Fix documentation of select command.
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007-2008 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 <fnmatch.h>
10 #include "para.h"
11 #include "error.h"
12 #include "string.h"
13 #include "afh.h"
14 #include "afs.h"
15 #include "list.h"
16
17 /**
18 * Contains statistical data of the currently admissible audio files.
19 *
20 * It is used to assign normalized score values to each admissible audio file.
21 */
22 struct afs_statistics {
23 /** Sum of num played over all admissible files. */
24 int64_t num_played_sum;
25 /** Sum of last played times over all admissible files. */
26 int64_t last_played_sum;
27 /** Quadratic deviation of num played time. */
28 int64_t num_played_qd;
29 /** Quadratic deviation of last played time. */
30 int64_t last_played_qd;
31 /** Number of admissible files */
32 unsigned num;
33 };
34 struct afs_statistics statistics;
35
36 /**
37 * Assign scores according to a mood_method.
38 *
39 * Each mood_method has its own mood_score_function. The first three parameters
40 * passed to that function are informations about the audio file whose score is
41 * to be computed. The data argument depends on the mood method this function
42 * is used for. It usually is the argument given at the end of a mood line.
43 *
44 * Mood score functions must return values between -100 and +100 inclusively.
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 char *path, const struct afs_info *afsi,
50 const struct afh_info *afhi, const void *data);
51
52 /**
53 * Pre-process a mood line.
54 *
55 * The mood_parser of a mood_method is called once at mood open time for each
56 * line of the current mood definition that contains the mood_method's name as
57 * a keyword. The line is passed to the mood_parser as the first argument. The
58 * mood_parser must determine whether the line is syntactically correct and
59 * return a positive value if so and a negative value otherwise.
60 *
61 * Some mood parsers pre-process the data given in the mood line to compute a
62 * structure which depends of the particular mood_method and which is used
63 * later in the mood_score_function of the mood_method. The mood_parser may
64 * store a pointer to its structure via the second argument.
65 *
66 * \sa mood_open(), mood_cleanup_function, mood_score_function.
67 */
68 typedef int mood_parser(const char *, void **);
69
70 /**
71 * Deallocate resources which were allocated by the mood_parser.
72 *
73 * This optional function of a mood_method is used to free any resources
74 * allocated in mood_open() by the mood_parser. The argument passed is a
75 * pointer to the mood_method specific data structure that was returned by the
76 * mood_parser.
77 *
78 * \sa mood_parser.
79 */
80 typedef void mood_cleanup_function(void *);
81
82 /**
83 * Used for scoring and to determine whether a file is admissible.
84 */
85 struct mood_method {
86 /* The name of the method. */
87 const char *name;
88 /** Pointer to the mood parser. */
89 mood_parser *parser;
90 /** Pointer to the score function */
91 mood_score_function *score_function;
92 /** Optional cleanup function. */
93 mood_cleanup_function *cleanup;
94 };
95
96 /**
97 * Each line of the current mood corresponds to a mood_item.
98 */
99 struct mood_item {
100 /** The method this line is referring to. */
101 const struct mood_method *method;
102 /** The data structure computed by the mood parser. */
103 void *parser_data;
104 /** The given score value, or zero if none was given. */
105 int32_t score_arg;
106 /** Non-zero if random scoring was requested. */
107 int random_score;
108 /** Whether the "not" keyword was given in the mood line. */
109 int logical_not;
110 /** The position in the list of items. */
111 struct list_head mood_item_node;
112 };
113
114 /**
115 * Created from the mood definition by mood_open().
116 *
117 * When a mood is opened, each line of its definition is investigated, and a
118 * corresponding mood item is produced. Each mood line starts with \p accept,
119 * \p deny, or \p score which determines the type of the mood line. For each
120 * such type a linked list is maintained whose entries are the mood items.
121 *
122 * \sa mood_item, mood_open().
123 */
124 struct mood {
125 /** The name of this mood. */
126 char *name;
127 /** The list of mood items of type \p accept. */
128 struct list_head accept_list;
129 /** The list of mood items of type \p deny. */
130 struct list_head deny_list;
131 /** The list of mood items of type \p score. */
132 struct list_head score_list;
133 };
134
135 static struct mood *current_mood;
136
137 /**
138 * Rough approximation to sqrt.
139 *
140 * \param x Integer of which to calculate the sqrt.
141 *
142 * \return An integer res with res * res <= x.
143 */
144 static uint64_t int_sqrt(uint64_t x)
145 {
146 uint64_t op, res, one = 1;
147 op = x;
148 res = 0;
149
150 one = one << 62;
151 while (one > op)
152 one >>= 2;
153
154 while (one != 0) {
155 if (op >= res + one) {
156 op = op - (res + one);
157 res = res + 2 * one;
158 }
159 res /= 2;
160 one /= 4;
161 }
162 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
163 return res;
164 }
165
166 static int mm_no_attributes_set_parser(const char *arg, __a_unused void **ignored)
167 {
168 if (arg && *arg)
169 PARA_WARNING_LOG("ignored junk at eol: %s\n", arg);
170 return 1;
171 }
172
173 static int mm_no_attributes_set_score_function(__a_unused const char *path,
174 const struct afs_info *afsi,
175 __a_unused const struct afh_info *afhi,
176 __a_unused const void *data)
177 {
178 if (!afsi->attributes)
179 return 100;
180 return -100;
181 }
182
183 static int mm_played_rarely_score_function(__a_unused const char *path,
184 const struct afs_info *afsi,
185 __a_unused const struct afh_info *afhi,
186 __a_unused const void *data)
187 {
188 unsigned num;
189 int ret = get_num_admissible_files(&num);
190
191 if (ret < 0)
192 return 0;
193 if (statistics.num_played_sum - num * afsi->num_played
194 > int_sqrt(statistics.num_played_qd * num))
195 return 100;
196 return -100;
197 }
198
199 static int mm_played_rarely_parser(const char *arg, __a_unused void **ignored)
200 {
201 if (arg && *arg)
202 PARA_WARNING_LOG("ignored junk at eol: %s\n", arg);
203 return 1;
204 }
205
206 static int mm_path_matches_score_function(const char *path,
207 __a_unused const struct afs_info *afsi,
208 __a_unused const struct afh_info *afhi,
209 const void *data)
210 {
211 if (fnmatch(data, path, 0))
212 return -100;
213 return 100;
214 }
215
216 static int mm_path_matches_parser(const char *arg, void **data)
217 {
218 *data = para_strdup(arg);
219 return 1;
220 }
221
222 static void mm_path_matches_cleanup(void *data)
223 {
224 free(data);
225 }
226
227 static int mm_is_set_parser(const char *arg, void **bitnum)
228 {
229 unsigned char *c = para_malloc(1);
230 int ret = get_attribute_bitnum_by_name(arg, c);
231
232 if (ret >= 0)
233 *bitnum = c;
234 else
235 free(c);
236 return ret;
237 }
238
239 static int mm_is_set_score_function(__a_unused const char *path,
240 __a_unused const struct afs_info *afsi,
241 __a_unused const struct afh_info *afhi,
242 const void *data)
243 {
244 const unsigned char *bn = data;
245 if (afsi->attributes & (1ULL << *bn))
246 return 100;
247 return -100;
248 }
249
250 /* returns 1 if row matches score item, negative otherwise */
251 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
252 long *score_arg_sum)
253 {
254 struct afs_info afsi;
255 struct afh_info afhi;
256 char *path;
257 int ret;
258
259 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
260 ret = 100;
261 if (item->method) {
262 ret = get_afsi_of_row(row, &afsi);
263 if (ret< 0)
264 return ret;
265 ret = get_afhi_of_row(row, &afhi);
266 if (ret< 0)
267 return ret;
268 ret = get_audio_file_path_of_row(row, &path);
269 if (ret< 0)
270 return ret;
271 ret = item->method->score_function(path, &afsi, &afhi,
272 item->parser_data);
273 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
274 return -1; /* no match */
275 }
276 if (item->random_score)
277 *score += PARA_ABS(ret) * para_random(100);
278 else
279 *score += PARA_ABS(ret) * item->score_arg;
280 return 1;
281 }
282
283 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
284 long *result)
285 {
286 struct mood_item *item;
287 int match = 0;
288 long score_arg_sum = 0, score = 0;
289
290 if (!m)
291 return -E_NO_MOOD;
292 /* reject audio file if it matches any entry in the deny list */
293 list_for_each_entry(item, &m->deny_list, mood_item_node)
294 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
295 return -E_NOT_ADMISSIBLE;
296 list_for_each_entry(item, &m->accept_list, mood_item_node)
297 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
298 match = 1;
299 /* reject if there is no matching entry in the accept list */
300 if (!match && !list_empty(&m->accept_list))
301 return -E_NOT_ADMISSIBLE;
302 list_for_each_entry(item, &m->score_list, mood_item_node)
303 add_item_score(aft_row, item, &score, &score_arg_sum);
304 if (score_arg_sum)
305 score /= score_arg_sum;
306 *result = score;
307 return 1;
308 }
309
310 #define DEFINE_MOOD_METHOD(_name) \
311 .parser = mm_ ## _name ## _parser, \
312 .score_function = mm_ ## _name ## _score_function, \
313 .name = #_name
314
315 #define DEFINE_MOOD_METHOD_WITH_CLEANUP(_name) \
316 DEFINE_MOOD_METHOD(_name), \
317 .cleanup = mm_ ## _name ## _cleanup
318
319 static const struct mood_method mood_methods[] = {
320 {DEFINE_MOOD_METHOD(no_attributes_set)},
321 {DEFINE_MOOD_METHOD(played_rarely)},
322 {DEFINE_MOOD_METHOD(is_set)},
323 {DEFINE_MOOD_METHOD_WITH_CLEANUP(path_matches)},
324 {.parser = NULL}
325 };
326
327 static void cleanup_list_entry(struct mood_item *item)
328 {
329 if (item->method && item->method->cleanup)
330 item->method->cleanup(item->parser_data);
331 else
332 free(item->parser_data);
333 list_del(&item->mood_item_node);
334 free(item);
335 }
336
337 static void destroy_mood(struct mood *m)
338 {
339 struct mood_item *tmp, *item;
340
341 if (!m)
342 return;
343 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
344 cleanup_list_entry(item);
345 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
346 cleanup_list_entry(item);
347 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
348 cleanup_list_entry(item);
349 free(m->name);
350 free(m);
351 }
352
353 static struct mood *alloc_new_mood(const char *name)
354 {
355 struct mood *m = para_calloc(sizeof(struct mood));
356 m->name = para_strdup(name);
357 INIT_LIST_HEAD(&m->accept_list);
358 INIT_LIST_HEAD(&m->deny_list);
359 INIT_LIST_HEAD(&m->score_list);
360 return m;
361 }
362
363 /** The different types of a mood line. */
364 enum mood_line_type {
365 /** Invalid. */
366 ML_INVALID,
367 /** Accept line. */
368 ML_ACCEPT,
369 /** Deny line. */
370 ML_DENY,
371 /** Score line. */
372 ML_SCORE
373 };
374
375 /** Data passed to the parser of a mood line. */
376 struct mood_line_parser_data {
377 /** The mood this mood line belongs to. */
378 struct mood *m;
379 /** The line number in the mood definition. */
380 unsigned line_num;
381 };
382
383 /*
384 * <accept [with score <score>] | deny [with score <score>] | score <score>>
385 * [if] [not] <mood_method> [options]
386 * <score> is either an integer or "random" which assigns a random score to
387 * all matching files
388 */
389
390 static int parse_mood_line(char *mood_line, void *data)
391 {
392 struct mood_line_parser_data *mlpd = data;
393 char **argv;
394 char *delim = " \t";
395 unsigned num_words;
396 char **w;
397 int i, ret;
398 enum mood_line_type mlt = ML_INVALID;
399 struct mood_item *mi = NULL;
400 char *buf = para_strdup(mood_line);
401
402 mlpd->line_num++;
403 num_words = split_args(buf, &argv, delim);
404 ret = 1;
405 if (!num_words) /* empty line */
406 goto out;
407 w = argv;
408 if (**w == '#') /* comment */
409 goto out;
410 if (!strcmp(*w, "accept"))
411 mlt = ML_ACCEPT;
412 else if (!strcmp(*w, "deny"))
413 mlt = ML_DENY;
414 else if (!strcmp(*w, "score"))
415 mlt = ML_SCORE;
416 ret = -E_MOOD_SYNTAX;
417 if (mlt == ML_INVALID)
418 goto out;
419 mi = para_calloc(sizeof(struct mood_item));
420 if (mlt != ML_SCORE) {
421 ret = -E_MOOD_SYNTAX;
422 w++;
423 if (!*w)
424 goto out;
425 if (strcmp(*w, "with"))
426 goto check_for_if;
427 w++;
428 if (!*w)
429 goto out;
430 if (strcmp(*w, "score"))
431 goto out;
432 }
433 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
434 ret = -E_MOOD_SYNTAX;
435 w++;
436 if (!*w)
437 goto out;
438 if (strcmp(*w, "random")) {
439 mi->random_score = 0;
440 ret = para_atoi32(*w, &mi->score_arg);
441 if (ret < 0)
442 goto out;
443 } else {
444 mi->random_score = 1;
445 if (!*(w + 1))
446 goto success; /* the line "score random" is valid */
447 }
448 } else
449 mi->score_arg = 0;
450 ret = -E_MOOD_SYNTAX;
451 w++;
452 if (!*w)
453 goto out;
454 check_for_if:
455 if (!strcmp(*w, "if")) {
456 ret = -E_MOOD_SYNTAX;
457 w++;
458 if (!*w)
459 goto out;
460 }
461 if (!strcmp(*w, "not")) {
462 ret = -E_MOOD_SYNTAX;
463 w++;
464 if (!*w)
465 goto out;
466 mi->logical_not = 1;
467 } else
468 mi->logical_not = 0;
469 for (i = 0; mood_methods[i].parser; i++) {
470 if (strcmp(*w, mood_methods[i].name))
471 continue;
472 break;
473 }
474 ret = -E_MOOD_SYNTAX;
475 if (!mood_methods[i].parser)
476 goto out;
477 w++;
478 ret = mood_methods[i].parser(*w, &mi->parser_data);
479 if (ret < 0)
480 goto out;
481 mi->method = &mood_methods[i];
482 success:
483 if (mlpd->m) {
484 if (mlt == ML_ACCEPT)
485 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
486 else if (mlt == ML_DENY)
487 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
488 else
489 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
490 }
491 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
492 (mlt == ML_DENY? "deny" : "score"), mi->method);
493 ret = 1;
494 out:
495 free(argv);
496 free(buf);
497 if (ret >= 0)
498 return ret;
499 if (mi) {
500 free(mi->parser_data);
501 free(mi);
502 }
503 return ret;
504 }
505
506 static int load_mood(const struct osl_row *mood_row, struct mood **m)
507 {
508 char *mood_name;
509 struct osl_object mood_def;
510 struct mood_line_parser_data mlpd = {.line_num = 0};
511 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
512
513 if (ret < 0)
514 return ret;
515 if (!*mood_name)
516 return -E_DUMMY_ROW;
517 mlpd.m = alloc_new_mood(mood_name);
518 ret = for_each_line_ro(mood_def.data, mood_def.size,
519 parse_mood_line, &mlpd);
520 osl_close_disk_object(&mood_def);
521 if (ret < 0) {
522 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
523 para_strerror(-ret));
524 destroy_mood(mlpd.m);
525 return ret;
526 }
527 *m = mlpd.m;
528 return 1;
529 }
530
531 static int check_mood(struct osl_row *mood_row, void *data)
532 {
533 struct para_buffer *pb = data;
534 char *mood_name;
535 struct osl_object mood_def;
536 struct mood_line_parser_data mlpd = {.line_num = 0};
537
538 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
539
540 if (ret < 0) {
541 para_printf(pb, "failed to get mood definition\n");
542 return ret;
543 }
544 if (!*mood_name) /* ignore dummy row */
545 goto out;
546 para_printf(pb, "checking mood %s...\n", mood_name);
547 ret = for_each_line_ro(mood_def.data, mood_def.size,
548 parse_mood_line, &mlpd);
549 if (ret < 0)
550 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
551 para_strerror(-ret));
552 out:
553 osl_close_disk_object(&mood_def);
554 return 1;
555 }
556
557 /**
558 * Check all moods for syntax errors.
559 *
560 * \param query Unused.
561 * \param result: Contains check messages.
562 */
563 int mood_check_callback(__a_unused const struct osl_object *query,
564 struct osl_object *result)
565 {
566 struct para_buffer pb = {.buf = NULL};
567
568 para_printf(&pb, "checking moods...\n");
569 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
570 check_mood);
571 result->data = pb.buf;
572 result->size = pb.size;
573 return 1;
574 }
575
576 #if 0
577 static unsigned int_log2(uint64_t x)
578 {
579 unsigned res = 0;
580
581 while (x) {
582 x /= 2;
583 res++;
584 }
585 return res;
586 }
587 #endif
588
589 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
590 {
591 if (!n || !qd)
592 return 0;
593 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
594 }
595
596 static long compute_num_played_score(struct afs_info *afsi)
597 {
598 return -normalized_value(afsi->num_played, statistics.num,
599 statistics.num_played_sum, statistics.num_played_qd);
600 }
601
602 static long compute_last_played_score(struct afs_info *afsi)
603 {
604 return -normalized_value(afsi->last_played, statistics.num,
605 statistics.last_played_sum, statistics.last_played_qd);
606 }
607
608 static long compute_dynamic_score(const struct osl_row *aft_row)
609 {
610 struct afs_info afsi;
611 int64_t score, nscore = 0, lscore = 0;
612 int ret;
613
614 ret = get_afsi_of_row(aft_row, &afsi);
615 if (ret < 0)
616 return -100;
617 nscore = compute_num_played_score(&afsi);
618 lscore = compute_last_played_score(&afsi);
619 score = nscore + lscore;
620 return score;
621 }
622
623 static int add_afs_statistics(const struct osl_row *row)
624 {
625 uint64_t n, x, s;
626 struct afs_info afsi;
627 int ret;
628
629 ret = get_afsi_of_row(row, &afsi);
630 if (ret < 0)
631 return ret;
632 n = statistics.num;
633 x = afsi.last_played;
634 s = statistics.last_played_sum;
635 if (n > 0)
636 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
637 statistics.last_played_sum += x;
638
639 x = afsi.num_played;
640 s = statistics.num_played_sum;
641 if (n > 0)
642 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
643 statistics.num_played_sum += x;
644 statistics.num++;
645 return 1;
646 }
647
648 static int del_afs_statistics(const struct osl_row *row)
649 {
650 uint64_t n, s, q, a, new_s;
651 struct afs_info afsi;
652 int ret;
653 ret = get_afsi_of_row(row, &afsi);
654 if (ret < 0)
655 return ret;
656 n = statistics.num;
657 assert(n);
658 if (n == 1) {
659 memset(&statistics, 0, sizeof(statistics));
660 return 1;
661 }
662
663 s = statistics.last_played_sum;
664 q = statistics.last_played_qd;
665 a = afsi.last_played;
666 new_s = s - a;
667 statistics.last_played_sum = new_s;
668 statistics.last_played_qd = q + s * s / n - a * a
669 - new_s * new_s / (n - 1);
670
671 s = statistics.num_played_sum;
672 q = statistics.num_played_qd;
673 a = afsi.num_played;
674 new_s = s - a;
675 statistics.num_played_sum = new_s;
676 statistics.num_played_qd = q + s * s / n - a * a
677 - new_s * new_s / (n - 1);
678
679 statistics.num--;
680 return 1;
681 }
682
683 /**
684 * Structure used during mood_open().
685 *
686 * At mood open time, we look at each file in the audio file table in order to
687 * determine whether it is admissible. If a file happens to be admissible, its
688 * mood score is computed by calling each relevant mood_score_function. Next,
689 * we update the afs_statistics and add a struct admissible_file_info to a
690 * temporary array.
691 *
692 * If all files have been processed that way, the final score of each
693 * admissible file is computed by adding the dynamic score (which depends on
694 * the afs_statistics) to the mood score. Finally, all audio files in the
695 * array are added to the score table and the admissible array is freed.
696 *
697 * \sa mood_method, admissible_array.
698 */
699 struct admissible_file_info
700 {
701 /** The admissible audio file. */
702 struct osl_row *aft_row;
703 /** Its score. */
704 long score;
705 };
706
707 /** The temporary array of admissible files. */
708 struct admissible_array {
709 /** Files are admissible wrt. this mood. */
710 struct mood *m;
711 /** The size of the array */
712 unsigned size;
713 /** Pointer to the array of admissible files. */
714 struct admissible_file_info *array;
715 };
716
717 /**
718 * Add an entry to the array of admissible files.
719 *
720 * \param aft_row The audio file to be added.
721 * \param private_data Pointer to a struct admissible_file_info.
722 *
723 * \return Negative on errors, positive on success.
724 */
725 static int add_if_admissible(struct osl_row *aft_row, void *data)
726 {
727 struct admissible_array *aa = data;
728 int ret;
729 long score = 0;
730
731 ret = compute_mood_score(aft_row, aa->m, &score);
732 if (ret < 0)
733 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
734 if (statistics.num >= aa->size) {
735 aa->size *= 2;
736 aa->size += 100;
737 aa->array = para_realloc(aa->array,
738 aa->size * sizeof(struct admissible_file_info));
739 }
740 aa->array[statistics.num].aft_row = aft_row;
741 aa->array[statistics.num].score = score;
742 ret = add_afs_statistics(aft_row);
743 if (ret < 0)
744 return ret;
745 return 1;
746 }
747
748 /**
749 * Compute the new quadratic deviation in case one element changes.
750 *
751 * \param n Number of elements.
752 * \param old_qd The quadratic deviation before the change.
753 * \param old_val The value that was replaced.
754 * \param new_val The replacement value.
755 * \param old_sum The sum of all elements before the update.
756 *
757 * \return The new quadratic deviation resulting from replacing old_val
758 * by new_val.
759 *
760 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
761 * their quadratic deviation
762 *
763 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
764 *
765 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
766 * the last number a_n was replaced by b) may be computed in O(1) time in terms
767 * of n, q, a_n, b, and S as
768 *
769 * q' = q + d * s - (2 * S + d) * d / n,
770 *
771 * where d = b - a_n, and s = b + a_n.
772 *
773 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
774 * s = 17, so
775 *
776 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
777 *
778 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
779 *
780 */
781 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
782 int64_t old_val, int64_t new_val, int64_t old_sum)
783 {
784 int64_t delta = new_val - old_val;
785 int64_t sigma = new_val + old_val;
786 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
787 }
788
789 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
790 {
791 unsigned n;
792 int ret = get_num_admissible_files(&n);
793
794 if (ret < 0)
795 return ret;
796 assert(n);
797
798 statistics.last_played_qd = update_quadratic_deviation(n,
799 statistics.last_played_qd, old_afsi->last_played,
800 new_afsi->last_played, statistics.last_played_sum);
801 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
802
803 statistics.num_played_qd = update_quadratic_deviation(n,
804 statistics.num_played_qd, old_afsi->num_played,
805 new_afsi->num_played, statistics.num_played_sum);
806 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
807 return 1;
808 }
809
810 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
811 {
812 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
813 return score_add(aft_row, score);
814 }
815
816 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
817 {
818 int ret = del_afs_statistics(aft_row);
819 if (ret < 0)
820 return ret;
821 return score_delete(aft_row);
822 }
823
824 /**
825 * Delete one entry from the statistics and from the score table.
826 *
827 * \param aft_row The audio file which is no longer admissible.
828 *
829 * \return Positive on success, negative on errors.
830 *
831 * \sa score_delete().
832 */
833 static int mood_delete_audio_file(const struct osl_row *aft_row)
834 {
835 int ret;
836
837 ret = row_belongs_to_score_table(aft_row, NULL);
838 if (ret < 0)
839 return ret;
840 if (!ret) /* not admissible, nothing to do */
841 return 1;
842 return delete_from_statistics_and_score_table(aft_row);
843 }
844
845 /**
846 * Compute the new score of an audio file wrt. the current mood.
847 *
848 * \param aft_row Determines the audio file.
849 * \param old_afsi The audio file selector info before updating.
850 *
851 * The \a old_afsi argument may be \p NULL which indicates that no changes to
852 * the audio file info were made.
853 *
854 * \return Positive on success, negative on errors.
855 */
856 static int mood_update_audio_file(const struct osl_row *aft_row,
857 struct afs_info *old_afsi)
858 {
859 long score, percent;
860 int ret, is_admissible, was_admissible = 0;
861 struct afs_info afsi;
862 unsigned rank;
863
864 if (!current_mood)
865 return 1; /* nothing to do */
866 ret = row_belongs_to_score_table(aft_row, &rank);
867 if (ret < 0)
868 return ret;
869 was_admissible = ret;
870 ret = compute_mood_score(aft_row, current_mood, &score);
871 is_admissible = (ret > 0);
872 if (!was_admissible && !is_admissible)
873 return 1;
874 if (was_admissible && !is_admissible)
875 return delete_from_statistics_and_score_table(aft_row);
876 if (!was_admissible && is_admissible) {
877 ret = add_afs_statistics(aft_row);
878 if (ret < 0)
879 return ret;
880 return add_to_score_table(aft_row, score);
881 }
882 /* update score */
883 ret = get_afsi_of_row(aft_row, &afsi);
884 if (ret < 0)
885 return ret;
886 if (old_afsi) {
887 ret = update_afs_statistics(old_afsi, &afsi);
888 if (ret < 0)
889 return ret;
890 }
891 score += compute_num_played_score(&afsi);
892 score += compute_last_played_score(&afsi);
893 score /= 3;
894 PARA_DEBUG_LOG("score: %li\n", score);
895 percent = (score + 100) / 3;
896 if (percent > 100)
897 percent = 100;
898 else if (percent < 0)
899 percent = 0;
900 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
901 return score_update(aft_row, percent);
902 }
903
904 static void log_statistics(void)
905 {
906 unsigned n = statistics.num;
907
908 if (!n) {
909 PARA_NOTICE_LOG("no admissible files\n");
910 return;
911 }
912 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
913 (long long int)(statistics.last_played_sum / n),
914 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
915 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
916 (long long int)statistics.num_played_sum / n,
917 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
918 }
919
920 /**
921 * Close the current mood.
922 *
923 * Free all resources of the current mood which were allocated during
924 * mood_open().
925 */
926 void close_current_mood(void)
927 {
928 destroy_mood(current_mood);
929 current_mood = NULL;
930 memset(&statistics, 0, sizeof(statistics));
931 }
932
933
934 /**
935 * Change the current mood.
936 *
937 * \param mood_name The name of the mood to open.
938 *
939 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
940 * and uses a scoring method based only on the \a last_played information.
941 *
942 * If there is already an open mood, it will be closed first.
943 *
944 * \return Positive on success, negative on errors. Loading the dummy mood
945 * always succeeds.
946 *
947 * \sa struct admissible_file_info, struct admissible_array, struct
948 * afs_info::last_played, mood_close().
949 */
950 int change_current_mood(char *mood_name)
951 {
952 int i, ret;
953 struct admissible_array aa = {
954 .size = 0,
955 .array = NULL
956 };
957
958 if (mood_name) {
959 struct mood *m;
960 struct osl_row *row;
961 struct osl_object obj = {
962 .data = mood_name,
963 .size = strlen(mood_name) + 1
964 };
965 ret = osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row);
966 if (ret < 0) {
967 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
968 return ret;
969 }
970 ret = load_mood(row, &m);
971 if (ret < 0)
972 return ret;
973 close_current_mood();
974 current_mood = m;
975 } else {
976 close_current_mood();
977 current_mood = alloc_new_mood("dummy");
978 }
979 aa.m = current_mood;
980 PARA_NOTICE_LOG("computing statistics of admissible files\n");
981 ret = audio_file_loop(&aa, add_if_admissible);
982 if (ret < 0)
983 return ret;
984 log_statistics();
985 PARA_INFO_LOG("%d admissible files \n", statistics.num);
986 for (i = 0; i < statistics.num; i++) {
987 struct admissible_file_info *a = aa.array + i;
988 ret = add_to_score_table(a->aft_row, a->score);
989 if (ret < 0)
990 goto out;
991 }
992 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
993 ret = statistics.num;
994 out:
995 free(aa.array);
996 return ret;
997 }
998 /**
999 * Close and re-open the current mood.
1000 *
1001 * This function is used if changes to the audio file table or the
1002 * attribute table were made that render the current list of admissible
1003 * files useless. For example, if an attribute is removed from the
1004 * attribute table, this function is called.
1005 *
1006 * \return Positive on success, negative on errors. If no mood is currently
1007 * open, the function returns success.
1008 *
1009 * \sa mood_open(), mood_close().
1010 */
1011 int reload_current_mood(void)
1012 {
1013 int ret;
1014 char *mood_name = NULL;
1015
1016 if (!current_mood)
1017 return 1;
1018 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
1019 current_mood->name : "(dummy)");
1020 if (current_mood->name)
1021 mood_name = para_strdup(current_mood->name);
1022 close_current_mood();
1023 ret = change_current_mood(mood_name);
1024 free(mood_name);
1025 return ret;
1026 }
1027
1028 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
1029 void *data)
1030 {
1031 switch(event) {
1032 /*
1033 * The three blob events might change the set of admissible files,
1034 * so we must reload the score list.
1035 */
1036 case BLOB_RENAME:
1037 case BLOB_REMOVE:
1038 case BLOB_ADD:
1039 if (data == moods_table || data == playlists_table)
1040 return 1; /* no reload necessary for these */
1041 return reload_current_mood();
1042 /* these also require reload of the score table */
1043 case ATTRIBUTE_ADD:
1044 case ATTRIBUTE_REMOVE:
1045 case ATTRIBUTE_RENAME:
1046 return reload_current_mood();
1047 /* changes to the aft only require to re-examine the audio file */
1048 case AFSI_CHANGE: {
1049 struct afsi_change_event_data *aced = data;
1050 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
1051 }
1052 case AFHI_CHANGE:
1053 case AUDIO_FILE_RENAME:
1054 case AUDIO_FILE_ADD:
1055 return mood_update_audio_file(data, NULL);
1056 case AUDIO_FILE_REMOVE:
1057 return mood_delete_audio_file(data);
1058 default:
1059 return 1;
1060 }
1061 }
1062