1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file mood.c Paraslash's mood handling functions. */
18 * Mood parser API. It's overkill to have an own header file for
19 * these declarations as they are only needed in this .c file.
22 int mp_init(const char *definition, int nbytes, struct mp_context **result,
24 bool mp_eval_row(const struct osl_row *aft_row, struct mp_context *ctx);
25 void mp_shutdown(struct mp_context *ctx);
28 * Contains statistical data of the currently admissible audio files.
30 * It is used to assign normalized score values to each admissible audio file.
32 struct afs_statistics {
33 /** Sum of num played over all admissible files. */
34 int64_t num_played_sum;
35 /** Sum of last played times over all admissible files. */
36 int64_t last_played_sum;
37 /** Quadratic deviation of num played count. */
38 int64_t num_played_qd;
39 /** Quadratic deviation of last played time. */
40 int64_t last_played_qd;
41 /** Correction factor for the num played score. */
42 int64_t num_played_correction;
43 /** Correction factor for the last played score. */
44 int64_t last_played_correction;
45 /** Common divisor of the correction factors. */
46 int64_t normalization_divisor;
47 /** Number of admissible files */
50 static struct afs_statistics statistics = {.normalization_divisor = 1};
53 /** The name of this mood. */
55 /** Info for the bison parser. */
56 struct mp_context *parser_context;
60 * If current_mood is NULL then no mood is currently open. If
61 * current_mood->name is NULL, the dummy mood is currently open.
63 static struct mood *current_mood;
66 * Find the position of the most-significant set bit.
68 * Copied and slightly adapted from the linux source tree, version 4.9.39
71 __a_const static uint32_t fls64(uint64_t v)
74 const uint64_t ones = ~(uint64_t)0U;
76 if ((v & (ones << 32)) == 0) {
80 if ((v & (ones << (64 - 16))) == 0) {
84 if ((v & (ones << (64 - 8))) == 0) {
88 if ((v & (ones << (64 - 4))) == 0) {
92 if ((v & (ones << (64 - 2))) == 0) {
96 if ((v & (ones << (64 - 1))) == 0)
102 * Compute the integer square root floor(sqrt(x)).
104 * Taken 2007 from the linux source tree.
106 __a_const static uint64_t int_sqrt(uint64_t x)
108 uint64_t op = x, res = 0, one = 1;
110 one = one << (fls64(x) & ~one);
112 if (op >= res + one) {
113 op = op - (res + one);
122 /* returns 1 if row admissible, 0 if not, negative on errors */
123 static int row_is_admissible(const struct osl_row *aft_row, struct mood *m)
127 return mp_eval_row(aft_row, m->parser_context);
130 static void destroy_mood(struct mood *m)
134 mp_shutdown(m->parser_context);
139 static struct mood *alloc_new_mood(const char *name)
141 struct mood *m = zalloc(sizeof(struct mood));
143 m->name = para_strdup(name);
147 static int load_mood(const struct osl_row *mood_row, struct mood **m,
151 struct osl_object mood_def;
154 ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
157 *errmsg = make_message(
158 "could not read mood definition");
162 *m = alloc_new_mood(mood_name);
163 PARA_INFO_LOG("opening mood %s\n", mood_name);
164 ret = mp_init(mood_def.data, mood_def.size, &(*m)->parser_context, errmsg);
165 osl_close_disk_object(&mood_def);
171 static int check_mood(struct osl_row *mood_row, void *data)
173 struct para_buffer *pb = data;
174 char *mood_name, *errmsg;
175 struct osl_object mood_def;
177 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
180 para_printf(pb, "cannot read mood\n");
183 if (!*mood_name) /* ignore dummy row */
185 m = alloc_new_mood("check");
186 ret = mp_init(mood_def.data, mood_def.size, &m->parser_context,
189 para_printf(pb, "%s: %s\n", mood_name, errmsg);
191 para_printf(pb, "%s\n", para_strerror(-ret));
194 ret = 1; /* don't fail the loop on invalid mood definitions */
196 osl_close_disk_object(&mood_def);
201 * Check all moods for syntax errors.
203 * \param aca Only ->pbout is used for diagnostics.
205 * \return Negative on fatal errors. Inconsistent mood definitions are not
206 * considered an error.
208 int mood_check_callback(struct afs_callback_arg *aca)
210 para_printf(&aca->pbout, "checking moods...\n");
211 return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, &aca->pbout,
216 * The normalized num_played and last_played values are defined as
218 * nn := -(np - mean_n) / sigma_n and nl := -(lp - mean_l) / sigma_l
220 * For a (hypothetical) file with np = 0 and lp = now we thus have
222 * nn = mean_n / sigma_n =: hn > 0
223 * nl = -(now - mean_l) / sigma_l =: hl < 0
225 * We design the score function so that both contributions get the same
226 * weight. Define the np and lp score of an arbitrary file as
228 * sn := nn * -hl and sl := nl * hn
231 * num_played mean/sigma: 87/14
232 * last_played mean/sigma: 45/32 days
234 * We have hn = 87 / 14 = 6.21 and hl = -45 / 32 = -1.41. Multiplying
235 * nn of every file with the correction factor 1.41 and nl with
236 * 6.21 makes the weight of the two contributions equal.
238 * The total score s := sn + sl has the representation
240 * s = -cn * (np - mean_n) - cl * (lp - mean_l)
242 * with positive correction factors
244 * cn = (now - mean_l) / (sqrt(ql) * sqrt(qn) / n)
245 * cl = mean_n / (sqrt(ql) * sqrt(qn) / n)
247 * where ql and qn are the quadratic deviations stored in the statistics
248 * structure and n is the number of admissible files. To avoid integer
249 * overflows and rounding errors we store the common divisor of the
250 * correction factors separately.
252 static long compute_score(struct afs_info *afsi)
254 int64_t mean_n, mean_l,score_n, score_l;
256 assert(statistics.normalization_divisor > 0);
257 assert(statistics.num > 0);
258 mean_n = statistics.num_played_sum / statistics.num;
259 mean_l = statistics.last_played_sum / statistics.num;
261 score_n = -((int64_t)afsi->num_played - mean_n)
262 * statistics.num_played_correction
263 / statistics.normalization_divisor;
264 score_l = -((int64_t)afsi->last_played - mean_l)
265 * statistics.last_played_correction
266 / statistics.normalization_divisor;
267 return (score_n + score_l) / 2;
270 static int add_afs_statistics(const struct osl_row *row)
273 struct afs_info afsi;
276 ret = get_afsi_of_row(row, &afsi);
280 x = afsi.last_played;
281 s = statistics.last_played_sum;
283 q = (x > s / n)? x - s / n : s / n - x;
284 statistics.last_played_qd += q * q * n / (n + 1);
286 statistics.last_played_sum += x;
289 s = statistics.num_played_sum;
291 q = (x > s / n)? x - s / n : s / n - x;
292 statistics.num_played_qd += q * q * n / (n + 1);
294 statistics.num_played_sum += x;
299 static int del_afs_statistics(const struct osl_row *row)
301 uint64_t n, s, q, a, new_s;
302 struct afs_info afsi;
304 ret = get_afsi_of_row(row, &afsi);
310 memset(&statistics, 0, sizeof(statistics));
311 statistics.normalization_divisor = 1;
315 s = statistics.last_played_sum;
316 q = statistics.last_played_qd;
317 a = afsi.last_played;
319 statistics.last_played_sum = new_s;
320 statistics.last_played_qd = q + s * s / n - a * a
321 - new_s * new_s / (n - 1);
323 s = statistics.num_played_sum;
324 q = statistics.num_played_qd;
327 statistics.num_played_sum = new_s;
328 statistics.num_played_qd = q + s * s / n - a * a
329 - new_s * new_s / (n - 1);
336 * At mood open time we determine the set of admissible files for the given
337 * mood where each file is identified by a pointer to a row of the audio file
338 * table. In the first pass the pointers are added to a temporary array and
339 * statistics are computed. When all admissible files have been processed in
340 * this way, the score of each admissible file is computed and the (row, score)
341 * pair is added to the score table. This has to be done in a second pass
342 * since the score depends on the statistics. Finally, the array is freed.
344 struct admissible_array {
345 /** Files are admissible wrt. this mood. */
347 /** The size of the array */
349 /** Pointer to the array of admissible files. */
350 struct osl_row **array;
354 * Check whether the given audio file is admissible. If it is, add it to array
355 * of admissible files.
357 static int add_if_admissible(struct osl_row *aft_row, void *data)
359 struct admissible_array *aa = data;
362 ret = row_is_admissible(aft_row, aa->m);
365 if (statistics.num >= aa->size) {
368 aa->array = arr_realloc(aa->array, aa->size,
369 sizeof(struct osl_row *));
371 aa->array[statistics.num] = aft_row;
372 return add_afs_statistics(aft_row);
376 * Compute the new quadratic deviation in case one element changes.
378 * \param n Number of elements.
379 * \param old_qd The quadratic deviation before the change.
380 * \param old_val The value that was replaced.
381 * \param new_val The replacement value.
382 * \param old_sum The sum of all elements before the update.
384 * \return The new quadratic deviation resulting from replacing old_val
387 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
388 * their quadratic deviation
390 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
392 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
393 * the last number a_n was replaced by b) may be computed in O(1) time in terms
394 * of n, q, a_n, b, and S as
396 * q' = q + d * s - (2 * S + d) * d / n
397 * = q + d * (s - 2 * S / n - d /n),
399 * where d = b - a_n, and s = b + a_n.
401 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
404 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
406 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
409 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
410 int64_t old_val, int64_t new_val, int64_t old_sum)
412 int64_t delta = new_val - old_val;
413 int64_t sigma = new_val + old_val;
414 return old_qd + delta * (sigma - 2 * old_sum / n - delta / n);
417 static int update_afs_statistics(struct afs_info *old_afsi,
418 struct afs_info *new_afsi)
421 int ret = get_num_admissible_files(&n);
427 statistics.last_played_qd = update_quadratic_deviation(n,
428 statistics.last_played_qd, old_afsi->last_played,
429 new_afsi->last_played, statistics.last_played_sum);
430 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
432 statistics.num_played_qd = update_quadratic_deviation(n,
433 statistics.num_played_qd, old_afsi->num_played,
434 new_afsi->num_played, statistics.num_played_sum);
435 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
439 static int add_to_score_table(const struct osl_row *aft_row)
442 struct afs_info afsi;
443 int ret = get_afsi_of_row(aft_row, &afsi);
447 score = compute_score(&afsi);
448 return score_add(aft_row, score);
451 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
453 int ret = del_afs_statistics(aft_row);
456 return score_delete(aft_row);
460 * Delete one entry from the statistics and from the score table.
462 * \param aft_row The audio file which is no longer admissible.
464 * \return Positive on success, negative on errors.
466 * \sa \ref score_delete().
468 static int mood_delete_audio_file(const struct osl_row *aft_row)
472 ret = row_belongs_to_score_table(aft_row, NULL);
475 if (!ret) /* not admissible, nothing to do */
477 return delete_from_statistics_and_score_table(aft_row);
481 * Compute the new score of an audio file wrt. the current mood.
483 * \param aft_row Determines the audio file.
484 * \param old_afsi The audio file selector info before updating.
486 * The \a old_afsi argument may be \p NULL which indicates that no changes to
487 * the audio file info were made.
489 * \return Positive on success, negative on errors.
491 static int mood_update_audio_file(const struct osl_row *aft_row,
492 struct afs_info *old_afsi)
495 int ret, is_admissible, was_admissible = 0;
496 struct afs_info afsi;
500 return 1; /* nothing to do */
501 ret = row_belongs_to_score_table(aft_row, &rank);
504 was_admissible = ret;
505 ret = row_is_admissible(aft_row, current_mood);
508 is_admissible = (ret > 0);
509 if (!was_admissible && !is_admissible)
511 if (was_admissible && !is_admissible)
512 return delete_from_statistics_and_score_table(aft_row);
513 if (!was_admissible && is_admissible) {
514 ret = add_afs_statistics(aft_row);
517 return add_to_score_table(aft_row);
520 ret = get_afsi_of_row(aft_row, &afsi);
524 ret = update_afs_statistics(old_afsi, &afsi);
528 score = compute_score(&afsi);
529 PARA_DEBUG_LOG("score: %li\n", score);
530 percent = (score + 100) / 3;
533 else if (percent < 0)
535 PARA_DEBUG_LOG("moving from rank %u to %li%%\n", rank, percent);
536 return score_update(aft_row, percent);
539 /* sse: seconds since epoch. */
540 static void log_statistics(int64_t sse)
542 unsigned n = statistics.num;
543 int mean_days, sigma_days;
545 assert(current_mood);
546 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name?
547 current_mood->name : "(dummy)");
549 PARA_WARNING_LOG("no admissible files\n");
552 PARA_NOTICE_LOG("%u admissible files\n", statistics.num);
553 mean_days = (sse - statistics.last_played_sum / n) / 3600 / 24;
554 sigma_days = int_sqrt(statistics.last_played_qd / n) / 3600 / 24;
555 PARA_NOTICE_LOG("last_played mean/sigma: %d/%d days\n", mean_days, sigma_days);
556 PARA_NOTICE_LOG("num_played mean/sigma: %" PRId64 "/%" PRIu64 "\n",
557 statistics.num_played_sum / n,
558 int_sqrt(statistics.num_played_qd / n));
559 PARA_NOTICE_LOG("num_played correction factor: %" PRId64 "\n",
560 statistics.num_played_correction);
561 PARA_NOTICE_LOG("last_played correction factor: %" PRId64 "\n",
562 statistics.last_played_correction);
563 PARA_NOTICE_LOG("normalization divisor: %" PRId64 "\n",
564 statistics.normalization_divisor);
568 * Close the current mood.
570 * Frees all resources of the current mood.
572 void close_current_mood(void)
574 destroy_mood(current_mood);
576 memset(&statistics, 0, sizeof(statistics));
577 statistics.normalization_divisor = 1;
580 static void compute_correction_factors(int64_t sse)
582 struct afs_statistics *s = &statistics;
585 s->normalization_divisor = int_sqrt(s->last_played_qd)
586 * int_sqrt(s->num_played_qd) / s->num / 100;
587 s->num_played_correction = sse - s->last_played_sum / s->num;
588 s->last_played_correction = s->num_played_sum / s->num;
590 if (s->num_played_correction == 0)
591 s->num_played_correction = 1;
592 if (s->normalization_divisor == 0)
593 s->normalization_divisor = 1;
594 if (s->last_played_correction == 0)
595 s->last_played_correction = 1;
599 * Change the current mood.
601 * \param mood_name The name of the mood to open.
602 * \param errmsg Error description is returned here.
604 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
605 * and uses a scoring method based only on the \a last_played information.
607 * The errmsg pointer may be NULL, in which case no error message will be
608 * returned. If a non-NULL pointer is given, the caller must free *errmsg.
610 * If there is already an open mood, it will be closed first.
612 * \return Positive on success, negative on errors.
614 * \sa struct \ref afs_info::last_played, \ref mp_eval_row().
616 int change_current_mood(const char *mood_name, char **errmsg)
619 struct admissible_array aa = {
624 * We can not use the "now" pointer from sched.c here because we are
625 * called before schedule(), which initializes "now".
632 struct osl_object obj;
635 *errmsg = make_message("empty mood name");
636 return -ERRNO_TO_PARA_ERROR(EINVAL);
638 obj.data = (char *)mood_name;
639 obj.size = strlen(mood_name) + 1;
640 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
643 *errmsg = make_message("no such mood: %s",
647 ret = load_mood(row, &m, errmsg);
650 close_current_mood();
652 } else { /* load dummy mood */
653 close_current_mood();
654 current_mood = alloc_new_mood(NULL);
657 PARA_NOTICE_LOG("computing statistics of admissible files\n");
658 ret = audio_file_loop(&aa, add_if_admissible);
661 *errmsg = make_message("audio file loop failed");
664 clock_get_realtime(&rnow);
665 compute_correction_factors(rnow.tv_sec);
666 log_statistics(rnow.tv_sec);
667 for (i = 0; i < statistics.num; i++) {
668 ret = add_to_score_table(aa.array[i]);
671 *errmsg = make_message(
672 "could not add row to score table");
676 ret = statistics.num;
680 close_current_mood();
685 * Close and re-open the current mood.
687 * This function is called on events which render the current list of
688 * admissible files useless, for example if an attribute is removed from the
691 * If no mood is currently open, the function returns success.
693 static int reload_current_mood(void)
696 char *mood_name = NULL;
698 ret = clear_score_table();
703 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
704 current_mood->name : "(dummy)");
705 if (current_mood->name)
706 mood_name = para_strdup(current_mood->name);
707 close_current_mood();
708 ret = change_current_mood(mood_name, NULL);
714 * Notification callback for the moods table.
716 * \param event Type of the event just occurred.
718 * \param data Its type depends on the event.
720 * This function updates the score table according to the event that has
721 * occurred. Two actions are possible: (a) reload the current mood, or (b)
722 * add/remove/update the row of the score table which corresponds to the audio
723 * file that has been modified or whose afs info has been changed. It depends
724 * on the type of the event which action (if any) is performed.
726 * The callbacks of command handlers such as com_add() or com_touch() which
727 * modify the audio file table call this function. The virtual streaming system
728 * also calls this after it has updated the afs info of the file it is about to
729 * stream (the one with the highest score). If the file stays admissible, its
730 * score is recomputed so that a different file is picked next time.
734 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
741 * The three blob events might change the set of admissible files,
742 * so we must reload the score list.
747 if (data == moods_table || data == playlists_table)
748 return 1; /* no reload necessary for these */
749 return reload_current_mood();
750 /* these also require reload of the score table */
752 case ATTRIBUTE_REMOVE:
753 case ATTRIBUTE_RENAME:
754 return reload_current_mood();
755 /* changes to the aft only require to re-examine the audio file */
757 struct afsi_change_event_data *aced = data;
758 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
761 case AUDIO_FILE_RENAME:
763 return mood_update_audio_file(data, NULL);
764 case AUDIO_FILE_REMOVE:
765 return mood_delete_audio_file(data);