| 1 | /* |
| 2 | * This file is part of DisOrder |
| 3 | * Copyright (C) 2008 Richard Kettlewell |
| 4 | * |
| 5 | * This program is free software: you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation, either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | /** @file server/schedule.c |
| 20 | * @brief Scheduled events |
| 21 | * |
| 22 | * @ref trackdb_scheduledb is a mapping from ID strings to encoded |
| 23 | * key-value pairs called 'actiondata'. |
| 24 | * |
| 25 | * Possible actiondata keys are: |
| 26 | * - @b when: when to perform this action (required) |
| 27 | * - @b who: originator for action (required) |
| 28 | * - @b action: action to perform (required) |
| 29 | * - @b track: for @c action=play, the track to play |
| 30 | * - @b key: for @c action=set-global, the global pref to set |
| 31 | * - @b value: for @c action=set-global, the value to set (omit to unset) |
| 32 | * - @b priority: the importance of this action |
| 33 | * - @b recurs: how the event recurs; NOT IMPLEMENTED |
| 34 | * - ...others to be defined |
| 35 | * |
| 36 | * Possible actions are: |
| 37 | * - @b play: play a track |
| 38 | * - @b set-global: set or unset a global pref |
| 39 | * - ...others to be defined |
| 40 | * |
| 41 | * Possible priorities are: |
| 42 | * - @b junk: junk actions that are in the past at startup are discarded |
| 43 | * - @b normal: normal actions that are in the past at startup are run |
| 44 | * immediately. (This the default.) |
| 45 | * - ...others to be defined |
| 46 | * |
| 47 | * On startup the schedule database is read and a timeout set on the event loop |
| 48 | * for each action. Similarly when an action is added, a timeout is set on the |
| 49 | * event loop. The timeout has the ID attached as user data so that the action |
| 50 | * can easily be found again. |
| 51 | * |
| 52 | * Recurring events are NOT IMPLEMENTED yet but this is the proposed |
| 53 | * interface: |
| 54 | * |
| 55 | * Recurring events are updated with a new 'when' field when they are processed |
| 56 | * (event on error). Non-recurring events are just deleted after processing. |
| 57 | * |
| 58 | * The recurs field is a whitespace-delimited list of criteria: |
| 59 | * - nn:nn or nn:nn:nn define a time of day, in local time. There must be |
| 60 | * at least one of these but can be more than one. |
| 61 | * - a day name (monday, tuesday, ...) defines the days of the week on |
| 62 | * which the event will recur. There can be more than one. |
| 63 | * - a day number and month name (1 january, 5 february, ...) defines |
| 64 | * the days of the year on which the event will recur. There can be |
| 65 | * more than one of these. |
| 66 | * |
| 67 | * Day and month names are case insensitive. Multiple languages are |
| 68 | * likely to be supported, especially if people send me pointers to |
| 69 | * their month and day names. Abbreviations are NOT supported, as |
| 70 | * there is more of a risk of a clash between different languages that |
| 71 | * way. |
| 72 | * |
| 73 | * If there are no week or year days then the event recurs every day. |
| 74 | * |
| 75 | * If there are both week and year days then the union of them is |
| 76 | * taken, rather than the intersection. |
| 77 | * |
| 78 | * TODO: support recurring events. |
| 79 | * |
| 80 | * TODO: add disorder-dump support |
| 81 | */ |
| 82 | #include "disorder-server.h" |
| 83 | |
| 84 | static int schedule_trigger(ev_source *ev, |
| 85 | const struct timeval *now, |
| 86 | void *u); |
| 87 | static int schedule_lookup(const char *id, |
| 88 | struct kvp *actiondata); |
| 89 | |
| 90 | /** @brief List of required fields in a scheduled event */ |
| 91 | static const char *const schedule_required[] = {"when", "who", "action"}; |
| 92 | |
| 93 | /** @brief Number of elements in @ref schedule_required */ |
| 94 | #define NREQUIRED (int)(sizeof schedule_required / sizeof *schedule_required) |
| 95 | |
| 96 | /** @brief Parse a scheduled event key and data |
| 97 | * @param k Pointer to key |
| 98 | * @param d Pointer to data |
| 99 | * @param idp Where to store event ID |
| 100 | * @param actiondatap Where to store parsed data |
| 101 | * @param whenp Where to store timestamp |
| 102 | * @return 0 on success, non-0 on error |
| 103 | * |
| 104 | * Rejects entries that are invalid in various ways. |
| 105 | */ |
| 106 | static int schedule_parse(const DBT *k, |
| 107 | const DBT *d, |
| 108 | char **idp, |
| 109 | struct kvp **actiondatap, |
| 110 | time_t *whenp) { |
| 111 | char *id; |
| 112 | struct kvp *actiondata; |
| 113 | int n; |
| 114 | |
| 115 | /* Reject bogus keys */ |
| 116 | if(!k->size || k->size > 128) { |
| 117 | disorder_error(0, "bogus schedule.db key (%lu bytes)", |
| 118 | (unsigned long)k->size); |
| 119 | return -1; |
| 120 | } |
| 121 | id = xstrndup(k->data, k->size); |
| 122 | actiondata = kvp_urldecode(d->data, d->size); |
| 123 | /* Reject items without the required fields */ |
| 124 | for(n = 0; n < NREQUIRED; ++n) { |
| 125 | if(!kvp_get(actiondata, schedule_required[n])) { |
| 126 | disorder_error(0, "scheduled event %s: missing required field '%s'", |
| 127 | id, schedule_required[n]); |
| 128 | return -1; |
| 129 | } |
| 130 | } |
| 131 | /* Return the results */ |
| 132 | if(idp) |
| 133 | *idp = id; |
| 134 | if(actiondatap) |
| 135 | *actiondatap = actiondata; |
| 136 | if(whenp) |
| 137 | *whenp = (time_t)atoll(kvp_get(actiondata, "when")); |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | /** @brief Delete via a cursor |
| 142 | * @return 0 or @c DB_LOCK_DEADLOCK */ |
| 143 | static int cdel(DBC *cursor) { |
| 144 | int err; |
| 145 | |
| 146 | switch(err = cursor->c_del(cursor, 0)) { |
| 147 | case 0: |
| 148 | break; |
| 149 | case DB_LOCK_DEADLOCK: |
| 150 | disorder_error(0, "error deleting from schedule.db: %s", db_strerror(err)); |
| 151 | break; |
| 152 | default: |
| 153 | disorder_fatal(0, "error deleting from schedule.db: %s", db_strerror(err)); |
| 154 | } |
| 155 | return err; |
| 156 | } |
| 157 | |
| 158 | /** @brief Initialize the schedule |
| 159 | * @param ev Event loop |
| 160 | * @param tid Transaction ID |
| 161 | * |
| 162 | * Sets a callback for all action times except for junk actions that are |
| 163 | * already in the past, which are discarded. |
| 164 | */ |
| 165 | static int schedule_init_tid(ev_source *ev, |
| 166 | DB_TXN *tid) { |
| 167 | DBC *cursor; |
| 168 | DBT k, d; |
| 169 | int err; |
| 170 | |
| 171 | cursor = trackdb_opencursor(trackdb_scheduledb, tid); |
| 172 | while(!(err = cursor->c_get(cursor, prepare_data(&k), prepare_data(&d), |
| 173 | DB_NEXT))) { |
| 174 | struct timeval when; |
| 175 | struct kvp *actiondata; |
| 176 | char *id; |
| 177 | |
| 178 | /* Parse the key. We destroy bogus entries on sight. */ |
| 179 | if(schedule_parse(&k, &d, &id, &actiondata, &when.tv_sec)) { |
| 180 | if((err = cdel(cursor))) |
| 181 | goto deadlocked; |
| 182 | continue; |
| 183 | } |
| 184 | when.tv_usec = 0; |
| 185 | /* The action might be in the past */ |
| 186 | if(when.tv_sec < xtime(0)) { |
| 187 | const char *priority = kvp_get(actiondata, "priority"); |
| 188 | |
| 189 | if(priority && !strcmp(priority, "junk")) { |
| 190 | /* Junk actions that are in the past are discarded during startup */ |
| 191 | /* TODO recurring events should be handled differently here */ |
| 192 | disorder_info("junk event %s is in the past, discarding", id); |
| 193 | if(cdel(cursor)) |
| 194 | goto deadlocked; |
| 195 | /* Skip this time */ |
| 196 | continue; |
| 197 | } |
| 198 | } |
| 199 | /* Arrange a callback when the scheduled event is due */ |
| 200 | ev_timeout(ev, 0/*handlep*/, &when, schedule_trigger, id); |
| 201 | } |
| 202 | switch(err) { |
| 203 | case DB_NOTFOUND: |
| 204 | err = 0; |
| 205 | break; |
| 206 | case DB_LOCK_DEADLOCK: |
| 207 | disorder_error(0, "error querying schedule.db: %s", db_strerror(err)); |
| 208 | break; |
| 209 | default: |
| 210 | disorder_fatal(0, "error querying schedule.db: %s", db_strerror(err)); |
| 211 | } |
| 212 | deadlocked: |
| 213 | if(trackdb_closecursor(cursor)) |
| 214 | err = DB_LOCK_DEADLOCK; |
| 215 | return err; |
| 216 | } |
| 217 | |
| 218 | /** @brief Initialize the schedule |
| 219 | * @param ev Event loop |
| 220 | * |
| 221 | * Sets a callback for all action times except for junk actions that are |
| 222 | * already in the past, which are discarded. |
| 223 | */ |
| 224 | void schedule_init(ev_source *ev) { |
| 225 | int e; |
| 226 | WITH_TRANSACTION(schedule_init_tid(ev, tid)); |
| 227 | } |
| 228 | |
| 229 | /******************************************************************************/ |
| 230 | |
| 231 | /** @brief Create a scheduled event |
| 232 | * @param id Event ID |
| 233 | * @param actiondata Action data |
| 234 | * @param tid Containing transaction |
| 235 | */ |
| 236 | static int schedule_add_tid(const char *id, |
| 237 | struct kvp *actiondata, |
| 238 | DB_TXN *tid) { |
| 239 | int err; |
| 240 | DBT k, d; |
| 241 | |
| 242 | memset(&k, 0, sizeof k); |
| 243 | k.data = (void *)id; |
| 244 | k.size = strlen(id); |
| 245 | switch(err = trackdb_scheduledb->put(trackdb_scheduledb, tid, &k, |
| 246 | encode_data(&d, actiondata), |
| 247 | DB_NOOVERWRITE)) { |
| 248 | case 0: |
| 249 | break; |
| 250 | case DB_LOCK_DEADLOCK: |
| 251 | disorder_error(0, "error updating schedule.db: %s", db_strerror(err)); |
| 252 | return err; |
| 253 | case DB_KEYEXIST: |
| 254 | return err; |
| 255 | default: |
| 256 | disorder_fatal(0, "error updating schedule.db: %s", db_strerror(err)); |
| 257 | } |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | /** @brief Create a scheduled event |
| 262 | * @param ev Event loop |
| 263 | * @param actiondata Action actiondata |
| 264 | * @return Scheduled event ID or NULL on error |
| 265 | * |
| 266 | * Events are rejected if they lack the required fields, if the user |
| 267 | * is not allowed to perform them or if they are scheduled for a time |
| 268 | * in the past. |
| 269 | */ |
| 270 | const char *schedule_add(ev_source *ev, |
| 271 | struct kvp *actiondata) { |
| 272 | int e, n; |
| 273 | const char *id; |
| 274 | struct timeval when; |
| 275 | |
| 276 | /* TODO: handle recurring events */ |
| 277 | /* Check that the required field are present */ |
| 278 | for(n = 0; n < NREQUIRED; ++n) { |
| 279 | if(!kvp_get(actiondata, schedule_required[n])) { |
| 280 | disorder_error(0, "new scheduled event is missing required field '%s'", |
| 281 | schedule_required[n]); |
| 282 | return 0; |
| 283 | } |
| 284 | } |
| 285 | /* Check that the user is allowed to do whatever it is */ |
| 286 | if(schedule_lookup("[new]", actiondata) < 0) |
| 287 | return 0; |
| 288 | when.tv_sec = atoll(kvp_get(actiondata, "when")); |
| 289 | when.tv_usec = 0; |
| 290 | /* Reject events in the past */ |
| 291 | if(when.tv_sec <= xtime(0)) { |
| 292 | disorder_error(0, "new scheduled event is in the past"); |
| 293 | return 0; |
| 294 | } |
| 295 | do { |
| 296 | id = random_id(); |
| 297 | WITH_TRANSACTION(schedule_add_tid(id, actiondata, tid)); |
| 298 | } while(e == DB_KEYEXIST); |
| 299 | ev_timeout(ev, 0/*handlep*/, &when, schedule_trigger, (void *)id); |
| 300 | return id; |
| 301 | } |
| 302 | |
| 303 | /******************************************************************************/ |
| 304 | |
| 305 | /** @brief Get the action data for a scheduled event |
| 306 | * @param id Event ID |
| 307 | * @return Event data or NULL |
| 308 | */ |
| 309 | struct kvp *schedule_get(const char *id) { |
| 310 | int e, n; |
| 311 | struct kvp *actiondata; |
| 312 | |
| 313 | WITH_TRANSACTION(trackdb_getdata(trackdb_scheduledb, id, &actiondata, tid)); |
| 314 | /* Check that the required field are present */ |
| 315 | for(n = 0; n < NREQUIRED; ++n) { |
| 316 | if(!kvp_get(actiondata, schedule_required[n])) { |
| 317 | disorder_error(0, "scheduled event %s is missing required field '%s'", |
| 318 | id, schedule_required[n]); |
| 319 | return 0; |
| 320 | } |
| 321 | } |
| 322 | return actiondata; |
| 323 | } |
| 324 | |
| 325 | /******************************************************************************/ |
| 326 | |
| 327 | /** @brief Delete a scheduled event |
| 328 | * @param id Event to delete |
| 329 | * @return 0 on success, non-0 if it did not exist |
| 330 | */ |
| 331 | int schedule_del(const char *id) { |
| 332 | int e; |
| 333 | |
| 334 | WITH_TRANSACTION(trackdb_delkey(trackdb_scheduledb, id, tid)); |
| 335 | return e == 0 ? 0 : -1; |
| 336 | } |
| 337 | |
| 338 | /******************************************************************************/ |
| 339 | |
| 340 | /** @brief Get a list of scheduled events |
| 341 | * @param neventsp Where to put count of events (or NULL) |
| 342 | * @return 0-terminate list of ID strings |
| 343 | */ |
| 344 | char **schedule_list(int *neventsp) { |
| 345 | int e; |
| 346 | struct vector v[1]; |
| 347 | |
| 348 | vector_init(v); |
| 349 | WITH_TRANSACTION(trackdb_listkeys(trackdb_scheduledb, v, tid)); |
| 350 | if(neventsp) |
| 351 | *neventsp = v->nvec; |
| 352 | return v->vec; |
| 353 | } |
| 354 | |
| 355 | /******************************************************************************/ |
| 356 | |
| 357 | static void schedule_play(ev_source *ev, |
| 358 | const char *id, |
| 359 | const char *who, |
| 360 | struct kvp *actiondata) { |
| 361 | const char *track = kvp_get(actiondata, "track"); |
| 362 | struct queue_entry *q; |
| 363 | |
| 364 | /* This stuff has rather a lot in common with c_play() */ |
| 365 | if(!track) { |
| 366 | disorder_error(0, "scheduled event %s: no track field", id); |
| 367 | return; |
| 368 | } |
| 369 | if(!trackdb_exists(track)) { |
| 370 | disorder_error(0, "scheduled event %s: no such track as %s", id, track); |
| 371 | return; |
| 372 | } |
| 373 | if(!(track = trackdb_resolve(track))) { |
| 374 | disorder_error(0, "scheduled event %s: cannot resolve track %s", id, track); |
| 375 | return; |
| 376 | } |
| 377 | disorder_info("scheduled event %s: %s play %s", id, who, track); |
| 378 | q = queue_add(track, who, WHERE_START, NULL, origin_scheduled); |
| 379 | queue_write(); |
| 380 | if(q == qhead.next && playing) |
| 381 | prepare(ev, q); |
| 382 | play(ev); |
| 383 | } |
| 384 | |
| 385 | static void schedule_set_global(ev_source attribute((unused)) *ev, |
| 386 | const char *id, |
| 387 | const char *who, |
| 388 | struct kvp *actiondata) { |
| 389 | const char *key = kvp_get(actiondata, "key"); |
| 390 | const char *value = kvp_get(actiondata, "value"); |
| 391 | |
| 392 | if(!key) { |
| 393 | disorder_error(0, "scheduled event %s: no key field", id); |
| 394 | return; |
| 395 | } |
| 396 | if(key[0] == '_') { |
| 397 | disorder_error(0, "scheduled event %s: cannot set internal global preferences (%s)", |
| 398 | id, key); |
| 399 | return; |
| 400 | } |
| 401 | if(value) |
| 402 | disorder_info("scheduled event %s: %s set-global %s=%s", |
| 403 | id, who, key, value); |
| 404 | else |
| 405 | disorder_info("scheduled event %s: %s set-global %s unset", id, who, key); |
| 406 | trackdb_set_global(key, value, who); |
| 407 | } |
| 408 | |
| 409 | /** @brief Table of schedule actions |
| 410 | * |
| 411 | * Must be kept sorted. |
| 412 | */ |
| 413 | static struct { |
| 414 | const char *name; |
| 415 | void (*callback)(ev_source *ev, |
| 416 | const char *id, const char *who, |
| 417 | struct kvp *actiondata); |
| 418 | rights_type right; |
| 419 | } schedule_actions[] = { |
| 420 | { "play", schedule_play, RIGHT_PLAY }, |
| 421 | { "set-global", schedule_set_global, RIGHT_GLOBAL_PREFS }, |
| 422 | }; |
| 423 | |
| 424 | /** @brief Look up a scheduled event |
| 425 | * @param id Event ID |
| 426 | * @param actiondata Event description |
| 427 | * @return index in schedule_actions[] on success, -1 on error |
| 428 | * |
| 429 | * Unknown events are rejected as are those that the user is not allowed to do. |
| 430 | */ |
| 431 | static int schedule_lookup(const char *id, |
| 432 | struct kvp *actiondata) { |
| 433 | const char *who = kvp_get(actiondata, "who"); |
| 434 | const char *action = kvp_get(actiondata, "action"); |
| 435 | const char *rights; |
| 436 | struct kvp *userinfo; |
| 437 | rights_type r; |
| 438 | int n; |
| 439 | |
| 440 | /* Look up the action */ |
| 441 | n = TABLE_FIND(schedule_actions, name, action); |
| 442 | if(n < 0) { |
| 443 | disorder_error(0, "scheduled event %s: unrecognized action '%s'", |
| 444 | id, action); |
| 445 | return -1; |
| 446 | } |
| 447 | /* Find the user */ |
| 448 | if(!(userinfo = trackdb_getuserinfo(who))) { |
| 449 | disorder_error(0, "scheduled event %s: user '%s' does not exist", id, who); |
| 450 | return -1; |
| 451 | } |
| 452 | /* Check that they have suitable rights */ |
| 453 | if(!(rights = kvp_get(userinfo, "rights"))) { |
| 454 | disorder_error(0, "scheduled event %s: user %s' has no rights???", id, who); |
| 455 | return -1; |
| 456 | } |
| 457 | if(parse_rights(rights, &r, 1)) { |
| 458 | disorder_error(0, "scheduled event %s: user %s has invalid rights '%s'", |
| 459 | id, who, rights); |
| 460 | return -1; |
| 461 | } |
| 462 | if(!(r & schedule_actions[n].right)) { |
| 463 | disorder_error(0, "scheduled event %s: user %s lacks rights for action %s", |
| 464 | id, who, action); |
| 465 | return -1; |
| 466 | } |
| 467 | return n; |
| 468 | } |
| 469 | |
| 470 | /** @brief Called when an action is due */ |
| 471 | static int schedule_trigger(ev_source *ev, |
| 472 | const struct timeval attribute((unused)) *now, |
| 473 | void *u) { |
| 474 | const char *action, *id = u; |
| 475 | struct kvp *actiondata = schedule_get(id); |
| 476 | int n; |
| 477 | |
| 478 | if(!actiondata) |
| 479 | return 0; |
| 480 | /* schedule_get() enforces these being present */ |
| 481 | action = kvp_get(actiondata, "action"); |
| 482 | /* Look up the action */ |
| 483 | n = schedule_lookup(id, actiondata); |
| 484 | if(n < 0) |
| 485 | goto done; |
| 486 | /* Go ahead and do it */ |
| 487 | schedule_actions[n].callback(ev, id, kvp_get(actiondata, "who"), actiondata); |
| 488 | done: |
| 489 | /* TODO: rewrite recurring events for their next trigger time, |
| 490 | * rather than deleting them */ |
| 491 | schedule_del(id); |
| 492 | return 0; |
| 493 | } |
| 494 | |
| 495 | /* |
| 496 | Local Variables: |
| 497 | c-basic-offset:2 |
| 498 | comment-column:40 |
| 499 | fill-column:79 |
| 500 | indent-tabs-mode:nil |
| 501 | End: |
| 502 | */ |