lib.h */