com_check(): Implement mood checking.
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007 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 "para.h"
10 #include "error.h"
11 #include "afh.h"
12 #include "afs.h"
13 #include "list.h"
14 #include "string.h"
15
16 /**
17 * Contains statistical data of the currently admissible audio files.
18 *
19 * It is used to assign normalized score values to each admissbile audio file.
20 */
21 struct afs_statistics {
22 /** sum of num played over all admissible files */
23 int64_t num_played_sum;
24 /** sum of last played times over all admissible files */
25 int64_t last_played_sum;
26 /** quadratic deviation of num played time */
27 int64_t num_played_qd;
28 /** quadratic deviation of last played time */
29 int64_t last_played_qd;
30 /** number of admissible files */
31 unsigned num;
32 };
33 struct afs_statistics statistics;
34
35 /**
36 * Assign scores according to a mood_method.
37 *
38 * Each mood_method has its own mood_score_function. The first parameter passed
39 * to that function is a pointer to a row of the audio file table. It
40 * determines the audio file for which a score is to be assigned. The second
41 * argument depends on the mood method this function is used for. It usually is
42 * the argument given at the end of a mood line.
43 *
44 * Mood score functions must return values between -100 and +100 inclisively.
45 * Boolean score functions should always return either -100 or +100.
46 *
47 * \sa struct mood_method, mood_parser.
48 */
49 typedef int mood_score_function(const struct osl_row*, void *);
50
51 /**
52 * Preprocess a mood line.
53 *
54 * The mood_parser of a mood_method is called once at mood open time for each
55 * line of the current mood definition that contains the mood_method's name as
56 * a keyword. The line is passed to the mood_parser as the first argument. The
57 * mood_parser must determine whether the line is syntactically correct and
58 * return a positive value if so and a negative value otherwise.
59 *
60 * Some mood parsers preprocess the data given in the mood line to compute a
61 * structure which depends of the particular mood_method and which is used
62 * later in the mood_score_function of the mood_method. The mood_parser may
63 * store a pointer to its structure via the second argument.
64 *
65 * \sa mood_open(), mood_cleanup_function, mood_score_function.
66 */
67 typedef int mood_parser(const char *, void **);
68
69 /**
70 * Deallocate resources which were allocated by the mood_parser.
71 *
72 * This optional function of a mood_method is used to free any resources
73 * allocated in mood_open() by the mood_parser. The argument passed is a
74 * pointer to the mood_method specific data structure that was returned by the
75 * mood_parser.
76 *
77 * \sa mood_parser.
78 */
79 typedef void mood_cleanup_function(void *);
80
81 /**
82 * Used for scoring and to determine whether a file is admissible.
83 */
84 struct mood_method {
85 /* The name of the method. */
86 const char *name;
87 /** Pointer to the mood parser. */
88 mood_parser *parser;
89 /** Pointer to the score function */
90 mood_score_function *score_function;
91 /** Optional cleanup function. */
92 mood_cleanup_function *cleanup;
93 };
94
95 /**
96 * Each line of the current mood corresponds to a mood_item.
97 */
98 struct mood_item {
99 /** The method this line is referring to. */
100 const struct mood_method *method;
101 /** The data structure computed by the mood parser. */
102 void *parser_data;
103 /** The given score value, or zero if none was given. */
104 long score_arg;
105 /** Non-zero if random scoring was requested. */
106 int random_score;
107 /** Whether the "not" keyword was given in the mood line. */
108 int logical_not;
109 /** The position in the list of items. */
110 struct list_head mood_item_node;
111 };
112
113 /**
114 * Created from the mood definition by mood_open().
115 *
116 * When a mood is opened, each line of its definition is investigated, and a
117 * corresponding mood item is produced. Each mood line starts with \p accept,
118 * \p deny, or \p score which determins the type of the mood line. For each
119 * such type a linked list is maintained whose entries are the mood items.
120 *
121 * \sa mood_item, mood_open().
122 */
123 struct mood {
124 /** The name of this mood. */
125 char *name;
126 /** The list of mood items of type \p accept. */
127 struct list_head accept_list;
128 /** The list of mood items of type \p deny. */
129 struct list_head deny_list;
130 /** The list of mood items of type \p score. */
131 struct list_head score_list;
132 };
133
134 static struct mood *current_mood;
135
136 /**
137 * Rough approximation to sqrt.
138 *
139 * \param x Integer of which to calculate the sqrt.
140 *
141 * \return An integer res with res * res <= x.
142 */
143 static uint64_t int_sqrt(uint64_t x)
144 {
145 uint64_t op, res, one = 1;
146 op = x;
147 res = 0;
148
149 one = one << 62;
150 while (one > op)
151 one >>= 2;
152
153 while (one != 0) {
154 if (op >= res + one) {
155 op = op - (res + one);
156 res = res + 2 * one;
157 }
158 res /= 2;
159 one /= 4;
160 }
161 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
162 return res;
163 }
164
165 static int mm_played_rarely_score_function(const struct osl_row *row,
166 __a_unused void *ignored)
167 {
168 struct afs_info afsi;
169 unsigned num;
170 int ret = get_afsi_of_row(row, &afsi);
171
172 if (ret < 0)
173 return 0;
174 ret = get_num_admissible_files(&num);
175 if (ret < 0)
176 return 0;
177 if (statistics.num_played_sum - num * afsi.num_played
178 > int_sqrt(statistics.num_played_qd * num))
179 return 100;
180 return -100;
181 }
182
183 static int mm_played_rarely_parser(const char *arg, __a_unused void **ignored)
184 {
185 if (*arg)
186 PARA_WARNING_LOG("ignored junk at eol: %s\n", arg);
187 return 1;
188 }
189
190 static int mm_name_like_score_function(const struct osl_row *row, void *preg)
191 {
192 char *path;
193 int ret = get_audio_file_path_of_row(row, &path);
194
195 if (ret < 0)
196 return 0;
197 ret = regexec((regex_t *)preg, path, 42, NULL, 0);
198 return (ret == REG_NOMATCH)? -100 : 100;
199 }
200
201 static int mm_name_like_parser(const char *arg, void **regex)
202 {
203 regex_t *preg = para_malloc(sizeof(*preg));
204 int ret = regcomp(preg, arg, REG_NOSUB);
205
206 if (ret) {
207 free(preg);
208 return -E_MOOD_REGEX;
209 }
210 *regex = preg;
211 return 1;
212 }
213
214 static void mm_name_like_cleanup(void *preg)
215 {
216 regfree(preg);
217 free(preg);
218 }
219
220 static int mm_is_set_parser(const char *arg, void **bitnum)
221 {
222 unsigned char *c = para_malloc(1);
223 int ret = get_attribute_bitnum_by_name(arg, c);
224
225 if (ret >= 0)
226 *bitnum = c;
227 else
228 free(c);
229 return ret;
230 }
231
232 static int mm_is_set_score_function(const struct osl_row *row, void *bitnum)
233 {
234 unsigned char *bn = bitnum;
235 struct afs_info afsi;
236 int ret = get_afsi_of_row(row, &afsi);
237
238 if (ret < 0)
239 return 0;
240 if (afsi.attributes & (1ULL << *bn))
241 return 100;
242 return -100;
243 }
244
245 /* returns 1 if row matches score item, -1 otherwise */
246 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
247 long *score_arg_sum)
248 {
249 int ret = 100;
250
251 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
252 if (item->method) {
253 ret = item->method->score_function(row, item->parser_data);
254 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
255 return -1; /* no match */
256 }
257 if (item->random_score)
258 *score += PARA_ABS(ret) * para_random(100);
259 else
260 *score += PARA_ABS(ret) * item->score_arg;
261 return 1;
262 }
263
264 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
265 long *result)
266 {
267 struct mood_item *item;
268 int match = 0;
269 long score_arg_sum = 0, score = 0;
270
271 if (!m)
272 return -E_NO_MOOD;
273 /* reject audio file if it matches any entry in the deny list */
274 list_for_each_entry(item, &m->deny_list, mood_item_node)
275 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
276 return -E_NOT_ADMISSIBLE;
277 list_for_each_entry(item, &m->accept_list, mood_item_node)
278 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
279 match = 1;
280 /* reject if there is no matching entry in the accept list */
281 if (!match && !list_empty(&m->accept_list))
282 return -E_NOT_ADMISSIBLE;
283 list_for_each_entry(item, &m->score_list, mood_item_node)
284 add_item_score(aft_row, item, &score, &score_arg_sum);
285 if (score_arg_sum)
286 score /= score_arg_sum;
287 *result = score;
288 return 1;
289 }
290
291 static const struct mood_method mood_methods[] = {
292 {
293 .parser = mm_played_rarely_parser,
294 .score_function = mm_played_rarely_score_function,
295 .name = "played_rarely"
296 },
297 {
298 .parser = mm_is_set_parser,
299 .score_function = mm_is_set_score_function,
300 .name = "is_set"
301 },
302 {
303 .parser = mm_name_like_parser,
304 .score_function = mm_name_like_score_function,
305 .cleanup = mm_name_like_cleanup,
306 .name = "name_like"
307 },
308 {
309 .parser = NULL
310 }
311 };
312
313 static void cleanup_list_entry(struct mood_item *item)
314 {
315 if (item->method && item->method->cleanup)
316 item->method->cleanup(item->parser_data);
317 else
318 free(item->parser_data);
319 list_del(&item->mood_item_node);
320 free(item);
321 }
322
323 static void destroy_mood(struct mood *m)
324 {
325 struct mood_item *tmp, *item;
326
327 if (!m)
328 return;
329 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
330 cleanup_list_entry(item);
331 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
332 cleanup_list_entry(item);
333 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
334 cleanup_list_entry(item);
335 free(m->name);
336 free(m);
337 }
338
339 static struct mood *alloc_new_mood(const char *name)
340 {
341 struct mood *m = para_calloc(sizeof(struct mood));
342 m->name = para_strdup(name);
343 INIT_LIST_HEAD(&m->accept_list);
344 INIT_LIST_HEAD(&m->deny_list);
345 INIT_LIST_HEAD(&m->score_list);
346 return m;
347 }
348
349 /** The different types of a mood line. */
350 enum mood_line_type {
351 /** Invalid. */
352 ML_INVALID,
353 /** Accept line. */
354 ML_ACCEPT,
355 /** Deny line. */
356 ML_DENY,
357 /** Score line. */
358 ML_SCORE
359 };
360
361 struct mood_line_parser_data {
362 struct mood *m;
363 unsigned line_num;
364 };
365
366 /*
367 * <accept [with score <score>] | deny [with score <score>] | score <score>>
368 * [if] [not] <mood_method> [options]
369 * <score> is either an integer or "random" which assigns a random score to
370 * all matching files
371 */
372
373 static int parse_mood_line(char *mood_line, void *data)
374 {
375 struct mood_line_parser_data *mlpd = data;
376 char **argv;
377 char *delim = " \t";
378 unsigned num_words;
379 char **w;
380 int i, ret;
381 enum mood_line_type mlt = ML_INVALID;
382 struct mood_item *mi = NULL;
383 char *buf = para_strdup(mood_line);
384
385 mlpd->line_num++;
386 num_words = split_args(buf, &argv, delim);
387 ret = 1;
388 if (!num_words) /* empty line */
389 goto out;
390 w = argv;
391 if (**w == '#') /* comment */
392 goto out;
393 if (!strcmp(*w, "accept"))
394 mlt = ML_ACCEPT;
395 else if (!strcmp(*w, "deny"))
396 mlt = ML_DENY;
397 else if (!strcmp(*w, "score"))
398 mlt = ML_SCORE;
399 ret = -E_MOOD_SYNTAX;
400 if (mlt == ML_INVALID)
401 goto out;
402 mi = para_calloc(sizeof(struct mood_item));
403 if (mlt != ML_SCORE) {
404 ret = -E_MOOD_SYNTAX;
405 w++;
406 if (!*w)
407 goto out;
408 if (!strcmp(*w, "with")) {
409 w++;
410 if (!*w)
411 goto out;
412 }
413 }
414 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
415 ret = -E_MOOD_SYNTAX;
416 w++;
417 if (!*w)
418 goto out;
419 if (strcmp(*w, "random")) {
420 mi->random_score = 0;
421 ret = para_atol(*w, &mi->score_arg);
422 if (ret < 0)
423 goto out;
424 } else {
425 mi->random_score = 1;
426 if (!*(w + 1))
427 goto success; /* the line "score random" is valid */
428 }
429 } else
430 mi->score_arg = 0;
431 ret = -E_MOOD_SYNTAX;
432 w++;
433 if (!*w)
434 goto out;
435 if (!strcmp(*w, "if")) {
436 ret = -E_MOOD_SYNTAX;
437 w++;
438 if (!*w)
439 goto out;
440 }
441 if (!strcmp(*w, "not")) {
442 ret = -E_MOOD_SYNTAX;
443 w++;
444 if (!*w)
445 goto out;
446 mi->logical_not = 1;
447 } else
448 mi->logical_not = 0;
449 for (i = 0; mood_methods[i].parser; i++) {
450 if (strcmp(*w, mood_methods[i].name))
451 continue;
452 break;
453 }
454 ret = -E_MOOD_SYNTAX;
455 if (!mood_methods[i].parser)
456 goto out;
457 w++;
458 ret = mood_methods[i].parser(*w, &mi->parser_data);
459 if (ret < 0)
460 goto out;
461 mi->method = &mood_methods[i];
462 success:
463 if (mlpd->m) {
464 if (mlt == ML_ACCEPT)
465 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
466 else if (mlt == ML_DENY)
467 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
468 else
469 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
470 }
471 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
472 (mlt == ML_DENY? "deny" : "score"), mi->method);
473 ret = 1;
474 out:
475 free(argv);
476 free(buf);
477 if (ret >= 0)
478 return ret;
479 if (mi) {
480 free(mi->parser_data);
481 free(mi);
482 }
483 return ret;
484 }
485
486 static int load_mood(const struct osl_row *mood_row, struct mood **m)
487 {
488 char *mood_name;
489 struct osl_object mood_def;
490 struct mood_line_parser_data mlpd = {.line_num = 0};
491 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
492
493 if (ret < 0)
494 return ret;
495 if (!*mood_name)
496 return -E_DUMMY_ROW;
497 mlpd.m = alloc_new_mood(mood_name);
498 ret = for_each_line_ro(mood_def.data, mood_def.size,
499 parse_mood_line, &mlpd);
500 osl_close_disk_object(&mood_def);
501 if (ret < 0) {
502 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
503 PARA_STRERROR(-ret));
504 destroy_mood(mlpd.m);
505 return ret;
506 }
507 PARA_INFO_LOG("loaded mood %s\n", mlpd.m->name);
508 *m = mlpd.m;
509 return 1;
510 }
511
512 /*
513 * Calls load_mood() and reverts its error value: It returns -E_MOOD_LOADED
514 * on _success_, and 1 on errors. This way the loop over all moods stops at the
515 * first valid mood.
516 */
517 static int load_mood_loop_func(struct osl_row *mood_row, void *data)
518 {
519 struct mood **m = data;
520 int ret = load_mood(mood_row, m);
521 if (ret < 0) {
522 if (ret != -E_DUMMY_ROW)
523 PARA_NOTICE_LOG("invalid mood (%d), trying next mood\n", ret);
524 return 1;
525 }
526 return -E_MOOD_LOADED;
527 }
528
529 static int load_first_available_mood(struct mood **m)
530 {
531 int ret = osl_rbtree_loop(moods_table, BLOBCOL_NAME, m,
532 load_mood_loop_func);
533 if (ret == -E_MOOD_LOADED) /* success */
534 return 1;
535 if (ret < 0)
536 return ret; /* error */
537 PARA_NOTICE_LOG("no valid mood found\n");
538 return -E_NO_MOOD;
539 }
540
541 static int check_mood(struct osl_row *mood_row, void *data)
542 {
543 struct para_buffer *pb = data;
544 char *mood_name;
545 struct osl_object mood_def;
546 struct mood_line_parser_data mlpd = {.line_num = 0};
547
548 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
549
550 if (ret < 0) {
551 para_printf(pb, "failed to get mood definition\n");
552 return ret;
553 }
554 if (!*mood_name) /* ignore dummy row */
555 goto out;
556 para_printf(pb, "checking mood %s...\n", mood_name);
557 ret = for_each_line_ro(mood_def.data, mood_def.size,
558 parse_mood_line, &mlpd);
559 if (ret < 0)
560 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
561 PARA_STRERROR(-ret));
562 out:
563 osl_close_disk_object(&mood_def);
564 return 1;
565 }
566
567 /**
568 * Check all moods for syntax errors.
569 *
570 * \param query Unused.
571 * \param result: Contains check messages.
572 */
573 int mood_check_callback(__a_unused const struct osl_object *query,
574 struct osl_object *result)
575 {
576 struct para_buffer pb = {.buf = NULL};
577
578 para_printf(&pb, "checking moods...\n");
579 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
580 check_mood);
581 result->data = pb.buf;
582 result->size = pb.size;
583 return 1;
584 }
585
586 #if 0
587 static unsigned int_log2(uint64_t x)
588 {
589 unsigned res = 0;
590
591 while (x) {
592 x /= 2;
593 res++;
594 }
595 return res;
596 }
597 #endif
598
599 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
600 {
601 if (!n || !qd)
602 return 0;
603 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
604 }
605
606 static long compute_num_played_score(struct afs_info *afsi)
607 {
608 return -normalized_value(afsi->num_played, statistics.num,
609 statistics.num_played_sum, statistics.num_played_qd);
610 }
611
612 static long compute_last_played_score(struct afs_info *afsi)
613 {
614 return -normalized_value(afsi->last_played, statistics.num,
615 statistics.last_played_sum, statistics.last_played_qd);
616 }
617
618 static long compute_dynamic_score(const struct osl_row *aft_row)
619 {
620 struct afs_info afsi;
621 int64_t score, nscore = 0, lscore = 0;
622 int ret;
623
624 ret = get_afsi_of_row(aft_row, &afsi);
625 if (ret < 0)
626 return -100;
627 nscore = compute_num_played_score(&afsi);
628 lscore = compute_last_played_score(&afsi);
629 score = nscore + lscore;
630 return score;
631 }
632
633 static int add_afs_statistics(const struct osl_row *row)
634 {
635 uint64_t n, x, s;
636 struct afs_info afsi;
637 int ret;
638
639 ret = get_afsi_of_row(row, &afsi);
640 if (ret < 0)
641 return ret;
642 n = statistics.num;
643 x = afsi.last_played;
644 s = statistics.last_played_sum;
645 if (n > 0)
646 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
647 statistics.last_played_sum += x;
648
649 x = afsi.num_played;
650 s = statistics.num_played_sum;
651 if (n > 0)
652 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
653 statistics.num_played_sum += x;
654 statistics.num++;
655 return 1;
656 }
657
658 static int del_afs_statistics(const struct osl_row *row)
659 {
660 uint64_t n, s, q, a, new_s;
661 struct afs_info afsi;
662 int ret;
663 ret = get_afsi_of_row(row, &afsi);
664 if (ret < 0)
665 return ret;
666 n = statistics.num;
667 assert(n);
668 if (n == 1) {
669 memset(&statistics, 0, sizeof(statistics));
670 return 1;
671 }
672
673 s = statistics.last_played_sum;
674 q = statistics.last_played_qd;
675 a = afsi.last_played;
676 new_s = s - a;
677 statistics.last_played_sum = new_s;
678 statistics.last_played_qd = q + s * s / n - a * a
679 - new_s * new_s / (n - 1);
680
681 s = statistics.num_played_sum;
682 q = statistics.num_played_qd;
683 a = afsi.num_played;
684 new_s = s - a;
685 statistics.num_played_sum = new_s;
686 statistics.num_played_qd = q + s * s / n - a * a
687 - new_s * new_s / (n - 1);
688
689 statistics.num--;
690 return 1;
691 }
692
693 /**
694 * Structure used during mood_open().
695 *
696 * At mood open time, we look at each file in the audio file table in order to
697 * determine whether it is admissible. If a file happens to be admissible, its
698 * mood score is computed by calling each relevant mood_score_function. Next,
699 * we update the afs_statistics and add a struct admissible_file_info to a
700 * temporary array.
701 *
702 * If all files have been processed that way, the final score of each
703 * admissible file is computed by adding the dynamic score (which depends on
704 * the afs_statistics) to the mood score. Finally, all audio files in the
705 * array are added to the score table and the admissible array is freed.
706 *
707 * \sa mood_method, admissible_array.
708 */
709 struct admissible_file_info
710 {
711 /** The admissible audio file. */
712 struct osl_row *aft_row;
713 /** Its score. */
714 long score;
715 };
716
717 /** The temporary array of admissible files. */
718 struct admissible_array {
719 /** Files are admissible wrt. this mood. */
720 struct mood *m;
721 /** The size of the array */
722 unsigned size;
723 /** Pointer to the array of admissible files. */
724 struct admissible_file_info *array;
725 };
726
727 /**
728 * Add an entry to the array of admissible files.
729 *
730 * \param aft_row The audio file to be added.
731 * \param private_data Pointer to a struct admissible_file_info.
732 *
733 * \return Negative on errors, positive on success.
734 */
735 static int add_if_admissible(struct osl_row *aft_row, void *data)
736 {
737 struct admissible_array *aa = data;
738 int ret;
739 long score = 0;
740
741 ret = compute_mood_score(aft_row, aa->m, &score);
742 if (ret < 0)
743 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
744 if (statistics.num >= aa->size) {
745 aa->size *= 2;
746 aa->size += 100;
747 aa->array = para_realloc(aa->array,
748 aa->size * sizeof(struct admissible_file_info));
749 }
750 aa->array[statistics.num].aft_row = aft_row;
751 aa->array[statistics.num].score = score;
752 ret = add_afs_statistics(aft_row);
753 if (ret < 0)
754 return ret;
755 return 1;
756 }
757
758 /**
759 * Compute the new quadratic deviation in case one element changes.
760 *
761 * \param n Number of elements.
762 * \param old_qd The quadratic deviation before the change.
763 * \param old_val The value that was repaced.
764 * \param new_val The replacement value.
765 * \param old_sum The sum of all elements before the update.
766 *
767 * \return The new quadratic deviation resulting from replacing old_val
768 * by new_val.
769 *
770 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
771 * their quadratic deviation
772 *
773 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
774 *
775 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
776 * the last number a_n was replaced by b) may be computed in O(1) time in terms
777 * of n, q, a_n, b, and S as
778 *
779 * q' = q + d * s - (2 * S + d) * d / n,
780 *
781 * where d = b - a_n, and s = b + a_n.
782 *
783 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
784 * s = 17, so
785 *
786 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
787 *
788 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
789 *
790 */
791 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
792 int64_t old_val, int64_t new_val, int64_t old_sum)
793 {
794 int64_t delta = new_val - old_val;
795 int64_t sigma = new_val + old_val;
796 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
797 }
798
799 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
800 {
801 unsigned n;
802 int ret = get_num_admissible_files(&n);
803
804 if (ret < 0)
805 return ret;
806 assert(n);
807
808 statistics.last_played_qd = update_quadratic_deviation(n,
809 statistics.last_played_qd, old_afsi->last_played,
810 new_afsi->last_played, statistics.last_played_sum);
811 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
812
813 statistics.num_played_qd = update_quadratic_deviation(n,
814 statistics.num_played_qd, old_afsi->num_played,
815 new_afsi->num_played, statistics.num_played_sum);
816 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
817 return 1;
818 }
819
820 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
821 {
822 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
823 return score_add(aft_row, score);
824 }
825
826 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
827 {
828 int ret = del_afs_statistics(aft_row);
829 if (ret < 0)
830 return ret;
831 return score_delete(aft_row);
832 }
833
834 /**
835 * Delete one entry from the statitics and from the score table.
836 *
837 * \param aft_row The audio file which is no longer admissible.
838 *
839 * \return Positive on success, negative on errors.
840 *
841 * \sa score_delete(), mood_update_audio_file().
842 */
843 int mood_delete_audio_file(const struct osl_row *aft_row)
844 {
845 int ret;
846
847 ret = row_belongs_to_score_table(aft_row);
848 if (ret < 0)
849 return ret;
850 if (!ret) /* not admissible, nothing to do */
851 return 1;
852 return delete_from_statistics_and_score_table(aft_row);
853 }
854
855 /**
856 * Compute the new score of an audio file wrt. the current mood.
857 *
858 * \param aft_row Determines the audio file.
859 * \param old_afsi The audio file selector info before updating.
860 *
861 * The \a old_afsi argument may be \p NULL which indicates that no changes to
862 * the audio file info were made.
863 *
864 * \return Positive on success, negative on errors.
865 */
866 int mood_update_audio_file(const struct osl_row *aft_row, struct afs_info *old_afsi)
867 {
868 long score, percent;
869 int ret, is_admissible, was_admissible = 0;
870 struct afs_info afsi;
871
872 if (!current_mood)
873 return 1; /* nothing to do */
874 ret = row_belongs_to_score_table(aft_row);
875 if (ret < 0)
876 return ret;
877 was_admissible = ret;
878 ret = compute_mood_score(aft_row, current_mood, &score);
879 is_admissible = (ret > 0);
880 if (!was_admissible && !is_admissible)
881 return 1;
882 if (was_admissible && !is_admissible)
883 return delete_from_statistics_and_score_table(aft_row);
884 if (!was_admissible && is_admissible) {
885 ret = add_afs_statistics(aft_row);
886 if (ret < 0)
887 return ret;
888 return add_to_score_table(aft_row, score);
889 }
890 /* update score */
891 ret = get_afsi_of_row(aft_row, &afsi);
892 if (ret < 0)
893 return ret;
894 if (old_afsi) {
895 ret = update_afs_statistics(old_afsi, &afsi);
896 if (ret < 0)
897 return ret;
898 }
899 score += compute_num_played_score(&afsi);
900 score += compute_last_played_score(&afsi);
901 score /= 3;
902 PARA_DEBUG_LOG("score: %li\n", score);
903 percent = (score + 100) / 3;
904 if (percent > 100)
905 percent = 100;
906 else if (percent < 0)
907 percent = 0;
908 PARA_DEBUG_LOG("re-inserting at %lu%%\n", percent);
909 return score_update(aft_row, percent);
910 }
911
912 static void log_statistics(void)
913 {
914 unsigned n = statistics.num;
915
916 if (!n) {
917 PARA_NOTICE_LOG("no admissible files\n");
918 return;
919 }
920 PARA_NOTICE_LOG("last_played mean: %lli, last_played sigma: %llu\n",
921 (long long int)(statistics.last_played_sum / n),
922 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
923 PARA_NOTICE_LOG("num_played mean: %lli, num_played sigma: %llu\n",
924 (long long int)statistics.num_played_sum / n,
925 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
926 }
927
928 /**
929 * Change the current mood.
930 *
931 * \param mood_name The name of the mood to open.
932 *
933 * There are two special cases: If \a mood_name is \a NULL, load the
934 * first available mood. If \a mood_name is the empty string "", load
935 * the dummy mood that accepts every audio file and uses a scoring method
936 * based only on the \a last_played information.
937 *
938 * If there is already an open mood, it will be closed first.
939 *
940 * \return Positive on success, negative on errors. Loading the dummy mood
941 * always succeeds.
942 *
943 * \sa struct admissible_file_info, struct admissible_array, struct
944 * afs_info::last_played, mood_close().
945 */
946 int change_current_mood(char *mood_name)
947 {
948 int i, ret;
949 struct admissible_array aa = {
950 .size = 0,
951 .array = NULL
952 };
953
954 if (!mood_name) {
955 struct mood *m;
956 ret = load_first_available_mood(&m);
957 if (ret < 0)
958 return ret;
959 destroy_mood(current_mood);
960 current_mood = m;
961 } else if (*mood_name) {
962 struct mood *m;
963 struct osl_row *row;
964 struct osl_object obj = {
965 .data = mood_name,
966 .size = strlen(mood_name) + 1
967 };
968 ret = osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row);
969 if (ret < 0) {
970 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
971 return ret;
972 }
973 ret = load_mood(row, &m);
974 if (ret < 0)
975 return ret;
976 destroy_mood(current_mood);
977 current_mood = m;
978 } else {
979 destroy_mood(current_mood);
980 current_mood = alloc_new_mood("dummy");
981 }
982 aa.m = current_mood;
983 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
984 PARA_INFO_LOG("%s\n", "computing statistics of admissible files");
985 ret = audio_file_loop(&aa, add_if_admissible);
986 if (ret < 0)
987 return ret;
988 log_statistics();
989 PARA_NOTICE_LOG("%d admissible files \n", statistics.num);
990 for (i = 0; i < statistics.num; i++) {
991 struct admissible_file_info *a = aa.array + i;
992 ret = add_to_score_table(a->aft_row, a->score);
993 if (ret < 0)
994 goto out;
995 }
996 PARA_NOTICE_LOG("score add complete\n");
997 ret = 1;
998 out:
999 free(aa.array);
1000 return ret;
1001 }
1002
1003 /**
1004 * Close the current mood.
1005 *
1006 * Free all resources of the current mood which were allocated during
1007 * mood_open().
1008 */
1009 void close_current_mood(void)
1010 {
1011 destroy_mood(current_mood);
1012 current_mood = NULL;
1013 memset(&statistics, 0, sizeof(statistics));
1014 }
1015
1016 /**
1017 * Close and re-open the current mood.
1018 *
1019 * This function is used if changes to the audio file table or the
1020 * attribute table were made that render the current list of admissible
1021 * files useless. For example, if an attribute is removed from the
1022 * attribute table, this function is called.
1023 *
1024 * \return Positive on success, negative on errors. If no mood is currently
1025 * open, the function returns success.
1026 *
1027 * \sa mood_open(), mood_close().
1028 */
1029 int reload_current_mood(void)
1030 {
1031 int ret;
1032 char *mood_name;
1033
1034 if (!current_mood)
1035 return 1;
1036 score_shutdown(0);
1037 mood_name = para_strdup(current_mood->name);
1038 close_current_mood();
1039 ret = change_current_mood(mood_name);
1040 free(mood_name);
1041 return ret;
1042 }