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Diffstat (limited to 'src/util/server_nc.c')
-rw-r--r-- | src/util/server_nc.c | 472 |
1 files changed, 0 insertions, 472 deletions
diff --git a/src/util/server_nc.c b/src/util/server_nc.c deleted file mode 100644 index a95cd7f6d..000000000 --- a/src/util/server_nc.c +++ /dev/null | |||
@@ -1,472 +0,0 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2010 GNUnet e.V. | ||
4 | |||
5 | GNUnet is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published | ||
7 | by the Free Software Foundation; either version 3, or (at your | ||
8 | option) any later version. | ||
9 | |||
10 | GNUnet is distributed in the hope that it will be useful, but | ||
11 | WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
13 | General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with GNUnet; see the file COPYING. If not, write to the | ||
17 | Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | ||
18 | Boston, MA 02110-1301, USA. | ||
19 | */ | ||
20 | |||
21 | /** | ||
22 | * @file util/server_nc.c | ||
23 | * @brief convenience functions for transmission of | ||
24 | * a notification stream | ||
25 | * @author Christian Grothoff | ||
26 | */ | ||
27 | |||
28 | #include "platform.h" | ||
29 | #include "gnunet_util_lib.h" | ||
30 | |||
31 | #define LOG(kind,...) GNUNET_log_from (kind, "util-server-nc", __VA_ARGS__) | ||
32 | |||
33 | |||
34 | /** | ||
35 | * Entry in list of messages pending to be transmitted. | ||
36 | */ | ||
37 | struct PendingMessageList | ||
38 | { | ||
39 | |||
40 | /** | ||
41 | * This is a doubly-linked list. | ||
42 | */ | ||
43 | struct PendingMessageList *next; | ||
44 | |||
45 | /** | ||
46 | * This is a doubly-linked list. | ||
47 | */ | ||
48 | struct PendingMessageList *prev; | ||
49 | |||
50 | /** | ||
51 | * Message to transmit (allocated at the end of this | ||
52 | * struct, do not free) | ||
53 | */ | ||
54 | const struct GNUNET_MessageHeader *msg; | ||
55 | |||
56 | /** | ||
57 | * Can this message be dropped? | ||
58 | */ | ||
59 | int can_drop; | ||
60 | |||
61 | }; | ||
62 | |||
63 | |||
64 | /** | ||
65 | * Lists of clients we manage for notifications. | ||
66 | */ | ||
67 | struct ClientList | ||
68 | { | ||
69 | |||
70 | /** | ||
71 | * This is a doubly linked list. | ||
72 | */ | ||
73 | struct ClientList *next; | ||
74 | |||
75 | /** | ||
76 | * This is a doubly linked list. | ||
77 | */ | ||
78 | struct ClientList *prev; | ||
79 | |||
80 | /** | ||
81 | * Overall context this client belongs to. | ||
82 | */ | ||
83 | struct GNUNET_SERVER_NotificationContext *nc; | ||
84 | |||
85 | /** | ||
86 | * Handle to the client. | ||
87 | */ | ||
88 | struct GNUNET_SERVER_Client *client; | ||
89 | |||
90 | /** | ||
91 | * Handle for pending transmission request to the client (or NULL). | ||
92 | */ | ||
93 | struct GNUNET_SERVER_TransmitHandle *th; | ||
94 | |||
95 | /** | ||
96 | * Head of linked list of requests queued for transmission. | ||
97 | */ | ||
98 | struct PendingMessageList *pending_head; | ||
99 | |||
100 | /** | ||
101 | * Tail of linked list of requests queued for transmission. | ||
102 | */ | ||
103 | struct PendingMessageList *pending_tail; | ||
104 | |||
105 | /** | ||
106 | * Number of messages currently in the list. | ||
107 | */ | ||
108 | unsigned int num_pending; | ||
109 | |||
110 | }; | ||
111 | |||
112 | |||
113 | /** | ||
114 | * The notification context is the key datastructure for a convenience | ||
115 | * API used for transmission of notifications to the client until the | ||
116 | * client disconnects (or the notification context is destroyed, in | ||
117 | * which case we disconnect these clients). Essentially, all | ||
118 | * (notification) messages are queued up until the client is able to | ||
119 | * read them. | ||
120 | */ | ||
121 | struct GNUNET_SERVER_NotificationContext | ||
122 | { | ||
123 | |||
124 | /** | ||
125 | * Server we do notifications for. | ||
126 | */ | ||
127 | struct GNUNET_SERVER_Handle *server; | ||
128 | |||
129 | /** | ||
130 | * Head of list of clients receiving notifications. | ||
131 | */ | ||
132 | struct ClientList *clients_head; | ||
133 | |||
134 | /** | ||
135 | * Tail of list of clients receiving notifications. | ||
136 | */ | ||
137 | struct ClientList *clients_tail; | ||
138 | |||
139 | /** | ||
140 | * Maximum number of optional messages to queue per client. | ||
141 | */ | ||
142 | unsigned int queue_length; | ||
143 | |||
144 | }; | ||
145 | |||
146 | |||
147 | /** | ||
148 | * Client has disconnected, clean up. | ||
149 | * | ||
150 | * @param cls our `struct GNUNET_SERVER_NotificationContext *` | ||
151 | * @param client handle of client that disconnected | ||
152 | */ | ||
153 | static void | ||
154 | handle_client_disconnect (void *cls, | ||
155 | struct GNUNET_SERVER_Client *client) | ||
156 | { | ||
157 | struct GNUNET_SERVER_NotificationContext *nc = cls; | ||
158 | struct ClientList *pos; | ||
159 | struct PendingMessageList *pml; | ||
160 | |||
161 | if (NULL == client) | ||
162 | { | ||
163 | nc->server = NULL; | ||
164 | return; | ||
165 | } | ||
166 | for (pos = nc->clients_head; NULL != pos; pos = pos->next) | ||
167 | if (pos->client == client) | ||
168 | break; | ||
169 | if (NULL == pos) | ||
170 | return; | ||
171 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
172 | "Client disconnected, cleaning up %u messages in NC queue\n", | ||
173 | pos->num_pending); | ||
174 | GNUNET_CONTAINER_DLL_remove (nc->clients_head, | ||
175 | nc->clients_tail, | ||
176 | pos); | ||
177 | while (NULL != (pml = pos->pending_head)) | ||
178 | { | ||
179 | GNUNET_CONTAINER_DLL_remove (pos->pending_head, | ||
180 | pos->pending_tail, | ||
181 | pml); | ||
182 | GNUNET_free (pml); | ||
183 | pos->num_pending--; | ||
184 | } | ||
185 | if (NULL != pos->th) | ||
186 | { | ||
187 | GNUNET_SERVER_notify_transmit_ready_cancel (pos->th); | ||
188 | pos->th = NULL; | ||
189 | } | ||
190 | GNUNET_SERVER_client_drop (client); | ||
191 | GNUNET_assert (0 == pos->num_pending); | ||
192 | GNUNET_free (pos); | ||
193 | } | ||
194 | |||
195 | |||
196 | /** | ||
197 | * Create a new notification context. | ||
198 | * | ||
199 | * @param server server for which this function creates the context | ||
200 | * @param queue_length maximum number of messages to keep in | ||
201 | * the notification queue; optional messages are dropped | ||
202 | * if the queue gets longer than this number of messages | ||
203 | * @return handle to the notification context | ||
204 | */ | ||
205 | struct GNUNET_SERVER_NotificationContext * | ||
206 | GNUNET_SERVER_notification_context_create (struct GNUNET_SERVER_Handle *server, | ||
207 | unsigned int queue_length) | ||
208 | { | ||
209 | struct GNUNET_SERVER_NotificationContext *ret; | ||
210 | |||
211 | ret = GNUNET_new (struct GNUNET_SERVER_NotificationContext); | ||
212 | ret->server = server; | ||
213 | ret->queue_length = queue_length; | ||
214 | GNUNET_SERVER_disconnect_notify (server, | ||
215 | &handle_client_disconnect, | ||
216 | ret); | ||
217 | return ret; | ||
218 | } | ||
219 | |||
220 | |||
221 | /** | ||
222 | * Destroy the context, force disconnect for all clients. | ||
223 | * | ||
224 | * @param nc context to destroy. | ||
225 | */ | ||
226 | void | ||
227 | GNUNET_SERVER_notification_context_destroy (struct GNUNET_SERVER_NotificationContext *nc) | ||
228 | { | ||
229 | struct ClientList *pos; | ||
230 | struct PendingMessageList *pml; | ||
231 | |||
232 | while (NULL != (pos = nc->clients_head)) | ||
233 | { | ||
234 | GNUNET_CONTAINER_DLL_remove (nc->clients_head, | ||
235 | nc->clients_tail, | ||
236 | pos); | ||
237 | if (NULL != pos->th) | ||
238 | { | ||
239 | GNUNET_SERVER_notify_transmit_ready_cancel (pos->th); | ||
240 | pos->th = NULL; | ||
241 | } | ||
242 | GNUNET_SERVER_client_drop (pos->client); | ||
243 | while (NULL != (pml = pos->pending_head)) | ||
244 | { | ||
245 | GNUNET_CONTAINER_DLL_remove (pos->pending_head, | ||
246 | pos->pending_tail, | ||
247 | pml); | ||
248 | GNUNET_free (pml); | ||
249 | pos->num_pending--; | ||
250 | } | ||
251 | GNUNET_assert (0 == pos->num_pending); | ||
252 | GNUNET_free (pos); | ||
253 | } | ||
254 | if (NULL != nc->server) | ||
255 | GNUNET_SERVER_disconnect_notify_cancel (nc->server, | ||
256 | &handle_client_disconnect, | ||
257 | nc); | ||
258 | GNUNET_free (nc); | ||
259 | } | ||
260 | |||
261 | |||
262 | /** | ||
263 | * Add a client to the notification context. | ||
264 | * | ||
265 | * @param nc context to modify | ||
266 | * @param client client to add | ||
267 | */ | ||
268 | void | ||
269 | GNUNET_SERVER_notification_context_add (struct GNUNET_SERVER_NotificationContext *nc, | ||
270 | struct GNUNET_SERVER_Client *client) | ||
271 | { | ||
272 | struct ClientList *cl; | ||
273 | |||
274 | for (cl = nc->clients_head; NULL != cl; cl = cl->next) | ||
275 | if (cl->client == client) | ||
276 | return; /* already present */ | ||
277 | cl = GNUNET_new (struct ClientList); | ||
278 | GNUNET_CONTAINER_DLL_insert (nc->clients_head, | ||
279 | nc->clients_tail, | ||
280 | cl); | ||
281 | cl->nc = nc; | ||
282 | cl->client = client; | ||
283 | GNUNET_SERVER_client_keep (client); | ||
284 | } | ||
285 | |||
286 | |||
287 | /** | ||
288 | * Function called to notify a client about the socket begin ready to | ||
289 | * queue more data. @a buf will be NULL and @a size zero if the socket | ||
290 | * was closed for writing in the meantime. | ||
291 | * | ||
292 | * @param cls the `struct ClientList *` | ||
293 | * @param size number of bytes available in @a buf | ||
294 | * @param buf where the callee should write the message | ||
295 | * @return number of bytes written to buf | ||
296 | */ | ||
297 | static size_t | ||
298 | transmit_message (void *cls, | ||
299 | size_t size, | ||
300 | void *buf) | ||
301 | { | ||
302 | struct ClientList *cl = cls; | ||
303 | char *cbuf = buf; | ||
304 | struct PendingMessageList *pml; | ||
305 | uint16_t msize; | ||
306 | size_t ret; | ||
307 | |||
308 | cl->th = NULL; | ||
309 | if (NULL == buf) | ||
310 | { | ||
311 | /* 'cl' should be freed via disconnect notification shortly */ | ||
312 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
313 | "Failed to transmit message from NC queue to client\n"); | ||
314 | return 0; | ||
315 | } | ||
316 | ret = 0; | ||
317 | while (NULL != (pml = cl->pending_head)) | ||
318 | { | ||
319 | msize = ntohs (pml->msg->size); | ||
320 | if (size < msize) | ||
321 | break; | ||
322 | GNUNET_CONTAINER_DLL_remove (cl->pending_head, | ||
323 | cl->pending_tail, | ||
324 | pml); | ||
325 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
326 | "Copying message of type %u and size %u from pending queue to transmission buffer\n", | ||
327 | ntohs (pml->msg->type), | ||
328 | msize); | ||
329 | GNUNET_memcpy (&cbuf[ret], pml->msg, msize); | ||
330 | ret += msize; | ||
331 | size -= msize; | ||
332 | GNUNET_free (pml); | ||
333 | cl->num_pending--; | ||
334 | } | ||
335 | if (NULL != pml) | ||
336 | { | ||
337 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
338 | "Have %u messages left in NC queue, will try transmission again\n", | ||
339 | cl->num_pending); | ||
340 | cl->th = | ||
341 | GNUNET_SERVER_notify_transmit_ready (cl->client, | ||
342 | ntohs (pml->msg->size), | ||
343 | GNUNET_TIME_UNIT_FOREVER_REL, | ||
344 | &transmit_message, cl); | ||
345 | } | ||
346 | else | ||
347 | { | ||
348 | GNUNET_assert (0 == cl->num_pending); | ||
349 | } | ||
350 | return ret; | ||
351 | } | ||
352 | |||
353 | |||
354 | /** | ||
355 | * Send a message to a particular client. | ||
356 | * | ||
357 | * @param nc context to modify | ||
358 | * @param client client to transmit to | ||
359 | * @param msg message to send | ||
360 | * @param can_drop can this message be dropped due to queue length limitations | ||
361 | */ | ||
362 | static void | ||
363 | do_unicast (struct GNUNET_SERVER_NotificationContext *nc, | ||
364 | struct ClientList *client, | ||
365 | const struct GNUNET_MessageHeader *msg, | ||
366 | int can_drop) | ||
367 | { | ||
368 | struct PendingMessageList *pml; | ||
369 | uint16_t size; | ||
370 | |||
371 | if ( (client->num_pending > nc->queue_length) && | ||
372 | (GNUNET_YES == can_drop) ) | ||
373 | { | ||
374 | LOG (GNUNET_ERROR_TYPE_INFO, | ||
375 | "Dropping message of type %u and size %u due to full queue (%u entries)\n", | ||
376 | ntohs (msg->type), ntohs (msg->size), (unsigned int) nc->queue_length); | ||
377 | return; /* drop! */ | ||
378 | } | ||
379 | if (client->num_pending > nc->queue_length) | ||
380 | { | ||
381 | /* FIXME: consider checking for other messages in the | ||
382 | * queue that are 'droppable' */ | ||
383 | } | ||
384 | client->num_pending++; | ||
385 | size = ntohs (msg->size); | ||
386 | pml = GNUNET_malloc (sizeof (struct PendingMessageList) + size); | ||
387 | pml->msg = (const struct GNUNET_MessageHeader *) &pml[1]; | ||
388 | pml->can_drop = can_drop; | ||
389 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
390 | "Adding message of type %u and size %u to pending queue (which has %u entries)\n", | ||
391 | ntohs (msg->type), | ||
392 | ntohs (msg->size), | ||
393 | (unsigned int) nc->queue_length); | ||
394 | GNUNET_memcpy (&pml[1], msg, size); | ||
395 | /* append */ | ||
396 | GNUNET_CONTAINER_DLL_insert_tail (client->pending_head, | ||
397 | client->pending_tail, | ||
398 | pml); | ||
399 | if (NULL == client->th) | ||
400 | client->th = | ||
401 | GNUNET_SERVER_notify_transmit_ready (client->client, | ||
402 | ntohs (client->pending_head-> | ||
403 | msg->size), | ||
404 | GNUNET_TIME_UNIT_FOREVER_REL, | ||
405 | &transmit_message, client); | ||
406 | } | ||
407 | |||
408 | |||
409 | /** | ||
410 | * Send a message to a particular client; must have | ||
411 | * already been added to the notification context. | ||
412 | * | ||
413 | * @param nc context to modify | ||
414 | * @param client client to transmit to | ||
415 | * @param msg message to send | ||
416 | * @param can_drop can this message be dropped due to queue length limitations | ||
417 | */ | ||
418 | void | ||
419 | GNUNET_SERVER_notification_context_unicast (struct GNUNET_SERVER_NotificationContext *nc, | ||
420 | struct GNUNET_SERVER_Client *client, | ||
421 | const struct GNUNET_MessageHeader *msg, | ||
422 | int can_drop) | ||
423 | { | ||
424 | struct ClientList *pos; | ||
425 | |||
426 | for (pos = nc->clients_head; NULL != pos; pos = pos->next) | ||
427 | if (pos->client == client) | ||
428 | break; | ||
429 | GNUNET_assert (NULL != pos); | ||
430 | do_unicast (nc, pos, msg, can_drop); | ||
431 | } | ||
432 | |||
433 | |||
434 | /** | ||
435 | * Send a message to all clients of this context. | ||
436 | * | ||
437 | * @param nc context to modify | ||
438 | * @param msg message to send | ||
439 | * @param can_drop can this message be dropped due to queue length limitations | ||
440 | */ | ||
441 | void | ||
442 | GNUNET_SERVER_notification_context_broadcast (struct | ||
443 | GNUNET_SERVER_NotificationContext *nc, | ||
444 | const struct GNUNET_MessageHeader *msg, | ||
445 | int can_drop) | ||
446 | { | ||
447 | struct ClientList *pos; | ||
448 | |||
449 | for (pos = nc->clients_head; NULL != pos; pos = pos->next) | ||
450 | do_unicast (nc, pos, msg, can_drop); | ||
451 | } | ||
452 | |||
453 | |||
454 | /** | ||
455 | * Return active number of subscribers in this context. | ||
456 | * | ||
457 | * @param nc context to query | ||
458 | * @return number of current subscribers | ||
459 | */ | ||
460 | unsigned int | ||
461 | GNUNET_SERVER_notification_context_get_size (struct GNUNET_SERVER_NotificationContext *nc) | ||
462 | { | ||
463 | unsigned int num; | ||
464 | struct ClientList *pos; | ||
465 | |||
466 | num = 0; | ||
467 | for (pos = nc->clients_head; NULL != pos; pos = pos->next) | ||
468 | num++; | ||
469 | return num; | ||
470 | } | ||
471 | |||
472 | /* end of server_nc.c */ | ||