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 static void destroy_mood(struct mood *m)
126 mp_shutdown(m->parser_context);
131 static struct mood *alloc_new_mood(const char *name)
133 struct mood *m = zalloc(sizeof(struct mood));
135 m->name = para_strdup(name);
139 static int load_mood(const struct osl_row *mood_row, struct mood **m,
143 struct osl_object mood_def;
146 ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
149 *errmsg = make_message(
150 "could not read mood definition");
154 *m = alloc_new_mood(mood_name);
155 PARA_INFO_LOG("opening mood %s\n", mood_name);
156 ret = mp_init(mood_def.data, mood_def.size, &(*m)->parser_context, errmsg);
157 osl_close_disk_object(&mood_def);
163 static int check_mood(struct osl_row *mood_row, void *data)
165 struct para_buffer *pb = data;
166 char *mood_name, *errmsg;
167 struct osl_object mood_def;
169 int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
172 para_printf(pb, "cannot read mood\n");
175 if (!*mood_name) /* ignore dummy row */
177 m = alloc_new_mood("check");
178 ret = mp_init(mood_def.data, mood_def.size, &m->parser_context,
181 para_printf(pb, "%s: %s\n", mood_name, errmsg);
183 para_printf(pb, "%s\n", para_strerror(-ret));
186 ret = 1; /* don't fail the loop on invalid mood definitions */
188 osl_close_disk_object(&mood_def);
193 * Check all moods for syntax errors.
195 * \param aca Only ->pbout is used for diagnostics.
197 * \return Negative on fatal errors. Inconsistent mood definitions are not
198 * considered an error.
200 int mood_check_callback(struct afs_callback_arg *aca)
202 para_printf(&aca->pbout, "checking moods...\n");
203 return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, &aca->pbout,
208 * The normalized num_played and last_played values are defined as
210 * nn := -(np - mean_n) / sigma_n and nl := -(lp - mean_l) / sigma_l
212 * For a (hypothetical) file with np = 0 and lp = now we thus have
214 * nn = mean_n / sigma_n =: hn > 0
215 * nl = -(now - mean_l) / sigma_l =: hl < 0
217 * We design the score function so that both contributions get the same
218 * weight. Define the np and lp score of an arbitrary file as
220 * sn := nn * -hl and sl := nl * hn
223 * num_played mean/sigma: 87/14
224 * last_played mean/sigma: 45/32 days
226 * We have hn = 87 / 14 = 6.21 and hl = -45 / 32 = -1.41. Multiplying
227 * nn of every file with the correction factor 1.41 and nl with
228 * 6.21 makes the weight of the two contributions equal.
230 * The total score s := sn + sl has the representation
232 * s = -cn * (np - mean_n) - cl * (lp - mean_l)
234 * with positive correction factors
236 * cn = (now - mean_l) / (sqrt(ql) * sqrt(qn) / n)
237 * cl = mean_n / (sqrt(ql) * sqrt(qn) / n)
239 * where ql and qn are the quadratic deviations stored in the statistics
240 * structure and n is the number of admissible files. To avoid integer
241 * overflows and rounding errors we store the common divisor of the
242 * correction factors separately.
244 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
248 return 100 * (n * x - sum) / (int64_t)int_sqrt(n) / (int64_t)int_sqrt(qd);
251 static long compute_score(struct afs_info *afsi)
253 long score = -normalized_value(afsi->num_played, statistics.num,
254 statistics.num_played_sum, statistics.num_played_qd);
255 score -= normalized_value(afsi->last_played, statistics.num,
256 statistics.last_played_sum, statistics.last_played_qd);
260 static int add_afs_statistics(const struct osl_row *row)
263 struct afs_info afsi;
266 ret = get_afsi_of_row(row, &afsi);
270 x = afsi.last_played;
271 s = statistics.last_played_sum;
273 q = (x > s / n)? x - s / n : s / n - x;
274 statistics.last_played_qd += q * q * n / (n + 1);
276 statistics.last_played_sum += x;
279 s = statistics.num_played_sum;
281 q = (x > s / n)? x - s / n : s / n - x;
282 statistics.num_played_qd += q * q * n / (n + 1);
284 statistics.num_played_sum += x;
289 static int del_afs_statistics(const struct osl_row *row)
291 uint64_t n, s, q, a, new_s;
292 struct afs_info afsi;
294 ret = get_afsi_of_row(row, &afsi);
300 memset(&statistics, 0, sizeof(statistics));
301 statistics.normalization_divisor = 1;
305 s = statistics.last_played_sum;
306 q = statistics.last_played_qd;
307 a = afsi.last_played;
309 statistics.last_played_sum = new_s;
310 statistics.last_played_qd = q + s * s / n - a * a
311 - new_s * new_s / (n - 1);
313 s = statistics.num_played_sum;
314 q = statistics.num_played_qd;
317 statistics.num_played_sum = new_s;
318 statistics.num_played_qd = q + s * s / n - a * a
319 - new_s * new_s / (n - 1);
326 * At mood open time we determine the set of admissible files for the given
327 * mood where each file is identified by a pointer to a row of the audio file
328 * table. In the first pass the pointers are added to a temporary array and
329 * statistics are computed. When all admissible files have been processed in
330 * this way, the score of each admissible file is computed and the (row, score)
331 * pair is added to the score table. This has to be done in a second pass
332 * since the score depends on the statistics. Finally, the array is freed.
334 struct admissible_array {
335 /** Files are admissible wrt. this mood. */
337 /** The size of the array */
339 /** Pointer to the array of admissible files. */
340 struct osl_row **array;
344 * Check whether the given audio file is admissible. If it is, add it to array
345 * of admissible files.
347 static int add_if_admissible(struct osl_row *aft_row, void *data)
349 struct admissible_array *aa = data;
351 if (!mp_eval_row(aft_row, aa->m->parser_context))
353 if (statistics.num >= aa->size) {
356 aa->array = arr_realloc(aa->array, aa->size,
357 sizeof(struct osl_row *));
359 aa->array[statistics.num] = aft_row;
360 return add_afs_statistics(aft_row);
364 * Compute the new quadratic deviation in case one element changes.
366 * \param n Number of elements.
367 * \param old_qd The quadratic deviation before the change.
368 * \param old_val The value that was replaced.
369 * \param new_val The replacement value.
370 * \param old_sum The sum of all elements before the update.
372 * \return The new quadratic deviation resulting from replacing old_val
375 * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
376 * their quadratic deviation
378 * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
380 * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
381 * the last number a_n was replaced by b) may be computed in O(1) time in terms
382 * of n, q, a_n, b, and S as
384 * q' = q + d * s - (2 * S + d) * d / n
385 * = q + d * (s - 2 * S / n - d /n),
387 * where d = b - a_n, and s = b + a_n.
389 * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
392 * q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
394 * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
397 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
398 int64_t old_val, int64_t new_val, int64_t old_sum)
400 int64_t delta = new_val - old_val;
401 int64_t sigma = new_val + old_val;
402 return old_qd + delta * (sigma - 2 * old_sum / n - delta / n);
405 static int update_afs_statistics(struct afs_info *old_afsi,
406 struct afs_info *new_afsi)
409 int ret = get_num_admissible_files(&n);
415 statistics.last_played_qd = update_quadratic_deviation(n,
416 statistics.last_played_qd, old_afsi->last_played,
417 new_afsi->last_played, statistics.last_played_sum);
418 statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
420 statistics.num_played_qd = update_quadratic_deviation(n,
421 statistics.num_played_qd, old_afsi->num_played,
422 new_afsi->num_played, statistics.num_played_sum);
423 statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
427 static int add_to_score_table(const struct osl_row *aft_row)
430 struct afs_info afsi;
431 int ret = get_afsi_of_row(aft_row, &afsi);
435 score = compute_score(&afsi);
436 return score_add(aft_row, score);
439 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
441 int ret = del_afs_statistics(aft_row);
444 return score_delete(aft_row);
448 * Delete one entry from the statistics and from the score table.
450 * \param aft_row The audio file which is no longer admissible.
452 * \return Positive on success, negative on errors.
454 * \sa \ref score_delete().
456 static int mood_delete_audio_file(const struct osl_row *aft_row)
460 ret = row_belongs_to_score_table(aft_row, NULL);
463 if (!ret) /* not admissible, nothing to do */
465 return delete_from_statistics_and_score_table(aft_row);
469 * Compute the new score of an audio file wrt. the current mood.
471 * \param aft_row Determines the audio file.
472 * \param old_afsi The audio file selector info before updating.
474 * The \a old_afsi argument may be \p NULL which indicates that no changes to
475 * the audio file info were made.
477 * \return Positive on success, negative on errors.
479 static int mood_update_audio_file(const struct osl_row *aft_row,
480 struct afs_info *old_afsi)
484 bool is_admissible, was_admissible;
485 struct afs_info afsi;
489 return 1; /* nothing to do */
490 ret = row_belongs_to_score_table(aft_row, &rank);
493 was_admissible = ret;
494 is_admissible = mp_eval_row(aft_row, current_mood->parser_context);
495 if (!was_admissible && !is_admissible)
497 if (was_admissible && !is_admissible)
498 return delete_from_statistics_and_score_table(aft_row);
499 if (!was_admissible && is_admissible) {
500 ret = add_afs_statistics(aft_row);
503 return add_to_score_table(aft_row);
506 ret = get_afsi_of_row(aft_row, &afsi);
510 ret = update_afs_statistics(old_afsi, &afsi);
514 score = compute_score(&afsi);
515 PARA_DEBUG_LOG("score: %li\n", score);
516 percent = (score + 100) / 3;
519 else if (percent < 0)
521 PARA_DEBUG_LOG("moving from rank %u to %li%%\n", rank, percent);
522 return score_update(aft_row, percent);
525 /* sse: seconds since epoch. */
526 static void log_statistics(int64_t sse)
528 unsigned n = statistics.num;
529 int mean_days, sigma_days;
531 assert(current_mood);
532 PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name?
533 current_mood->name : "(dummy)");
535 PARA_WARNING_LOG("no admissible files\n");
538 PARA_NOTICE_LOG("%u admissible files\n", statistics.num);
539 mean_days = (sse - statistics.last_played_sum / n) / 3600 / 24;
540 sigma_days = int_sqrt(statistics.last_played_qd / n) / 3600 / 24;
541 PARA_NOTICE_LOG("last_played mean/sigma: %d/%d days\n", mean_days, sigma_days);
542 PARA_NOTICE_LOG("num_played mean/sigma: %" PRId64 "/%" PRIu64 "\n",
543 statistics.num_played_sum / n,
544 int_sqrt(statistics.num_played_qd / n));
545 PARA_NOTICE_LOG("num_played correction factor: %" PRId64 "\n",
546 statistics.num_played_correction);
547 PARA_NOTICE_LOG("last_played correction factor: %" PRId64 "\n",
548 statistics.last_played_correction);
549 PARA_NOTICE_LOG("normalization divisor: %" PRId64 "\n",
550 statistics.normalization_divisor);
554 * Close the current mood.
556 * Frees all resources of the current mood.
558 void close_current_mood(void)
560 destroy_mood(current_mood);
562 memset(&statistics, 0, sizeof(statistics));
563 statistics.normalization_divisor = 1;
566 static void compute_correction_factors(int64_t sse)
568 struct afs_statistics *s = &statistics;
571 s->normalization_divisor = int_sqrt(s->last_played_qd)
572 * int_sqrt(s->num_played_qd) / s->num / 100;
573 s->num_played_correction = sse - s->last_played_sum / s->num;
574 s->last_played_correction = s->num_played_sum / s->num;
576 if (s->num_played_correction == 0)
577 s->num_played_correction = 1;
578 if (s->normalization_divisor == 0)
579 s->normalization_divisor = 1;
580 if (s->last_played_correction == 0)
581 s->last_played_correction = 1;
585 * Change the current mood.
587 * \param mood_name The name of the mood to open.
588 * \param errmsg Error description is returned here.
590 * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
591 * and uses a scoring method based only on the \a last_played information.
593 * The errmsg pointer may be NULL, in which case no error message will be
594 * returned. If a non-NULL pointer is given, the caller must free *errmsg.
596 * If there is already an open mood, it will be closed first.
598 * \return Positive on success, negative on errors.
600 * \sa struct \ref afs_info::last_played, \ref mp_eval_row().
602 int change_current_mood(const char *mood_name, char **errmsg)
605 struct admissible_array aa = {
610 * We can not use the "now" pointer from sched.c here because we are
611 * called before schedule(), which initializes "now".
618 struct osl_object obj;
621 *errmsg = make_message("empty mood name");
622 return -ERRNO_TO_PARA_ERROR(EINVAL);
624 obj.data = (char *)mood_name;
625 obj.size = strlen(mood_name) + 1;
626 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
629 *errmsg = make_message("no such mood: %s",
633 ret = load_mood(row, &m, errmsg);
636 close_current_mood();
638 } else { /* load dummy mood */
639 close_current_mood();
640 current_mood = alloc_new_mood(NULL);
643 PARA_NOTICE_LOG("computing statistics of admissible files\n");
644 ret = audio_file_loop(&aa, add_if_admissible);
647 *errmsg = make_message("audio file loop failed");
650 clock_get_realtime(&rnow);
651 compute_correction_factors(rnow.tv_sec);
652 log_statistics(rnow.tv_sec);
653 for (i = 0; i < statistics.num; i++) {
654 ret = add_to_score_table(aa.array[i]);
657 *errmsg = make_message(
658 "could not add row to score table");
662 ret = statistics.num;
666 close_current_mood();
671 * Close and re-open the current mood.
673 * This function is called on events which render the current list of
674 * admissible files useless, for example if an attribute is removed from the
677 static int reload_current_mood(void)
680 char *mood_name = NULL;
682 assert(current_mood);
683 ret = clear_score_table();
686 PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
687 current_mood->name : "(dummy)");
688 if (current_mood->name)
689 mood_name = para_strdup(current_mood->name);
690 close_current_mood();
691 ret = change_current_mood(mood_name, NULL);
697 * Notification callback for the moods table.
699 * \param event Type of the event just occurred.
701 * \param data Its type depends on the event.
703 * This function updates the score table according to the event that has
704 * occurred. Two actions are possible: (a) reload the current mood, or (b)
705 * add/remove/update the row of the score table which corresponds to the audio
706 * file that has been modified or whose afs info has been changed. It depends
707 * on the type of the event which action (if any) is performed.
709 * The callbacks of command handlers such as com_add() or com_touch() which
710 * modify the audio file table call this function. The virtual streaming system
711 * also calls this after it has updated the afs info of the file it is about to
712 * stream (the one with the highest score). If the file stays admissible, its
713 * score is recomputed so that a different file is picked next time.
717 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
724 * The three blob events might change the set of admissible files,
725 * so we must reload the score list.
730 if (data == moods_table || data == playlists_table)
731 return 1; /* no reload necessary for these */
732 return reload_current_mood();
733 /* these also require reload of the score table */
735 case ATTRIBUTE_REMOVE:
736 case ATTRIBUTE_RENAME:
737 return reload_current_mood();
738 /* changes to the aft only require to re-examine the audio file */
740 struct afsi_change_event_data *aced = data;
741 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
744 case AUDIO_FILE_RENAME:
746 return mood_update_audio_file(data, NULL);
747 case AUDIO_FILE_REMOVE:
748 return mood_delete_audio_file(data);