Fix para_strerror() and use osl() wrapper for osl library calls.
[paraslash.git] / mood.c
1 /*
2 * Copyright (C) 2007-2009 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 <osl.h>
11 #include "para.h"
12 #include "error.h"
13 #include "string.h"
14 #include "afh.h"
15 #include "afs.h"
16 #include "list.h"
17 #include "ipc.h"
18
19 /**
20 * Contains statistical data of the currently admissible audio files.
21 *
22 * It is used to assign normalized score values to each admissible audio file.
23 */
24 struct afs_statistics {
25 /** Sum of num played over all admissible files. */
26 int64_t num_played_sum;
27 /** Sum of last played times over all admissible files. */
28 int64_t last_played_sum;
29 /** Quadratic deviation of num played time. */
30 int64_t num_played_qd;
31 /** Quadratic deviation of last played time. */
32 int64_t last_played_qd;
33 /** Number of admissible files */
34 unsigned num;
35 };
36 struct afs_statistics statistics;
37
38 /**
39 * Assign scores according to a mood_method.
40 *
41 * Each mood_method has its own mood_score_function. The first three parameters
42 * passed to that function are informations about the audio file whose score is
43 * to be computed. The data argument depends on the mood method this function
44 * is used for. It usually is the argument given at the end of a mood line.
45 *
46 * Mood score functions must return values between -100 and +100 inclusively.
47 * Boolean score functions should always return either -100 or +100.
48 *
49 * \sa struct mood_method, mood_parser.
50 */
51 typedef int mood_score_function(const char *path, const struct afs_info *afsi,
52 const struct afh_info *afhi, const void *data);
53
54 /**
55 * Pre-process a mood line.
56 *
57 * The mood_parser of a mood_method is called once at mood open time for each
58 * line of the current mood definition that contains the mood_method's name as
59 * a keyword. The line is passed to the mood_parser as the first argument. The
60 * mood_parser must determine whether the line is syntactically correct and
61 * return a positive value if so and a negative value otherwise.
62 *
63 * Some mood parsers pre-process the data given in the mood line to compute a
64 * structure which depends of the particular mood_method and which is used
65 * later in the mood_score_function of the mood_method. The mood_parser may
66 * store a pointer to its structure via the second argument.
67 *
68 * \sa mood_open(), mood_cleanup_function, mood_score_function.
69 */
70 typedef int mood_parser(const char *, void **);
71
72 /**
73 * Deallocate resources which were allocated by the mood_parser.
74 *
75 * This optional function of a mood_method is used to free any resources
76 * allocated in mood_open() by the mood_parser. The argument passed is a
77 * pointer to the mood_method specific data structure that was returned by the
78 * mood_parser.
79 *
80 * \sa mood_parser.
81 */
82 typedef void mood_cleanup_function(void *);
83
84 /**
85 * Used for scoring and to determine whether a file is admissible.
86 */
87 struct mood_method {
88 /** The name of the method. */
89 const char *name;
90 /** Pointer to the mood parser. */
91 mood_parser *parser;
92 /** Pointer to the score function */
93 mood_score_function *score_function;
94 /** Optional cleanup function. */
95 mood_cleanup_function *cleanup;
96 };
97
98 /**
99 * Each line of the current mood corresponds to a mood_item.
100 */
101 struct mood_item {
102 /** The method this line is referring to. */
103 const struct mood_method *method;
104 /** The data structure computed by the mood parser. */
105 void *parser_data;
106 /** The given score value, or zero if none was given. */
107 int32_t score_arg;
108 /** Non-zero if random scoring was requested. */
109 int random_score;
110 /** Whether the "not" keyword was given in the mood line. */
111 int logical_not;
112 /** The position in the list of items. */
113 struct list_head mood_item_node;
114 };
115
116 /**
117 * Created from the mood definition by mood_open().
118 *
119 * When a mood is opened, each line of its definition is investigated, and a
120 * corresponding mood item is produced. Each mood line starts with \p accept,
121 * \p deny, or \p score which determines the type of the mood line. For each
122 * such type a linked list is maintained whose entries are the mood items.
123 *
124 * \sa mood_item, mood_open().
125 */
126 struct mood {
127 /** The name of this mood. */
128 char *name;
129 /** The list of mood items of type \p accept. */
130 struct list_head accept_list;
131 /** The list of mood items of type \p deny. */
132 struct list_head deny_list;
133 /** The list of mood items of type \p score. */
134 struct list_head score_list;
135 };
136
137 static struct mood *current_mood;
138
139 /**
140 * Rough approximation to sqrt.
141 *
142 * \param x Integer of which to calculate the sqrt.
143 *
144 * \return An integer res with res * res <= x.
145 */
146 static uint64_t int_sqrt(uint64_t x)
147 {
148 uint64_t op, res, one = 1;
149 op = x;
150 res = 0;
151
152 one = one << 62;
153 while (one > op)
154 one >>= 2;
155
156 while (one != 0) {
157 if (op >= res + one) {
158 op = op - (res + one);
159 res = res + 2 * one;
160 }
161 res /= 2;
162 one /= 4;
163 }
164 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
165 return res;
166 }
167
168 static int mm_no_attributes_set_parser(const char *arg, __a_unused void **ignored)
169 {
170 if (arg && *arg)
171 PARA_WARNING_LOG("ignored junk at eol: %s\n", arg);
172 return 1;
173 }
174
175 static int mm_no_attributes_set_score_function(__a_unused const char *path,
176 const struct afs_info *afsi,
177 __a_unused const struct afh_info *afhi,
178 __a_unused const void *data)
179 {
180 if (!afsi->attributes)
181 return 100;
182 return -100;
183 }
184
185 static int mm_played_rarely_score_function(__a_unused const char *path,
186 const struct afs_info *afsi,
187 __a_unused const struct afh_info *afhi,
188 __a_unused const void *data)
189 {
190 unsigned num;
191 int ret = get_num_admissible_files(&num);
192
193 if (ret < 0)
194 return 0;
195 if (statistics.num_played_sum - num * afsi->num_played
196 > int_sqrt(statistics.num_played_qd * num))
197 return 100;
198 return -100;
199 }
200
201 static int mm_played_rarely_parser(const char *arg, __a_unused void **ignored)
202 {
203 if (arg && *arg)
204 PARA_WARNING_LOG("ignored junk at eol: %s\n", arg);
205 return 1;
206 }
207
208 static int mm_path_matches_score_function(const char *path,
209 __a_unused const struct afs_info *afsi,
210 __a_unused const struct afh_info *afhi,
211 const void *data)
212 {
213 if (fnmatch(data, path, 0))
214 return -100;
215 return 100;
216 }
217
218 static int mm_path_matches_parser(const char *arg, void **data)
219 {
220 *data = para_strdup(arg);
221 return 1;
222 }
223
224 static void mm_path_matches_cleanup(void *data)
225 {
226 free(data);
227 }
228
229 static int mm_is_set_parser(const char *arg, void **bitnum)
230 {
231 unsigned char *c = para_malloc(1);
232 int ret = get_attribute_bitnum_by_name(arg, c);
233
234 if (ret >= 0)
235 *bitnum = c;
236 else
237 free(c);
238 return ret;
239 }
240
241 static int mm_is_set_score_function(__a_unused const char *path,
242 __a_unused const struct afs_info *afsi,
243 __a_unused const struct afh_info *afhi,
244 const void *data)
245 {
246 const unsigned char *bn = data;
247 if (afsi->attributes & (1ULL << *bn))
248 return 100;
249 return -100;
250 }
251
252 /* returns 1 if row matches score item, negative otherwise */
253 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
254 long *score_arg_sum)
255 {
256 struct afs_info afsi;
257 struct afh_info afhi;
258 char *path;
259 int ret;
260
261 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
262 ret = 100;
263 if (item->method) {
264 ret = get_afsi_of_row(row, &afsi);
265 if (ret< 0)
266 return ret;
267 ret = get_afhi_of_row(row, &afhi);
268 if (ret< 0)
269 return ret;
270 free(afhi.info_string); /* don't need the tag info */
271 ret = get_audio_file_path_of_row(row, &path);
272 if (ret< 0)
273 return ret;
274 ret = item->method->score_function(path, &afsi, &afhi,
275 item->parser_data);
276 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
277 return -1; /* no match */
278 }
279 if (item->random_score)
280 *score += PARA_ABS(ret) * para_random(100);
281 else
282 *score += PARA_ABS(ret) * item->score_arg;
283 return 1;
284 }
285
286 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
287 long *result)
288 {
289 struct mood_item *item;
290 int match = 0;
291 long score_arg_sum = 0, score = 0;
292
293 if (!m)
294 return -E_NO_MOOD;
295 /* reject audio file if it matches any entry in the deny list */
296 list_for_each_entry(item, &m->deny_list, mood_item_node)
297 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
298 return -E_NOT_ADMISSIBLE;
299 list_for_each_entry(item, &m->accept_list, mood_item_node)
300 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
301 match = 1;
302 /* reject if there is no matching entry in the accept list */
303 if (!match && !list_empty(&m->accept_list))
304 return -E_NOT_ADMISSIBLE;
305 list_for_each_entry(item, &m->score_list, mood_item_node)
306 add_item_score(aft_row, item, &score, &score_arg_sum);
307 if (score_arg_sum)
308 score /= score_arg_sum;
309 *result = score;
310 return 1;
311 }
312
313 #define DEFINE_MOOD_METHOD(_name) \
314 .parser = mm_ ## _name ## _parser, \
315 .score_function = mm_ ## _name ## _score_function, \
316 .name = #_name
317
318 #define DEFINE_MOOD_METHOD_WITH_CLEANUP(_name) \
319 DEFINE_MOOD_METHOD(_name), \
320 .cleanup = mm_ ## _name ## _cleanup
321
322 static const struct mood_method mood_methods[] = {
323 {DEFINE_MOOD_METHOD(no_attributes_set)},
324 {DEFINE_MOOD_METHOD(played_rarely)},
325 {DEFINE_MOOD_METHOD(is_set)},
326 {DEFINE_MOOD_METHOD_WITH_CLEANUP(path_matches)},
327 {.parser = NULL}
328 };
329
330 static void cleanup_list_entry(struct mood_item *item)
331 {
332 if (item->method && item->method->cleanup)
333 item->method->cleanup(item->parser_data);
334 else
335 free(item->parser_data);
336 list_del(&item->mood_item_node);
337 free(item);
338 }
339
340 static void destroy_mood(struct mood *m)
341 {
342 struct mood_item *tmp, *item;
343
344 if (!m)
345 return;
346 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
347 cleanup_list_entry(item);
348 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
349 cleanup_list_entry(item);
350 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
351 cleanup_list_entry(item);
352 free(m->name);
353 free(m);
354 }
355
356 static struct mood *alloc_new_mood(const char *name)
357 {
358 struct mood *m = para_calloc(sizeof(struct mood));
359 m->name = para_strdup(name);
360 INIT_LIST_HEAD(&m->accept_list);
361 INIT_LIST_HEAD(&m->deny_list);
362 INIT_LIST_HEAD(&m->score_list);
363 return m;
364 }
365
366 /** The different types of a mood line. */
367 enum mood_line_type {
368 /** Invalid. */
369 ML_INVALID,
370 /** Accept line. */
371 ML_ACCEPT,
372 /** Deny line. */
373 ML_DENY,
374 /** Score line. */
375 ML_SCORE
376 };
377
378 /** Data passed to the parser of a mood line. */
379 struct mood_line_parser_data {
380 /** The mood this mood line belongs to. */
381 struct mood *m;
382 /** The line number in the mood definition. */
383 unsigned line_num;
384 };
385
386 /*
387 * <accept [with score <score>] | deny [with score <score>] | score <score>>
388 * [if] [not] <mood_method> [options]
389 * <score> is either an integer or "random" which assigns a random score to
390 * all matching files
391 */
392
393 static int parse_mood_line(char *mood_line, void *data)
394 {
395 struct mood_line_parser_data *mlpd = data;
396 char **argv;
397 char *delim = " \t";
398 unsigned num_words;
399 char **w;
400 int i, ret;
401 enum mood_line_type mlt = ML_INVALID;
402 struct mood_item *mi = NULL;
403 char *buf = para_strdup(mood_line);
404
405 mlpd->line_num++;
406 num_words = split_args(buf, &argv, delim);
407 ret = 1;
408 if (!num_words) /* empty line */
409 goto out;
410 w = argv;
411 if (**w == '#') /* comment */
412 goto out;
413 if (!strcmp(*w, "accept"))
414 mlt = ML_ACCEPT;
415 else if (!strcmp(*w, "deny"))
416 mlt = ML_DENY;
417 else if (!strcmp(*w, "score"))
418 mlt = ML_SCORE;
419 ret = -E_MOOD_SYNTAX;
420 if (mlt == ML_INVALID)
421 goto out;
422 mi = para_calloc(sizeof(struct mood_item));
423 if (mlt != ML_SCORE) {
424 ret = -E_MOOD_SYNTAX;
425 w++;
426 if (!*w)
427 goto out;
428 if (strcmp(*w, "with"))
429 goto check_for_if;
430 w++;
431 if (!*w)
432 goto out;
433 if (strcmp(*w, "score"))
434 goto out;
435 }
436 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
437 ret = -E_MOOD_SYNTAX;
438 w++;
439 if (!*w)
440 goto out;
441 if (strcmp(*w, "random")) {
442 mi->random_score = 0;
443 ret = para_atoi32(*w, &mi->score_arg);
444 if (ret < 0)
445 goto out;
446 } else {
447 mi->random_score = 1;
448 if (!*(w + 1))
449 goto success; /* the line "score random" is valid */
450 }
451 } else
452 mi->score_arg = 0;
453 ret = -E_MOOD_SYNTAX;
454 w++;
455 if (!*w)
456 goto out;
457 check_for_if:
458 if (!strcmp(*w, "if")) {
459 ret = -E_MOOD_SYNTAX;
460 w++;
461 if (!*w)
462 goto out;
463 }
464 if (!strcmp(*w, "not")) {
465 ret = -E_MOOD_SYNTAX;
466 w++;
467 if (!*w)
468 goto out;
469 mi->logical_not = 1;
470 } else
471 mi->logical_not = 0;
472 for (i = 0; mood_methods[i].parser; i++) {
473 if (strcmp(*w, mood_methods[i].name))
474 continue;
475 break;
476 }
477 ret = -E_MOOD_SYNTAX;
478 if (!mood_methods[i].parser)
479 goto out;
480 w++;
481 ret = mood_methods[i].parser(*w, &mi->parser_data);
482 if (ret < 0)
483 goto out;
484 mi->method = &mood_methods[i];
485 success:
486 if (mlpd->m) {
487 if (mlt == ML_ACCEPT)
488 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
489 else if (mlt == ML_DENY)
490 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
491 else
492 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
493 }
494 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
495 (mlt == ML_DENY? "deny" : "score"), mi->method);
496 ret = 1;
497 out:
498 free(argv);
499 free(buf);
500 if (ret >= 0)
501 return ret;
502 if (mi) {
503 free(mi->parser_data);
504 free(mi);
505 }
506 return ret;
507 }
508
509 static int load_mood(const struct osl_row *mood_row, struct mood **m)
510 {
511 char *mood_name;
512 struct osl_object mood_def;
513 struct mood_line_parser_data mlpd = {.line_num = 0};
514 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
515
516 if (ret < 0)
517 return ret;
518 if (!*mood_name)
519 return -E_DUMMY_ROW;
520 mlpd.m = alloc_new_mood(mood_name);
521 ret = for_each_line_ro(mood_def.data, mood_def.size,
522 parse_mood_line, &mlpd);
523 osl_close_disk_object(&mood_def);
524 if (ret < 0) {
525 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
526 para_strerror(-ret));
527 destroy_mood(mlpd.m);
528 return ret;
529 }
530 *m = mlpd.m;
531 return 1;
532 }
533
534 static int check_mood(struct osl_row *mood_row, void *data)
535 {
536 struct para_buffer *pb = data;
537 char *mood_name;
538 struct osl_object mood_def;
539 struct mood_line_parser_data mlpd = {.line_num = 0};
540
541 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
542
543 if (ret < 0) {
544 para_printf(pb, "failed to get mood definition: %s\n",
545 para_strerror(-ret));
546 return ret;
547 }
548 if (!*mood_name) /* ignore dummy row */
549 goto out;
550 ret = para_printf(pb, "checking mood %s...\n", mood_name);
551 if (ret < 0)
552 goto out;
553 ret = for_each_line_ro(mood_def.data, mood_def.size,
554 parse_mood_line, &mlpd);
555 if (ret < 0)
556 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
557 para_strerror(-ret));
558 out:
559 osl_close_disk_object(&mood_def);
560 return ret;
561 }
562
563 /**
564 * Check all moods for syntax errors.
565 *
566 * \param fd The afs socket.
567 * \param query Unused.
568 */
569 void mood_check_callback(int fd, __a_unused const struct osl_object *query)
570 {
571 struct para_buffer pb = {
572 .max_size = SHMMAX,
573 .private_data = &fd,
574 .max_size_handler = pass_buffer_as_shm
575 };
576
577 int ret = para_printf(&pb, "checking moods...\n");
578 if (ret < 0)
579 return;
580 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
581 check_mood);
582 if (pb.offset)
583 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
584 free(pb.buf);
585 }
586
587 #if 0
588 static unsigned int_log2(uint64_t x)
589 {
590 unsigned res = 0;
591
592 while (x) {
593 x /= 2;
594 res++;
595 }
596 return res;
597 }
598 #endif
599
600 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
601 {
602 if (!n || !qd)
603 return 0;
604 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
605 }
606
607 static long compute_num_played_score(struct afs_info *afsi)
608 {
609 return -normalized_value(afsi->num_played, statistics.num,
610 statistics.num_played_sum, statistics.num_played_qd);
611 }
612
613 static long compute_last_played_score(struct afs_info *afsi)
614 {
615 return -normalized_value(afsi->last_played, statistics.num,
616 statistics.last_played_sum, statistics.last_played_qd);
617 }
618
619 static long compute_dynamic_score(const struct osl_row *aft_row)
620 {
621 struct afs_info afsi;
622 int64_t score, nscore = 0, lscore = 0;
623 int ret;
624
625 ret = get_afsi_of_row(aft_row, &afsi);
626 if (ret < 0)
627 return -100;
628 nscore = compute_num_played_score(&afsi);
629 lscore = compute_last_played_score(&afsi);
630 score = nscore + lscore;
631 return score;
632 }
633
634 static int add_afs_statistics(const struct osl_row *row)
635 {
636 uint64_t n, x, s;
637 struct afs_info afsi;
638 int ret;
639
640 ret = get_afsi_of_row(row, &afsi);
641 if (ret < 0)
642 return ret;
643 n = statistics.num;
644 x = afsi.last_played;
645 s = statistics.last_played_sum;
646 if (n > 0)
647 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
648 statistics.last_played_sum += x;
649
650 x = afsi.num_played;
651 s = statistics.num_played_sum;
652 if (n > 0)
653 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
654 statistics.num_played_sum += x;
655 statistics.num++;
656 return 1;
657 }
658
659 static int del_afs_statistics(const struct osl_row *row)
660 {
661 uint64_t n, s, q, a, new_s;
662 struct afs_info afsi;
663 int ret;
664 ret = get_afsi_of_row(row, &afsi);
665 if (ret < 0)
666 return ret;
667 n = statistics.num;
668 assert(n);
669 if (n == 1) {
670 memset(&statistics, 0, sizeof(statistics));
671 return 1;
672 }
673
674 s = statistics.last_played_sum;
675 q = statistics.last_played_qd;
676 a = afsi.last_played;
677 new_s = s - a;
678 statistics.last_played_sum = new_s;
679 statistics.last_played_qd = q + s * s / n - a * a
680 - new_s * new_s / (n - 1);
681
682 s = statistics.num_played_sum;
683 q = statistics.num_played_qd;
684 a = afsi.num_played;
685 new_s = s - a;
686 statistics.num_played_sum = new_s;
687 statistics.num_played_qd = q + s * s / n - a * a
688 - new_s * new_s / (n - 1);
689
690 statistics.num--;
691 return 1;
692 }
693
694 /**
695 * Structure used during mood_open().
696 *
697 * At mood open time, we look at each file in the audio file table in order to
698 * determine whether it is admissible. If a file happens to be admissible, its
699 * mood score is computed by calling each relevant mood_score_function. Next,
700 * we update the afs_statistics and add a struct admissible_file_info to a
701 * temporary array.
702 *
703 * If all files have been processed that way, the final score of each
704 * admissible file is computed by adding the dynamic score (which depends on
705 * the afs_statistics) to the mood score. Finally, all audio files in the
706 * array are added to the score table and the admissible array is freed.
707 *
708 * \sa mood_method, admissible_array.
709 */
710 struct admissible_file_info
711 {
712 /** The admissible audio file. */
713 struct osl_row *aft_row;
714 /** Its score. */
715 long score;
716 };
717
718 /** The temporary array of admissible files. */
719 struct admissible_array {
720 /** Files are admissible wrt. this mood. */
721 struct mood *m;
722 /** The size of the array */
723 unsigned size;
724 /** Pointer to the array of admissible files. */
725 struct admissible_file_info *array;
726 };
727
728 /**
729 * Add an entry to the array of admissible files.
730 *
731 * \param aft_row The audio file to be added.
732 * \param private_data Pointer to a struct admissible_file_info.
733 *
734 * \return Negative on errors, positive on success.
735 */
736 static int add_if_admissible(struct osl_row *aft_row, void *data)
737 {
738 struct admissible_array *aa = data;
739 int ret;
740 long score = 0;
741
742 ret = compute_mood_score(aft_row, aa->m, &score);
743 if (ret < 0)
744 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
745 if (statistics.num >= aa->size) {
746 aa->size *= 2;
747 aa->size += 100;
748 aa->array = para_realloc(aa->array,
749 aa->size * sizeof(struct admissible_file_info));
750 }
751 aa->array[statistics.num].aft_row = aft_row;
752 aa->array[statistics.num].score = score;
753 ret = add_afs_statistics(aft_row);
754 if (ret < 0)
755 return ret;
756 return 1;
757 }
758
759 /**
760 * Compute the new quadratic deviation in case one element changes.
761 *
762 * \param n Number of elements.
763 * \param old_qd The quadratic deviation before the change.
764 * \param old_val The value that was replaced.
765 * \param new_val The replacement value.
766 * \param old_sum The sum of all elements before the update.
767 *
768 * \return The new quadratic deviation resulting from replacing old_val
769 * by new_val.
770 *
771 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
772 * their quadratic deviation
773 *
774 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
775 *
776 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
777 * the last number a_n was replaced by b) may be computed in O(1) time in terms
778 * of n, q, a_n, b, and S as
779 *
780 * q' = q + d * s - (2 * S + d) * d / n,
781 *
782 * where d = b - a_n, and s = b + a_n.
783 *
784 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
785 * s = 17, so
786 *
787 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
788 *
789 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
790 *
791 */
792 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
793 int64_t old_val, int64_t new_val, int64_t old_sum)
794 {
795 int64_t delta = new_val - old_val;
796 int64_t sigma = new_val + old_val;
797 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
798 }
799
800 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
801 {
802 unsigned n;
803 int ret = get_num_admissible_files(&n);
804
805 if (ret < 0)
806 return ret;
807 assert(n);
808
809 statistics.last_played_qd = update_quadratic_deviation(n,
810 statistics.last_played_qd, old_afsi->last_played,
811 new_afsi->last_played, statistics.last_played_sum);
812 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
813
814 statistics.num_played_qd = update_quadratic_deviation(n,
815 statistics.num_played_qd, old_afsi->num_played,
816 new_afsi->num_played, statistics.num_played_sum);
817 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
818 return 1;
819 }
820
821 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
822 {
823 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
824 return score_add(aft_row, score);
825 }
826
827 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
828 {
829 int ret = del_afs_statistics(aft_row);
830 if (ret < 0)
831 return ret;
832 return score_delete(aft_row);
833 }
834
835 /**
836 * Delete one entry from the statistics and from the score table.
837 *
838 * \param aft_row The audio file which is no longer admissible.
839 *
840 * \return Positive on success, negative on errors.
841 *
842 * \sa score_delete().
843 */
844 static int mood_delete_audio_file(const struct osl_row *aft_row)
845 {
846 int ret;
847
848 ret = row_belongs_to_score_table(aft_row, NULL);
849 if (ret < 0)
850 return ret;
851 if (!ret) /* not admissible, nothing to do */
852 return 1;
853 return delete_from_statistics_and_score_table(aft_row);
854 }
855
856 /**
857 * Compute the new score of an audio file wrt. the current mood.
858 *
859 * \param aft_row Determines the audio file.
860 * \param old_afsi The audio file selector info before updating.
861 *
862 * The \a old_afsi argument may be \p NULL which indicates that no changes to
863 * the audio file info were made.
864 *
865 * \return Positive on success, negative on errors.
866 */
867 static int mood_update_audio_file(const struct osl_row *aft_row,
868 struct afs_info *old_afsi)
869 {
870 long score, percent;
871 int ret, is_admissible, was_admissible = 0;
872 struct afs_info afsi;
873 unsigned rank;
874
875 if (!current_mood)
876 return 1; /* nothing to do */
877 ret = row_belongs_to_score_table(aft_row, &rank);
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("moving from rank %u to %lu%%\n", rank, 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_INFO_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_INFO_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 * Close the current mood.
933 *
934 * Free all resources of the current mood which were allocated during
935 * mood_open().
936 */
937 void close_current_mood(void)
938 {
939 destroy_mood(current_mood);
940 current_mood = NULL;
941 memset(&statistics, 0, sizeof(statistics));
942 }
943
944
945 /**
946 * Change the current mood.
947 *
948 * \param mood_name The name of the mood to open.
949 *
950 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
951 * and uses a scoring method based only on the \a last_played information.
952 *
953 * If there is already an open mood, it will be closed first.
954 *
955 * \return Positive on success, negative on errors. Loading the dummy mood
956 * always succeeds.
957 *
958 * \sa struct admissible_file_info, struct admissible_array, struct
959 * afs_info::last_played, mood_close().
960 */
961 int change_current_mood(char *mood_name)
962 {
963 int i, ret;
964 struct admissible_array aa = {
965 .size = 0,
966 .array = NULL
967 };
968
969 if (mood_name) {
970 struct mood *m;
971 struct osl_row *row;
972 struct osl_object obj = {
973 .data = mood_name,
974 .size = strlen(mood_name) + 1
975 };
976 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
977 if (ret < 0) {
978 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
979 return ret;
980 }
981 ret = load_mood(row, &m);
982 if (ret < 0)
983 return ret;
984 close_current_mood();
985 current_mood = m;
986 } else {
987 close_current_mood();
988 current_mood = alloc_new_mood("dummy");
989 }
990 aa.m = current_mood;
991 PARA_NOTICE_LOG("computing statistics of admissible files\n");
992 ret = audio_file_loop(&aa, add_if_admissible);
993 if (ret < 0)
994 return ret;
995 log_statistics();
996 PARA_INFO_LOG("%d admissible files \n", statistics.num);
997 for (i = 0; i < statistics.num; i++) {
998 struct admissible_file_info *a = aa.array + i;
999 ret = add_to_score_table(a->aft_row, a->score);
1000 if (ret < 0)
1001 goto out;
1002 }
1003 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
1004 ret = statistics.num;
1005 out:
1006 free(aa.array);
1007 return ret;
1008 }
1009 /**
1010 * Close and re-open the current mood.
1011 *
1012 * This function is used if changes to the audio file table or the
1013 * attribute table were made that render the current list of admissible
1014 * files useless. For example, if an attribute is removed from the
1015 * attribute table, this function is called.
1016 *
1017 * \return Positive on success, negative on errors. If no mood is currently
1018 * open, the function returns success.
1019 *
1020 * \sa mood_open(), mood_close().
1021 */
1022 int reload_current_mood(void)
1023 {
1024 int ret;
1025 char *mood_name = NULL;
1026
1027 if (!current_mood)
1028 return 1;
1029 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
1030 current_mood->name : "(dummy)");
1031 if (current_mood->name)
1032 mood_name = para_strdup(current_mood->name);
1033 close_current_mood();
1034 ret = change_current_mood(mood_name);
1035 free(mood_name);
1036 return ret;
1037 }
1038
1039 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
1040 void *data)
1041 {
1042 switch(event) {
1043 /*
1044 * The three blob events might change the set of admissible files,
1045 * so we must reload the score list.
1046 */
1047 case BLOB_RENAME:
1048 case BLOB_REMOVE:
1049 case BLOB_ADD:
1050 if (data == moods_table || data == playlists_table)
1051 return 1; /* no reload necessary for these */
1052 return reload_current_mood();
1053 /* these also require reload of the score table */
1054 case ATTRIBUTE_ADD:
1055 case ATTRIBUTE_REMOVE:
1056 case ATTRIBUTE_RENAME:
1057 return reload_current_mood();
1058 /* changes to the aft only require to re-examine the audio file */
1059 case AFSI_CHANGE: {
1060 struct afsi_change_event_data *aced = data;
1061 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
1062 }
1063 case AFHI_CHANGE:
1064 case AUDIO_FILE_RENAME:
1065 case AUDIO_FILE_ADD:
1066 return mood_update_audio_file(data, NULL);
1067 case AUDIO_FILE_REMOVE:
1068 return mood_delete_audio_file(data);
1069 default:
1070 return 1;
1071 }
1072 }
1073