Speed up mood loading.
[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 "afh.h"
13 #include "afs.h"
14 #include "list.h"
15 #include "string.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 parameter passed
40 * to that function is a pointer to a row of the audio file table. It
41 * determines the audio file for which a score is to be assigned. The second
42 * argument depends on the mood method this function is used for. It usually is
43 * the argument given at the end of a mood line.
44 *
45 * Mood score functions must return values between -100 and +100 inclusively.
46 * Boolean score functions should always return either -100 or +100.
47 *
48 * \sa struct mood_method, mood_parser.
49 */
50 typedef int mood_score_function(const char *path, const struct afs_info *afsi,
51 const struct audio_format_info *afhi, const void *data);
52
53 /**
54 * Pre-process a mood line.
55 *
56 * The mood_parser of a mood_method is called once at mood open time for each
57 * line of the current mood definition that contains the mood_method's name as
58 * a keyword. The line is passed to the mood_parser as the first argument. The
59 * mood_parser must determine whether the line is syntactically correct and
60 * return a positive value if so and a negative value otherwise.
61 *
62 * Some mood parsers pre-process the data given in the mood line to compute a
63 * structure which depends of the particular mood_method and which is used
64 * later in the mood_score_function of the mood_method. The mood_parser may
65 * store a pointer to its structure via the second argument.
66 *
67 * \sa mood_open(), mood_cleanup_function, mood_score_function.
68 */
69 typedef int mood_parser(const char *, void **);
70
71 /**
72 * Deallocate resources which were allocated by the mood_parser.
73 *
74 * This optional function of a mood_method is used to free any resources
75 * allocated in mood_open() by the mood_parser. The argument passed is a
76 * pointer to the mood_method specific data structure that was returned by the
77 * mood_parser.
78 *
79 * \sa mood_parser.
80 */
81 typedef void mood_cleanup_function(void *);
82
83 /**
84 * Used for scoring and to determine whether a file is admissible.
85 */
86 struct mood_method {
87 /* The name of the method. */
88 const char *name;
89 /** Pointer to the mood parser. */
90 mood_parser *parser;
91 /** Pointer to the score function */
92 mood_score_function *score_function;
93 /** Optional cleanup function. */
94 mood_cleanup_function *cleanup;
95 };
96
97 /**
98 * Each line of the current mood corresponds to a mood_item.
99 */
100 struct mood_item {
101 /** The method this line is referring to. */
102 const struct mood_method *method;
103 /** The data structure computed by the mood parser. */
104 void *parser_data;
105 /** The given score value, or zero if none was given. */
106 int32_t score_arg;
107 /** Non-zero if random scoring was requested. */
108 int random_score;
109 /** Whether the "not" keyword was given in the mood line. */
110 int logical_not;
111 /** The position in the list of items. */
112 struct list_head mood_item_node;
113 };
114
115 /**
116 * Created from the mood definition by mood_open().
117 *
118 * When a mood is opened, each line of its definition is investigated, and a
119 * corresponding mood item is produced. Each mood line starts with \p accept,
120 * \p deny, or \p score which determines the type of the mood line. For each
121 * such type a linked list is maintained whose entries are the mood items.
122 *
123 * \sa mood_item, mood_open().
124 */
125 struct mood {
126 /** The name of this mood. */
127 char *name;
128 /** The list of mood items of type \p accept. */
129 struct list_head accept_list;
130 /** The list of mood items of type \p deny. */
131 struct list_head deny_list;
132 /** The list of mood items of type \p score. */
133 struct list_head score_list;
134 };
135
136 static struct mood *current_mood;
137
138 /**
139 * Rough approximation to sqrt.
140 *
141 * \param x Integer of which to calculate the sqrt.
142 *
143 * \return An integer res with res * res <= x.
144 */
145 static uint64_t int_sqrt(uint64_t x)
146 {
147 uint64_t op, res, one = 1;
148 op = x;
149 res = 0;
150
151 one = one << 62;
152 while (one > op)
153 one >>= 2;
154
155 while (one != 0) {
156 if (op >= res + one) {
157 op = op - (res + one);
158 res = res + 2 * one;
159 }
160 res /= 2;
161 one /= 4;
162 }
163 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
164 return res;
165 }
166
167 static int mm_played_rarely_score_function(__a_unused const char *path,
168 const struct afs_info *afsi,
169 __a_unused const struct audio_format_info *afhi,
170 __a_unused const void *data)
171 {
172 unsigned num;
173 int ret = get_num_admissible_files(&num);
174
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 char *path,
191 __a_unused const struct afs_info *afsi,
192 __a_unused const struct audio_format_info *afhi,
193 const void *data)
194 {
195 if (fnmatch(data, path, 0))
196 return -100;
197 return 100;
198 }
199
200 static int mm_name_like_parser(const char *arg, void **data)
201 {
202 *data = para_strdup(arg);
203 return 1;
204 }
205
206 static void mm_name_like_cleanup(void *data)
207 {
208 free(data);
209 }
210
211 static int mm_is_set_parser(const char *arg, void **bitnum)
212 {
213 unsigned char *c = para_malloc(1);
214 int ret = get_attribute_bitnum_by_name(arg, c);
215
216 if (ret >= 0)
217 *bitnum = c;
218 else
219 free(c);
220 return ret;
221 }
222
223 static int mm_is_set_score_function(__a_unused const char *path,
224 __a_unused const struct afs_info *afsi,
225 __a_unused const struct audio_format_info *afhi,
226 const void *data)
227 {
228 const unsigned char *bn = data;
229 if (afsi->attributes & (1ULL << *bn))
230 return 100;
231 return -100;
232 }
233
234 /* returns 1 if row matches score item, negative otherwise */
235 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
236 long *score_arg_sum)
237 {
238 struct afs_info afsi;
239 struct audio_format_info afhi;
240 char *path;
241 int ret;
242
243 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
244 ret = 100;
245 if (item->method) {
246 ret = get_afsi_of_row(row, &afsi);
247 if (ret< 0)
248 return ret;
249 ret = get_afhi_of_row(row, &afhi);
250 if (ret< 0)
251 return ret;
252 ret = get_audio_file_path_of_row(row, &path);
253 if (ret< 0)
254 return ret;
255 ret = item->method->score_function(path, &afsi, &afhi,
256 item->parser_data);
257 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
258 return -1; /* no match */
259 }
260 if (item->random_score)
261 *score += PARA_ABS(ret) * para_random(100);
262 else
263 *score += PARA_ABS(ret) * item->score_arg;
264 return 1;
265 }
266
267 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
268 long *result)
269 {
270 struct mood_item *item;
271 int match = 0;
272 long score_arg_sum = 0, score = 0;
273
274 if (!m)
275 return -E_NO_MOOD;
276 /* reject audio file if it matches any entry in the deny list */
277 list_for_each_entry(item, &m->deny_list, mood_item_node)
278 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
279 return -E_NOT_ADMISSIBLE;
280 list_for_each_entry(item, &m->accept_list, mood_item_node)
281 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
282 match = 1;
283 /* reject if there is no matching entry in the accept list */
284 if (!match && !list_empty(&m->accept_list))
285 return -E_NOT_ADMISSIBLE;
286 list_for_each_entry(item, &m->score_list, mood_item_node)
287 add_item_score(aft_row, item, &score, &score_arg_sum);
288 if (score_arg_sum)
289 score /= score_arg_sum;
290 *result = score;
291 return 1;
292 }
293
294 static const struct mood_method mood_methods[] = {
295 {
296 .parser = mm_played_rarely_parser,
297 .score_function = mm_played_rarely_score_function,
298 .name = "played_rarely"
299 },
300 {
301 .parser = mm_is_set_parser,
302 .score_function = mm_is_set_score_function,
303 .name = "is_set"
304 },
305 {
306 .parser = mm_name_like_parser,
307 .score_function = mm_name_like_score_function,
308 .cleanup = mm_name_like_cleanup,
309 .name = "name_like"
310 },
311 {
312 .parser = NULL
313 }
314 };
315
316 static void cleanup_list_entry(struct mood_item *item)
317 {
318 if (item->method && item->method->cleanup)
319 item->method->cleanup(item->parser_data);
320 else
321 free(item->parser_data);
322 list_del(&item->mood_item_node);
323 free(item);
324 }
325
326 static void destroy_mood(struct mood *m)
327 {
328 struct mood_item *tmp, *item;
329
330 if (!m)
331 return;
332 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
333 cleanup_list_entry(item);
334 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
335 cleanup_list_entry(item);
336 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
337 cleanup_list_entry(item);
338 free(m->name);
339 free(m);
340 }
341
342 static struct mood *alloc_new_mood(const char *name)
343 {
344 struct mood *m = para_calloc(sizeof(struct mood));
345 m->name = para_strdup(name);
346 INIT_LIST_HEAD(&m->accept_list);
347 INIT_LIST_HEAD(&m->deny_list);
348 INIT_LIST_HEAD(&m->score_list);
349 return m;
350 }
351
352 /** The different types of a mood line. */
353 enum mood_line_type {
354 /** Invalid. */
355 ML_INVALID,
356 /** Accept line. */
357 ML_ACCEPT,
358 /** Deny line. */
359 ML_DENY,
360 /** Score line. */
361 ML_SCORE
362 };
363
364 struct mood_line_parser_data {
365 struct mood *m;
366 unsigned line_num;
367 };
368
369 /*
370 * <accept [with score <score>] | deny [with score <score>] | score <score>>
371 * [if] [not] <mood_method> [options]
372 * <score> is either an integer or "random" which assigns a random score to
373 * all matching files
374 */
375
376 static int parse_mood_line(char *mood_line, void *data)
377 {
378 struct mood_line_parser_data *mlpd = data;
379 char **argv;
380 char *delim = " \t";
381 unsigned num_words;
382 char **w;
383 int i, ret;
384 enum mood_line_type mlt = ML_INVALID;
385 struct mood_item *mi = NULL;
386 char *buf = para_strdup(mood_line);
387
388 mlpd->line_num++;
389 num_words = split_args(buf, &argv, delim);
390 ret = 1;
391 if (!num_words) /* empty line */
392 goto out;
393 w = argv;
394 if (**w == '#') /* comment */
395 goto out;
396 if (!strcmp(*w, "accept"))
397 mlt = ML_ACCEPT;
398 else if (!strcmp(*w, "deny"))
399 mlt = ML_DENY;
400 else if (!strcmp(*w, "score"))
401 mlt = ML_SCORE;
402 ret = -E_MOOD_SYNTAX;
403 if (mlt == ML_INVALID)
404 goto out;
405 mi = para_calloc(sizeof(struct mood_item));
406 if (mlt != ML_SCORE) {
407 ret = -E_MOOD_SYNTAX;
408 w++;
409 if (!*w)
410 goto out;
411 if (!strcmp(*w, "with")) {
412 w++;
413 if (!*w)
414 goto out;
415 }
416 }
417 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
418 ret = -E_MOOD_SYNTAX;
419 w++;
420 if (!*w)
421 goto out;
422 if (strcmp(*w, "random")) {
423 mi->random_score = 0;
424 ret = para_atoi32(*w, &mi->score_arg);
425 if (ret < 0)
426 goto out;
427 } else {
428 mi->random_score = 1;
429 if (!*(w + 1))
430 goto success; /* the line "score random" is valid */
431 }
432 } else
433 mi->score_arg = 0;
434 ret = -E_MOOD_SYNTAX;
435 w++;
436 if (!*w)
437 goto out;
438 if (!strcmp(*w, "if")) {
439 ret = -E_MOOD_SYNTAX;
440 w++;
441 if (!*w)
442 goto out;
443 }
444 if (!strcmp(*w, "not")) {
445 ret = -E_MOOD_SYNTAX;
446 w++;
447 if (!*w)
448 goto out;
449 mi->logical_not = 1;
450 } else
451 mi->logical_not = 0;
452 for (i = 0; mood_methods[i].parser; i++) {
453 if (strcmp(*w, mood_methods[i].name))
454 continue;
455 break;
456 }
457 ret = -E_MOOD_SYNTAX;
458 if (!mood_methods[i].parser)
459 goto out;
460 w++;
461 ret = mood_methods[i].parser(*w, &mi->parser_data);
462 if (ret < 0)
463 goto out;
464 mi->method = &mood_methods[i];
465 success:
466 if (mlpd->m) {
467 if (mlt == ML_ACCEPT)
468 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
469 else if (mlt == ML_DENY)
470 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
471 else
472 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
473 }
474 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
475 (mlt == ML_DENY? "deny" : "score"), mi->method);
476 ret = 1;
477 out:
478 free(argv);
479 free(buf);
480 if (ret >= 0)
481 return ret;
482 if (mi) {
483 free(mi->parser_data);
484 free(mi);
485 }
486 return ret;
487 }
488
489 static int load_mood(const struct osl_row *mood_row, struct mood **m)
490 {
491 char *mood_name;
492 struct osl_object mood_def;
493 struct mood_line_parser_data mlpd = {.line_num = 0};
494 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
495
496 if (ret < 0)
497 return ret;
498 if (!*mood_name)
499 return -E_DUMMY_ROW;
500 mlpd.m = alloc_new_mood(mood_name);
501 ret = for_each_line_ro(mood_def.data, mood_def.size,
502 parse_mood_line, &mlpd);
503 osl_close_disk_object(&mood_def);
504 if (ret < 0) {
505 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
506 PARA_STRERROR(-ret));
507 destroy_mood(mlpd.m);
508 return ret;
509 }
510 PARA_INFO_LOG("loaded mood %s\n", mlpd.m->name);
511 *m = mlpd.m;
512 return 1;
513 }
514
515 /*
516 * Calls load_mood() and reverts its error value: It returns -E_MOOD_LOADED
517 * on _success_, and 1 on errors. This way the loop over all moods stops at the
518 * first valid mood.
519 */
520 static int load_mood_loop_func(struct osl_row *mood_row, void *data)
521 {
522 struct mood **m = data;
523 int ret = load_mood(mood_row, m);
524 if (ret < 0) {
525 if (ret != -E_DUMMY_ROW)
526 PARA_NOTICE_LOG("invalid mood (%d), trying next mood\n", ret);
527 return 1;
528 }
529 return -E_MOOD_LOADED;
530 }
531
532 static int load_first_available_mood(struct mood **m)
533 {
534 int ret = osl_rbtree_loop(moods_table, BLOBCOL_NAME, m,
535 load_mood_loop_func);
536 if (ret == -E_MOOD_LOADED) /* success */
537 return 1;
538 if (ret < 0)
539 return ret; /* error */
540 PARA_NOTICE_LOG("no valid mood found\n");
541 return -E_NO_MOOD;
542 }
543
544 static int check_mood(struct osl_row *mood_row, void *data)
545 {
546 struct para_buffer *pb = data;
547 char *mood_name;
548 struct osl_object mood_def;
549 struct mood_line_parser_data mlpd = {.line_num = 0};
550
551 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
552
553 if (ret < 0) {
554 para_printf(pb, "failed to get mood definition\n");
555 return ret;
556 }
557 if (!*mood_name) /* ignore dummy row */
558 goto out;
559 para_printf(pb, "checking mood %s...\n", mood_name);
560 ret = for_each_line_ro(mood_def.data, mood_def.size,
561 parse_mood_line, &mlpd);
562 if (ret < 0)
563 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
564 PARA_STRERROR(-ret));
565 out:
566 osl_close_disk_object(&mood_def);
567 return 1;
568 }
569
570 /**
571 * Check all moods for syntax errors.
572 *
573 * \param query Unused.
574 * \param result: Contains check messages.
575 */
576 int mood_check_callback(__a_unused const struct osl_object *query,
577 struct osl_object *result)
578 {
579 struct para_buffer pb = {.buf = NULL};
580
581 para_printf(&pb, "checking moods...\n");
582 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
583 check_mood);
584 result->data = pb.buf;
585 result->size = pb.size;
586 return 1;
587 }
588
589 #if 0
590 static unsigned int_log2(uint64_t x)
591 {
592 unsigned res = 0;
593
594 while (x) {
595 x /= 2;
596 res++;
597 }
598 return res;
599 }
600 #endif
601
602 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
603 {
604 if (!n || !qd)
605 return 0;
606 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
607 }
608
609 static long compute_num_played_score(struct afs_info *afsi)
610 {
611 return -normalized_value(afsi->num_played, statistics.num,
612 statistics.num_played_sum, statistics.num_played_qd);
613 }
614
615 static long compute_last_played_score(struct afs_info *afsi)
616 {
617 return -normalized_value(afsi->last_played, statistics.num,
618 statistics.last_played_sum, statistics.last_played_qd);
619 }
620
621 static long compute_dynamic_score(const struct osl_row *aft_row)
622 {
623 struct afs_info afsi;
624 int64_t score, nscore = 0, lscore = 0;
625 int ret;
626
627 ret = get_afsi_of_row(aft_row, &afsi);
628 if (ret < 0)
629 return -100;
630 nscore = compute_num_played_score(&afsi);
631 lscore = compute_last_played_score(&afsi);
632 score = nscore + lscore;
633 return score;
634 }
635
636 static int add_afs_statistics(const struct osl_row *row)
637 {
638 uint64_t n, x, s;
639 struct afs_info afsi;
640 int ret;
641
642 ret = get_afsi_of_row(row, &afsi);
643 if (ret < 0)
644 return ret;
645 n = statistics.num;
646 x = afsi.last_played;
647 s = statistics.last_played_sum;
648 if (n > 0)
649 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
650 statistics.last_played_sum += x;
651
652 x = afsi.num_played;
653 s = statistics.num_played_sum;
654 if (n > 0)
655 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
656 statistics.num_played_sum += x;
657 statistics.num++;
658 return 1;
659 }
660
661 static int del_afs_statistics(const struct osl_row *row)
662 {
663 uint64_t n, s, q, a, new_s;
664 struct afs_info afsi;
665 int ret;
666 ret = get_afsi_of_row(row, &afsi);
667 if (ret < 0)
668 return ret;
669 n = statistics.num;
670 assert(n);
671 if (n == 1) {
672 memset(&statistics, 0, sizeof(statistics));
673 return 1;
674 }
675
676 s = statistics.last_played_sum;
677 q = statistics.last_played_qd;
678 a = afsi.last_played;
679 new_s = s - a;
680 statistics.last_played_sum = new_s;
681 statistics.last_played_qd = q + s * s / n - a * a
682 - new_s * new_s / (n - 1);
683
684 s = statistics.num_played_sum;
685 q = statistics.num_played_qd;
686 a = afsi.num_played;
687 new_s = s - a;
688 statistics.num_played_sum = new_s;
689 statistics.num_played_qd = q + s * s / n - a * a
690 - new_s * new_s / (n - 1);
691
692 statistics.num--;
693 return 1;
694 }
695
696 /**
697 * Structure used during mood_open().
698 *
699 * At mood open time, we look at each file in the audio file table in order to
700 * determine whether it is admissible. If a file happens to be admissible, its
701 * mood score is computed by calling each relevant mood_score_function. Next,
702 * we update the afs_statistics and add a struct admissible_file_info to a
703 * temporary array.
704 *
705 * If all files have been processed that way, the final score of each
706 * admissible file is computed by adding the dynamic score (which depends on
707 * the afs_statistics) to the mood score. Finally, all audio files in the
708 * array are added to the score table and the admissible array is freed.
709 *
710 * \sa mood_method, admissible_array.
711 */
712 struct admissible_file_info
713 {
714 /** The admissible audio file. */
715 struct osl_row *aft_row;
716 /** Its score. */
717 long score;
718 };
719
720 /** The temporary array of admissible files. */
721 struct admissible_array {
722 /** Files are admissible wrt. this mood. */
723 struct mood *m;
724 /** The size of the array */
725 unsigned size;
726 /** Pointer to the array of admissible files. */
727 struct admissible_file_info *array;
728 };
729
730 /**
731 * Add an entry to the array of admissible files.
732 *
733 * \param aft_row The audio file to be added.
734 * \param private_data Pointer to a struct admissible_file_info.
735 *
736 * \return Negative on errors, positive on success.
737 */
738 static int add_if_admissible(struct osl_row *aft_row, void *data)
739 {
740 struct admissible_array *aa = data;
741 int ret;
742 long score = 0;
743
744 ret = compute_mood_score(aft_row, aa->m, &score);
745 if (ret < 0)
746 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
747 if (statistics.num >= aa->size) {
748 aa->size *= 2;
749 aa->size += 100;
750 aa->array = para_realloc(aa->array,
751 aa->size * sizeof(struct admissible_file_info));
752 }
753 aa->array[statistics.num].aft_row = aft_row;
754 aa->array[statistics.num].score = score;
755 ret = add_afs_statistics(aft_row);
756 if (ret < 0)
757 return ret;
758 return 1;
759 }
760
761 /**
762 * Compute the new quadratic deviation in case one element changes.
763 *
764 * \param n Number of elements.
765 * \param old_qd The quadratic deviation before the change.
766 * \param old_val The value that was replaced.
767 * \param new_val The replacement value.
768 * \param old_sum The sum of all elements before the update.
769 *
770 * \return The new quadratic deviation resulting from replacing old_val
771 * by new_val.
772 *
773 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
774 * their quadratic deviation
775 *
776 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
777 *
778 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
779 * the last number a_n was replaced by b) may be computed in O(1) time in terms
780 * of n, q, a_n, b, and S as
781 *
782 * q' = q + d * s - (2 * S + d) * d / n,
783 *
784 * where d = b - a_n, and s = b + a_n.
785 *
786 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
787 * s = 17, so
788 *
789 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
790 *
791 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
792 *
793 */
794 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
795 int64_t old_val, int64_t new_val, int64_t old_sum)
796 {
797 int64_t delta = new_val - old_val;
798 int64_t sigma = new_val + old_val;
799 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
800 }
801
802 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
803 {
804 unsigned n;
805 int ret = get_num_admissible_files(&n);
806
807 if (ret < 0)
808 return ret;
809 assert(n);
810
811 statistics.last_played_qd = update_quadratic_deviation(n,
812 statistics.last_played_qd, old_afsi->last_played,
813 new_afsi->last_played, statistics.last_played_sum);
814 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
815
816 statistics.num_played_qd = update_quadratic_deviation(n,
817 statistics.num_played_qd, old_afsi->num_played,
818 new_afsi->num_played, statistics.num_played_sum);
819 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
820 return 1;
821 }
822
823 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
824 {
825 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
826 return score_add(aft_row, score);
827 }
828
829 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
830 {
831 int ret = del_afs_statistics(aft_row);
832 if (ret < 0)
833 return ret;
834 return score_delete(aft_row);
835 }
836
837 /**
838 * Delete one entry from the statistics and from the score table.
839 *
840 * \param aft_row The audio file which is no longer admissible.
841 *
842 * \return Positive on success, negative on errors.
843 *
844 * \sa score_delete(), mood_update_audio_file().
845 */
846 int mood_delete_audio_file(const struct osl_row *aft_row)
847 {
848 int ret;
849
850 ret = row_belongs_to_score_table(aft_row);
851 if (ret < 0)
852 return ret;
853 if (!ret) /* not admissible, nothing to do */
854 return 1;
855 return delete_from_statistics_and_score_table(aft_row);
856 }
857
858 /**
859 * Compute the new score of an audio file wrt. the current mood.
860 *
861 * \param aft_row Determines the audio file.
862 * \param old_afsi The audio file selector info before updating.
863 *
864 * The \a old_afsi argument may be \p NULL which indicates that no changes to
865 * the audio file info were made.
866 *
867 * \return Positive on success, negative on errors.
868 */
869 int mood_update_audio_file(const struct osl_row *aft_row, struct afs_info *old_afsi)
870 {
871 long score, percent;
872 int ret, is_admissible, was_admissible = 0;
873 struct afs_info afsi;
874
875 if (!current_mood)
876 return 1; /* nothing to do */
877 ret = row_belongs_to_score_table(aft_row);
878 if (ret < 0)
879 return ret;
880 was_admissible = ret;
881 ret = compute_mood_score(aft_row, current_mood, &score);
882 is_admissible = (ret > 0);
883 if (!was_admissible && !is_admissible)
884 return 1;
885 if (was_admissible && !is_admissible)
886 return delete_from_statistics_and_score_table(aft_row);
887 if (!was_admissible && is_admissible) {
888 ret = add_afs_statistics(aft_row);
889 if (ret < 0)
890 return ret;
891 return add_to_score_table(aft_row, score);
892 }
893 /* update score */
894 ret = get_afsi_of_row(aft_row, &afsi);
895 if (ret < 0)
896 return ret;
897 if (old_afsi) {
898 ret = update_afs_statistics(old_afsi, &afsi);
899 if (ret < 0)
900 return ret;
901 }
902 score += compute_num_played_score(&afsi);
903 score += compute_last_played_score(&afsi);
904 score /= 3;
905 PARA_DEBUG_LOG("score: %li\n", score);
906 percent = (score + 100) / 3;
907 if (percent > 100)
908 percent = 100;
909 else if (percent < 0)
910 percent = 0;
911 PARA_DEBUG_LOG("re-inserting at %lu%%\n", percent);
912 return score_update(aft_row, percent);
913 }
914
915 static void log_statistics(void)
916 {
917 unsigned n = statistics.num;
918
919 if (!n) {
920 PARA_NOTICE_LOG("no admissible files\n");
921 return;
922 }
923 PARA_NOTICE_LOG("last_played mean: %lli, last_played sigma: %llu\n",
924 (long long int)(statistics.last_played_sum / n),
925 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
926 PARA_NOTICE_LOG("num_played mean: %lli, num_played sigma: %llu\n",
927 (long long int)statistics.num_played_sum / n,
928 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
929 }
930
931 /**
932 * Change the current mood.
933 *
934 * \param mood_name The name of the mood to open.
935 *
936 * There are two special cases: If \a mood_name is \a NULL, load the
937 * first available mood. If \a mood_name is the empty string "", load
938 * the dummy mood that accepts every audio file and uses a scoring method
939 * based only on the \a last_played information.
940 *
941 * If there is already an open mood, it will be closed first.
942 *
943 * \return Positive on success, negative on errors. Loading the dummy mood
944 * always succeeds.
945 *
946 * \sa struct admissible_file_info, struct admissible_array, struct
947 * afs_info::last_played, mood_close().
948 */
949 int change_current_mood(char *mood_name)
950 {
951 int i, ret;
952 struct admissible_array aa = {
953 .size = 0,
954 .array = NULL
955 };
956
957 if (!mood_name) {
958 struct mood *m;
959 ret = load_first_available_mood(&m);
960 if (ret < 0)
961 return ret;
962 destroy_mood(current_mood);
963 current_mood = m;
964 } else if (*mood_name) {
965 struct mood *m;
966 struct osl_row *row;
967 struct osl_object obj = {
968 .data = mood_name,
969 .size = strlen(mood_name) + 1
970 };
971 ret = osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row);
972 if (ret < 0) {
973 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
974 return ret;
975 }
976 ret = load_mood(row, &m);
977 if (ret < 0)
978 return ret;
979 destroy_mood(current_mood);
980 current_mood = m;
981 } else {
982 destroy_mood(current_mood);
983 current_mood = alloc_new_mood("dummy");
984 }
985 aa.m = current_mood;
986 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
987 PARA_INFO_LOG("%s\n", "computing statistics of admissible files");
988 ret = audio_file_loop(&aa, add_if_admissible);
989 if (ret < 0)
990 return ret;
991 log_statistics();
992 PARA_NOTICE_LOG("%d admissible files \n", statistics.num);
993 for (i = 0; i < statistics.num; i++) {
994 struct admissible_file_info *a = aa.array + i;
995 ret = add_to_score_table(a->aft_row, a->score);
996 if (ret < 0)
997 goto out;
998 }
999 PARA_NOTICE_LOG("score add complete\n");
1000 ret = 1;
1001 out:
1002 free(aa.array);
1003 return ret;
1004 }
1005
1006 /**
1007 * Close the current mood.
1008 *
1009 * Free all resources of the current mood which were allocated during
1010 * mood_open().
1011 */
1012 void close_current_mood(void)
1013 {
1014 destroy_mood(current_mood);
1015 current_mood = NULL;
1016 memset(&statistics, 0, sizeof(statistics));
1017 }
1018
1019 /**
1020 * Close and re-open the current mood.
1021 *
1022 * This function is used if changes to the audio file table or the
1023 * attribute table were made that render the current list of admissible
1024 * files useless. For example, if an attribute is removed from the
1025 * attribute table, this function is called.
1026 *
1027 * \return Positive on success, negative on errors. If no mood is currently
1028 * open, the function returns success.
1029 *
1030 * \sa mood_open(), mood_close().
1031 */
1032 int reload_current_mood(void)
1033 {
1034 int ret;
1035 char *mood_name;
1036
1037 if (!current_mood)
1038 return 1;
1039 score_shutdown(0);
1040 mood_name = para_strdup(current_mood->name);
1041 close_current_mood();
1042 ret = change_current_mood(mood_name);
1043 free(mood_name);
1044 return ret;
1045 }