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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"
42 * 32-bit bandwidth used for network exchange by GNUnet, in bytes per second.
44 struct GNUNET_BANDWIDTH_Value32NBO
47 * The actual value (bytes per second).
49 uint32_t value__ GNUNET_PACKED;
54 * Struct to track available bandwidth. Combines a time stamp with a
55 * number of bytes transmitted, a quota and a maximum amount that
56 * carries over. Not opaque so that it can be inlined into data
57 * structures (reducing malloc-ing); however, values should not be
58 * accessed directly by clients (hence the '__').
60 struct GNUNET_BANDWIDTH_Tracker
63 * Number of bytes consumed since we last updated the tracker.
65 int64_t consumption_since_last_update__;
68 * Time when we last updated the tracker.
70 struct GNUNET_TIME_Absolute last_update__;
73 * Bandwidth limit to enforce in bytes per s.
75 uint32_t available_bytes_per_s__;
78 * Maximum number of seconds over which bandwidth may "accumulate".
79 * Note that additionally, we also always allow at least
80 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate.
82 uint32_t max_carry_s__;
87 * Create a new bandwidth value.
89 * @param bytes_per_second value to create
90 * @return the new bandwidth value
92 struct GNUNET_BANDWIDTH_Value32NBO
93 GNUNET_BANDWIDTH_value_init (uint32_t bytes_per_second);
97 * Maximum possible bandwidth value.
99 #define GNUNET_BANDWIDTH_VALUE_MAX GNUNET_BANDWIDTH_value_init(UINT32_MAX)
103 * At the given bandwidth, calculate how much traffic will be
104 * available until the given deadline.
106 * @param bps bandwidth
107 * @param deadline when is the deadline
108 * @return number of bytes available at bps until deadline
111 GNUNET_BANDWIDTH_value_get_available_until (struct GNUNET_BANDWIDTH_Value32NBO bps,
112 struct GNUNET_TIME_Relative deadline);
116 * At the given bandwidth, calculate how long it would take for
117 * 'size' bytes to be transmitted.
119 * @param bps bandwidth
120 * @param size number of bytes we want to have available
121 * @return how long it would take
123 struct GNUNET_TIME_Relative
124 GNUNET_BANDWIDTH_value_get_delay_for (struct GNUNET_BANDWIDTH_Value32NBO bps,
130 * Compute the MIN of two bandwidth values.
132 * @param b1 first value
133 * @param b2 second value
134 * @return the min of b1 and b2
136 struct GNUNET_BANDWIDTH_Value32NBO
137 GNUNET_BANDWIDTH_value_min (struct GNUNET_BANDWIDTH_Value32NBO b1,
138 struct GNUNET_BANDWIDTH_Value32NBO b2);
142 * Initialize bandwidth tracker. Note that in addition to the
143 * 'max_carry_s' limit, we also always allow at least
144 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
145 * bytes-per-second limit is so small that within 'max_carry_s' not
146 * even GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
147 * ignored and replaced by GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
150 * @param av tracker to initialize
151 * @param bytes_per_second_limit initial limit to assume
152 * @param max_carry_s maximum number of seconds unused bandwidth
153 * may accumulate before it expires
156 GNUNET_BANDWIDTH_tracker_init (struct GNUNET_BANDWIDTH_Tracker *av,
157 struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit,
158 uint32_t max_carry_s);
162 * Notify the tracker that a certain number of bytes of bandwidth have
163 * been consumed. Note that it is legal to consume bytes even if not
164 * enough bandwidth is available (in that case,
165 * GNUNET_BANDWIDTH_tracker_get_delay may return non-zero delay values
166 * even for a size of zero for a while).
168 * @param av tracker to update
169 * @param size number of bytes consumed
170 * @return GNUNET_YES if this consumption is above the limit
173 GNUNET_BANDWIDTH_tracker_consume (struct GNUNET_BANDWIDTH_Tracker *av,
178 * Compute how long we should wait until consuming 'size'
179 * bytes of bandwidth in order to stay within the given
182 * @param av tracker to query
183 * @param size number of bytes we would like to consume
184 * @return time to wait for consumption to be OK
186 struct GNUNET_TIME_Relative
187 GNUNET_BANDWIDTH_tracker_get_delay (struct GNUNET_BANDWIDTH_Tracker *av,
192 * Compute how many bytes are available for consumption right now.
195 * @param av tracker to query
196 * @return number of bytes available for consumption right now
199 GNUNET_BANDWIDTH_tracker_get_available (struct GNUNET_BANDWIDTH_Tracker *av);
203 * Update quota of bandwidth tracker.
205 * @param av tracker to initialize
206 * @param bytes_per_second_limit new limit to assume
209 GNUNET_BANDWIDTH_tracker_update_quota (struct GNUNET_BANDWIDTH_Tracker *av,
210 struct GNUNET_BANDWIDTH_Value32NBO bytes_per_second_limit);
213 #if 0 /* keep Emacsens' auto-indent happy */
220 /* ifndef GNUNET_BANDWIDTH_LIB_H */
222 /* end of gnunet_bandwidth_lib.h */