afh_recv: Improve documentation of --begin-chunk.
[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, "cannot read mood\n");
414 return ret;
415 }
416 if (!*mood_name) /* ignore dummy row */
417 goto out;
418 para_printf(pb, "checking mood %s...\n", mood_name);
419 ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
420 parse_mood_line, &mlpd);
421 if (ret < 0)
422 para_printf(pb, "mood %s: error in line %u: %s\n", mood_name,
423 mlpd.line_num, para_strerror(-ret));
424 ret = 1; /* don't fail the loop on invalid mood definitions */
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 aca Only ->pbout is used for diagnostics.
434 *
435 * \return Negative on fatal errors. Inconsistent mood definitions are not
436 * considered an error.
437 */
438 int mood_check_callback(struct afs_callback_arg *aca)
439 {
440 para_printf(&aca->pbout, "checking moods...\n");
441 return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, &aca->pbout,
442 check_mood));
443 }
444
445 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
446 {
447 if (!n || !qd)
448 return 0;
449 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
450 }
451
452 static long compute_score(struct afs_info *afsi, long mood_score)
453 {
454 mood_score -= normalized_value(afsi->num_played, statistics.num,
455 statistics.num_played_sum, statistics.num_played_qd);
456 mood_score -= normalized_value(afsi->last_played, statistics.num,
457 statistics.last_played_sum, statistics.last_played_qd);
458 return mood_score / 3;
459 }
460
461 static int add_afs_statistics(const struct osl_row *row)
462 {
463 uint64_t n, x, s;
464 struct afs_info afsi;
465 int ret;
466
467 ret = get_afsi_of_row(row, &afsi);
468 if (ret < 0)
469 return ret;
470 n = statistics.num;
471 x = afsi.last_played;
472 s = statistics.last_played_sum;
473 if (n > 0)
474 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
475 statistics.last_played_sum += x;
476
477 x = afsi.num_played;
478 s = statistics.num_played_sum;
479 if (n > 0)
480 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
481 statistics.num_played_sum += x;
482 statistics.num++;
483 return 1;
484 }
485
486 static int del_afs_statistics(const struct osl_row *row)
487 {
488 uint64_t n, s, q, a, new_s;
489 struct afs_info afsi;
490 int ret;
491 ret = get_afsi_of_row(row, &afsi);
492 if (ret < 0)
493 return ret;
494 n = statistics.num;
495 assert(n);
496 if (n == 1) {
497 memset(&statistics, 0, sizeof(statistics));
498 return 1;
499 }
500
501 s = statistics.last_played_sum;
502 q = statistics.last_played_qd;
503 a = afsi.last_played;
504 new_s = s - a;
505 statistics.last_played_sum = new_s;
506 statistics.last_played_qd = q + s * s / n - a * a
507 - new_s * new_s / (n - 1);
508
509 s = statistics.num_played_sum;
510 q = statistics.num_played_qd;
511 a = afsi.num_played;
512 new_s = s - a;
513 statistics.num_played_sum = new_s;
514 statistics.num_played_qd = q + s * s / n - a * a
515 - new_s * new_s / (n - 1);
516
517 statistics.num--;
518 return 1;
519 }
520
521 /**
522 * Structure used during mood_open().
523 *
524 * At mood open time we determine the set of admissible files for the given
525 * mood. The mood score of each admissible file is computed by adding up all
526 * mood item scores. Next, we update the afs statistics and append a struct
527 * admissible_file_info to a temporary array.
528 *
529 * When all files have been processed in this way, the final score of each
530 * admissible file is computed by adding the dynamic score (which depends on
531 * the afs_statistics and the current time) to the mood score. Finally, all
532 * audio files in the temporary array are added to the score table and the
533 * array is freed.
534 *
535 * \sa mood_method, admissible_array.
536 */
537 struct admissible_file_info
538 {
539 /** The admissible audio file. */
540 struct osl_row *aft_row;
541 /** Its score. */
542 long score;
543 };
544
545 /** The temporary array of admissible files. */
546 struct admissible_array {
547 /** Files are admissible wrt. this mood. */
548 struct mood *m;
549 /** The size of the array */
550 unsigned size;
551 /** Pointer to the array of admissible files. */
552 struct admissible_file_info *array;
553 };
554
555 /**
556 * Add an entry to the array of admissible files.
557 *
558 * \param aft_row The audio file to be added.
559 * \param private_data Pointer to a struct admissible_file_info.
560 *
561 * \return 1 if row admissible, 0 if not, negative on errors.
562 */
563 static int add_if_admissible(struct osl_row *aft_row, void *data)
564 {
565 struct admissible_array *aa = data;
566 int ret;
567 long score = 0;
568
569 ret = compute_mood_score(aft_row, aa->m, &score);
570 if (ret <= 0)
571 return ret;
572 if (statistics.num >= aa->size) {
573 aa->size *= 2;
574 aa->size += 100;
575 aa->array = para_realloc(aa->array,
576 aa->size * sizeof(struct admissible_file_info));
577 }
578 aa->array[statistics.num].aft_row = aft_row;
579 aa->array[statistics.num].score = score;
580 ret = add_afs_statistics(aft_row);
581 if (ret < 0)
582 return ret;
583 return 1;
584 }
585
586 /**
587 * Compute the new quadratic deviation in case one element changes.
588 *
589 * \param n Number of elements.
590 * \param old_qd The quadratic deviation before the change.
591 * \param old_val The value that was replaced.
592 * \param new_val The replacement value.
593 * \param old_sum The sum of all elements before the update.
594 *
595 * \return The new quadratic deviation resulting from replacing old_val
596 * by new_val.
597 *
598 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
599 * their quadratic deviation
600 *
601 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
602 *
603 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
604 * the last number a_n was replaced by b) may be computed in O(1) time in terms
605 * of n, q, a_n, b, and S as
606 *
607 * q' = q + d * s - (2 * S + d) * d / n,
608 *
609 * where d = b - a_n, and s = b + a_n.
610 *
611 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
612 * s = 17, so
613 *
614 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
615 *
616 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
617 *
618 */
619 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
620 int64_t old_val, int64_t new_val, int64_t old_sum)
621 {
622 int64_t delta = new_val - old_val;
623 int64_t sigma = new_val + old_val;
624 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
625 }
626
627 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
628 {
629 unsigned n;
630 int ret = get_num_admissible_files(&n);
631
632 if (ret < 0)
633 return ret;
634 assert(n);
635
636 statistics.last_played_qd = update_quadratic_deviation(n,
637 statistics.last_played_qd, old_afsi->last_played,
638 new_afsi->last_played, statistics.last_played_sum);
639 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
640
641 statistics.num_played_qd = update_quadratic_deviation(n,
642 statistics.num_played_qd, old_afsi->num_played,
643 new_afsi->num_played, statistics.num_played_sum);
644 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
645 return 1;
646 }
647
648 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
649 {
650 long score;
651 struct afs_info afsi;
652 int ret = get_afsi_of_row(aft_row, &afsi);
653
654 if (ret < 0)
655 return ret;
656 score = compute_score(&afsi, mood_score);
657 return score_add(aft_row, score);
658 }
659
660 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
661 {
662 int ret = del_afs_statistics(aft_row);
663 if (ret < 0)
664 return ret;
665 return score_delete(aft_row);
666 }
667
668 /**
669 * Delete one entry from the statistics and from the score table.
670 *
671 * \param aft_row The audio file which is no longer admissible.
672 *
673 * \return Positive on success, negative on errors.
674 *
675 * \sa score_delete().
676 */
677 static int mood_delete_audio_file(const struct osl_row *aft_row)
678 {
679 int ret;
680
681 ret = row_belongs_to_score_table(aft_row, NULL);
682 if (ret < 0)
683 return ret;
684 if (!ret) /* not admissible, nothing to do */
685 return 1;
686 return delete_from_statistics_and_score_table(aft_row);
687 }
688
689 /**
690 * Compute the new score of an audio file wrt. the current mood.
691 *
692 * \param aft_row Determines the audio file.
693 * \param old_afsi The audio file selector info before updating.
694 *
695 * The \a old_afsi argument may be \p NULL which indicates that no changes to
696 * the audio file info were made.
697 *
698 * \return Positive on success, negative on errors.
699 */
700 static int mood_update_audio_file(const struct osl_row *aft_row,
701 struct afs_info *old_afsi)
702 {
703 long score, percent;
704 int ret, is_admissible, was_admissible = 0;
705 struct afs_info afsi;
706 unsigned rank;
707
708 if (!current_mood)
709 return 1; /* nothing to do */
710 ret = row_belongs_to_score_table(aft_row, &rank);
711 if (ret < 0)
712 return ret;
713 was_admissible = ret;
714 ret = compute_mood_score(aft_row, current_mood, &score);
715 if (ret < 0)
716 return ret;
717 is_admissible = (ret > 0);
718 if (!was_admissible && !is_admissible)
719 return 1;
720 if (was_admissible && !is_admissible)
721 return delete_from_statistics_and_score_table(aft_row);
722 if (!was_admissible && is_admissible) {
723 ret = add_afs_statistics(aft_row);
724 if (ret < 0)
725 return ret;
726 return add_to_score_table(aft_row, score);
727 }
728 /* update score */
729 ret = get_afsi_of_row(aft_row, &afsi);
730 if (ret < 0)
731 return ret;
732 if (old_afsi) {
733 ret = update_afs_statistics(old_afsi, &afsi);
734 if (ret < 0)
735 return ret;
736 }
737 score = compute_score(&afsi, score);
738 PARA_DEBUG_LOG("score: %li\n", score);
739 percent = (score + 100) / 3;
740 if (percent > 100)
741 percent = 100;
742 else if (percent < 0)
743 percent = 0;
744 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
745 return score_update(aft_row, percent);
746 }
747
748 static void log_statistics(void)
749 {
750 unsigned n = statistics.num;
751
752 if (!n) {
753 PARA_NOTICE_LOG("no admissible files\n");
754 return;
755 }
756 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
757 (long long int)(statistics.last_played_sum / n),
758 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
759 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
760 (long long int)statistics.num_played_sum / n,
761 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
762 }
763
764 /**
765 * Close the current mood.
766 *
767 * Free all resources of the current mood which were allocated during
768 * mood_open().
769 */
770 void close_current_mood(void)
771 {
772 destroy_mood(current_mood);
773 current_mood = NULL;
774 memset(&statistics, 0, sizeof(statistics));
775 }
776
777 /**
778 * Change the current mood.
779 *
780 * \param mood_name The name of the mood to open.
781 *
782 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
783 * and uses a scoring method based only on the \a last_played information.
784 *
785 * If there is already an open mood, it will be closed first.
786 *
787 * \return Positive on success, negative on errors. Loading the dummy mood
788 * always succeeds.
789 *
790 * \sa struct admissible_file_info, struct admissible_array, struct
791 * afs_info::last_played, mood_close().
792 */
793 int change_current_mood(char *mood_name)
794 {
795 int i, ret;
796 struct admissible_array aa = {
797 .size = 0,
798 .array = NULL
799 };
800
801 if (mood_name) {
802 struct mood *m;
803 struct osl_row *row;
804 struct osl_object obj = {
805 .data = mood_name,
806 .size = strlen(mood_name) + 1
807 };
808 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
809 if (ret < 0) {
810 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
811 return ret;
812 }
813 ret = load_mood(row, &m);
814 if (ret < 0)
815 return ret;
816 close_current_mood();
817 current_mood = m;
818 } else { /* load dummy mood */
819 close_current_mood();
820 current_mood = alloc_new_mood(NULL);
821 }
822 aa.m = current_mood;
823 PARA_NOTICE_LOG("computing statistics of admissible files\n");
824 ret = audio_file_loop(&aa, add_if_admissible);
825 if (ret < 0)
826 return ret;
827 log_statistics();
828 PARA_INFO_LOG("%d admissible files\n", statistics.num);
829 for (i = 0; i < statistics.num; i++) {
830 struct admissible_file_info *a = aa.array + i;
831 ret = add_to_score_table(a->aft_row, a->score);
832 if (ret < 0)
833 goto out;
834 }
835 PARA_NOTICE_LOG("loaded mood %s\n", mood_name? mood_name : "(dummy)");
836 ret = statistics.num;
837 out:
838 free(aa.array);
839 return ret;
840 }
841 /**
842 * Close and re-open the current mood.
843 *
844 * This function is used if changes to the audio file table or the
845 * attribute table were made that render the current list of admissible
846 * files useless. For example, if an attribute is removed from the
847 * attribute table, this function is called.
848 *
849 * \return Positive on success, negative on errors. If no mood is currently
850 * open, the function returns success.
851 *
852 * \sa mood_open(), mood_close().
853 */
854 static int reload_current_mood(void)
855 {
856 int ret;
857 char *mood_name = NULL;
858
859 ret = clear_score_table();
860 if (ret < 0)
861 return ret;
862 if (!current_mood)
863 return 1;
864 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
865 current_mood->name : "(dummy)");
866 if (current_mood->name)
867 mood_name = para_strdup(current_mood->name);
868 close_current_mood();
869 ret = change_current_mood(mood_name);
870 free(mood_name);
871 return ret;
872 }
873
874 /**
875 * Notification callback for the moods table.
876 *
877 * \param event Type of the event just occurred.
878 * \param pb Unused.
879 * \param data Its type depends on the event.
880 *
881 * This function performs actions required due to the occurrence of the given
882 * event. Possible actions include reload of the current mood and update of the
883 * score of an audio file.
884 *
885 * \return Standard.
886 */
887 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
888 void *data)
889 {
890 if (!current_mood)
891 return 0;
892 switch (event) {
893 /*
894 * The three blob events might change the set of admissible files,
895 * so we must reload the score list.
896 */
897 case BLOB_RENAME:
898 case BLOB_REMOVE:
899 case BLOB_ADD:
900 if (data == moods_table || data == playlists_table)
901 return 1; /* no reload necessary for these */
902 return reload_current_mood();
903 /* these also require reload of the score table */
904 case ATTRIBUTE_ADD:
905 case ATTRIBUTE_REMOVE:
906 case ATTRIBUTE_RENAME:
907 return reload_current_mood();
908 /* changes to the aft only require to re-examine the audio file */
909 case AFSI_CHANGE: {
910 struct afsi_change_event_data *aced = data;
911 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
912 }
913 case AFHI_CHANGE:
914 case AUDIO_FILE_RENAME:
915 case AUDIO_FILE_ADD:
916 return mood_update_audio_file(data, NULL);
917 case AUDIO_FILE_REMOVE:
918 return mood_delete_audio_file(data);
919 default:
920 return 1;
921 }
922 }