Move mood methods to a separate file.
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007-2009 Andre Noll <maan@systemlinux.org>
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
21 /**
22 * Contains statistical data of the currently admissible audio files.
23 *
24 * It is used to assign normalized score values to each admissible audio file.
25 */
26 struct afs_statistics {
27 /** Sum of num played over all admissible files. */
28 int64_t num_played_sum;
29 /** Sum of last played times over all admissible files. */
30 int64_t last_played_sum;
31 /** Quadratic deviation of num played time. */
32 int64_t num_played_qd;
33 /** Quadratic deviation of last played time. */
34 int64_t last_played_qd;
35 /** Number of admissible files */
36 unsigned num;
37 };
38 struct afs_statistics statistics;
39
40 /**
41 * Each line of the current mood corresponds to a mood_item.
42 */
43 struct mood_item {
44 /** The method this line is referring to. */
45 const struct mood_method *method;
46 /** The data structure computed by the mood parser. */
47 void *parser_data;
48 /** The given score value, or zero if none was given. */
49 int32_t score_arg;
50 /** Non-zero if random scoring was requested. */
51 int random_score;
52 /** Whether the "not" keyword was given in the mood line. */
53 int logical_not;
54 /** The position in the list of items. */
55 struct list_head mood_item_node;
56 };
57
58 /**
59 * Created from the mood definition by mood_open().
60 *
61 * When a mood is opened, each line of its definition is investigated, and a
62 * corresponding mood item is produced. Each mood line starts with \p accept,
63 * \p deny, or \p score which determines the type of the mood line. For each
64 * such type a linked list is maintained whose entries are the mood items.
65 *
66 * \sa mood_item, mood_open().
67 */
68 struct mood {
69 /** The name of this mood. */
70 char *name;
71 /** The list of mood items of type \p accept. */
72 struct list_head accept_list;
73 /** The list of mood items of type \p deny. */
74 struct list_head deny_list;
75 /** The list of mood items of type \p score. */
76 struct list_head score_list;
77 };
78
79 static struct mood *current_mood;
80
81 /**
82 * Rough approximation to sqrt.
83 *
84 * \param x Integer of which to calculate the sqrt.
85 *
86 * \return An integer res with res * res <= x.
87 */
88 static uint64_t int_sqrt(uint64_t x)
89 {
90 uint64_t op, res, one = 1;
91 op = x;
92 res = 0;
93
94 one = one << 62;
95 while (one > op)
96 one >>= 2;
97
98 while (one != 0) {
99 if (op >= res + one) {
100 op = op - (res + one);
101 res = res + 2 * one;
102 }
103 res /= 2;
104 one /= 4;
105 }
106 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
107 return res;
108 }
109
110 /* returns 1 if row matches score item, negative otherwise */
111 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
112 long *score_arg_sum)
113 {
114 struct afs_info afsi;
115 struct afh_info afhi;
116 char *path;
117 int ret;
118
119 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
120 ret = 100;
121 if (item->method) {
122 ret = get_afsi_of_row(row, &afsi);
123 if (ret< 0)
124 return ret;
125 ret = get_afhi_of_row(row, &afhi);
126 if (ret< 0)
127 return ret;
128 ret = get_audio_file_path_of_row(row, &path);
129 if (ret< 0)
130 return ret;
131 ret = item->method->score_function(path, &afsi, &afhi,
132 item->parser_data);
133 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
134 return -1; /* no match */
135 }
136 if (item->random_score)
137 *score += PARA_ABS(ret) * para_random(100);
138 else
139 *score += PARA_ABS(ret) * item->score_arg;
140 return 1;
141 }
142
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 match = 0;
148 long score_arg_sum = 0, score = 0;
149
150 if (!m)
151 return -E_NO_MOOD;
152 /* reject audio file if it matches any entry in the deny list */
153 list_for_each_entry(item, &m->deny_list, mood_item_node)
154 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
155 return -E_NOT_ADMISSIBLE;
156 list_for_each_entry(item, &m->accept_list, mood_item_node)
157 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
158 match = 1;
159 /* reject if there is no matching entry in the accept list */
160 if (!match && !list_empty(&m->accept_list))
161 return -E_NOT_ADMISSIBLE;
162 list_for_each_entry(item, &m->score_list, mood_item_node)
163 add_item_score(aft_row, item, &score, &score_arg_sum);
164 if (score_arg_sum)
165 score /= score_arg_sum;
166 *result = score;
167 return 1;
168 }
169
170 static void cleanup_list_entry(struct mood_item *item)
171 {
172 if (item->method && item->method->cleanup)
173 item->method->cleanup(item->parser_data);
174 else
175 free(item->parser_data);
176 list_del(&item->mood_item_node);
177 free(item);
178 }
179
180 static void destroy_mood(struct mood *m)
181 {
182 struct mood_item *tmp, *item;
183
184 if (!m)
185 return;
186 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
187 cleanup_list_entry(item);
188 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
189 cleanup_list_entry(item);
190 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
191 cleanup_list_entry(item);
192 free(m->name);
193 free(m);
194 }
195
196 static struct mood *alloc_new_mood(const char *name)
197 {
198 struct mood *m = para_calloc(sizeof(struct mood));
199 m->name = para_strdup(name);
200 INIT_LIST_HEAD(&m->accept_list);
201 INIT_LIST_HEAD(&m->deny_list);
202 INIT_LIST_HEAD(&m->score_list);
203 return m;
204 }
205
206 /** The different types of a mood line. */
207 enum mood_line_type {
208 /** Invalid. */
209 ML_INVALID,
210 /** Accept line. */
211 ML_ACCEPT,
212 /** Deny line. */
213 ML_DENY,
214 /** Score line. */
215 ML_SCORE
216 };
217
218 /** Data passed to the parser of a mood line. */
219 struct mood_line_parser_data {
220 /** The mood this mood line belongs to. */
221 struct mood *m;
222 /** The line number in the mood definition. */
223 unsigned line_num;
224 };
225
226 /*
227 * <accept [with score <score>] | deny [with score <score>] | score <score>>
228 * [if] [not] <mood_method> [options]
229 * <score> is either an integer or "random" which assigns a random score to
230 * all matching files
231 */
232
233 static int parse_mood_line(char *mood_line, void *data)
234 {
235 struct mood_line_parser_data *mlpd = data;
236 char **argv;
237 unsigned num_words;
238 char **w;
239 int i, ret;
240 enum mood_line_type mlt = ML_INVALID;
241 struct mood_item *mi = NULL;
242
243 mlpd->line_num++;
244 ret = create_argv(mood_line, " \t", &argv);
245 if (ret < 0)
246 return ret;
247 num_words = ret;
248 if (!num_words) /* empty line */
249 goto out;
250 w = argv;
251 if (**w == '#') /* comment */
252 goto out;
253 if (!strcmp(*w, "accept"))
254 mlt = ML_ACCEPT;
255 else if (!strcmp(*w, "deny"))
256 mlt = ML_DENY;
257 else if (!strcmp(*w, "score"))
258 mlt = ML_SCORE;
259 ret = -E_MOOD_SYNTAX;
260 if (mlt == ML_INVALID)
261 goto out;
262 mi = para_calloc(sizeof(struct mood_item));
263 if (mlt != ML_SCORE) {
264 ret = -E_MOOD_SYNTAX;
265 w++;
266 if (!*w)
267 goto out;
268 if (strcmp(*w, "with"))
269 goto check_for_if;
270 w++;
271 if (!*w)
272 goto out;
273 if (strcmp(*w, "score"))
274 goto out;
275 }
276 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
277 ret = -E_MOOD_SYNTAX;
278 w++;
279 if (!*w)
280 goto out;
281 if (strcmp(*w, "random")) {
282 mi->random_score = 0;
283 ret = para_atoi32(*w, &mi->score_arg);
284 if (ret < 0)
285 goto out;
286 } else {
287 mi->random_score = 1;
288 if (!*(w + 1))
289 goto success; /* the line "score random" is valid */
290 }
291 } else
292 mi->score_arg = 0;
293 ret = -E_MOOD_SYNTAX;
294 w++;
295 if (!*w)
296 goto out;
297 check_for_if:
298 if (!strcmp(*w, "if")) {
299 ret = -E_MOOD_SYNTAX;
300 w++;
301 if (!*w)
302 goto out;
303 }
304 if (!strcmp(*w, "not")) {
305 ret = -E_MOOD_SYNTAX;
306 w++;
307 if (!*w)
308 goto out;
309 mi->logical_not = 1;
310 } else
311 mi->logical_not = 0;
312 for (i = 0; mood_methods[i].parser; i++) {
313 if (strcmp(*w, mood_methods[i].name))
314 continue;
315 break;
316 }
317 ret = -E_MOOD_SYNTAX;
318 if (!mood_methods[i].parser)
319 goto out;
320 ret = mood_methods[i].parser(num_words - 1 - (w - argv), w,
321 &mi->parser_data);
322 if (ret < 0)
323 goto out;
324 mi->method = &mood_methods[i];
325 success:
326 if (mlpd->m) {
327 if (mlt == ML_ACCEPT)
328 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
329 else if (mlt == ML_DENY)
330 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
331 else
332 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
333 }
334 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
335 (mlt == ML_DENY? "deny" : "score"), mi->method);
336 ret = 1;
337 out:
338 free_argv(argv);
339 if (ret >= 0)
340 return ret;
341 if (mi) {
342 free(mi->parser_data);
343 free(mi);
344 }
345 return ret;
346 }
347
348 static int load_mood(const struct osl_row *mood_row, struct mood **m)
349 {
350 char *mood_name;
351 struct osl_object mood_def;
352 struct mood_line_parser_data mlpd = {.line_num = 0};
353 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
354
355 if (ret < 0)
356 return ret;
357 if (!*mood_name)
358 return -E_DUMMY_ROW;
359 mlpd.m = alloc_new_mood(mood_name);
360 ret = for_each_line_ro(mood_def.data, mood_def.size,
361 parse_mood_line, &mlpd);
362 osl_close_disk_object(&mood_def);
363 if (ret < 0) {
364 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
365 para_strerror(-ret));
366 destroy_mood(mlpd.m);
367 return ret;
368 }
369 *m = mlpd.m;
370 return 1;
371 }
372
373 static int check_mood(struct osl_row *mood_row, void *data)
374 {
375 struct para_buffer *pb = data;
376 char *mood_name;
377 struct osl_object mood_def;
378 struct mood_line_parser_data mlpd = {.line_num = 0};
379
380 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
381
382 if (ret < 0) {
383 para_printf(pb, "failed to get mood definition: %s\n",
384 para_strerror(-ret));
385 return ret;
386 }
387 if (!*mood_name) /* ignore dummy row */
388 goto out;
389 ret = para_printf(pb, "checking mood %s...\n", mood_name);
390 if (ret < 0)
391 goto out;
392 ret = for_each_line_ro(mood_def.data, mood_def.size,
393 parse_mood_line, &mlpd);
394 if (ret < 0)
395 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
396 para_strerror(-ret));
397 out:
398 osl_close_disk_object(&mood_def);
399 return ret;
400 }
401
402 /**
403 * Check all moods for syntax errors.
404 *
405 * \param fd The afs socket.
406 * \param query Unused.
407 */
408 void mood_check_callback(int fd, __a_unused const struct osl_object *query)
409 {
410 struct para_buffer pb = {
411 .max_size = SHMMAX,
412 .private_data = &fd,
413 .max_size_handler = pass_buffer_as_shm
414 };
415
416 int ret = para_printf(&pb, "checking moods...\n");
417 if (ret < 0)
418 return;
419 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
420 check_mood);
421 if (pb.offset)
422 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
423 free(pb.buf);
424 }
425
426 #if 0
427 static unsigned int_log2(uint64_t x)
428 {
429 unsigned res = 0;
430
431 while (x) {
432 x /= 2;
433 res++;
434 }
435 return res;
436 }
437 #endif
438
439 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
440 {
441 if (!n || !qd)
442 return 0;
443 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
444 }
445
446 static long compute_num_played_score(struct afs_info *afsi)
447 {
448 return -normalized_value(afsi->num_played, statistics.num,
449 statistics.num_played_sum, statistics.num_played_qd);
450 }
451
452 static long compute_last_played_score(struct afs_info *afsi)
453 {
454 return -normalized_value(afsi->last_played, statistics.num,
455 statistics.last_played_sum, statistics.last_played_qd);
456 }
457
458 static long compute_dynamic_score(const struct osl_row *aft_row)
459 {
460 struct afs_info afsi;
461 int64_t score, nscore = 0, lscore = 0;
462 int ret;
463
464 ret = get_afsi_of_row(aft_row, &afsi);
465 if (ret < 0)
466 return -100;
467 nscore = compute_num_played_score(&afsi);
468 lscore = compute_last_played_score(&afsi);
469 score = nscore + lscore;
470 return score;
471 }
472
473 static int add_afs_statistics(const struct osl_row *row)
474 {
475 uint64_t n, x, s;
476 struct afs_info afsi;
477 int ret;
478
479 ret = get_afsi_of_row(row, &afsi);
480 if (ret < 0)
481 return ret;
482 n = statistics.num;
483 x = afsi.last_played;
484 s = statistics.last_played_sum;
485 if (n > 0)
486 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
487 statistics.last_played_sum += x;
488
489 x = afsi.num_played;
490 s = statistics.num_played_sum;
491 if (n > 0)
492 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
493 statistics.num_played_sum += x;
494 statistics.num++;
495 return 1;
496 }
497
498 static int del_afs_statistics(const struct osl_row *row)
499 {
500 uint64_t n, s, q, a, new_s;
501 struct afs_info afsi;
502 int ret;
503 ret = get_afsi_of_row(row, &afsi);
504 if (ret < 0)
505 return ret;
506 n = statistics.num;
507 assert(n);
508 if (n == 1) {
509 memset(&statistics, 0, sizeof(statistics));
510 return 1;
511 }
512
513 s = statistics.last_played_sum;
514 q = statistics.last_played_qd;
515 a = afsi.last_played;
516 new_s = s - a;
517 statistics.last_played_sum = new_s;
518 statistics.last_played_qd = q + s * s / n - a * a
519 - new_s * new_s / (n - 1);
520
521 s = statistics.num_played_sum;
522 q = statistics.num_played_qd;
523 a = afsi.num_played;
524 new_s = s - a;
525 statistics.num_played_sum = new_s;
526 statistics.num_played_qd = q + s * s / n - a * a
527 - new_s * new_s / (n - 1);
528
529 statistics.num--;
530 return 1;
531 }
532
533 /**
534 * Structure used during mood_open().
535 *
536 * At mood open time, we look at each file in the audio file table in order to
537 * determine whether it is admissible. If a file happens to be admissible, its
538 * mood score is computed by calling each relevant mood_score_function. Next,
539 * we update the afs_statistics and add a struct admissible_file_info to a
540 * temporary array.
541 *
542 * If all files have been processed that way, the final score of each
543 * admissible file is computed by adding the dynamic score (which depends on
544 * the afs_statistics) to the mood score. Finally, all audio files in the
545 * array are added to the score table and the admissible array is freed.
546 *
547 * \sa mood_method, admissible_array.
548 */
549 struct admissible_file_info
550 {
551 /** The admissible audio file. */
552 struct osl_row *aft_row;
553 /** Its score. */
554 long score;
555 };
556
557 /** The temporary array of admissible files. */
558 struct admissible_array {
559 /** Files are admissible wrt. this mood. */
560 struct mood *m;
561 /** The size of the array */
562 unsigned size;
563 /** Pointer to the array of admissible files. */
564 struct admissible_file_info *array;
565 };
566
567 /**
568 * Add an entry to the array of admissible files.
569 *
570 * \param aft_row The audio file to be added.
571 * \param private_data Pointer to a struct admissible_file_info.
572 *
573 * \return Negative on errors, positive on success.
574 */
575 static int add_if_admissible(struct osl_row *aft_row, void *data)
576 {
577 struct admissible_array *aa = data;
578 int ret;
579 long score = 0;
580
581 ret = compute_mood_score(aft_row, aa->m, &score);
582 if (ret < 0)
583 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
584 if (statistics.num >= aa->size) {
585 aa->size *= 2;
586 aa->size += 100;
587 aa->array = para_realloc(aa->array,
588 aa->size * sizeof(struct admissible_file_info));
589 }
590 aa->array[statistics.num].aft_row = aft_row;
591 aa->array[statistics.num].score = score;
592 ret = add_afs_statistics(aft_row);
593 if (ret < 0)
594 return ret;
595 return 1;
596 }
597
598 /**
599 * Compute the new quadratic deviation in case one element changes.
600 *
601 * \param n Number of elements.
602 * \param old_qd The quadratic deviation before the change.
603 * \param old_val The value that was replaced.
604 * \param new_val The replacement value.
605 * \param old_sum The sum of all elements before the update.
606 *
607 * \return The new quadratic deviation resulting from replacing old_val
608 * by new_val.
609 *
610 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
611 * their quadratic deviation
612 *
613 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
614 *
615 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
616 * the last number a_n was replaced by b) may be computed in O(1) time in terms
617 * of n, q, a_n, b, and S as
618 *
619 * q' = q + d * s - (2 * S + d) * d / n,
620 *
621 * where d = b - a_n, and s = b + a_n.
622 *
623 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
624 * s = 17, so
625 *
626 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
627 *
628 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
629 *
630 */
631 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
632 int64_t old_val, int64_t new_val, int64_t old_sum)
633 {
634 int64_t delta = new_val - old_val;
635 int64_t sigma = new_val + old_val;
636 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
637 }
638
639 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
640 {
641 unsigned n;
642 int ret = get_num_admissible_files(&n);
643
644 if (ret < 0)
645 return ret;
646 assert(n);
647
648 statistics.last_played_qd = update_quadratic_deviation(n,
649 statistics.last_played_qd, old_afsi->last_played,
650 new_afsi->last_played, statistics.last_played_sum);
651 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
652
653 statistics.num_played_qd = update_quadratic_deviation(n,
654 statistics.num_played_qd, old_afsi->num_played,
655 new_afsi->num_played, statistics.num_played_sum);
656 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
657 return 1;
658 }
659
660 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
661 {
662 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
663 return score_add(aft_row, score);
664 }
665
666 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
667 {
668 int ret = del_afs_statistics(aft_row);
669 if (ret < 0)
670 return ret;
671 return score_delete(aft_row);
672 }
673
674 /**
675 * Delete one entry from the statistics and from the score table.
676 *
677 * \param aft_row The audio file which is no longer admissible.
678 *
679 * \return Positive on success, negative on errors.
680 *
681 * \sa score_delete().
682 */
683 static int mood_delete_audio_file(const struct osl_row *aft_row)
684 {
685 int ret;
686
687 ret = row_belongs_to_score_table(aft_row, NULL);
688 if (ret < 0)
689 return ret;
690 if (!ret) /* not admissible, nothing to do */
691 return 1;
692 return delete_from_statistics_and_score_table(aft_row);
693 }
694
695 /**
696 * Compute the new score of an audio file wrt. the current mood.
697 *
698 * \param aft_row Determines the audio file.
699 * \param old_afsi The audio file selector info before updating.
700 *
701 * The \a old_afsi argument may be \p NULL which indicates that no changes to
702 * the audio file info were made.
703 *
704 * \return Positive on success, negative on errors.
705 */
706 static int mood_update_audio_file(const struct osl_row *aft_row,
707 struct afs_info *old_afsi)
708 {
709 long score, percent;
710 int ret, is_admissible, was_admissible = 0;
711 struct afs_info afsi;
712 unsigned rank;
713
714 if (!current_mood)
715 return 1; /* nothing to do */
716 ret = row_belongs_to_score_table(aft_row, &rank);
717 if (ret < 0)
718 return ret;
719 was_admissible = ret;
720 ret = compute_mood_score(aft_row, current_mood, &score);
721 is_admissible = (ret > 0);
722 if (!was_admissible && !is_admissible)
723 return 1;
724 if (was_admissible && !is_admissible)
725 return delete_from_statistics_and_score_table(aft_row);
726 if (!was_admissible && is_admissible) {
727 ret = add_afs_statistics(aft_row);
728 if (ret < 0)
729 return ret;
730 return add_to_score_table(aft_row, score);
731 }
732 /* update score */
733 ret = get_afsi_of_row(aft_row, &afsi);
734 if (ret < 0)
735 return ret;
736 if (old_afsi) {
737 ret = update_afs_statistics(old_afsi, &afsi);
738 if (ret < 0)
739 return ret;
740 }
741 score += compute_num_played_score(&afsi);
742 score += compute_last_played_score(&afsi);
743 score /= 3;
744 PARA_DEBUG_LOG("score: %li\n", score);
745 percent = (score + 100) / 3;
746 if (percent > 100)
747 percent = 100;
748 else if (percent < 0)
749 percent = 0;
750 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
751 return score_update(aft_row, percent);
752 }
753
754 static void log_statistics(void)
755 {
756 unsigned n = statistics.num;
757
758 if (!n) {
759 PARA_NOTICE_LOG("no admissible files\n");
760 return;
761 }
762 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
763 (long long int)(statistics.last_played_sum / n),
764 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
765 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
766 (long long int)statistics.num_played_sum / n,
767 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
768 }
769
770 /**
771 * Close the current mood.
772 *
773 * Free all resources of the current mood which were allocated during
774 * mood_open().
775 */
776 void close_current_mood(void)
777 {
778 destroy_mood(current_mood);
779 current_mood = NULL;
780 memset(&statistics, 0, sizeof(statistics));
781 }
782
783 /**
784 * Change the current mood.
785 *
786 * \param mood_name The name of the mood to open.
787 *
788 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
789 * and uses a scoring method based only on the \a last_played information.
790 *
791 * If there is already an open mood, it will be closed first.
792 *
793 * \return Positive on success, negative on errors. Loading the dummy mood
794 * always succeeds.
795 *
796 * \sa struct admissible_file_info, struct admissible_array, struct
797 * afs_info::last_played, mood_close().
798 */
799 int change_current_mood(char *mood_name)
800 {
801 int i, ret;
802 struct admissible_array aa = {
803 .size = 0,
804 .array = NULL
805 };
806
807 if (mood_name) {
808 struct mood *m;
809 struct osl_row *row;
810 struct osl_object obj = {
811 .data = mood_name,
812 .size = strlen(mood_name) + 1
813 };
814 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
815 if (ret < 0) {
816 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
817 return ret;
818 }
819 ret = load_mood(row, &m);
820 if (ret < 0)
821 return ret;
822 close_current_mood();
823 current_mood = m;
824 } else {
825 close_current_mood();
826 current_mood = alloc_new_mood("dummy");
827 }
828 aa.m = current_mood;
829 PARA_NOTICE_LOG("computing statistics of admissible files\n");
830 ret = audio_file_loop(&aa, add_if_admissible);
831 if (ret < 0)
832 return ret;
833 log_statistics();
834 PARA_INFO_LOG("%d admissible files \n", statistics.num);
835 for (i = 0; i < statistics.num; i++) {
836 struct admissible_file_info *a = aa.array + i;
837 ret = add_to_score_table(a->aft_row, a->score);
838 if (ret < 0)
839 goto out;
840 }
841 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
842 ret = statistics.num;
843 out:
844 free(aa.array);
845 return ret;
846 }
847 /**
848 * Close and re-open the current mood.
849 *
850 * This function is used if changes to the audio file table or the
851 * attribute table were made that render the current list of admissible
852 * files useless. For example, if an attribute is removed from the
853 * attribute table, this function is called.
854 *
855 * \return Positive on success, negative on errors. If no mood is currently
856 * open, the function returns success.
857 *
858 * \sa mood_open(), mood_close().
859 */
860 int reload_current_mood(void)
861 {
862 int ret;
863 char *mood_name = NULL;
864
865 if (!current_mood)
866 return 1;
867 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
868 current_mood->name : "(dummy)");
869 if (current_mood->name)
870 mood_name = para_strdup(current_mood->name);
871 close_current_mood();
872 ret = change_current_mood(mood_name);
873 free(mood_name);
874 return ret;
875 }
876
877 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
878 void *data)
879 {
880 switch(event) {
881 /*
882 * The three blob events might change the set of admissible files,
883 * so we must reload the score list.
884 */
885 case BLOB_RENAME:
886 case BLOB_REMOVE:
887 case BLOB_ADD:
888 if (data == moods_table || data == playlists_table)
889 return 1; /* no reload necessary for these */
890 return reload_current_mood();
891 /* these also require reload of the score table */
892 case ATTRIBUTE_ADD:
893 case ATTRIBUTE_REMOVE:
894 case ATTRIBUTE_RENAME:
895 return reload_current_mood();
896 /* changes to the aft only require to re-examine the audio file */
897 case AFSI_CHANGE: {
898 struct afsi_change_event_data *aced = data;
899 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
900 }
901 case AFHI_CHANGE:
902 case AUDIO_FILE_RENAME:
903 case AUDIO_FILE_ADD:
904 return mood_update_audio_file(data, NULL);
905 case AUDIO_FILE_REMOVE:
906 return mood_delete_audio_file(data);
907 default:
908 return 1;
909 }
910 }
911