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Diffstat (limited to 'src/pq/pq_event.c')
-rw-r--r-- | src/pq/pq_event.c | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/src/pq/pq_event.c b/src/pq/pq_event.c new file mode 100644 index 000000000..ecb942230 --- /dev/null +++ b/src/pq/pq_event.c | |||
@@ -0,0 +1,396 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet | ||
3 | Copyright (C) 2021 GNUnet e.V. | ||
4 | |||
5 | GNUnet is free software: you can redistribute it and/or modify it | ||
6 | under the terms of the GNU Affero General Public License as published | ||
7 | by the Free Software Foundation, either version 3 of the License, | ||
8 | or (at your 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 | Affero General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU Affero General Public License | ||
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
17 | |||
18 | SPDX-License-Identifier: AGPL3.0-or-later | ||
19 | */ | ||
20 | /** | ||
21 | * @file pq/pq_event.c | ||
22 | * @brief event notifications via Postgres | ||
23 | * @author Christian Grothoff | ||
24 | */ | ||
25 | #include "platform.h" | ||
26 | #include "pq.h" | ||
27 | #include <pthread.h> | ||
28 | |||
29 | |||
30 | /** | ||
31 | * Handle for an active LISTENer to the database. | ||
32 | */ | ||
33 | struct GNUNET_PQ_EventHandler | ||
34 | { | ||
35 | /** | ||
36 | * Channel name. | ||
37 | */ | ||
38 | struct GNUNET_ShortHashCode sh; | ||
39 | |||
40 | /** | ||
41 | * Function to call on events. | ||
42 | */ | ||
43 | GNUNET_PQ_EventCallback cb; | ||
44 | |||
45 | /** | ||
46 | * Closure for @e cb. | ||
47 | */ | ||
48 | void *cb_cls; | ||
49 | |||
50 | /** | ||
51 | * Database context this event handler is with. | ||
52 | */ | ||
53 | struct GNUNET_PQ_Context *db; | ||
54 | }; | ||
55 | |||
56 | |||
57 | |||
58 | |||
59 | /** | ||
60 | * Convert @a es to a short hash. | ||
61 | * | ||
62 | * @param es spec to hash to an identifier | ||
63 | * @param[out] sh short hash to set | ||
64 | */ | ||
65 | static void | ||
66 | es_to_sh (const struct GNUNET_PQ_EventHeaderP *es, | ||
67 | struct GNUNET_ShortHashCode *sh) | ||
68 | { | ||
69 | struct GNUNET_HashCode h_channel; | ||
70 | |||
71 | GNUNET_CRYPTO_hash (es, | ||
72 | ntohs (es->size), | ||
73 | &h_channel); | ||
74 | GNUNET_static_assert (sizeof (*sh) <= sizeof (h_channel)); | ||
75 | memcpy (sh, | ||
76 | &h_channel, | ||
77 | sizeof (*sh)); | ||
78 | } | ||
79 | |||
80 | |||
81 | /** | ||
82 | * Convert @a sh to a Postgres identifier. | ||
83 | * | ||
84 | * @param sh short hash to convert to an identifier | ||
85 | * @param[out] identifier by default, Postgres supports | ||
86 | * NAMEDATALEN=64 character identifiers | ||
87 | * @return end position of the identifier | ||
88 | */ | ||
89 | static char * | ||
90 | sh_to_channel (struct GNUNET_ShortHashCode *sh, | ||
91 | char identifier[64]) | ||
92 | { | ||
93 | char *end; | ||
94 | |||
95 | end = GNUNET_STRINGS_data_to_string (sh, | ||
96 | sizeof (*sh), | ||
97 | identifier, | ||
98 | 63); | ||
99 | GNUNET_assert (NULL != end); | ||
100 | *end = '\0'; | ||
101 | return end; | ||
102 | } | ||
103 | |||
104 | |||
105 | /** | ||
106 | * Convert @a es to a Postgres identifier. | ||
107 | * | ||
108 | * @param es spec to hash to an identifier | ||
109 | * @param[out] identifier by default, Postgres supports | ||
110 | * NAMEDATALEN=64 character identifiers | ||
111 | * @return end position of the identifier | ||
112 | */ | ||
113 | static char * | ||
114 | es_to_channel (const struct GNUNET_PQ_EventHeaderP *es, | ||
115 | char identifier[64]) | ||
116 | { | ||
117 | struct GNUNET_ShortHashCode sh; | ||
118 | |||
119 | es_to_sh (es, | ||
120 | &sh); | ||
121 | return sh_to_channel (&sh, | ||
122 | identifier); | ||
123 | } | ||
124 | |||
125 | |||
126 | /** | ||
127 | * Closure for #do_notify(). | ||
128 | */ | ||
129 | struct NotifyContext | ||
130 | { | ||
131 | /** | ||
132 | * Extra argument of the notification, or NULL. | ||
133 | */ | ||
134 | void *extra; | ||
135 | |||
136 | /** | ||
137 | * Number of bytes in @e extra. | ||
138 | */ | ||
139 | size_t extra_size; | ||
140 | }; | ||
141 | |||
142 | |||
143 | /** | ||
144 | * Function called on every event handler that | ||
145 | * needs to be triggered. | ||
146 | * | ||
147 | * @param cls a `struct NotifyContext` | ||
148 | * @param sh channel name | ||
149 | * @param value a `struct GNUNET_PQ_EventHandler` | ||
150 | * @return #GNUNET_OK continue to iterate | ||
151 | */ | ||
152 | static int | ||
153 | do_notify (void *cls, | ||
154 | const struct GNUNET_ShortHashCode *sh, | ||
155 | void *value) | ||
156 | { | ||
157 | struct NotifyContext *ctx = cls; | ||
158 | struct GNUNET_PQ_EventHandler *eh = value; | ||
159 | |||
160 | eh->cb (eh->cb_cls, | ||
161 | ctx->extra, | ||
162 | ctx->extra_size); | ||
163 | return GNUNET_OK; | ||
164 | } | ||
165 | |||
166 | |||
167 | void | ||
168 | GNUNET_PQ_event_set_socket_callback (struct GNUNET_PQ_Context *db, | ||
169 | GNUNET_PQ_SocketCallback sc, | ||
170 | void *sc_cls) | ||
171 | { | ||
172 | int fd; | ||
173 | |||
174 | db->sc = sc; | ||
175 | db->sc_cls = sc_cls; | ||
176 | if (NULL == sc) | ||
177 | return; | ||
178 | GNUNET_assert (0 == | ||
179 | pthread_mutex_lock (&db->notify_lock)); | ||
180 | fd = PQsocket (db->conn); | ||
181 | if ( (-1 != fd) && | ||
182 | (0 != GNUNET_CONTAINER_multishortmap_size (db->channel_map)) ) | ||
183 | sc (sc_cls, | ||
184 | fd); | ||
185 | GNUNET_assert (0 == | ||
186 | pthread_mutex_unlock (&db->notify_lock)); | ||
187 | } | ||
188 | |||
189 | |||
190 | void | ||
191 | GNUNET_PQ_event_do_poll (struct GNUNET_PQ_Context *db) | ||
192 | { | ||
193 | PGnotify *n; | ||
194 | |||
195 | GNUNET_assert (0 == | ||
196 | pthread_mutex_lock (&db->notify_lock)); | ||
197 | while (NULL != (n = PQnotifies (db->conn))) | ||
198 | { | ||
199 | struct GNUNET_ShortHashCode sh; | ||
200 | struct NotifyContext ctx = { | ||
201 | .extra = NULL | ||
202 | }; | ||
203 | |||
204 | if (GNUNET_OK != | ||
205 | GNUNET_STRINGS_string_to_data (n->relname, | ||
206 | strlen (n->relname), | ||
207 | &sh, | ||
208 | sizeof (sh))) | ||
209 | { | ||
210 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
211 | "Ignoring notification for unsupported channel identifier `%s'\n", | ||
212 | n->relname); | ||
213 | continue; | ||
214 | } | ||
215 | if ( (NULL != n->extra) && | ||
216 | (GNUNET_OK != | ||
217 | GNUNET_STRINGS_string_to_data_alloc (n->extra, | ||
218 | strlen (n->extra), | ||
219 | &ctx.extra, | ||
220 | &ctx.extra_size))) | ||
221 | { | ||
222 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
223 | "Ignoring notification for unsupported extra data `%s' on channel `%s'\n", | ||
224 | n->extra, | ||
225 | n->relname); | ||
226 | continue; | ||
227 | } | ||
228 | GNUNET_CONTAINER_multishortmap_iterate (db->channel_map, | ||
229 | &do_notify, | ||
230 | &ctx); | ||
231 | GNUNET_free (ctx.extra); | ||
232 | } | ||
233 | GNUNET_assert (0 == | ||
234 | pthread_mutex_unlock (&db->notify_lock)); | ||
235 | } | ||
236 | |||
237 | |||
238 | void | ||
239 | GNUNET_PQ_event_scheduler_start (struct GNUNET_PQ_Context *db) | ||
240 | { | ||
241 | GNUNET_break (0); // FIXME: not implemented | ||
242 | } | ||
243 | |||
244 | |||
245 | void | ||
246 | GNUNET_PQ_event_scheduler_stop (struct GNUNET_PQ_Context *db) | ||
247 | { | ||
248 | GNUNET_break (0); // FIXME: not implemented | ||
249 | } | ||
250 | |||
251 | |||
252 | static void | ||
253 | manage_subscribe (struct GNUNET_PQ_Context *db, | ||
254 | const char *cmd, | ||
255 | struct GNUNET_PQ_EventHandler *eh) | ||
256 | { | ||
257 | char sql[16 + 64]; | ||
258 | char *end; | ||
259 | PGresult *result; | ||
260 | |||
261 | end = stpcpy (sql, | ||
262 | cmd); | ||
263 | end = sh_to_channel (&eh->sh, | ||
264 | end); | ||
265 | result = PQexec (db->conn, | ||
266 | sql); | ||
267 | if (PGRES_COMMAND_OK != PQresultStatus (result)) | ||
268 | { | ||
269 | GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, | ||
270 | "pq", | ||
271 | "Failed to execute `%s': %s/%s/%s/%s/%s", | ||
272 | sql, | ||
273 | PQresultErrorField (result, | ||
274 | PG_DIAG_MESSAGE_PRIMARY), | ||
275 | PQresultErrorField (result, | ||
276 | PG_DIAG_MESSAGE_DETAIL), | ||
277 | PQresultErrorMessage (result), | ||
278 | PQresStatus (PQresultStatus (result)), | ||
279 | PQerrorMessage (db->conn)); | ||
280 | } | ||
281 | PQclear (result); | ||
282 | } | ||
283 | |||
284 | |||
285 | struct GNUNET_PQ_EventHandler * | ||
286 | GNUNET_PQ_event_listen (struct GNUNET_PQ_Context *db, | ||
287 | const struct GNUNET_PQ_EventHeaderP *es, | ||
288 | GNUNET_PQ_EventCallback cb, | ||
289 | void *cb_cls) | ||
290 | { | ||
291 | struct GNUNET_PQ_EventHandler *eh; | ||
292 | bool was_zero; | ||
293 | |||
294 | eh = GNUNET_new (struct GNUNET_PQ_EventHandler); | ||
295 | eh->db = db; | ||
296 | es_to_sh (es, | ||
297 | &eh->sh); | ||
298 | eh->cb = cb; | ||
299 | eh->cb_cls = cb_cls; | ||
300 | GNUNET_assert (0 == | ||
301 | pthread_mutex_lock (&db->notify_lock)); | ||
302 | was_zero = (0 == GNUNET_CONTAINER_multishortmap_size (db->channel_map)); | ||
303 | GNUNET_assert (GNUNET_OK == | ||
304 | GNUNET_CONTAINER_multishortmap_put (db->channel_map, | ||
305 | &eh->sh, | ||
306 | eh, | ||
307 | GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE)); | ||
308 | if ( (NULL != db->sc) && | ||
309 | was_zero) | ||
310 | { | ||
311 | int fd = PQsocket (db->conn); | ||
312 | |||
313 | if (-1 != fd) | ||
314 | db->sc (db->sc_cls, | ||
315 | fd); | ||
316 | } | ||
317 | manage_subscribe (db, | ||
318 | "LISTEN ", | ||
319 | eh); | ||
320 | GNUNET_assert (0 == | ||
321 | pthread_mutex_unlock (&db->notify_lock)); | ||
322 | return eh; | ||
323 | } | ||
324 | |||
325 | |||
326 | void | ||
327 | GNUNET_PQ_event_listen_cancel (struct GNUNET_PQ_EventHandler *eh) | ||
328 | { | ||
329 | struct GNUNET_PQ_Context *db = eh->db; | ||
330 | |||
331 | GNUNET_assert (0 == | ||
332 | pthread_mutex_lock (&db->notify_lock)); | ||
333 | GNUNET_assert (GNUNET_OK == | ||
334 | GNUNET_CONTAINER_multishortmap_remove (db->channel_map, | ||
335 | &eh->sh, | ||
336 | eh)); | ||
337 | |||
338 | manage_subscribe (db, | ||
339 | "UNLISTEN ", | ||
340 | eh); | ||
341 | if ( (NULL != db->sc) && | ||
342 | (0 == GNUNET_CONTAINER_multishortmap_size (db->channel_map)) ) | ||
343 | { | ||
344 | db->sc (db->sc_cls, | ||
345 | -1); | ||
346 | } | ||
347 | GNUNET_assert (0 == | ||
348 | pthread_mutex_unlock (&db->notify_lock)); | ||
349 | } | ||
350 | |||
351 | |||
352 | void | ||
353 | GNUNET_PQ_event_notify (struct GNUNET_PQ_Context *db, | ||
354 | const struct GNUNET_PQ_EventHeaderP *es, | ||
355 | const void *extra, | ||
356 | size_t extra_size) | ||
357 | { | ||
358 | char sql[16 + 64 + extra_size * 8 / 5 + 8]; | ||
359 | char *end; | ||
360 | PGresult *result; | ||
361 | |||
362 | end = stpcpy (sql, | ||
363 | "NOTIFY "); | ||
364 | end = es_to_channel (es, | ||
365 | end); | ||
366 | end = stpcpy (end, | ||
367 | "'"); | ||
368 | end = GNUNET_STRINGS_data_to_string (extra, | ||
369 | extra_size, | ||
370 | end, | ||
371 | sizeof (sql) - (end - sql) - 1); | ||
372 | GNUNET_assert (NULL != end); | ||
373 | *end = '\0'; | ||
374 | end = stpcpy (end, | ||
375 | "'"); | ||
376 | result = PQexec (db->conn, | ||
377 | sql); | ||
378 | if (PGRES_COMMAND_OK != PQresultStatus (result)) | ||
379 | { | ||
380 | GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, | ||
381 | "pq", | ||
382 | "Failed to execute `%s': %s/%s/%s/%s/%s", | ||
383 | sql, | ||
384 | PQresultErrorField (result, | ||
385 | PG_DIAG_MESSAGE_PRIMARY), | ||
386 | PQresultErrorField (result, | ||
387 | PG_DIAG_MESSAGE_DETAIL), | ||
388 | PQresultErrorMessage (result), | ||
389 | PQresStatus (PQresultStatus (result)), | ||
390 | PQerrorMessage (db->conn)); | ||
391 | } | ||
392 | PQclear (result); | ||
393 | } | ||
394 | |||
395 | /* end of pq_event.c */ | ||
396 | |||