aboutsummaryrefslogtreecommitdiff
path: root/src/include/gnunet_bandwidth_lib.h
blob: 9130ff57ed5f91f6dc55c2745dc3b966ab32dd10 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
/*
     This file is part of GNUnet.
     Copyright (C) 2010 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     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
     Affero General Public License for more details.

     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
 */

/**
 * @author Christian Grothoff
 *
 * @file
 * Functions related to bandwidth (unit)
 *
 * @defgroup bandwidth  Bandwidth library
 * Functions related to bandwidth (unit)
 * @{
 */

#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"

GNUNET_NETWORK_STRUCT_BEGIN

/**
 * 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;
};

GNUNET_NETWORK_STRUCT_END


/**
 * Callback to be called by the bandwidth tracker if the tracker
 * was updated and the client should update it's delay values
 *
 * @param cls a closure to pass
 */
typedef void (*GNUNET_BANDWIDTH_TrackerUpdateCallback) (void *cls);


/**
 * Callback to be called by the bandwidth tracker if the tracker
 * was updated and the client should update it's delay values
 *
 * @param cls a closure to pass
 */
typedef void (*GNUNET_BANDWIDTH_ExcessNotificationCallback) (void *cls);


/**
 * 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
{
  /**
   * Closure for @e update_cb.
   */
  void *update_cb_cls;

  /**
   * Function we call if the tracker's bandwidth is increased and a
   * previously returned timeout might now expire earlier.
   */
  GNUNET_BANDWIDTH_TrackerUpdateCallback update_cb;

  /**
   * Closure for @e excess_cb.
   */
  void *excess_cb_cls;

  /**
   * Function we call if the tracker is about to throw
   * away bandwidth due to excess (max carry exceeded).
   */
  GNUNET_BANDWIDTH_ExcessNotificationCallback excess_cb;

  /**
   * Number of bytes consumed since we last updated the tracker.
   */
  int64_t consumption_since_last_update__;

  /**
   * Task scheduled to call the @e excess_cb once we have
   * reached the maximum bandwidth the tracker can hold.
   */
  struct GNUNET_SCHEDULER_Task *excess_task;

  /**
   * Time when we last updated the tracker.
   */
  struct GNUNET_TIME_Absolute last_update__;

  /**
   * Bandwidth limit to enforce in bytes per second.
   */
  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_MAX_MESSAGE_SIZE to accumulate.
   */
  uint32_t max_carry_s__;
};


/**
 * Convenience definition to use for 0-bandwidth.
 */
#define GNUNET_BANDWIDTH_ZERO GNUNET_BANDWIDTH_value_init (0)


/**
 * 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);


/**
 * 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);


/**
 * Compute the SUM of two bandwidth values.
 *
 * @param b1 first value
 * @param b2 second value
 * @return the sum of b1 and b2
 */
struct GNUNET_BANDWIDTH_Value32NBO
GNUNET_BANDWIDTH_value_sum (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_MAX_MESSAGE_SIZE to accumulate.  So if the
 * bytes-per-second limit is so small that within 'max_carry_s' not
 * even #GNUNET_MAX_MESSAGE_SIZE is allowed to accumulate, it is
 * ignored and replaced by #GNUNET_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 @a update_cb 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);


/**
 * Initialize bandwidth tracker.  Note that in addition to the
 * 'max_carry_s' limit, we also always allow at least
 * #GNUNET_MAX_MESSAGE_SIZE to accumulate.  So if the
 * bytes-per-second limit is so small that within 'max_carry_s' not
 * even #GNUNET_MAX_MESSAGE_SIZE is allowed to accumulate, it is
 * ignored and replaced by #GNUNET_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 @a update_cb 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_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);


/**
 * Stop notifying about tracker updates and excess notifications
 *
 * @param av the respective trackers
 */
void
GNUNET_BANDWIDTH_tracker_notification_stop (
  struct GNUNET_BANDWIDTH_Tracker *av);


/**
 * 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 @a 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 group */

/* end of gnunet_bandwidth_lib.h */