ce5c1c7e87fbd76d2ca3599309ce0eb3e0dbd691
[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 <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 audio_format_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 audio_format_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 audio_format_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_name_like_score_function(const char *path,
207 __a_unused const struct afs_info *afsi,
208 __a_unused const struct audio_format_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_name_like_parser(const char *arg, void **data)
217 {
218 *data = para_strdup(arg);
219 return 1;
220 }
221
222 static void mm_name_like_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 audio_format_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 audio_format_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(name_like)},
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 struct mood_line_parser_data {
376 struct mood *m;
377 unsigned line_num;
378 };
379
380 /*
381 * <accept [with score <score>] | deny [with score <score>] | score <score>>
382 * [if] [not] <mood_method> [options]
383 * <score> is either an integer or "random" which assigns a random score to
384 * all matching files
385 */
386
387 static int parse_mood_line(char *mood_line, void *data)
388 {
389 struct mood_line_parser_data *mlpd = data;
390 char **argv;
391 char *delim = " \t";
392 unsigned num_words;
393 char **w;
394 int i, ret;
395 enum mood_line_type mlt = ML_INVALID;
396 struct mood_item *mi = NULL;
397 char *buf = para_strdup(mood_line);
398
399 mlpd->line_num++;
400 num_words = split_args(buf, &argv, delim);
401 ret = 1;
402 if (!num_words) /* empty line */
403 goto out;
404 w = argv;
405 if (**w == '#') /* comment */
406 goto out;
407 if (!strcmp(*w, "accept"))
408 mlt = ML_ACCEPT;
409 else if (!strcmp(*w, "deny"))
410 mlt = ML_DENY;
411 else if (!strcmp(*w, "score"))
412 mlt = ML_SCORE;
413 ret = -E_MOOD_SYNTAX;
414 if (mlt == ML_INVALID)
415 goto out;
416 mi = para_calloc(sizeof(struct mood_item));
417 if (mlt != ML_SCORE) {
418 ret = -E_MOOD_SYNTAX;
419 w++;
420 if (!*w)
421 goto out;
422 if (!strcmp(*w, "with")) {
423 w++;
424 if (!*w)
425 goto out;
426 }
427 }
428 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
429 ret = -E_MOOD_SYNTAX;
430 w++;
431 if (!*w)
432 goto out;
433 if (strcmp(*w, "random")) {
434 mi->random_score = 0;
435 ret = para_atoi32(*w, &mi->score_arg);
436 if (ret < 0)
437 goto out;
438 } else {
439 mi->random_score = 1;
440 if (!*(w + 1))
441 goto success; /* the line "score random" is valid */
442 }
443 } else
444 mi->score_arg = 0;
445 ret = -E_MOOD_SYNTAX;
446 w++;
447 if (!*w)
448 goto out;
449 if (!strcmp(*w, "if")) {
450 ret = -E_MOOD_SYNTAX;
451 w++;
452 if (!*w)
453 goto out;
454 }
455 if (!strcmp(*w, "not")) {
456 ret = -E_MOOD_SYNTAX;
457 w++;
458 if (!*w)
459 goto out;
460 mi->logical_not = 1;
461 } else
462 mi->logical_not = 0;
463 for (i = 0; mood_methods[i].parser; i++) {
464 if (strcmp(*w, mood_methods[i].name))
465 continue;
466 break;
467 }
468 ret = -E_MOOD_SYNTAX;
469 if (!mood_methods[i].parser)
470 goto out;
471 w++;
472 ret = mood_methods[i].parser(*w, &mi->parser_data);
473 if (ret < 0)
474 goto out;
475 mi->method = &mood_methods[i];
476 success:
477 if (mlpd->m) {
478 if (mlt == ML_ACCEPT)
479 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
480 else if (mlt == ML_DENY)
481 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
482 else
483 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
484 }
485 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
486 (mlt == ML_DENY? "deny" : "score"), mi->method);
487 ret = 1;
488 out:
489 free(argv);
490 free(buf);
491 if (ret >= 0)
492 return ret;
493 if (mi) {
494 free(mi->parser_data);
495 free(mi);
496 }
497 return ret;
498 }
499
500 static int load_mood(const struct osl_row *mood_row, struct mood **m)
501 {
502 char *mood_name;
503 struct osl_object mood_def;
504 struct mood_line_parser_data mlpd = {.line_num = 0};
505 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
506
507 if (ret < 0)
508 return ret;
509 if (!*mood_name)
510 return -E_DUMMY_ROW;
511 mlpd.m = alloc_new_mood(mood_name);
512 ret = for_each_line_ro(mood_def.data, mood_def.size,
513 parse_mood_line, &mlpd);
514 osl_close_disk_object(&mood_def);
515 if (ret < 0) {
516 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
517 PARA_STRERROR(-ret));
518 destroy_mood(mlpd.m);
519 return ret;
520 }
521 *m = mlpd.m;
522 return 1;
523 }
524
525 static int check_mood(struct osl_row *mood_row, void *data)
526 {
527 struct para_buffer *pb = data;
528 char *mood_name;
529 struct osl_object mood_def;
530 struct mood_line_parser_data mlpd = {.line_num = 0};
531
532 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
533
534 if (ret < 0) {
535 para_printf(pb, "failed to get mood definition\n");
536 return ret;
537 }
538 if (!*mood_name) /* ignore dummy row */
539 goto out;
540 para_printf(pb, "checking mood %s...\n", mood_name);
541 ret = for_each_line_ro(mood_def.data, mood_def.size,
542 parse_mood_line, &mlpd);
543 if (ret < 0)
544 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
545 PARA_STRERROR(-ret));
546 out:
547 osl_close_disk_object(&mood_def);
548 return 1;
549 }
550
551 /**
552 * Check all moods for syntax errors.
553 *
554 * \param query Unused.
555 * \param result: Contains check messages.
556 */
557 int mood_check_callback(__a_unused const struct osl_object *query,
558 struct osl_object *result)
559 {
560 struct para_buffer pb = {.buf = NULL};
561
562 para_printf(&pb, "checking moods...\n");
563 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
564 check_mood);
565 result->data = pb.buf;
566 result->size = pb.size;
567 return 1;
568 }
569
570 #if 0
571 static unsigned int_log2(uint64_t x)
572 {
573 unsigned res = 0;
574
575 while (x) {
576 x /= 2;
577 res++;
578 }
579 return res;
580 }
581 #endif
582
583 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
584 {
585 if (!n || !qd)
586 return 0;
587 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
588 }
589
590 static long compute_num_played_score(struct afs_info *afsi)
591 {
592 return -normalized_value(afsi->num_played, statistics.num,
593 statistics.num_played_sum, statistics.num_played_qd);
594 }
595
596 static long compute_last_played_score(struct afs_info *afsi)
597 {
598 return -normalized_value(afsi->last_played, statistics.num,
599 statistics.last_played_sum, statistics.last_played_qd);
600 }
601
602 static long compute_dynamic_score(const struct osl_row *aft_row)
603 {
604 struct afs_info afsi;
605 int64_t score, nscore = 0, lscore = 0;
606 int ret;
607
608 ret = get_afsi_of_row(aft_row, &afsi);
609 if (ret < 0)
610 return -100;
611 nscore = compute_num_played_score(&afsi);
612 lscore = compute_last_played_score(&afsi);
613 score = nscore + lscore;
614 return score;
615 }
616
617 static int add_afs_statistics(const struct osl_row *row)
618 {
619 uint64_t n, x, s;
620 struct afs_info afsi;
621 int ret;
622
623 ret = get_afsi_of_row(row, &afsi);
624 if (ret < 0)
625 return ret;
626 n = statistics.num;
627 x = afsi.last_played;
628 s = statistics.last_played_sum;
629 if (n > 0)
630 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
631 statistics.last_played_sum += x;
632
633 x = afsi.num_played;
634 s = statistics.num_played_sum;
635 if (n > 0)
636 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
637 statistics.num_played_sum += x;
638 statistics.num++;
639 return 1;
640 }
641
642 static int del_afs_statistics(const struct osl_row *row)
643 {
644 uint64_t n, s, q, a, new_s;
645 struct afs_info afsi;
646 int ret;
647 ret = get_afsi_of_row(row, &afsi);
648 if (ret < 0)
649 return ret;
650 n = statistics.num;
651 assert(n);
652 if (n == 1) {
653 memset(&statistics, 0, sizeof(statistics));
654 return 1;
655 }
656
657 s = statistics.last_played_sum;
658 q = statistics.last_played_qd;
659 a = afsi.last_played;
660 new_s = s - a;
661 statistics.last_played_sum = new_s;
662 statistics.last_played_qd = q + s * s / n - a * a
663 - new_s * new_s / (n - 1);
664
665 s = statistics.num_played_sum;
666 q = statistics.num_played_qd;
667 a = afsi.num_played;
668 new_s = s - a;
669 statistics.num_played_sum = new_s;
670 statistics.num_played_qd = q + s * s / n - a * a
671 - new_s * new_s / (n - 1);
672
673 statistics.num--;
674 return 1;
675 }
676
677 /**
678 * Structure used during mood_open().
679 *
680 * At mood open time, we look at each file in the audio file table in order to
681 * determine whether it is admissible. If a file happens to be admissible, its
682 * mood score is computed by calling each relevant mood_score_function. Next,
683 * we update the afs_statistics and add a struct admissible_file_info to a
684 * temporary array.
685 *
686 * If all files have been processed that way, the final score of each
687 * admissible file is computed by adding the dynamic score (which depends on
688 * the afs_statistics) to the mood score. Finally, all audio files in the
689 * array are added to the score table and the admissible array is freed.
690 *
691 * \sa mood_method, admissible_array.
692 */
693 struct admissible_file_info
694 {
695 /** The admissible audio file. */
696 struct osl_row *aft_row;
697 /** Its score. */
698 long score;
699 };
700
701 /** The temporary array of admissible files. */
702 struct admissible_array {
703 /** Files are admissible wrt. this mood. */
704 struct mood *m;
705 /** The size of the array */
706 unsigned size;
707 /** Pointer to the array of admissible files. */
708 struct admissible_file_info *array;
709 };
710
711 /**
712 * Add an entry to the array of admissible files.
713 *
714 * \param aft_row The audio file to be added.
715 * \param private_data Pointer to a struct admissible_file_info.
716 *
717 * \return Negative on errors, positive on success.
718 */
719 static int add_if_admissible(struct osl_row *aft_row, void *data)
720 {
721 struct admissible_array *aa = data;
722 int ret;
723 long score = 0;
724
725 ret = compute_mood_score(aft_row, aa->m, &score);
726 if (ret < 0)
727 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
728 if (statistics.num >= aa->size) {
729 aa->size *= 2;
730 aa->size += 100;
731 aa->array = para_realloc(aa->array,
732 aa->size * sizeof(struct admissible_file_info));
733 }
734 aa->array[statistics.num].aft_row = aft_row;
735 aa->array[statistics.num].score = score;
736 ret = add_afs_statistics(aft_row);
737 if (ret < 0)
738 return ret;
739 return 1;
740 }
741
742 /**
743 * Compute the new quadratic deviation in case one element changes.
744 *
745 * \param n Number of elements.
746 * \param old_qd The quadratic deviation before the change.
747 * \param old_val The value that was replaced.
748 * \param new_val The replacement value.
749 * \param old_sum The sum of all elements before the update.
750 *
751 * \return The new quadratic deviation resulting from replacing old_val
752 * by new_val.
753 *
754 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
755 * their quadratic deviation
756 *
757 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
758 *
759 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
760 * the last number a_n was replaced by b) may be computed in O(1) time in terms
761 * of n, q, a_n, b, and S as
762 *
763 * q' = q + d * s - (2 * S + d) * d / n,
764 *
765 * where d = b - a_n, and s = b + a_n.
766 *
767 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
768 * s = 17, so
769 *
770 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
771 *
772 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
773 *
774 */
775 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
776 int64_t old_val, int64_t new_val, int64_t old_sum)
777 {
778 int64_t delta = new_val - old_val;
779 int64_t sigma = new_val + old_val;
780 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
781 }
782
783 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
784 {
785 unsigned n;
786 int ret = get_num_admissible_files(&n);
787
788 if (ret < 0)
789 return ret;
790 assert(n);
791
792 statistics.last_played_qd = update_quadratic_deviation(n,
793 statistics.last_played_qd, old_afsi->last_played,
794 new_afsi->last_played, statistics.last_played_sum);
795 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
796
797 statistics.num_played_qd = update_quadratic_deviation(n,
798 statistics.num_played_qd, old_afsi->num_played,
799 new_afsi->num_played, statistics.num_played_sum);
800 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
801 return 1;
802 }
803
804 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
805 {
806 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
807 return score_add(aft_row, score);
808 }
809
810 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
811 {
812 int ret = del_afs_statistics(aft_row);
813 if (ret < 0)
814 return ret;
815 return score_delete(aft_row);
816 }
817
818 /**
819 * Delete one entry from the statistics and from the score table.
820 *
821 * \param aft_row The audio file which is no longer admissible.
822 *
823 * \return Positive on success, negative on errors.
824 *
825 * \sa score_delete().
826 */
827 static int mood_delete_audio_file(const struct osl_row *aft_row)
828 {
829 int ret;
830
831 ret = row_belongs_to_score_table(aft_row, NULL);
832 if (ret < 0)
833 return ret;
834 if (!ret) /* not admissible, nothing to do */
835 return 1;
836 return delete_from_statistics_and_score_table(aft_row);
837 }
838
839 /**
840 * Compute the new score of an audio file wrt. the current mood.
841 *
842 * \param aft_row Determines the audio file.
843 * \param old_afsi The audio file selector info before updating.
844 *
845 * The \a old_afsi argument may be \p NULL which indicates that no changes to
846 * the audio file info were made.
847 *
848 * \return Positive on success, negative on errors.
849 */
850 static int mood_update_audio_file(const struct osl_row *aft_row,
851 struct afs_info *old_afsi)
852 {
853 long score, percent;
854 int ret, is_admissible, was_admissible = 0;
855 struct afs_info afsi;
856 unsigned rank;
857
858 if (!current_mood)
859 return 1; /* nothing to do */
860 ret = row_belongs_to_score_table(aft_row, &rank);
861 if (ret < 0)
862 return ret;
863 was_admissible = ret;
864 ret = compute_mood_score(aft_row, current_mood, &score);
865 is_admissible = (ret > 0);
866 if (!was_admissible && !is_admissible)
867 return 1;
868 if (was_admissible && !is_admissible)
869 return delete_from_statistics_and_score_table(aft_row);
870 if (!was_admissible && is_admissible) {
871 ret = add_afs_statistics(aft_row);
872 if (ret < 0)
873 return ret;
874 return add_to_score_table(aft_row, score);
875 }
876 /* update score */
877 ret = get_afsi_of_row(aft_row, &afsi);
878 if (ret < 0)
879 return ret;
880 if (old_afsi) {
881 ret = update_afs_statistics(old_afsi, &afsi);
882 if (ret < 0)
883 return ret;
884 }
885 score += compute_num_played_score(&afsi);
886 score += compute_last_played_score(&afsi);
887 score /= 3;
888 PARA_DEBUG_LOG("score: %li\n", score);
889 percent = (score + 100) / 3;
890 if (percent > 100)
891 percent = 100;
892 else if (percent < 0)
893 percent = 0;
894 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
895 return score_update(aft_row, percent);
896 }
897
898 static void log_statistics(void)
899 {
900 unsigned n = statistics.num;
901
902 if (!n) {
903 PARA_NOTICE_LOG("no admissible files\n");
904 return;
905 }
906 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
907 (long long int)(statistics.last_played_sum / n),
908 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
909 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
910 (long long int)statistics.num_played_sum / n,
911 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
912 }
913
914 /**
915 * Close the current mood.
916 *
917 * Free all resources of the current mood which were allocated during
918 * mood_open().
919 */
920 void close_current_mood(void)
921 {
922 destroy_mood(current_mood);
923 current_mood = NULL;
924 memset(&statistics, 0, sizeof(statistics));
925 }
926
927
928 /**
929 * Change the current mood.
930 *
931 * \param mood_name The name of the mood to open.
932 *
933 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
934 * and uses a scoring method based only on the \a last_played information.
935 *
936 * If there is already an open mood, it will be closed first.
937 *
938 * \return Positive on success, negative on errors. Loading the dummy mood
939 * always succeeds.
940 *
941 * \sa struct admissible_file_info, struct admissible_array, struct
942 * afs_info::last_played, mood_close().
943 */
944 int change_current_mood(char *mood_name)
945 {
946 int i, ret;
947 struct admissible_array aa = {
948 .size = 0,
949 .array = NULL
950 };
951
952 if (mood_name) {
953 struct mood *m;
954 struct osl_row *row;
955 struct osl_object obj = {
956 .data = mood_name,
957 .size = strlen(mood_name) + 1
958 };
959 ret = osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row);
960 if (ret < 0) {
961 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
962 return ret;
963 }
964 ret = load_mood(row, &m);
965 if (ret < 0)
966 return ret;
967 close_current_mood();
968 current_mood = m;
969 } else {
970 close_current_mood();
971 current_mood = alloc_new_mood("dummy");
972 }
973 aa.m = current_mood;
974 PARA_NOTICE_LOG("computing statistics of admissible files\n");
975 ret = audio_file_loop(&aa, add_if_admissible);
976 if (ret < 0)
977 return ret;
978 log_statistics();
979 PARA_INFO_LOG("%d admissible files \n", statistics.num);
980 for (i = 0; i < statistics.num; i++) {
981 struct admissible_file_info *a = aa.array + i;
982 ret = add_to_score_table(a->aft_row, a->score);
983 if (ret < 0)
984 goto out;
985 }
986 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
987 ret = statistics.num;
988 out:
989 free(aa.array);
990 return ret;
991 }
992 /**
993 * Close and re-open the current mood.
994 *
995 * This function is used if changes to the audio file table or the
996 * attribute table were made that render the current list of admissible
997 * files useless. For example, if an attribute is removed from the
998 * attribute table, this function is called.
999 *
1000 * \return Positive on success, negative on errors. If no mood is currently
1001 * open, the function returns success.
1002 *
1003 * \sa mood_open(), mood_close().
1004 */
1005 int reload_current_mood(void)
1006 {
1007 int ret;
1008 char *mood_name = NULL;
1009
1010 PARA_NOTICE_LOG("reloading current mood\n");
1011 if (!current_mood)
1012 return 1;
1013 if (current_mood->name)
1014 mood_name = para_strdup(current_mood->name);
1015 close_current_mood();
1016 ret = change_current_mood(mood_name);
1017 free(mood_name);
1018 return ret;
1019 }
1020
1021 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
1022 void *data)
1023 {
1024 switch(event) {
1025 /*
1026 * The three blob events might change the set of admissible files,
1027 * so we must reload the score list.
1028 */
1029 case BLOB_RENAME:
1030 case BLOB_REMOVE:
1031 case BLOB_ADD:
1032 if (data == moods_table || data == playlists_table)
1033 return 1; /* no reload necessary for these */
1034 return reload_current_mood();
1035 /* these also require reload of the score table */
1036 case ATTRIBUTE_ADD:
1037 case ATTRIBUTE_REMOVE:
1038 case ATTRIBUTE_RENAME:
1039 return reload_current_mood();
1040 /* changes to the aft only require to re-examine the audio file */
1041 case AFSI_CHANGE: {
1042 struct afsi_change_event_data *aced = data;
1043 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
1044 }
1045 case AFHI_CHANGE:
1046 case AUDIO_FILE_RENAME:
1047 case AUDIO_FILE_ADD:
1048 return mood_update_audio_file(data, NULL);
1049 case AUDIO_FILE_REMOVE:
1050 return mood_delete_audio_file(data);
1051 default:
1052 return 1;
1053 }
1054 return 1;
1055 }
1056