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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
56 * Struct to track available bandwidth. Combines a time stamp with a
57 * number of bytes transmitted, a quota and a maximum amount that
58 * carries over. Not opaque so that it can be inlined into data
59 * structures (reducing malloc-ing); however, values should not be
60 * accessed directly by clients (hence the '__').
62 struct GNUNET_BANDWIDTH_Tracker
65 * Number of bytes consumed since we last updated the tracker.
67 int64_t consumption_since_last_update__;
70 * Time when we last updated the tracker.
72 struct GNUNET_TIME_Absolute last_update__;
75 * Bandwidth limit to enforce in bytes per s.
77 uint32_t available_bytes_per_s__;
80 * Maximum number of seconds over which bandwidth may "accumulate".
81 * Note that additionally, we also always allow at least
82 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate.
84 uint32_t max_carry_s__;
89 * Create a new bandwidth value.
91 * @param bytes_per_second value to create
92 * @return the new bandwidth value
94 struct GNUNET_BANDWIDTH_Value32NBO
95 GNUNET_BANDWIDTH_value_init (uint32_t bytes_per_second);
99 * Maximum possible bandwidth value.
101 #define GNUNET_BANDWIDTH_VALUE_MAX GNUNET_BANDWIDTH_value_init(UINT32_MAX)
105 * At the given bandwidth, calculate how much traffic will be
106 * available until the given deadline.
108 * @param bps bandwidth
109 * @param deadline when is the deadline
110 * @return number of bytes available at bps until deadline
113 GNUNET_BANDWIDTH_value_get_available_until (struct GNUNET_BANDWIDTH_Value32NBO
115 struct GNUNET_TIME_Relative
120 * At the given bandwidth, calculate how long it would take for
121 * 'size' bytes to be transmitted.
123 * @param bps bandwidth
124 * @param size number of bytes we want to have available
125 * @return how long it would take
127 struct GNUNET_TIME_Relative
128 GNUNET_BANDWIDTH_value_get_delay_for (struct GNUNET_BANDWIDTH_Value32NBO bps,
134 * Compute the MIN of two bandwidth values.
136 * @param b1 first value
137 * @param b2 second value
138 * @return the min of b1 and b2
140 struct GNUNET_BANDWIDTH_Value32NBO
141 GNUNET_BANDWIDTH_value_min (struct GNUNET_BANDWIDTH_Value32NBO b1,
142 struct GNUNET_BANDWIDTH_Value32NBO b2);
146 * Initialize bandwidth tracker. Note that in addition to the
147 * 'max_carry_s' limit, we also always allow at least
148 * GNUNET_SERVER_MAX_MESSAGE_SIZE to accumulate. So if the
149 * bytes-per-second limit is so small that within 'max_carry_s' not
150 * even GNUNET_SERVER_MAX_MESSAGE_SIZE is allowed to accumulate, it is
151 * ignored and replaced by GNUNET_SERVER_MAX_MESSAGE_SIZE (which is in
154 * @param av tracker to initialize
155 * @param bytes_per_second_limit initial limit to assume
156 * @param max_carry_s maximum number of seconds unused bandwidth
157 * may accumulate before it expires
160 GNUNET_BANDWIDTH_tracker_init (struct GNUNET_BANDWIDTH_Tracker *av,
161 struct GNUNET_BANDWIDTH_Value32NBO
162 bytes_per_second_limit, uint32_t max_carry_s);
166 * Notify the tracker that a certain number of bytes of bandwidth have
167 * been consumed. Note that it is legal to consume bytes even if not
168 * enough bandwidth is available (in that case,
169 * GNUNET_BANDWIDTH_tracker_get_delay may return non-zero delay values
170 * even for a size of zero for a while).
172 * @param av tracker to update
173 * @param size number of bytes consumed
174 * @return GNUNET_YES if this consumption is above the limit
177 GNUNET_BANDWIDTH_tracker_consume (struct GNUNET_BANDWIDTH_Tracker *av,
182 * Compute how long we should wait until consuming 'size'
183 * bytes of bandwidth in order to stay within the given
186 * @param av tracker to query
187 * @param size number of bytes we would like to consume
188 * @return time to wait for consumption to be OK
190 struct GNUNET_TIME_Relative
191 GNUNET_BANDWIDTH_tracker_get_delay (struct GNUNET_BANDWIDTH_Tracker *av,
196 * Compute how many bytes are available for consumption right now.
199 * @param av tracker to query
200 * @return number of bytes available for consumption right now
203 GNUNET_BANDWIDTH_tracker_get_available (struct GNUNET_BANDWIDTH_Tracker *av);
207 * Update quota of bandwidth tracker.
209 * @param av tracker to initialize
210 * @param bytes_per_second_limit new limit to assume
213 GNUNET_BANDWIDTH_tracker_update_quota (struct GNUNET_BANDWIDTH_Tracker *av,
214 struct GNUNET_BANDWIDTH_Value32NBO
215 bytes_per_second_limit);
218 #if 0 /* keep Emacsens' auto-indent happy */
225 /* ifndef GNUNET_BANDWIDTH_LIB_H */
227 /* end of gnunet_bandwidth_lib.h */