Let afs callbacks return an error code.
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file mood.c Paraslash's mood handling functions. */
8
9 #include <regex.h>
10 #include <osl.h>
11
12 #include "para.h"
13 #include "error.h"
14 #include "string.h"
15 #include "afh.h"
16 #include "afs.h"
17 #include "list.h"
18 #include "ipc.h"
19 #include "mm.h"
20 #include "sideband.h"
21 #include "mood.h"
22
23 /**
24 * Contains statistical data of the currently admissible audio files.
25 *
26 * It is used to assign normalized score values to each admissible audio file.
27 */
28 struct afs_statistics {
29 /** Sum of num played over all admissible files. */
30 int64_t num_played_sum;
31 /** Sum of last played times over all admissible files. */
32 int64_t last_played_sum;
33 /** Quadratic deviation of num played count. */
34 int64_t num_played_qd;
35 /** Quadratic deviation of last played time. */
36 int64_t last_played_qd;
37 /** Number of admissible files */
38 unsigned num;
39 };
40 static struct afs_statistics statistics;
41
42 /**
43 * Each line of the current mood corresponds to a mood_item.
44 */
45 struct mood_item {
46 /** The method this line is referring to. */
47 const struct mood_method *method;
48 /** The data structure computed by the mood parser. */
49 void *parser_data;
50 /** The given score value, or zero if none was given. */
51 int32_t score_arg;
52 /** Non-zero if random scoring was requested. */
53 int random_score;
54 /** Whether the "not" keyword was given in the mood line. */
55 int logical_not;
56 /** The position in the list of items. */
57 struct list_head mood_item_node;
58 };
59
60 /**
61 * Created from the mood definition by mood_open().
62 *
63 * When a mood is opened, each line of its definition is investigated, and a
64 * corresponding mood item is produced. Each mood line starts with \p accept,
65 * \p deny, or \p score which determines the type of the mood line. For each
66 * such type a linked list is maintained whose entries are the mood items.
67 *
68 * \sa mood_item, mood_open().
69 */
70 struct mood {
71 /** The name of this mood. */
72 char *name;
73 /** The list of mood items of type \p accept. */
74 struct list_head accept_list;
75 /** The list of mood items of type \p deny. */
76 struct list_head deny_list;
77 /** The list of mood items of type \p score. */
78 struct list_head score_list;
79 };
80
81 /*
82 * If current_mood is NULL then no mood is currently open. If
83 * current_mood->name is NULL, the dummy mood is currently open
84 */
85 static struct mood *current_mood;
86
87 /**
88 * Rough approximation to sqrt.
89 *
90 * \param x Integer of which to calculate the sqrt.
91 *
92 * \return An integer res with res * res <= x.
93 */
94 __a_const static uint64_t int_sqrt(uint64_t x)
95 {
96 uint64_t op, res, one = 1;
97 op = x;
98 res = 0;
99
100 one = one << 62;
101 while (one > op)
102 one >>= 2;
103
104 while (one != 0) {
105 if (op >= res + one) {
106 op = op - (res + one);
107 res = res + 2 * one;
108 }
109 res /= 2;
110 one /= 4;
111 }
112 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
113 return res;
114 }
115
116 /*
117 * Returns true if row matches, false if it does not match. In any case score
118 * and score_arg_sum are set/increased accordingly.
119 */
120 static bool get_item_score(struct mood_item *item, const struct afs_info *afsi,
121 const struct afh_info *afhi, const char *path, long *score,
122 long *score_arg_sum)
123 {
124 int ret;
125 bool match = true;
126
127 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
128 ret = 100;
129 if (item->method) {
130 ret = item->method->score_function(path, afsi, afhi,
131 item->parser_data);
132 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
133 match = false;
134 }
135 if (item->random_score)
136 *score = PARA_ABS(ret) * para_random(100);
137 else
138 *score = PARA_ABS(ret) * item->score_arg;
139 return match;
140 }
141
142 /* returns 1 if row admissible, 0 if not, negative on errors */
143 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
144 long *result)
145 {
146 struct mood_item *item;
147 int ret;
148 bool match;
149 long score_arg_sum = 0, score = 0, item_score;
150 struct afs_info afsi;
151 struct afh_info afhi;
152 char *path;
153
154 if (!m)
155 return -E_NO_MOOD;
156 ret = get_afsi_of_row(aft_row, &afsi);
157 if (ret< 0)
158 return ret;
159 ret = get_afhi_of_row(aft_row, &afhi);
160 if (ret< 0)
161 return ret;
162 ret = get_audio_file_path_of_row(aft_row, &path);
163 if (ret< 0)
164 return ret;
165 /* reject audio file if it matches any entry in the deny list */
166 list_for_each_entry(item, &m->deny_list, mood_item_node) {
167 match = get_item_score(item, &afsi, &afhi, path, &item_score,
168 &score_arg_sum);
169 if (match) /* not admissible */
170 return 0;
171 score += item_score;
172 }
173 match = false;
174 list_for_each_entry(item, &m->accept_list, mood_item_node) {
175 ret = get_item_score(item, &afsi, &afhi, path, &item_score,
176 &score_arg_sum);
177 if (ret == 0)
178 continue;
179 match = true;
180 score += item_score;
181 }
182 /* reject if there is no matching entry in the accept list */
183 if (!match && !list_empty(&m->accept_list))
184 return 0;
185 list_for_each_entry(item, &m->score_list, mood_item_node) {
186 match = get_item_score(item, &afsi, &afhi, path, &item_score,
187 &score_arg_sum);
188 if (match)
189 score += item_score;
190 }
191 if (score_arg_sum)
192 score /= score_arg_sum;
193 *result = score;
194 return 1;
195 }
196
197 static void cleanup_list_entry(struct mood_item *item)
198 {
199 if (item->method && item->method->cleanup)
200 item->method->cleanup(item->parser_data);
201 else
202 free(item->parser_data);
203 list_del(&item->mood_item_node);
204 free(item);
205 }
206
207 static void destroy_mood(struct mood *m)
208 {
209 struct mood_item *tmp, *item;
210
211 if (!m)
212 return;
213 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
214 cleanup_list_entry(item);
215 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
216 cleanup_list_entry(item);
217 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
218 cleanup_list_entry(item);
219 free(m->name);
220 free(m);
221 }
222
223 static struct mood *alloc_new_mood(const char *name)
224 {
225 struct mood *m = para_calloc(sizeof(struct mood));
226 if (name)
227 m->name = para_strdup(name);
228 INIT_LIST_HEAD(&m->accept_list);
229 INIT_LIST_HEAD(&m->deny_list);
230 INIT_LIST_HEAD(&m->score_list);
231 return m;
232 }
233
234 /** The different types of a mood line. */
235 enum mood_line_type {
236 /** Invalid. */
237 ML_INVALID,
238 /** Accept line. */
239 ML_ACCEPT,
240 /** Deny line. */
241 ML_DENY,
242 /** Score line. */
243 ML_SCORE
244 };
245
246 /** Data passed to the parser of a mood line. */
247 struct mood_line_parser_data {
248 /** The mood this mood line belongs to. */
249 struct mood *m;
250 /** The line number in the mood definition. */
251 unsigned line_num;
252 };
253
254 /*
255 * <accept [with score <score>] | deny [with score <score>] | score <score>>
256 * [if] [not] <mood_method> [options]
257 * <score> is either an integer or "random" which assigns a random score to
258 * all matching files
259 */
260
261 static int parse_mood_line(char *mood_line, void *data)
262 {
263 struct mood_line_parser_data *mlpd = data;
264 char **argv;
265 unsigned num_words;
266 char **w;
267 int i, ret;
268 enum mood_line_type mlt = ML_INVALID;
269 struct mood_item *mi = NULL;
270
271 mlpd->line_num++;
272 ret = create_argv(mood_line, " \t", &argv);
273 if (ret < 0)
274 return ret;
275 num_words = ret;
276 if (!num_words) /* empty line */
277 goto out;
278 w = argv;
279 if (**w == '#') /* comment */
280 goto out;
281 if (!strcmp(*w, "accept"))
282 mlt = ML_ACCEPT;
283 else if (!strcmp(*w, "deny"))
284 mlt = ML_DENY;
285 else if (!strcmp(*w, "score"))
286 mlt = ML_SCORE;
287 ret = -E_MOOD_SYNTAX;
288 if (mlt == ML_INVALID)
289 goto out;
290 mi = para_calloc(sizeof(struct mood_item));
291 if (mlt != ML_SCORE) {
292 ret = -E_MOOD_SYNTAX;
293 w++;
294 if (!*w)
295 goto out;
296 if (strcmp(*w, "with"))
297 goto check_for_if;
298 w++;
299 if (!*w)
300 goto out;
301 if (strcmp(*w, "score"))
302 goto out;
303 }
304 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
305 ret = -E_MOOD_SYNTAX;
306 w++;
307 if (!*w)
308 goto out;
309 if (strcmp(*w, "random")) {
310 mi->random_score = 0;
311 ret = para_atoi32(*w, &mi->score_arg);
312 if (ret < 0)
313 goto out;
314 } else {
315 mi->random_score = 1;
316 if (!*(w + 1))
317 goto success; /* the line "score random" is valid */
318 }
319 } else
320 mi->score_arg = 0;
321 ret = -E_MOOD_SYNTAX;
322 w++;
323 if (!*w)
324 goto out;
325 check_for_if:
326 if (!strcmp(*w, "if")) {
327 ret = -E_MOOD_SYNTAX;
328 w++;
329 if (!*w)
330 goto out;
331 }
332 if (!strcmp(*w, "not")) {
333 ret = -E_MOOD_SYNTAX;
334 w++;
335 if (!*w)
336 goto out;
337 mi->logical_not = 1;
338 } else
339 mi->logical_not = 0;
340 for (i = 0; mood_methods[i].parser; i++) {
341 if (strcmp(*w, mood_methods[i].name))
342 continue;
343 break;
344 }
345 ret = -E_MOOD_SYNTAX;
346 if (!mood_methods[i].parser)
347 goto out;
348 ret = mood_methods[i].parser(num_words - 1 - (w - argv), w,
349 &mi->parser_data);
350 if (ret < 0)
351 goto out;
352 mi->method = &mood_methods[i];
353 success:
354 if (mlpd->m) {
355 if (mlt == ML_ACCEPT)
356 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
357 else if (mlt == ML_DENY)
358 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
359 else
360 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
361 }
362 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
363 (mlt == ML_DENY? "deny" : "score"), mi->method);
364 ret = 1;
365 out:
366 free_argv(argv);
367 if (ret >= 0)
368 return ret;
369 if (mi) {
370 free(mi->parser_data);
371 free(mi);
372 }
373 return ret;
374 }
375
376 static int load_mood(const struct osl_row *mood_row, struct mood **m)
377 {
378 char *mood_name;
379 struct osl_object mood_def;
380 struct mood_line_parser_data mlpd = {.line_num = 0};
381 int ret;
382
383 *m = NULL;
384 ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
385 if (ret < 0)
386 return ret;
387 if (!*mood_name)
388 return -E_DUMMY_ROW;
389 mlpd.m = alloc_new_mood(mood_name);
390 ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
391 parse_mood_line, &mlpd);
392 osl_close_disk_object(&mood_def);
393 if (ret < 0) {
394 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
395 para_strerror(-ret));
396 destroy_mood(mlpd.m);
397 return ret;
398 }
399 *m = mlpd.m;
400 return 1;
401 }
402
403 static int check_mood(struct osl_row *mood_row, void *data)
404 {
405 struct para_buffer *pb = data;
406 char *mood_name;
407 struct osl_object mood_def;
408 struct mood_line_parser_data mlpd = {.line_num = 0};
409
410 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
411
412 if (ret < 0) {
413 para_printf(pb, "failed to get mood definition: %s\n",
414 para_strerror(-ret));
415 return ret;
416 }
417 if (!*mood_name) /* ignore dummy row */
418 goto out;
419 para_printf(pb, "checking mood %s...\n", mood_name);
420 ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
421 parse_mood_line, &mlpd);
422 if (ret < 0)
423 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
424 para_strerror(-ret));
425 out:
426 osl_close_disk_object(&mood_def);
427 return ret;
428 }
429
430 /**
431 * Check all moods for syntax errors.
432 *
433 * \param fd The afs socket.
434 * \param query Unused.
435 *
436 * \return Currently this function always returns zero.
437 */
438 int mood_check_callback(int fd, __a_unused const struct osl_object *query)
439 {
440 struct para_buffer pb = {
441 .max_size = shm_get_shmmax(),
442 .private_data = &(struct afs_max_size_handler_data) {
443 .fd = fd,
444 .band = SBD_OUTPUT
445 },
446 .max_size_handler = afs_max_size_handler
447 };
448
449 para_printf(&pb, "checking moods...\n");
450 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
451 check_mood);
452 flush_and_free_pb(&pb);
453 return 0;
454 }
455
456 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
457 {
458 if (!n || !qd)
459 return 0;
460 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
461 }
462
463 static long compute_score(struct afs_info *afsi, long mood_score)
464 {
465 mood_score -= normalized_value(afsi->num_played, statistics.num,
466 statistics.num_played_sum, statistics.num_played_qd);
467 mood_score -= normalized_value(afsi->last_played, statistics.num,
468 statistics.last_played_sum, statistics.last_played_qd);
469 return mood_score / 3;
470 }
471
472 static int add_afs_statistics(const struct osl_row *row)
473 {
474 uint64_t n, x, s;
475 struct afs_info afsi;
476 int ret;
477
478 ret = get_afsi_of_row(row, &afsi);
479 if (ret < 0)
480 return ret;
481 n = statistics.num;
482 x = afsi.last_played;
483 s = statistics.last_played_sum;
484 if (n > 0)
485 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
486 statistics.last_played_sum += x;
487
488 x = afsi.num_played;
489 s = statistics.num_played_sum;
490 if (n > 0)
491 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
492 statistics.num_played_sum += x;
493 statistics.num++;
494 return 1;
495 }
496
497 static int del_afs_statistics(const struct osl_row *row)
498 {
499 uint64_t n, s, q, a, new_s;
500 struct afs_info afsi;
501 int ret;
502 ret = get_afsi_of_row(row, &afsi);
503 if (ret < 0)
504 return ret;
505 n = statistics.num;
506 assert(n);
507 if (n == 1) {
508 memset(&statistics, 0, sizeof(statistics));
509 return 1;
510 }
511
512 s = statistics.last_played_sum;
513 q = statistics.last_played_qd;
514 a = afsi.last_played;
515 new_s = s - a;
516 statistics.last_played_sum = new_s;
517 statistics.last_played_qd = q + s * s / n - a * a
518 - new_s * new_s / (n - 1);
519
520 s = statistics.num_played_sum;
521 q = statistics.num_played_qd;
522 a = afsi.num_played;
523 new_s = s - a;
524 statistics.num_played_sum = new_s;
525 statistics.num_played_qd = q + s * s / n - a * a
526 - new_s * new_s / (n - 1);
527
528 statistics.num--;
529 return 1;
530 }
531
532 /**
533 * Structure used during mood_open().
534 *
535 * At mood open time we determine the set of admissible files for the given
536 * mood. The mood score of each admissible file is computed by adding up all
537 * mood item scores. Next, we update the afs statistics and append a struct
538 * admissible_file_info to a temporary array.
539 *
540 * When all files have been processed in this way, the final score of each
541 * admissible file is computed by adding the dynamic score (which depends on
542 * the afs_statistics and the current time) to the mood score. Finally, all
543 * audio files in the temporary array are added to the score table and the
544 * array is freed.
545 *
546 * \sa mood_method, admissible_array.
547 */
548 struct admissible_file_info
549 {
550 /** The admissible audio file. */
551 struct osl_row *aft_row;
552 /** Its score. */
553 long score;
554 };
555
556 /** The temporary array of admissible files. */
557 struct admissible_array {
558 /** Files are admissible wrt. this mood. */
559 struct mood *m;
560 /** The size of the array */
561 unsigned size;
562 /** Pointer to the array of admissible files. */
563 struct admissible_file_info *array;
564 };
565
566 /**
567 * Add an entry to the array of admissible files.
568 *
569 * \param aft_row The audio file to be added.
570 * \param private_data Pointer to a struct admissible_file_info.
571 *
572 * \return 1 if row admissible, 0 if not, negative on errors.
573 */
574 static int add_if_admissible(struct osl_row *aft_row, void *data)
575 {
576 struct admissible_array *aa = data;
577 int ret;
578 long score = 0;
579
580 ret = compute_mood_score(aft_row, aa->m, &score);
581 if (ret <= 0)
582 return ret;
583 if (statistics.num >= aa->size) {
584 aa->size *= 2;
585 aa->size += 100;
586 aa->array = para_realloc(aa->array,
587 aa->size * sizeof(struct admissible_file_info));
588 }
589 aa->array[statistics.num].aft_row = aft_row;
590 aa->array[statistics.num].score = score;
591 ret = add_afs_statistics(aft_row);
592 if (ret < 0)
593 return ret;
594 return 1;
595 }
596
597 /**
598 * Compute the new quadratic deviation in case one element changes.
599 *
600 * \param n Number of elements.
601 * \param old_qd The quadratic deviation before the change.
602 * \param old_val The value that was replaced.
603 * \param new_val The replacement value.
604 * \param old_sum The sum of all elements before the update.
605 *
606 * \return The new quadratic deviation resulting from replacing old_val
607 * by new_val.
608 *
609 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
610 * their quadratic deviation
611 *
612 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
613 *
614 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
615 * the last number a_n was replaced by b) may be computed in O(1) time in terms
616 * of n, q, a_n, b, and S as
617 *
618 * q' = q + d * s - (2 * S + d) * d / n,
619 *
620 * where d = b - a_n, and s = b + a_n.
621 *
622 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
623 * s = 17, so
624 *
625 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
626 *
627 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
628 *
629 */
630 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
631 int64_t old_val, int64_t new_val, int64_t old_sum)
632 {
633 int64_t delta = new_val - old_val;
634 int64_t sigma = new_val + old_val;
635 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
636 }
637
638 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
639 {
640 unsigned n;
641 int ret = get_num_admissible_files(&n);
642
643 if (ret < 0)
644 return ret;
645 assert(n);
646
647 statistics.last_played_qd = update_quadratic_deviation(n,
648 statistics.last_played_qd, old_afsi->last_played,
649 new_afsi->last_played, statistics.last_played_sum);
650 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
651
652 statistics.num_played_qd = update_quadratic_deviation(n,
653 statistics.num_played_qd, old_afsi->num_played,
654 new_afsi->num_played, statistics.num_played_sum);
655 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
656 return 1;
657 }
658
659 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
660 {
661 long score;
662 struct afs_info afsi;
663 int ret = get_afsi_of_row(aft_row, &afsi);
664
665 if (ret < 0)
666 return ret;
667 score = compute_score(&afsi, mood_score);
668 return score_add(aft_row, score);
669 }
670
671 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
672 {
673 int ret = del_afs_statistics(aft_row);
674 if (ret < 0)
675 return ret;
676 return score_delete(aft_row);
677 }
678
679 /**
680 * Delete one entry from the statistics and from the score table.
681 *
682 * \param aft_row The audio file which is no longer admissible.
683 *
684 * \return Positive on success, negative on errors.
685 *
686 * \sa score_delete().
687 */
688 static int mood_delete_audio_file(const struct osl_row *aft_row)
689 {
690 int ret;
691
692 ret = row_belongs_to_score_table(aft_row, NULL);
693 if (ret < 0)
694 return ret;
695 if (!ret) /* not admissible, nothing to do */
696 return 1;
697 return delete_from_statistics_and_score_table(aft_row);
698 }
699
700 /**
701 * Compute the new score of an audio file wrt. the current mood.
702 *
703 * \param aft_row Determines the audio file.
704 * \param old_afsi The audio file selector info before updating.
705 *
706 * The \a old_afsi argument may be \p NULL which indicates that no changes to
707 * the audio file info were made.
708 *
709 * \return Positive on success, negative on errors.
710 */
711 static int mood_update_audio_file(const struct osl_row *aft_row,
712 struct afs_info *old_afsi)
713 {
714 long score, percent;
715 int ret, is_admissible, was_admissible = 0;
716 struct afs_info afsi;
717 unsigned rank;
718
719 if (!current_mood)
720 return 1; /* nothing to do */
721 ret = row_belongs_to_score_table(aft_row, &rank);
722 if (ret < 0)
723 return ret;
724 was_admissible = ret;
725 ret = compute_mood_score(aft_row, current_mood, &score);
726 if (ret < 0)
727 return ret;
728 is_admissible = (ret > 0);
729 if (!was_admissible && !is_admissible)
730 return 1;
731 if (was_admissible && !is_admissible)
732 return delete_from_statistics_and_score_table(aft_row);
733 if (!was_admissible && is_admissible) {
734 ret = add_afs_statistics(aft_row);
735 if (ret < 0)
736 return ret;
737 return add_to_score_table(aft_row, score);
738 }
739 /* update score */
740 ret = get_afsi_of_row(aft_row, &afsi);
741 if (ret < 0)
742 return ret;
743 if (old_afsi) {
744 ret = update_afs_statistics(old_afsi, &afsi);
745 if (ret < 0)
746 return ret;
747 }
748 score = compute_score(&afsi, score);
749 PARA_DEBUG_LOG("score: %li\n", score);
750 percent = (score + 100) / 3;
751 if (percent > 100)
752 percent = 100;
753 else if (percent < 0)
754 percent = 0;
755 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
756 return score_update(aft_row, percent);
757 }
758
759 static void log_statistics(void)
760 {
761 unsigned n = statistics.num;
762
763 if (!n) {
764 PARA_NOTICE_LOG("no admissible files\n");
765 return;
766 }
767 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
768 (long long int)(statistics.last_played_sum / n),
769 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
770 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
771 (long long int)statistics.num_played_sum / n,
772 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
773 }
774
775 /**
776 * Close the current mood.
777 *
778 * Free all resources of the current mood which were allocated during
779 * mood_open().
780 */
781 void close_current_mood(void)
782 {
783 destroy_mood(current_mood);
784 current_mood = NULL;
785 memset(&statistics, 0, sizeof(statistics));
786 }
787
788 /**
789 * Change the current mood.
790 *
791 * \param mood_name The name of the mood to open.
792 *
793 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
794 * and uses a scoring method based only on the \a last_played information.
795 *
796 * If there is already an open mood, it will be closed first.
797 *
798 * \return Positive on success, negative on errors. Loading the dummy mood
799 * always succeeds.
800 *
801 * \sa struct admissible_file_info, struct admissible_array, struct
802 * afs_info::last_played, mood_close().
803 */
804 int change_current_mood(char *mood_name)
805 {
806 int i, ret;
807 struct admissible_array aa = {
808 .size = 0,
809 .array = NULL
810 };
811
812 if (mood_name) {
813 struct mood *m;
814 struct osl_row *row;
815 struct osl_object obj = {
816 .data = mood_name,
817 .size = strlen(mood_name) + 1
818 };
819 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
820 if (ret < 0) {
821 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
822 return ret;
823 }
824 ret = load_mood(row, &m);
825 if (ret < 0)
826 return ret;
827 close_current_mood();
828 current_mood = m;
829 } else { /* load dummy mood */
830 close_current_mood();
831 current_mood = alloc_new_mood(NULL);
832 }
833 aa.m = current_mood;
834 PARA_NOTICE_LOG("computing statistics of admissible files\n");
835 ret = audio_file_loop(&aa, add_if_admissible);
836 if (ret < 0)
837 return ret;
838 log_statistics();
839 PARA_INFO_LOG("%d admissible files\n", statistics.num);
840 for (i = 0; i < statistics.num; i++) {
841 struct admissible_file_info *a = aa.array + i;
842 ret = add_to_score_table(a->aft_row, a->score);
843 if (ret < 0)
844 goto out;
845 }
846 PARA_NOTICE_LOG("loaded mood %s\n", mood_name? mood_name : "(dummy)");
847 ret = statistics.num;
848 out:
849 free(aa.array);
850 return ret;
851 }
852 /**
853 * Close and re-open the current mood.
854 *
855 * This function is used if changes to the audio file table or the
856 * attribute table were made that render the current list of admissible
857 * files useless. For example, if an attribute is removed from the
858 * attribute table, this function is called.
859 *
860 * \return Positive on success, negative on errors. If no mood is currently
861 * open, the function returns success.
862 *
863 * \sa mood_open(), mood_close().
864 */
865 static int reload_current_mood(void)
866 {
867 int ret;
868 char *mood_name = NULL;
869
870 if (!current_mood)
871 return 1;
872 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
873 current_mood->name : "(dummy)");
874 if (current_mood->name)
875 mood_name = para_strdup(current_mood->name);
876 close_current_mood();
877 ret = change_current_mood(mood_name);
878 free(mood_name);
879 return ret;
880 }
881
882 /**
883 * Notification callback for the moods table.
884 *
885 * \param event Type of the event just occurred.
886 * \param pb Unused.
887 * \param data Its type depends on the event.
888 *
889 * This function performs actions required due to the occurrence of the given
890 * event. Possible actions include reload of the current mood and update of the
891 * score of an audio file.
892 *
893 * \return Standard.
894 */
895 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
896 void *data)
897 {
898 int ret;
899
900 if (!current_mood)
901 return 0;
902 switch (event) {
903 /*
904 * The three blob events might change the set of admissible files,
905 * so we must reload the score list.
906 */
907 case BLOB_RENAME:
908 case BLOB_REMOVE:
909 case BLOB_ADD:
910 if (data == moods_table || data == playlists_table)
911 return 1; /* no reload necessary for these */
912 ret = clear_score_table();
913 if (ret < 0)
914 PARA_CRIT_LOG("clear score table returned %s\n",
915 para_strerror(-ret));
916 return reload_current_mood();
917 /* these also require reload of the score table */
918 case ATTRIBUTE_ADD:
919 case ATTRIBUTE_REMOVE:
920 case ATTRIBUTE_RENAME:
921 return reload_current_mood();
922 /* changes to the aft only require to re-examine the audio file */
923 case AFSI_CHANGE: {
924 struct afsi_change_event_data *aced = data;
925 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
926 }
927 case AFHI_CHANGE:
928 case AUDIO_FILE_RENAME:
929 case AUDIO_FILE_ADD:
930 return mood_update_audio_file(data, NULL);
931 case AUDIO_FILE_REMOVE:
932 return mood_delete_audio_file(data);
933 default:
934 return 1;
935 }
936 }