Add documentation to struct rc4_context.
[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 <time.h>
10 #include <regex.h>
11 #include <fnmatch.h>
12 #include <osl.h>
13
14 #include "para.h"
15 #include "error.h"
16 #include "string.h"
17 #include "afh.h"
18 #include "afs.h"
19 #include "list.h"
20 #include "ipc.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 struct afs_statistics statistics;
40
41 /**
42 * Assign scores according to a mood_method.
43 *
44 * Each mood_method has its own mood_score_function. The first three parameters
45 * passed to that function are informations about the audio file whose score is
46 * to be computed. The data argument depends on the mood method this function
47 * is used for. It usually is the argument given at the end of a mood line.
48 *
49 * Mood score functions must return values between -100 and +100 inclusively.
50 * Boolean score functions should always return either -100 or +100.
51 *
52 * \sa struct mood_method, mood_parser.
53 */
54 typedef int mood_score_function(const char *path, const struct afs_info *afsi,
55 const struct afh_info *afhi, const void *data);
56
57 /**
58 * Pre-process a mood line.
59 *
60 * The mood_parser of a mood_method is called once at mood open time for each
61 * line of the current mood definition that contains the mood_method's name as
62 * a keyword. The line is passed to the mood_parser as the first argument. The
63 * mood_parser must determine whether the line is syntactically correct and
64 * return a positive value if so and a negative value otherwise.
65 *
66 * Some mood parsers pre-process the data given in the mood line to compute a
67 * structure which depends of the particular mood_method and which is used
68 * later in the mood_score_function of the mood_method. The mood_parser may
69 * store a pointer to its structure via the void** pointer.
70 *
71 * \sa mood_open(), mood_cleanup_function, mood_score_function.
72 */
73 typedef int mood_parser(int, char **, void **);
74
75 /**
76 * Deallocate resources which were allocated by the mood_parser.
77 *
78 * This optional function of a mood_method is used to free any resources
79 * allocated in mood_open() by the mood_parser. The argument passed is a
80 * pointer to the mood_method specific data structure that was returned by the
81 * mood_parser.
82 *
83 * \sa mood_parser.
84 */
85 typedef void mood_cleanup_function(void *);
86
87 /**
88 * Used for scoring and to determine whether a file is admissible.
89 */
90 struct mood_method {
91 /** The name of the method. */
92 const char *name;
93 /** Pointer to the mood parser. */
94 mood_parser *parser;
95 /** Pointer to the score function */
96 mood_score_function *score_function;
97 /** Optional cleanup function. */
98 mood_cleanup_function *cleanup;
99 };
100
101 /**
102 * Each line of the current mood corresponds to a mood_item.
103 */
104 struct mood_item {
105 /** The method this line is referring to. */
106 const struct mood_method *method;
107 /** The data structure computed by the mood parser. */
108 void *parser_data;
109 /** The given score value, or zero if none was given. */
110 int32_t score_arg;
111 /** Non-zero if random scoring was requested. */
112 int random_score;
113 /** Whether the "not" keyword was given in the mood line. */
114 int logical_not;
115 /** The position in the list of items. */
116 struct list_head mood_item_node;
117 };
118
119 /**
120 * Created from the mood definition by mood_open().
121 *
122 * When a mood is opened, each line of its definition is investigated, and a
123 * corresponding mood item is produced. Each mood line starts with \p accept,
124 * \p deny, or \p score which determines the type of the mood line. For each
125 * such type a linked list is maintained whose entries are the mood items.
126 *
127 * \sa mood_item, mood_open().
128 */
129 struct mood {
130 /** The name of this mood. */
131 char *name;
132 /** The list of mood items of type \p accept. */
133 struct list_head accept_list;
134 /** The list of mood items of type \p deny. */
135 struct list_head deny_list;
136 /** The list of mood items of type \p score. */
137 struct list_head score_list;
138 };
139
140 static struct mood *current_mood;
141
142 /**
143 * Rough approximation to sqrt.
144 *
145 * \param x Integer of which to calculate the sqrt.
146 *
147 * \return An integer res with res * res <= x.
148 */
149 static uint64_t int_sqrt(uint64_t x)
150 {
151 uint64_t op, res, one = 1;
152 op = x;
153 res = 0;
154
155 one = one << 62;
156 while (one > op)
157 one >>= 2;
158
159 while (one != 0) {
160 if (op >= res + one) {
161 op = op - (res + one);
162 res = res + 2 * one;
163 }
164 res /= 2;
165 one /= 4;
166 }
167 // PARA_NOTICE_LOG("sqrt(%llu) = %llu\n", x, res);
168 return res;
169 }
170
171 #define MOOD_COMPARATORS \
172 MC(LESS, <) \
173 MC(LESS_OR_EQUAL, <=) \
174 MC(EQUAL, =) \
175 MC(EQUAL2, ==) \
176 MC(NOT_EQUAL, !=) \
177 MC(NOT_EQUAL2, <>) \
178 MC(GREATER, >) \
179 MC(GREATER_OR_EQUAL, >=) \
180
181 #define MC(a, b) MC_ ## a,
182 enum mood_comparator_id {MOOD_COMPARATORS NUM_MOOD_COMPARATORS};
183 #undef MC
184 #define MC(a, b) # b,
185 const char const *mood_comparators[] = {MOOD_COMPARATORS};
186 #undef MC
187
188 static int parse_mood_comparator(const char *word)
189 {
190 int i;
191
192 for (i = 0; i < NUM_MOOD_COMPARATORS; i++)
193 if (!strcmp(word, mood_comparators[i]))
194 return i;
195 return -E_MOOD_SYNTAX;
196 }
197
198 static int compare_int32(int32_t a, int32_t b, enum mood_comparator_id id)
199 {
200 int res;
201
202 switch (id) {
203 case MC_LESS:
204 res = a < b; break;
205 case MC_LESS_OR_EQUAL:
206 res = a <= b; break;
207 case MC_EQUAL:
208 case MC_EQUAL2:
209 res = a == b; break;
210 case MC_NOT_EQUAL:
211 case MC_NOT_EQUAL2:
212 res = a != b; break;
213 case MC_GREATER:
214 res = a > b; break;
215 case MC_GREATER_OR_EQUAL:
216 res = a >= b; break;
217 default:
218 PARA_EMERG_LOG("BUG: invalid mood comparator\n");
219 exit(EXIT_FAILURE);
220 }
221 return res? 100 : -100;
222 }
223
224 struct mm_year_data {
225 /** The year given at the mood line. */
226 int32_t year;
227 /** Used to detect Y2K issues. */
228 int32_t current_year;
229 /** <, <=, =, !=, >=, or >. */
230 enum mood_comparator_id id;
231 };
232
233 static int mm_year_parser(int argc, char **argv, void **private)
234 {
235 int ret = -E_MOOD_SYNTAX;
236 struct mm_year_data *mmyd = para_malloc(sizeof(*mmyd));
237 time_t current_time;
238 struct tm *gmt;
239
240 if (argc != 2)
241 goto err;
242 ret = parse_mood_comparator(argv[1]);
243 mmyd->id = ret;
244 if (ret < 0)
245 goto err;
246 ret = para_atoi32(argv[2], &mmyd->year);
247 if (ret < 0)
248 goto err;
249 current_time = time(NULL);
250 gmt = gmtime(&current_time);
251 /* tm_year is the number of years since 1900 */
252 mmyd->current_year = gmt->tm_year + 1900;
253 *private = mmyd;
254 return 1;
255 err:
256 free(mmyd);
257 return ret;
258 }
259
260 static int mm_year_score_function(__a_unused const char *path,
261 __a_unused const struct afs_info *afsi,
262 const struct afh_info *afhi,
263 const void *private)
264 {
265 const struct mm_year_data *mmyd = private;
266 int32_t tag_year;
267 int ret = para_atoi32(afhi->tags.year, &tag_year);
268
269 if (ret < 0) /* year tag not present or not a number */
270 return -100;
271 if (tag_year < 0)
272 return -100;
273 /* try to work around Y2K issues */
274 if (tag_year < 100) {
275 tag_year += 1900;
276 if (tag_year + 100 <= mmyd->current_year)
277 tag_year += 100; /* assume tag_year >= 2000 */
278 }
279 return compare_int32(tag_year, mmyd->year, mmyd->id);
280 }
281
282 static void mm_year_cleanup(void *private)
283 {
284 free(private);
285 }
286
287 static int mm_no_attributes_set_parser(int argc, __a_unused char **argv,
288 __a_unused void **ignored)
289 {
290 return argc? -E_MOOD_SYNTAX : 1;
291 }
292
293 static int mm_no_attributes_set_score_function(__a_unused const char *path,
294 const struct afs_info *afsi,
295 __a_unused const struct afh_info *afhi,
296 __a_unused const void *data)
297 {
298 if (!afsi->attributes)
299 return 100;
300 return -100;
301 }
302
303 static int mm_played_rarely_score_function(__a_unused const char *path,
304 const struct afs_info *afsi,
305 __a_unused const struct afh_info *afhi,
306 __a_unused const void *data)
307 {
308 unsigned num;
309 int ret = get_num_admissible_files(&num);
310
311 if (ret < 0)
312 return 0;
313 if (statistics.num_played_sum - num * afsi->num_played
314 > int_sqrt(statistics.num_played_qd * num))
315 return 100;
316 return -100;
317 }
318
319 static int mm_played_rarely_parser(int argc, __a_unused char **argv,
320 __a_unused void **ignored)
321 {
322 return argc? -E_MOOD_SYNTAX : 1;
323 }
324
325 static int mm_path_matches_score_function(const char *path,
326 __a_unused const struct afs_info *afsi,
327 __a_unused const struct afh_info *afhi,
328 const void *data)
329 {
330 if (fnmatch(data, path, 0))
331 return -100;
332 return 100;
333 }
334
335 static int mm_path_matches_parser(int argc, char **argv, void **data)
336 {
337 if (argc != 1)
338 return -E_MOOD_SYNTAX;
339 *data = para_strdup(argv[1]);
340 return 1;
341 }
342
343 static void mm_path_matches_cleanup(void *data)
344 {
345 free(data);
346 }
347
348 static int mm_is_set_parser(int argc, char **argv, void **bitnum)
349 {
350 int ret;
351 unsigned char c, *res;
352
353 if (argc != 1)
354 return -E_MOOD_SYNTAX;
355 ret = get_attribute_bitnum_by_name(argv[1], &c);
356 if (ret < 0)
357 return ret;
358 res = para_malloc(1);
359 *res = c;
360 *bitnum = res;
361 return 1;
362 }
363
364 static int mm_is_set_score_function(__a_unused const char *path,
365 __a_unused const struct afs_info *afsi,
366 __a_unused const struct afh_info *afhi,
367 const void *data)
368 {
369 const unsigned char *bn = data;
370 if (afsi->attributes & (1ULL << *bn))
371 return 100;
372 return -100;
373 }
374
375 /* returns 1 if row matches score item, negative otherwise */
376 static int add_item_score(const struct osl_row *row, struct mood_item *item, long *score,
377 long *score_arg_sum)
378 {
379 struct afs_info afsi;
380 struct afh_info afhi;
381 char *path;
382 int ret;
383
384 *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
385 ret = 100;
386 if (item->method) {
387 ret = get_afsi_of_row(row, &afsi);
388 if (ret< 0)
389 return ret;
390 ret = get_afhi_of_row(row, &afhi);
391 if (ret< 0)
392 return ret;
393 ret = get_audio_file_path_of_row(row, &path);
394 if (ret< 0)
395 return ret;
396 ret = item->method->score_function(path, &afsi, &afhi,
397 item->parser_data);
398 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
399 return -1; /* no match */
400 }
401 if (item->random_score)
402 *score += PARA_ABS(ret) * para_random(100);
403 else
404 *score += PARA_ABS(ret) * item->score_arg;
405 return 1;
406 }
407
408 static int compute_mood_score(const struct osl_row *aft_row, struct mood *m,
409 long *result)
410 {
411 struct mood_item *item;
412 int match = 0;
413 long score_arg_sum = 0, score = 0;
414
415 if (!m)
416 return -E_NO_MOOD;
417 /* reject audio file if it matches any entry in the deny list */
418 list_for_each_entry(item, &m->deny_list, mood_item_node)
419 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
420 return -E_NOT_ADMISSIBLE;
421 list_for_each_entry(item, &m->accept_list, mood_item_node)
422 if (add_item_score(aft_row, item, &score, &score_arg_sum) > 0)
423 match = 1;
424 /* reject if there is no matching entry in the accept list */
425 if (!match && !list_empty(&m->accept_list))
426 return -E_NOT_ADMISSIBLE;
427 list_for_each_entry(item, &m->score_list, mood_item_node)
428 add_item_score(aft_row, item, &score, &score_arg_sum);
429 if (score_arg_sum)
430 score /= score_arg_sum;
431 *result = score;
432 return 1;
433 }
434
435 #define DEFINE_MOOD_METHOD(_name) \
436 .parser = mm_ ## _name ## _parser, \
437 .score_function = mm_ ## _name ## _score_function, \
438 .name = #_name
439
440 #define DEFINE_MOOD_METHOD_WITH_CLEANUP(_name) \
441 DEFINE_MOOD_METHOD(_name), \
442 .cleanup = mm_ ## _name ## _cleanup
443
444 static const struct mood_method mood_methods[] = {
445 {DEFINE_MOOD_METHOD(no_attributes_set)},
446 {DEFINE_MOOD_METHOD(played_rarely)},
447 {DEFINE_MOOD_METHOD(is_set)},
448 {DEFINE_MOOD_METHOD_WITH_CLEANUP(path_matches)},
449 {DEFINE_MOOD_METHOD_WITH_CLEANUP(year)},
450 {.parser = NULL}
451 };
452
453 static void cleanup_list_entry(struct mood_item *item)
454 {
455 if (item->method && item->method->cleanup)
456 item->method->cleanup(item->parser_data);
457 else
458 free(item->parser_data);
459 list_del(&item->mood_item_node);
460 free(item);
461 }
462
463 static void destroy_mood(struct mood *m)
464 {
465 struct mood_item *tmp, *item;
466
467 if (!m)
468 return;
469 list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
470 cleanup_list_entry(item);
471 list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
472 cleanup_list_entry(item);
473 list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
474 cleanup_list_entry(item);
475 free(m->name);
476 free(m);
477 }
478
479 static struct mood *alloc_new_mood(const char *name)
480 {
481 struct mood *m = para_calloc(sizeof(struct mood));
482 m->name = para_strdup(name);
483 INIT_LIST_HEAD(&m->accept_list);
484 INIT_LIST_HEAD(&m->deny_list);
485 INIT_LIST_HEAD(&m->score_list);
486 return m;
487 }
488
489 /** The different types of a mood line. */
490 enum mood_line_type {
491 /** Invalid. */
492 ML_INVALID,
493 /** Accept line. */
494 ML_ACCEPT,
495 /** Deny line. */
496 ML_DENY,
497 /** Score line. */
498 ML_SCORE
499 };
500
501 /** Data passed to the parser of a mood line. */
502 struct mood_line_parser_data {
503 /** The mood this mood line belongs to. */
504 struct mood *m;
505 /** The line number in the mood definition. */
506 unsigned line_num;
507 };
508
509 /*
510 * <accept [with score <score>] | deny [with score <score>] | score <score>>
511 * [if] [not] <mood_method> [options]
512 * <score> is either an integer or "random" which assigns a random score to
513 * all matching files
514 */
515
516 static int parse_mood_line(char *mood_line, void *data)
517 {
518 struct mood_line_parser_data *mlpd = data;
519 char **argv;
520 unsigned num_words;
521 char **w;
522 int i, ret;
523 enum mood_line_type mlt = ML_INVALID;
524 struct mood_item *mi = NULL;
525
526 mlpd->line_num++;
527 ret = create_argv(mood_line, " \t", &argv);
528 if (ret < 0)
529 return ret;
530 num_words = ret;
531 if (!num_words) /* empty line */
532 goto out;
533 w = argv;
534 if (**w == '#') /* comment */
535 goto out;
536 if (!strcmp(*w, "accept"))
537 mlt = ML_ACCEPT;
538 else if (!strcmp(*w, "deny"))
539 mlt = ML_DENY;
540 else if (!strcmp(*w, "score"))
541 mlt = ML_SCORE;
542 ret = -E_MOOD_SYNTAX;
543 if (mlt == ML_INVALID)
544 goto out;
545 mi = para_calloc(sizeof(struct mood_item));
546 if (mlt != ML_SCORE) {
547 ret = -E_MOOD_SYNTAX;
548 w++;
549 if (!*w)
550 goto out;
551 if (strcmp(*w, "with"))
552 goto check_for_if;
553 w++;
554 if (!*w)
555 goto out;
556 if (strcmp(*w, "score"))
557 goto out;
558 }
559 if (mlt == ML_SCORE || !strcmp(*w, "score")) {
560 ret = -E_MOOD_SYNTAX;
561 w++;
562 if (!*w)
563 goto out;
564 if (strcmp(*w, "random")) {
565 mi->random_score = 0;
566 ret = para_atoi32(*w, &mi->score_arg);
567 if (ret < 0)
568 goto out;
569 } else {
570 mi->random_score = 1;
571 if (!*(w + 1))
572 goto success; /* the line "score random" is valid */
573 }
574 } else
575 mi->score_arg = 0;
576 ret = -E_MOOD_SYNTAX;
577 w++;
578 if (!*w)
579 goto out;
580 check_for_if:
581 if (!strcmp(*w, "if")) {
582 ret = -E_MOOD_SYNTAX;
583 w++;
584 if (!*w)
585 goto out;
586 }
587 if (!strcmp(*w, "not")) {
588 ret = -E_MOOD_SYNTAX;
589 w++;
590 if (!*w)
591 goto out;
592 mi->logical_not = 1;
593 } else
594 mi->logical_not = 0;
595 for (i = 0; mood_methods[i].parser; i++) {
596 if (strcmp(*w, mood_methods[i].name))
597 continue;
598 break;
599 }
600 ret = -E_MOOD_SYNTAX;
601 if (!mood_methods[i].parser)
602 goto out;
603 ret = mood_methods[i].parser(num_words - 1 - (w - argv), w,
604 &mi->parser_data);
605 if (ret < 0)
606 goto out;
607 mi->method = &mood_methods[i];
608 success:
609 if (mlpd->m) {
610 if (mlt == ML_ACCEPT)
611 para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
612 else if (mlt == ML_DENY)
613 para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
614 else
615 para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
616 }
617 PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
618 (mlt == ML_DENY? "deny" : "score"), mi->method);
619 ret = 1;
620 out:
621 free_argv(argv);
622 if (ret >= 0)
623 return ret;
624 if (mi) {
625 free(mi->parser_data);
626 free(mi);
627 }
628 return ret;
629 }
630
631 static int load_mood(const struct osl_row *mood_row, struct mood **m)
632 {
633 char *mood_name;
634 struct osl_object mood_def;
635 struct mood_line_parser_data mlpd = {.line_num = 0};
636 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
637
638 if (ret < 0)
639 return ret;
640 if (!*mood_name)
641 return -E_DUMMY_ROW;
642 mlpd.m = alloc_new_mood(mood_name);
643 ret = for_each_line_ro(mood_def.data, mood_def.size,
644 parse_mood_line, &mlpd);
645 osl_close_disk_object(&mood_def);
646 if (ret < 0) {
647 PARA_ERROR_LOG("unable to load mood %s: %s\n", mlpd.m->name,
648 para_strerror(-ret));
649 destroy_mood(mlpd.m);
650 return ret;
651 }
652 *m = mlpd.m;
653 return 1;
654 }
655
656 static int check_mood(struct osl_row *mood_row, void *data)
657 {
658 struct para_buffer *pb = data;
659 char *mood_name;
660 struct osl_object mood_def;
661 struct mood_line_parser_data mlpd = {.line_num = 0};
662
663 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
664
665 if (ret < 0) {
666 para_printf(pb, "failed to get mood definition: %s\n",
667 para_strerror(-ret));
668 return ret;
669 }
670 if (!*mood_name) /* ignore dummy row */
671 goto out;
672 ret = para_printf(pb, "checking mood %s...\n", mood_name);
673 if (ret < 0)
674 goto out;
675 ret = for_each_line_ro(mood_def.data, mood_def.size,
676 parse_mood_line, &mlpd);
677 if (ret < 0)
678 para_printf(pb, "%s line %u: %s\n", mood_name, mlpd.line_num,
679 para_strerror(-ret));
680 out:
681 osl_close_disk_object(&mood_def);
682 return ret;
683 }
684
685 /**
686 * Check all moods for syntax errors.
687 *
688 * \param fd The afs socket.
689 * \param query Unused.
690 */
691 void mood_check_callback(int fd, __a_unused const struct osl_object *query)
692 {
693 struct para_buffer pb = {
694 .max_size = SHMMAX,
695 .private_data = &fd,
696 .max_size_handler = pass_buffer_as_shm
697 };
698
699 int ret = para_printf(&pb, "checking moods...\n");
700 if (ret < 0)
701 return;
702 osl_rbtree_loop(moods_table, BLOBCOL_ID, &pb,
703 check_mood);
704 if (pb.offset)
705 pass_buffer_as_shm(pb.buf, pb.offset, &fd);
706 free(pb.buf);
707 }
708
709 #if 0
710 static unsigned int_log2(uint64_t x)
711 {
712 unsigned res = 0;
713
714 while (x) {
715 x /= 2;
716 res++;
717 }
718 return res;
719 }
720 #endif
721
722 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
723 {
724 if (!n || !qd)
725 return 0;
726 return 100 * (n * x - sum) / (int64_t)int_sqrt(n * qd);
727 }
728
729 static long compute_num_played_score(struct afs_info *afsi)
730 {
731 return -normalized_value(afsi->num_played, statistics.num,
732 statistics.num_played_sum, statistics.num_played_qd);
733 }
734
735 static long compute_last_played_score(struct afs_info *afsi)
736 {
737 return -normalized_value(afsi->last_played, statistics.num,
738 statistics.last_played_sum, statistics.last_played_qd);
739 }
740
741 static long compute_dynamic_score(const struct osl_row *aft_row)
742 {
743 struct afs_info afsi;
744 int64_t score, nscore = 0, lscore = 0;
745 int ret;
746
747 ret = get_afsi_of_row(aft_row, &afsi);
748 if (ret < 0)
749 return -100;
750 nscore = compute_num_played_score(&afsi);
751 lscore = compute_last_played_score(&afsi);
752 score = nscore + lscore;
753 return score;
754 }
755
756 static int add_afs_statistics(const struct osl_row *row)
757 {
758 uint64_t n, x, s;
759 struct afs_info afsi;
760 int ret;
761
762 ret = get_afsi_of_row(row, &afsi);
763 if (ret < 0)
764 return ret;
765 n = statistics.num;
766 x = afsi.last_played;
767 s = statistics.last_played_sum;
768 if (n > 0)
769 statistics.last_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
770 statistics.last_played_sum += x;
771
772 x = afsi.num_played;
773 s = statistics.num_played_sum;
774 if (n > 0)
775 statistics.num_played_qd += (x - s / n) * (x - s / n) * n / (n + 1);
776 statistics.num_played_sum += x;
777 statistics.num++;
778 return 1;
779 }
780
781 static int del_afs_statistics(const struct osl_row *row)
782 {
783 uint64_t n, s, q, a, new_s;
784 struct afs_info afsi;
785 int ret;
786 ret = get_afsi_of_row(row, &afsi);
787 if (ret < 0)
788 return ret;
789 n = statistics.num;
790 assert(n);
791 if (n == 1) {
792 memset(&statistics, 0, sizeof(statistics));
793 return 1;
794 }
795
796 s = statistics.last_played_sum;
797 q = statistics.last_played_qd;
798 a = afsi.last_played;
799 new_s = s - a;
800 statistics.last_played_sum = new_s;
801 statistics.last_played_qd = q + s * s / n - a * a
802 - new_s * new_s / (n - 1);
803
804 s = statistics.num_played_sum;
805 q = statistics.num_played_qd;
806 a = afsi.num_played;
807 new_s = s - a;
808 statistics.num_played_sum = new_s;
809 statistics.num_played_qd = q + s * s / n - a * a
810 - new_s * new_s / (n - 1);
811
812 statistics.num--;
813 return 1;
814 }
815
816 /**
817 * Structure used during mood_open().
818 *
819 * At mood open time, we look at each file in the audio file table in order to
820 * determine whether it is admissible. If a file happens to be admissible, its
821 * mood score is computed by calling each relevant mood_score_function. Next,
822 * we update the afs_statistics and add a struct admissible_file_info to a
823 * temporary array.
824 *
825 * If all files have been processed that way, the final score of each
826 * admissible file is computed by adding the dynamic score (which depends on
827 * the afs_statistics) to the mood score. Finally, all audio files in the
828 * array are added to the score table and the admissible array is freed.
829 *
830 * \sa mood_method, admissible_array.
831 */
832 struct admissible_file_info
833 {
834 /** The admissible audio file. */
835 struct osl_row *aft_row;
836 /** Its score. */
837 long score;
838 };
839
840 /** The temporary array of admissible files. */
841 struct admissible_array {
842 /** Files are admissible wrt. this mood. */
843 struct mood *m;
844 /** The size of the array */
845 unsigned size;
846 /** Pointer to the array of admissible files. */
847 struct admissible_file_info *array;
848 };
849
850 /**
851 * Add an entry to the array of admissible files.
852 *
853 * \param aft_row The audio file to be added.
854 * \param private_data Pointer to a struct admissible_file_info.
855 *
856 * \return Negative on errors, positive on success.
857 */
858 static int add_if_admissible(struct osl_row *aft_row, void *data)
859 {
860 struct admissible_array *aa = data;
861 int ret;
862 long score = 0;
863
864 ret = compute_mood_score(aft_row, aa->m, &score);
865 if (ret < 0)
866 return (ret == -E_NOT_ADMISSIBLE)? 1 : ret;
867 if (statistics.num >= aa->size) {
868 aa->size *= 2;
869 aa->size += 100;
870 aa->array = para_realloc(aa->array,
871 aa->size * sizeof(struct admissible_file_info));
872 }
873 aa->array[statistics.num].aft_row = aft_row;
874 aa->array[statistics.num].score = score;
875 ret = add_afs_statistics(aft_row);
876 if (ret < 0)
877 return ret;
878 return 1;
879 }
880
881 /**
882 * Compute the new quadratic deviation in case one element changes.
883 *
884 * \param n Number of elements.
885 * \param old_qd The quadratic deviation before the change.
886 * \param old_val The value that was replaced.
887 * \param new_val The replacement value.
888 * \param old_sum The sum of all elements before the update.
889 *
890 * \return The new quadratic deviation resulting from replacing old_val
891 * by new_val.
892 *
893 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
894 * their quadratic deviation
895 *
896 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
897 *
898 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
899 * the last number a_n was replaced by b) may be computed in O(1) time in terms
900 * of n, q, a_n, b, and S as
901 *
902 * q' = q + d * s - (2 * S + d) * d / n,
903 *
904 * where d = b - a_n, and s = b + a_n.
905 *
906 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
907 * s = 17, so
908 *
909 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
910 *
911 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
912 *
913 */
914 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
915 int64_t old_val, int64_t new_val, int64_t old_sum)
916 {
917 int64_t delta = new_val - old_val;
918 int64_t sigma = new_val + old_val;
919 return old_qd + delta * sigma - (2 * old_sum + delta) * delta / n;
920 }
921
922 static int update_afs_statistics(struct afs_info *old_afsi, struct afs_info *new_afsi)
923 {
924 unsigned n;
925 int ret = get_num_admissible_files(&n);
926
927 if (ret < 0)
928 return ret;
929 assert(n);
930
931 statistics.last_played_qd = update_quadratic_deviation(n,
932 statistics.last_played_qd, old_afsi->last_played,
933 new_afsi->last_played, statistics.last_played_sum);
934 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
935
936 statistics.num_played_qd = update_quadratic_deviation(n,
937 statistics.num_played_qd, old_afsi->num_played,
938 new_afsi->num_played, statistics.num_played_sum);
939 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
940 return 1;
941 }
942
943 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
944 {
945 long score = (compute_dynamic_score(aft_row) + mood_score) / 3;
946 return score_add(aft_row, score);
947 }
948
949 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
950 {
951 int ret = del_afs_statistics(aft_row);
952 if (ret < 0)
953 return ret;
954 return score_delete(aft_row);
955 }
956
957 /**
958 * Delete one entry from the statistics and from the score table.
959 *
960 * \param aft_row The audio file which is no longer admissible.
961 *
962 * \return Positive on success, negative on errors.
963 *
964 * \sa score_delete().
965 */
966 static int mood_delete_audio_file(const struct osl_row *aft_row)
967 {
968 int ret;
969
970 ret = row_belongs_to_score_table(aft_row, NULL);
971 if (ret < 0)
972 return ret;
973 if (!ret) /* not admissible, nothing to do */
974 return 1;
975 return delete_from_statistics_and_score_table(aft_row);
976 }
977
978 /**
979 * Compute the new score of an audio file wrt. the current mood.
980 *
981 * \param aft_row Determines the audio file.
982 * \param old_afsi The audio file selector info before updating.
983 *
984 * The \a old_afsi argument may be \p NULL which indicates that no changes to
985 * the audio file info were made.
986 *
987 * \return Positive on success, negative on errors.
988 */
989 static int mood_update_audio_file(const struct osl_row *aft_row,
990 struct afs_info *old_afsi)
991 {
992 long score, percent;
993 int ret, is_admissible, was_admissible = 0;
994 struct afs_info afsi;
995 unsigned rank;
996
997 if (!current_mood)
998 return 1; /* nothing to do */
999 ret = row_belongs_to_score_table(aft_row, &rank);
1000 if (ret < 0)
1001 return ret;
1002 was_admissible = ret;
1003 ret = compute_mood_score(aft_row, current_mood, &score);
1004 is_admissible = (ret > 0);
1005 if (!was_admissible && !is_admissible)
1006 return 1;
1007 if (was_admissible && !is_admissible)
1008 return delete_from_statistics_and_score_table(aft_row);
1009 if (!was_admissible && is_admissible) {
1010 ret = add_afs_statistics(aft_row);
1011 if (ret < 0)
1012 return ret;
1013 return add_to_score_table(aft_row, score);
1014 }
1015 /* update score */
1016 ret = get_afsi_of_row(aft_row, &afsi);
1017 if (ret < 0)
1018 return ret;
1019 if (old_afsi) {
1020 ret = update_afs_statistics(old_afsi, &afsi);
1021 if (ret < 0)
1022 return ret;
1023 }
1024 score += compute_num_played_score(&afsi);
1025 score += compute_last_played_score(&afsi);
1026 score /= 3;
1027 PARA_DEBUG_LOG("score: %li\n", score);
1028 percent = (score + 100) / 3;
1029 if (percent > 100)
1030 percent = 100;
1031 else if (percent < 0)
1032 percent = 0;
1033 PARA_DEBUG_LOG("moving from rank %u to %lu%%\n", rank, percent);
1034 return score_update(aft_row, percent);
1035 }
1036
1037 static void log_statistics(void)
1038 {
1039 unsigned n = statistics.num;
1040
1041 if (!n) {
1042 PARA_NOTICE_LOG("no admissible files\n");
1043 return;
1044 }
1045 PARA_INFO_LOG("last_played mean: %lli, last_played sigma: %llu\n",
1046 (long long int)(statistics.last_played_sum / n),
1047 (long long unsigned)int_sqrt(statistics.last_played_qd / n));
1048 PARA_INFO_LOG("num_played mean: %lli, num_played sigma: %llu\n",
1049 (long long int)statistics.num_played_sum / n,
1050 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
1051 }
1052
1053 /**
1054 * Close the current mood.
1055 *
1056 * Free all resources of the current mood which were allocated during
1057 * mood_open().
1058 */
1059 void close_current_mood(void)
1060 {
1061 destroy_mood(current_mood);
1062 current_mood = NULL;
1063 memset(&statistics, 0, sizeof(statistics));
1064 }
1065
1066
1067 /**
1068 * Change the current mood.
1069 *
1070 * \param mood_name The name of the mood to open.
1071 *
1072 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
1073 * and uses a scoring method based only on the \a last_played information.
1074 *
1075 * If there is already an open mood, it will be closed first.
1076 *
1077 * \return Positive on success, negative on errors. Loading the dummy mood
1078 * always succeeds.
1079 *
1080 * \sa struct admissible_file_info, struct admissible_array, struct
1081 * afs_info::last_played, mood_close().
1082 */
1083 int change_current_mood(char *mood_name)
1084 {
1085 int i, ret;
1086 struct admissible_array aa = {
1087 .size = 0,
1088 .array = NULL
1089 };
1090
1091 if (mood_name) {
1092 struct mood *m;
1093 struct osl_row *row;
1094 struct osl_object obj = {
1095 .data = mood_name,
1096 .size = strlen(mood_name) + 1
1097 };
1098 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
1099 if (ret < 0) {
1100 PARA_NOTICE_LOG("no such mood: %s\n", mood_name);
1101 return ret;
1102 }
1103 ret = load_mood(row, &m);
1104 if (ret < 0)
1105 return ret;
1106 close_current_mood();
1107 current_mood = m;
1108 } else {
1109 close_current_mood();
1110 current_mood = alloc_new_mood("dummy");
1111 }
1112 aa.m = current_mood;
1113 PARA_NOTICE_LOG("computing statistics of admissible files\n");
1114 ret = audio_file_loop(&aa, add_if_admissible);
1115 if (ret < 0)
1116 return ret;
1117 log_statistics();
1118 PARA_INFO_LOG("%d admissible files \n", statistics.num);
1119 for (i = 0; i < statistics.num; i++) {
1120 struct admissible_file_info *a = aa.array + i;
1121 ret = add_to_score_table(a->aft_row, a->score);
1122 if (ret < 0)
1123 goto out;
1124 }
1125 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name);
1126 ret = statistics.num;
1127 out:
1128 free(aa.array);
1129 return ret;
1130 }
1131 /**
1132 * Close and re-open the current mood.
1133 *
1134 * This function is used if changes to the audio file table or the
1135 * attribute table were made that render the current list of admissible
1136 * files useless. For example, if an attribute is removed from the
1137 * attribute table, this function is called.
1138 *
1139 * \return Positive on success, negative on errors. If no mood is currently
1140 * open, the function returns success.
1141 *
1142 * \sa mood_open(), mood_close().
1143 */
1144 int reload_current_mood(void)
1145 {
1146 int ret;
1147 char *mood_name = NULL;
1148
1149 if (!current_mood)
1150 return 1;
1151 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
1152 current_mood->name : "(dummy)");
1153 if (current_mood->name)
1154 mood_name = para_strdup(current_mood->name);
1155 close_current_mood();
1156 ret = change_current_mood(mood_name);
1157 free(mood_name);
1158 return ret;
1159 }
1160
1161 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
1162 void *data)
1163 {
1164 switch(event) {
1165 /*
1166 * The three blob events might change the set of admissible files,
1167 * so we must reload the score list.
1168 */
1169 case BLOB_RENAME:
1170 case BLOB_REMOVE:
1171 case BLOB_ADD:
1172 if (data == moods_table || data == playlists_table)
1173 return 1; /* no reload necessary for these */
1174 return reload_current_mood();
1175 /* these also require reload of the score table */
1176 case ATTRIBUTE_ADD:
1177 case ATTRIBUTE_REMOVE:
1178 case ATTRIBUTE_RENAME:
1179 return reload_current_mood();
1180 /* changes to the aft only require to re-examine the audio file */
1181 case AFSI_CHANGE: {
1182 struct afsi_change_event_data *aced = data;
1183 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
1184 }
1185 case AFHI_CHANGE:
1186 case AUDIO_FILE_RENAME:
1187 case AUDIO_FILE_ADD:
1188 return mood_update_audio_file(data, NULL);
1189 case AUDIO_FILE_REMOVE:
1190 return mood_delete_audio_file(data);
1191 default:
1192 return 1;
1193 }
1194 }
1195