mood.c: Avoid overflow in update_quadratic_deviation().
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007-2013 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 <regex.h>
10 #include <osl.h>
11
12 #include "para.h"
13 #include "error.h"
14 #include "string.h"
15 #include "afh.h"
16 #include "afs.h"
17 #include "list.h"
18 #include "ipc.h"
19 #include "mm.h"
20 #include "sideband.h"
21
22 /**
23 * Contains statistical data of the currently admissible audio files.
24 *
25 * It is used to assign normalized score values to each admissible audio file.
26 */
27 struct afs_statistics {
28 /** Sum of num played over all admissible files. */
29 int64_t num_played_sum;
30 /** Sum of last played times over all admissible files. */
31 int64_t last_played_sum;
32 /** Quadratic deviation of num played time. */
33 int64_t num_played_qd;
34 /** Quadratic deviation of last played time. */
35 int64_t last_played_qd;
36 /** Number of admissible files */
37 unsigned num;
38 };
39 static struct afs_statistics statistics;
40
41 /**
42 * Each line of the current mood corresponds to a mood_item.
43 */
44 struct mood_item {
45 /** The method this line is referring to. */
46 const struct mood_method *method;
47 /** The data structure computed by the mood parser. */
48 void *parser_data;
49 /** The given score value, or zero if none was given. */
50 int32_t score_arg;
51 /** Non-zero if random scoring was requested. */
52 int random_score;
53 /** Whether the "not" keyword was given in the mood line. */
54 int logical_not;
55 /** The position in the list of items. */
56 struct list_head mood_item_node;
57 };
58
59 /**
60 * Created from the mood definition by mood_open().
61 *
62 * When a mood is opened, each line of its definition is investigated, and a
63 * corresponding mood item is produced. Each mood line starts with \p accept,
64 * \p deny, or \p score which determines the type of the mood line. For each
65 * such type a linked list is maintained whose entries are the mood items.
66 *
67 * \sa mood_item, mood_open().
68 */
69 struct mood {
70 /** The name of this mood. */
71 char *name;
72 /** The list of mood items of type \p accept. */
73 struct list_head accept_list;
74 /** The list of mood items of type \p deny. */
75 struct list_head deny_list;
76 /** The list of mood items of type \p score. */
77 struct list_head score_list;
78 };
79
80 /*
81 * If current_mood is NULL then no mood is currently open. If
82 * current_mood->name is NULL, the dummy mood is currently open
83 */
84 static struct mood *current_mood;
85
86 /**
87 * Rough approximation to sqrt.
88 *
89 * \param x Integer of which to calculate the sqrt.
90 *
91 * \return An integer res with res * res <= x.
92 */
93 __a_const static uint64_t int_sqrt(uint64_t x)
94 {
95 uint64_t op, res, one = 1;
96 op = x;
97 res = 0;
98
99 one = one << 62;
100 while (one > op)
101 one >>= 2;
102
103 while (one != 0) {
104 if (op >= res + one) {
105 op = op - (res + one);
106 res = res + 2 * one;
107 }
108 res /= 2;
109 one /= 4;
110 }
111 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
112 return res;
113 }
114
115 /*
116 * Returns true if row matches, false if it does not match. In any case score
117 * and score_arg_sum are set/increased accordingly.
118 */
119 static bool get_item_score(struct mood_item *item, const struct afs_info *afsi,
120 const struct afh_info *afhi, const char *path, long *score,
121 long *score_arg_sum)
122 {
123 int ret;
124 bool match = true;
125
126 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
127 ret = 100;
128 if (item->method) {
129 ret = item->method->score_function(path, afsi, afhi,
130 item->parser_data);
131 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
132 match = false;
133 }
134 if (item->random_score)
135 *score = PARA_ABS(ret) * para_random(100);
136 else
137 *score = PARA_ABS(ret) * item->score_arg;
138 return match;
139 }
140
141 /* returns 1 if row admissible, 0 if not, negative on errors */
142 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
143 long *result)
144 {
145 struct mood_item *item;
146 int ret;
147 bool match;
148 long score_arg_sum = 0, score = 0, item_score;
149 struct afs_info afsi;
150 struct afh_info afhi;
151 char *path;
152
153 if (!m)
154 return -E_NO_MOOD;
155 ret = get_afsi_of_row(aft_row, &afsi);
156 if (ret< 0)
157 return ret;
158 ret = get_afhi_of_row(aft_row, &afhi);
159 if (ret< 0)
160 return ret;
161 ret = get_audio_file_path_of_row(aft_row, &path);
162 if (ret< 0)
163 return ret;
164 /* reject audio file if it matches any entry in the deny list */
165 list_for_each_entry(item, &m->deny_list, mood_item_node) {
166 match = get_item_score(item, &afsi, &afhi, path, &item_score,
167 &score_arg_sum);
168 if (match) /* not admissible */
169 return 0;
170 score += item_score;
171 }
172 match = false;
173 list_for_each_entry(item, &m->accept_list, mood_item_node) {
174 ret = get_item_score(item, &afsi, &afhi, path, &item_score,
175 &score_arg_sum);
176 if (ret == 0)
177 continue;
178 match = true;
179 score += item_score;
180 }
181 /* reject if there is no matching entry in the accept list */
182 if (!match && !list_empty(&m->accept_list))
183 return 0;
184 list_for_each_entry(item, &m->score_list, mood_item_node) {
185 match = get_item_score(item, &afsi, &afhi, path, &item_score,
186 &score_arg_sum);
187 if (match)
188 score += item_score;
189 }
190 if (score_arg_sum)
191 score /= score_arg_sum;
192 *result = score;
193 return 1;
194 }
195
196 static void cleanup_list_entry(struct mood_item *item)
197 {
198 if (item->method && item->method->cleanup)
199 item->method->cleanup(item->parser_data);
200 else
201 free(item->parser_data);
202 list_del(&item->mood_item_node);
203 free(item);
204 }
205
206 static void destroy_mood(struct mood *m)
207 {
208 struct mood_item *tmp, *item;
209
210 if (!m)
211 return;
212 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
213 cleanup_list_entry(item);
214 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
215 cleanup_list_entry(item);
216 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
217 cleanup_list_entry(item);
218 free(m->name);
219 free(m);
220 }
221
222 static struct mood *alloc_new_mood(const char *name)
223 {
224 struct mood *m = para_calloc(sizeof(struct mood));
225 if (name)
226 m->name = para_strdup(name);
227 INIT_LIST_HEAD(&m->accept_list);
228 INIT_LIST_HEAD(&m->deny_list);
229 INIT_LIST_HEAD(&m->score_list);
230 return m;
231 }
232
233 /** The different types of a mood line. */
234 enum mood_line_type {
235 /** Invalid. */
236 ML_INVALID,
237 /** Accept line. */
238 ML_ACCEPT,
239 /** Deny line. */
240 ML_DENY,
241 /** Score line. */
242 ML_SCORE
243 };
244
245 /** Data passed to the parser of a mood line. */
246 struct mood_line_parser_data {
247 /** The mood this mood line belongs to. */
248 struct mood *m;
249 /** The line number in the mood definition. */
250 unsigned line_num;
251 };
252
253 /*
254 * <accept [with score <score>] | deny [with score <score>] | score <score>>
255 * [if] [not] <mood_method> [options]
256 * <score> is either an integer or "random" which assigns a random score to
257 * all matching files
258 */
259
260 static int parse_mood_line(char *mood_line, void *data)
261 {
262 struct mood_line_parser_data *mlpd = data;
263 char **argv;
264 unsigned num_words;
265 char **w;
266 int i, ret;
267 enum mood_line_type mlt = ML_INVALID;
268 struct mood_item *mi = NULL;
269
270 mlpd->line_num++;
271 ret = create_argv(mood_line, " \t", &argv);
272 if (ret < 0)
273 return ret;
274 num_words = ret;
275 if (!num_words) /* empty line */
276 goto out;
277 w = argv;
278 if (**w == '#') /* comment */
279 goto out;
280 if (!strcmp(*w, "accept"))
281 mlt = ML_ACCEPT;
282 else if (!strcmp(*w, "deny"))
283 mlt = ML_DENY;
284 else if (!strcmp(*w, "score"))
285 mlt = ML_SCORE;
286 ret = -E_MOOD_SYNTAX;
287 if (mlt == ML_INVALID)
288 goto out;
289 mi = para_calloc(sizeof(struct mood_item));
290 if (mlt != ML_SCORE) {
291 ret = -E_MOOD_SYNTAX;
292 w++;
293 if (!*w)
294 goto out;
295 if (strcmp(*w, "with"))
296 goto check_for_if;
297 w++;
298 if (!*w)
299 goto out;
300 if (strcmp(*w, "score"))
301 goto out;
302 }
303 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
304 ret = -E_MOOD_SYNTAX;
305 w++;
306 if (!*w)
307 goto out;
308 if (strcmp(*w, "random")) {
309 mi->random_score = 0;
310 ret = para_atoi32(*w, &mi->score_arg);
311 if (ret < 0)
312 goto out;
313 } else {
314 mi->random_score = 1;
315 if (!*(w + 1))
316 goto success; /* the line "score random" is valid */
317 }
318 } else
319 mi->score_arg = 0;
320 ret = -E_MOOD_SYNTAX;
321 w++;
322 if (!*w)
323 goto out;
324 check_for_if:
325 if (!strcmp(*w, "if")) {
326 ret = -E_MOOD_SYNTAX;
327 w++;
328 if (!*w)
329 goto out;
330 }
331 if (!strcmp(*w, "not")) {
332 ret = -E_MOOD_SYNTAX;
333 w++;
334 if (!*w)
335 goto out;
336 mi->logical_not = 1;
337 } else
338 mi->logical_not = 0;
339 for (i = 0; mood_methods[i].parser; i++) {
340 if (strcmp(*w, mood_methods[i].name))
341 continue;
342 break;
343 }
344 ret = -E_MOOD_SYNTAX;
345 if (!mood_methods[i].parser)
346 goto out;
347 ret = mood_methods[i].parser(num_words - 1 - (w - argv), w,
348 &mi->parser_data);
349 if (ret < 0)
350 goto out;
351 mi->method = &mood_methods[i];
352 success:
353 if (mlpd->m) {
354 if (mlt == ML_ACCEPT)
355 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
356 else if (mlt == ML_DENY)
357 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
358 else
359 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
360 }
361 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
362 (mlt == ML_DENY? "deny" : "score"), mi->method);
363 ret = 1;
364 out:
365 free_argv(argv);
366 if (ret >= 0)
367 return ret;
368 if (mi) {
369 free(mi->parser_data);
370 free(mi);
371 }
372 return ret;
373 }
374
375 static int load_mood(const struct osl_row *mood_row, struct mood **m)
376 {
377 char *mood_name;
378 struct osl_object mood_def;
379 struct mood_line_parser_data mlpd = {.line_num = 0};
380 int ret;
381
382 *m = NULL;
383 ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
384 if (ret < 0)
385 return ret;
386 if (!*mood_name)
387 return -E_DUMMY_ROW;
388 mlpd.m = alloc_new_mood(mood_name);
389 ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
390 parse_mood_line, &mlpd);
391 osl_close_disk_object(&mood_def);
392 if (ret < 0) {
393 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
394 para_strerror(-ret));
395 destroy_mood(mlpd.m);
396 return ret;
397 }
398 *m = mlpd.m;
399 return 1;
400 }
401
402 static int check_mood(struct osl_row *mood_row, void *data)
403 {
404 struct para_buffer *pb = data;
405 char *mood_name;
406 struct osl_object mood_def;
407 struct mood_line_parser_data mlpd = {.line_num = 0};
408
409 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
410
411 if (ret < 0) {
412 para_printf(pb, "failed to get mood definition: %s\n",
413 para_strerror(-ret));
414 return ret;
415 }
416 if (!*mood_name) /* ignore dummy row */
417 goto out;
418 ret = para_printf(pb, "checking mood %s...\n", mood_name);
419 if (ret < 0)
420 goto out;
421 ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
422 parse_mood_line, &mlpd);
423 if (ret < 0)
424 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
425 para_strerror(-ret));
426 out:
427 osl_close_disk_object(&mood_def);
428 return ret;
429 }
430
431 /**
432 * Check all moods for syntax errors.
433 *
434 * \param fd The afs socket.
435 * \param query Unused.
436 */
437 void mood_check_callback(int fd, __a_unused const struct osl_object *query)
438 {
439 struct para_buffer pb = {
440 .max_size = shm_get_shmmax(),
441 .private_data = &(struct afs_max_size_handler_data) {
442 .fd = fd,
443 .band = SBD_OUTPUT
444 },
445 .max_size_handler = afs_max_size_handler
446 };
447
448 int ret = para_printf(&pb, "checking moods...\n");
449 if (ret < 0)
450 return;
451 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
452 check_mood);
453 if (pb.offset)
454 pass_buffer_as_shm(fd, SBD_OUTPUT, pb.buf, pb.offset);
455 free(pb.buf);
456 }
457
458 #if 0
459 static unsigned int_log2(uint64_t x)
460 {
461 unsigned res = 0;
462
463 while (x) {
464 x /= 2;
465 res++;
466 }
467 return res;
468 }
469 #endif
470
471 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
472 {
473 if (!n || !qd)
474 return 0;
475 return 100 * (n * x - sum) / (int64_t)int_sqrt(n) / (int64_t)int_sqrt(qd);
476 }
477
478 static long compute_num_played_score(struct afs_info *afsi)
479 {
480 return -normalized_value(afsi->num_played, statistics.num,
481 statistics.num_played_sum, statistics.num_played_qd);
482 }
483
484 static long compute_last_played_score(struct afs_info *afsi)
485 {
486 return -normalized_value(afsi->last_played, statistics.num,
487 statistics.last_played_sum, statistics.last_played_qd);
488 }
489
490 static long compute_dynamic_score(const struct osl_row *aft_row)
491 {
492 struct afs_info afsi;
493 int64_t score, nscore = 0, lscore = 0;
494 int ret;
495
496 ret = get_afsi_of_row(aft_row, &afsi);
497 if (ret < 0)
498 return -100;
499 nscore = compute_num_played_score(&afsi);
500 lscore = compute_last_played_score(&afsi);
501 score = nscore + lscore;
502 return score;
503 }
504
505 static int add_afs_statistics(const struct osl_row *row)
506 {
507 uint64_t n, x, s, q;
508 struct afs_info afsi;
509 int ret;
510
511 ret = get_afsi_of_row(row, &afsi);
512 if (ret < 0)
513 return ret;
514 n = statistics.num;
515 x = afsi.last_played;
516 s = statistics.last_played_sum;
517 if (n > 0) {
518 q = (x > s / n)? x - s / n : s / n - x;
519 statistics.last_played_qd += q * q * n / (n + 1);
520 }
521 statistics.last_played_sum += x;
522
523 x = afsi.num_played;
524 s = statistics.num_played_sum;
525 if (n > 0) {
526 q = (x > s / n)? x - s / n : s / n - x;
527 statistics.num_played_qd += q * q * n / (n + 1);
528 }
529 statistics.num_played_sum += x;
530 statistics.num++;
531 return 1;
532 }
533
534 static int del_afs_statistics(const struct osl_row *row)
535 {
536 uint64_t n, s, q, a, new_s;
537 struct afs_info afsi;
538 int ret;
539 ret = get_afsi_of_row(row, &afsi);
540 if (ret < 0)
541 return ret;
542 n = statistics.num;
543 assert(n);
544 if (n == 1) {
545 memset(&statistics, 0, sizeof(statistics));
546 return 1;
547 }
548
549 s = statistics.last_played_sum;
550 q = statistics.last_played_qd;
551 a = afsi.last_played;
552 new_s = s - a;
553 statistics.last_played_sum = new_s;
554 statistics.last_played_qd = q + s * s / n - a * a
555 - new_s * new_s / (n - 1);
556
557 s = statistics.num_played_sum;
558 q = statistics.num_played_qd;
559 a = afsi.num_played;
560 new_s = s - a;
561 statistics.num_played_sum = new_s;
562 statistics.num_played_qd = q + s * s / n - a * a
563 - new_s * new_s / (n - 1);
564
565 statistics.num--;
566 return 1;
567 }
568
569 /**
570 * Structure used during mood_open().
571 *
572 * At mood open time, we look at each file in the audio file table in order to
573 * determine whether it is admissible. If a file happens to be admissible, its
574 * mood score is computed by calling each relevant mood_score_function. Next,
575 * we update the afs_statistics and add a struct admissible_file_info to a
576 * temporary array.
577 *
578 * If all files have been processed that way, the final score of each
579 * admissible file is computed by adding the dynamic score (which depends on
580 * the afs_statistics) to the mood score. Finally, all audio files in the
581 * array are added to the score table and the admissible array is freed.
582 *
583 * \sa mood_method, admissible_array.
584 */
585 struct admissible_file_info
586 {
587 /** The admissible audio file. */
588 struct osl_row *aft_row;
589 /** Its score. */
590 long score;
591 };
592
593 /** The temporary array of admissible files. */
594 struct admissible_array {
595 /** Files are admissible wrt. this mood. */
596 struct mood *m;
597 /** The size of the array */
598 unsigned size;
599 /** Pointer to the array of admissible files. */
600 struct admissible_file_info *array;
601 };
602
603 /**
604 * Add an entry to the array of admissible files.
605 *
606 * \param aft_row The audio file to be added.
607 * \param private_data Pointer to a struct admissible_file_info.
608 *
609 * \return 1 if row admissible, 0 if not, negative on errors.
610 */
611 static int add_if_admissible(struct osl_row *aft_row, void *data)
612 {
613 struct admissible_array *aa = data;
614 int ret;
615 long score = 0;
616
617 ret = compute_mood_score(aft_row, aa->m, &score);
618 if (ret <= 0)
619 return ret;
620 if (statistics.num >= aa->size) {
621 aa->size *= 2;
622 aa->size += 100;
623 aa->array = para_realloc(aa->array,
624 aa->size * sizeof(struct admissible_file_info));
625 }
626 aa->array[statistics.num].aft_row = aft_row;
627 aa->array[statistics.num].score = score;
628 ret = add_afs_statistics(aft_row);
629 if (ret < 0)
630 return ret;
631 return 1;
632 }
633
634 /**
635 * Compute the new quadratic deviation in case one element changes.
636 *
637 * \param n Number of elements.
638 * \param old_qd The quadratic deviation before the change.
639 * \param old_val The value that was replaced.
640 * \param new_val The replacement value.
641 * \param old_sum The sum of all elements before the update.
642 *
643 * \return The new quadratic deviation resulting from replacing old_val
644 * by new_val.
645 *
646 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
647 * their quadratic deviation
648 *
649 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
650 *
651 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
652 * the last number a_n was replaced by b) may be computed in O(1) time in terms
653 * of n, q, a_n, b, and S as
654 *
655 * q' = q + d * s - (2 * S + d) * d / n
656 * = q + d * (s - 2 * S / n - d /n),
657 *
658 * where d = b - a_n, and s = b + a_n.
659 *
660 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
661 * s = 17, so
662 *
663 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
664 *
665 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
666 *
667 */
668 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
669 int64_t old_val, int64_t new_val, int64_t old_sum)
670 {
671 int64_t delta = new_val - old_val;
672 int64_t sigma = new_val + old_val;
673 return old_qd + delta * (sigma - 2 * old_sum / n - delta / n);
674 }
675
676 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
677 {
678 unsigned n;
679 int ret = get_num_admissible_files(&n);
680
681 if (ret < 0)
682 return ret;
683 assert(n);
684
685 statistics.last_played_qd = update_quadratic_deviation(n,
686 statistics.last_played_qd, old_afsi->last_played,
687 new_afsi->last_played, statistics.last_played_sum);
688 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
689
690 statistics.num_played_qd = update_quadratic_deviation(n,
691 statistics.num_played_qd, old_afsi->num_played,
692 new_afsi->num_played, statistics.num_played_sum);
693 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
694 return 1;
695 }
696
697 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
698 {
699 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
700 return score_add(aft_row, score);
701 }
702
703 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
704 {
705 int ret = del_afs_statistics(aft_row);
706 if (ret < 0)
707 return ret;
708 return score_delete(aft_row);
709 }
710
711 /**
712 * Delete one entry from the statistics and from the score table.
713 *
714 * \param aft_row The audio file which is no longer admissible.
715 *
716 * \return Positive on success, negative on errors.
717 *
718 * \sa score_delete().
719 */
720 static int mood_delete_audio_file(const struct osl_row *aft_row)
721 {
722 int ret;
723
724 ret = row_belongs_to_score_table(aft_row, NULL);
725 if (ret < 0)
726 return ret;
727 if (!ret) /* not admissible, nothing to do */
728 return 1;
729 return delete_from_statistics_and_score_table(aft_row);
730 }
731
732 /**
733 * Compute the new score of an audio file wrt. the current mood.
734 *
735 * \param aft_row Determines the audio file.
736 * \param old_afsi The audio file selector info before updating.
737 *
738 * The \a old_afsi argument may be \p NULL which indicates that no changes to
739 * the audio file info were made.
740 *
741 * \return Positive on success, negative on errors.
742 */
743 static int mood_update_audio_file(const struct osl_row *aft_row,
744 struct afs_info *old_afsi)
745 {
746 long score, percent;
747 int ret, is_admissible, was_admissible = 0;
748 struct afs_info afsi;
749 unsigned rank;
750
751 if (!current_mood)
752 return 1; /* nothing to do */
753 ret = row_belongs_to_score_table(aft_row, &rank);
754 if (ret < 0)
755 return ret;
756 was_admissible = ret;
757 ret = compute_mood_score(aft_row, current_mood, &score);
758 if (ret < 0)
759 return ret;
760 is_admissible = (ret > 0);
761 if (!was_admissible && !is_admissible)
762 return 1;
763 if (was_admissible && !is_admissible)
764 return delete_from_statistics_and_score_table(aft_row);
765 if (!was_admissible && is_admissible) {
766 ret = add_afs_statistics(aft_row);
767 if (ret < 0)
768 return ret;
769 return add_to_score_table(aft_row, score);
770 }
771 /* update score */
772 ret = get_afsi_of_row(aft_row, &afsi);
773 if (ret < 0)
774 return ret;
775 if (old_afsi) {
776 ret = update_afs_statistics(old_afsi, &afsi);
777 if (ret < 0)
778 return ret;
779 }
780 score += compute_num_played_score(&afsi);
781 score += compute_last_played_score(&afsi);
782 score /= 3;
783 PARA_DEBUG_LOG("score: %li\n", score);
784 percent = (score + 100) / 3;
785 if (percent > 100)
786 percent = 100;
787 else if (percent < 0)
788 percent = 0;
789 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
790 return score_update(aft_row, percent);
791 }
792
793 static void log_statistics(void)
794 {
795 unsigned n = statistics.num;
796
797 if (!n) {
798 PARA_NOTICE_LOG("no admissible files\n");
799 return;
800 }
801 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
802 (long long int)(statistics.last_played_sum / n),
803 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
804 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
805 (long long int)statistics.num_played_sum / n,
806 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
807 }
808
809 /**
810 * Close the current mood.
811 *
812 * Free all resources of the current mood which were allocated during
813 * mood_open().
814 */
815 void close_current_mood(void)
816 {
817 destroy_mood(current_mood);
818 current_mood = NULL;
819 memset(&statistics, 0, sizeof(statistics));
820 }
821
822 /**
823 * Change the current mood.
824 *
825 * \param mood_name The name of the mood to open.
826 *
827 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
828 * and uses a scoring method based only on the \a last_played information.
829 *
830 * If there is already an open mood, it will be closed first.
831 *
832 * \return Positive on success, negative on errors. Loading the dummy mood
833 * always succeeds.
834 *
835 * \sa struct admissible_file_info, struct admissible_array, struct
836 * afs_info::last_played, mood_close().
837 */
838 int change_current_mood(char *mood_name)
839 {
840 int i, ret;
841 struct admissible_array aa = {
842 .size = 0,
843 .array = NULL
844 };
845
846 if (mood_name) {
847 struct mood *m;
848 struct osl_row *row;
849 struct osl_object obj = {
850 .data = mood_name,
851 .size = strlen(mood_name) + 1
852 };
853 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
854 if (ret < 0) {
855 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
856 return ret;
857 }
858 ret = load_mood(row, &m);
859 if (ret < 0)
860 return ret;
861 close_current_mood();
862 current_mood = m;
863 } else { /* load dummy mood */
864 close_current_mood();
865 current_mood = alloc_new_mood(NULL);
866 }
867 aa.m = current_mood;
868 PARA_NOTICE_LOG("computing statistics of admissible files\n");
869 ret = audio_file_loop(&aa, add_if_admissible);
870 if (ret < 0)
871 return ret;
872 log_statistics();
873 PARA_INFO_LOG("%d admissible files \n", statistics.num);
874 for (i = 0; i < statistics.num; i++) {
875 struct admissible_file_info *a = aa.array + i;
876 ret = add_to_score_table(a->aft_row, a->score);
877 if (ret < 0)
878 goto out;
879 }
880 PARA_NOTICE_LOG("loaded mood %s\n", mood_name? mood_name : "(dummy)");
881 ret = statistics.num;
882 out:
883 free(aa.array);
884 return ret;
885 }
886 /**
887 * Close and re-open the current mood.
888 *
889 * This function is used if changes to the audio file table or the
890 * attribute table were made that render the current list of admissible
891 * files useless. For example, if an attribute is removed from the
892 * attribute table, this function is called.
893 *
894 * \return Positive on success, negative on errors. If no mood is currently
895 * open, the function returns success.
896 *
897 * \sa mood_open(), mood_close().
898 */
899 static int reload_current_mood(void)
900 {
901 int ret;
902 char *mood_name = NULL;
903
904 ret = clear_score_table();
905 if (ret < 0)
906 return ret;
907 if (!current_mood)
908 return 1;
909 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
910 current_mood->name : "(dummy)");
911 if (current_mood->name)
912 mood_name = para_strdup(current_mood->name);
913 close_current_mood();
914 ret = change_current_mood(mood_name);
915 free(mood_name);
916 return ret;
917 }
918
919 /**
920 * Notification callback for the moods table.
921 *
922 * \param event Type of the event just occurred.
923 * \param pb Unused.
924 * \param data Its type depends on the event.
925 *
926 * This function performs actions required due to the occurrence of the given
927 * event. Possible actions include reload of the current mood and update of the
928 * score of an audio file.
929 *
930 * \return Standard.
931 */
932 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
933 void *data)
934 {
935 if (!current_mood)
936 return 0;
937 switch (event) {
938 /*
939 * The three blob events might change the set of admissible files,
940 * so we must reload the score list.
941 */
942 case BLOB_RENAME:
943 case BLOB_REMOVE:
944 case BLOB_ADD:
945 if (data == moods_table || data == playlists_table)
946 return 1; /* no reload necessary for these */
947 return reload_current_mood();
948 /* these also require reload of the score table */
949 case ATTRIBUTE_ADD:
950 case ATTRIBUTE_REMOVE:
951 case ATTRIBUTE_RENAME:
952 return reload_current_mood();
953 /* changes to the aft only require to re-examine the audio file */
954 case AFSI_CHANGE: {
955 struct afsi_change_event_data *aced = data;
956 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
957 }
958 case AFHI_CHANGE:
959 case AUDIO_FILE_RENAME:
960 case AUDIO_FILE_ADD:
961 return mood_update_audio_file(data, NULL);
962 case AUDIO_FILE_REMOVE:
963 return mood_delete_audio_file(data);
964 default:
965 return 1;
966 }
967 }