mood.c

   1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /** \file mood.c Paraslash's mood handling functions. */
   4
   5 #include <regex.h>
   6 #include <osl.h>
   7 #include <lopsub.h>
   8
   9 #include "para.h"
  10 #include "error.h"
  11 #include "string.h"
  12 #include "afh.h"
  13 #include "afs.h"
  14 #include "list.h"
  15 #include "mm.h"
  16 #include "mood.h"
  17
  18 /*
  19  * Mood parser API. It's overkill to have an own header file for
  20  * these declarations as they are only needed in this .c file.
  21  */
  22 struct mp_context;
  23 int mp_init(const char *definition, int nbytes, struct mp_context **result,
  24                  char **errmsg);
  25 bool mp_eval_row(const struct osl_row *aft_row, struct mp_context *ctx);
  26 void mp_shutdown(struct mp_context *ctx);
  27
  28 /**
  29  * Contains statistical data of the currently admissible audio files.
  30  *
  31  * It is used to assign normalized score values to each admissible audio file.
  32  */
  33 struct afs_statistics {
  34         /** Sum of num played over all admissible files. */
  35         int64_t num_played_sum;
  36         /** Sum of last played times over all admissible files. */
  37         int64_t last_played_sum;
  38         /** Quadratic deviation of num played count. */
  39         int64_t num_played_qd;
  40         /** Quadratic deviation of last played time. */
  41         int64_t last_played_qd;
  42         /** Number of admissible files */
  43         unsigned num;
  44 };
  45 static struct afs_statistics statistics;
  46
  47 /**
  48  * Each line of the current mood corresponds to a mood_item.
  49  */
  50 struct mood_item {
  51         /** The method this line is referring to. */
  52         const struct mood_method *method;
  53         /** The data structure computed by the mood parser. */
  54         void *parser_data;
  55         /** The given score value, or zero if none was given. */
  56         int32_t score_arg;
  57         /** Non-zero if random scoring was requested. */
  58         int random_score;
  59         /** Whether the "not" keyword was given in the mood line. */
  60         int logical_not;
  61         /** The position in the list of items. */
  62         struct list_head mood_item_node;
  63 };
  64
  65 /*
  66  * Created from the mood definition by \ref change_current_mood().
  67  *
  68  * When a mood is opened, each line of its definition is investigated, and a
  69  * corresponding mood item is produced. Each mood line starts with accept,
  70  * deny, or score which determines the type of the mood line. For each such
  71  * type a linked list is maintained whose entries are the mood items.
  72  */
  73 struct mood {
  74         /** The name of this mood. */
  75         char *name;
  76         /** The list of mood items of type \p accept. */
  77         struct list_head accept_list;
  78         /** The list of mood items of type \p deny. */
  79         struct list_head deny_list;
  80         /** The list of mood items of type \p score. */
  81         struct list_head score_list;
  82         /* Only used for version 2 moods. */
  83         struct mp_context *parser_context;
  84 };
  85
  86 /*
  87  * If current_mood is NULL then no mood is currently open. If
  88  * current_mood->name is NULL, the dummy mood is currently open.
  89  */
  90 static struct mood *current_mood;
  91
  92 /*
  93  * Find the position of the most-significant set bit.
  94  *
  95  * Copied and slightly adapted from the linux source tree, version 4.9.39
  96  * (2017-07).
  97  */
  98 __a_const static uint32_t fls64(uint64_t v)
  99 {
 100         int n = 63;
 101         const uint64_t ones = ~(uint64_t)0U;
 102
 103         if ((v & (ones << 32)) == 0) {
 104                 n -= 32;
 105                 v <<= 32;
 106         }
 107         if ((v & (ones << (64 - 16))) == 0) {
 108                 n -= 16;
 109                 v <<= 16;
 110         }
 111         if ((v & (ones << (64 - 8))) == 0) {
 112                 n -= 8;
 113                 v <<= 8;
 114         }
 115         if ((v & (ones << (64 - 4))) == 0) {
 116                 n -= 4;
 117                 v <<= 4;
 118         }
 119         if ((v & (ones << (64 - 2))) == 0) {
 120                 n -= 2;
 121                 v <<= 2;
 122         }
 123         if ((v & (ones << (64 - 1))) == 0)
 124                 n -= 1;
 125         return n;
 126 }
 127
 128 /*
 129  * Compute the integer square root floor(sqrt(x)).
 130  *
 131  * Taken 2007 from the linux source tree.
 132  */
 133 __a_const static uint64_t int_sqrt(uint64_t x)
 134 {
 135         uint64_t op = x, res = 0, one = 1;
 136
 137         one = one << (fls64(x) & ~one);
 138         while (one != 0) {
 139                 if (op >= res + one) {
 140                         op = op - (res + one);
 141                         res = res + 2 * one;
 142                 }
 143                 res /= 2;
 144                 one /= 4;
 145         }
 146         return res;
 147 }
 148
 149 /*
 150  * Returns true if row matches, false if it does not match. In any case score
 151  * and score_arg_sum are set/increased accordingly.
 152  */
 153 static bool get_item_score(struct mood_item *item, const struct afs_info *afsi,
 154                 const struct afh_info *afhi, const char *path, long *score,
 155                 long *score_arg_sum)
 156 {
 157         int ret;
 158         bool match = true;
 159
 160         *score_arg_sum += item->random_score? 100 : PARA_ABS(item->score_arg);
 161         ret = 100;
 162         if (item->method) {
 163                 ret = item->method->score_function(path, afsi, afhi,
 164                         item->parser_data);
 165                 if ((ret < 0 && !item->logical_not) || (ret >= 0 && item->logical_not))
 166                         match = false;
 167         }
 168         if (item->random_score)
 169                 *score = PARA_ABS(ret) * para_random(100);
 170         else
 171                 *score = PARA_ABS(ret) * item->score_arg;
 172         return match;
 173 }
 174
 175 /* returns 1 if row admissible, 0 if not, negative on errors */
 176 static int row_is_admissible(const struct osl_row *aft_row, struct mood *m,
 177                 long *scorep)
 178 {
 179         struct mood_item *item;
 180         int ret;
 181         bool match;
 182         long score_arg_sum = 0, score = 0, item_score;
 183         struct afs_info afsi;
 184         struct afh_info afhi;
 185         char *path;
 186
 187         if (!m)
 188                 return -E_NO_MOOD;
 189         if (m->parser_context) {
 190                 *scorep = 0;
 191                 return mp_eval_row(aft_row, m->parser_context);
 192         }
 193         ret = get_afsi_of_row(aft_row, &afsi);
 194         if (ret < 0)
 195                 return ret;
 196         ret = get_afhi_of_row(aft_row, &afhi);
 197         if (ret < 0)
 198                 return ret;
 199         ret = get_audio_file_path_of_row(aft_row, &path);
 200         if (ret < 0)
 201                 return ret;
 202         /* reject audio file if it matches any entry in the deny list */
 203         list_for_each_entry(item, &m->deny_list, mood_item_node) {
 204                 match = get_item_score(item, &afsi, &afhi, path, &item_score,
 205                         &score_arg_sum);
 206                 if (match) /* not admissible */
 207                         return 0;
 208                 score += item_score;
 209         }
 210         match = false;
 211         list_for_each_entry(item, &m->accept_list, mood_item_node) {
 212                 ret = get_item_score(item, &afsi, &afhi, path, &item_score,
 213                         &score_arg_sum);
 214                 if (ret == 0)
 215                         continue;
 216                 match = true;
 217                 score += item_score;
 218         }
 219         /* reject if there is no matching entry in the accept list */
 220         if (!match && !list_empty(&m->accept_list))
 221                 return 0;
 222         list_for_each_entry(item, &m->score_list, mood_item_node) {
 223                 match = get_item_score(item, &afsi, &afhi, path, &item_score,
 224                         &score_arg_sum);
 225                 if (match)
 226                         score += item_score;
 227         }
 228         if (score_arg_sum)
 229                 score /= score_arg_sum;
 230         *scorep = score;
 231         return 1;
 232 }
 233
 234 static void cleanup_list_entry(struct mood_item *item)
 235 {
 236         if (item->method && item->method->cleanup)
 237                 item->method->cleanup(item->parser_data);
 238         else
 239                 free(item->parser_data);
 240         list_del(&item->mood_item_node);
 241         free(item);
 242 }
 243
 244 static void destroy_mood(struct mood *m)
 245 {
 246         struct mood_item *tmp, *item;
 247
 248         if (!m)
 249                 return;
 250         list_for_each_entry_safe(item, tmp, &m->accept_list, mood_item_node)
 251                 cleanup_list_entry(item);
 252         list_for_each_entry_safe(item, tmp, &m->deny_list, mood_item_node)
 253                 cleanup_list_entry(item);
 254         list_for_each_entry_safe(item, tmp, &m->score_list, mood_item_node)
 255                 cleanup_list_entry(item);
 256         free(m->name);
 257         mp_shutdown(m->parser_context);
 258         free(m);
 259 }
 260
 261 static struct mood *alloc_new_mood(const char *name)
 262 {
 263         struct mood *m = para_calloc(sizeof(struct mood));
 264         if (name)
 265                 m->name = para_strdup(name);
 266         init_list_head(&m->accept_list);
 267         init_list_head(&m->deny_list);
 268         init_list_head(&m->score_list);
 269         return m;
 270 }
 271
 272 /** The different types of a mood line. */
 273 enum mood_line_type {
 274         /** Invalid. */
 275         ML_INVALID,
 276         /** Accept line. */
 277         ML_ACCEPT,
 278         /** Deny line. */
 279         ML_DENY,
 280         /** Score line. */
 281         ML_SCORE
 282 };
 283
 284 /** Data passed to the parser of a mood line. */
 285 struct mood_line_parser_data {
 286         /** The mood this mood line belongs to. */
 287         struct mood *m;
 288         /** The line number in the mood definition. */
 289         unsigned line_num;
 290 };
 291
 292 /*
 293  * <accept [with score <score>] | deny [with score <score>]  | score <score>>
 294  *      [if] [not] <mood_method> [options]
 295  * <score> is either an integer or "random" which assigns a random score to
 296  * all matching files
 297  */
 298 static int parse_mood_line(char *mood_line, void *data)
 299 {
 300         struct mood_line_parser_data *mlpd = data;
 301         char **argv;
 302         unsigned num_words;
 303         char **w;
 304         int i, ret;
 305         enum mood_line_type mlt = ML_INVALID;
 306         struct mood_item *mi = NULL;
 307
 308         mlpd->line_num++;
 309         ret = create_argv(mood_line, " \t", &argv);
 310         if (ret < 0)
 311                 return ret;
 312         num_words = ret;
 313         if (!num_words) /* empty line */
 314                 goto out;
 315         w = argv;
 316         if (**w == '#') /* comment */
 317                 goto out;
 318         if (!strcmp(*w, "accept"))
 319                 mlt = ML_ACCEPT;
 320         else if (!strcmp(*w, "deny"))
 321                 mlt = ML_DENY;
 322         else if (!strcmp(*w, "score"))
 323                 mlt = ML_SCORE;
 324         ret = -E_MOOD_SYNTAX;
 325         if (mlt == ML_INVALID)
 326                 goto out;
 327         mi = para_calloc(sizeof(struct mood_item));
 328         if (mlt != ML_SCORE) {
 329                 ret = -E_MOOD_SYNTAX;
 330                 w++;
 331                 if (!*w)
 332                         goto out;
 333                 if (strcmp(*w, "with"))
 334                         goto check_for_if;
 335                 w++;
 336                 if (!*w)
 337                         goto out;
 338                 if (strcmp(*w, "score"))
 339                         goto out;
 340         }
 341         if (mlt == ML_SCORE || !strcmp(*w, "score")) {
 342                 ret = -E_MOOD_SYNTAX;
 343                 w++;
 344                 if (!*w)
 345                         goto out;
 346                 if (strcmp(*w, "random")) {
 347                         mi->random_score = 0;
 348                         ret = para_atoi32(*w, &mi->score_arg);
 349                         if (ret < 0)
 350                                 goto out;
 351                 } else {
 352                         mi->random_score = 1;
 353                         if (!*(w + 1))
 354                         goto success; /* the line "score random" is valid */
 355                 }
 356         } else
 357                 mi->score_arg = 0;
 358         ret = -E_MOOD_SYNTAX;
 359         w++;
 360         if (!*w)
 361                 goto out;
 362 check_for_if:
 363         if (!strcmp(*w, "if")) {
 364                 ret = -E_MOOD_SYNTAX;
 365                 w++;
 366                 if (!*w)
 367                         goto out;
 368         }
 369         if (!strcmp(*w, "not")) {
 370                 ret = -E_MOOD_SYNTAX;
 371                 w++;
 372                 if (!*w)
 373                         goto out;
 374                 mi->logical_not = 1;
 375         } else
 376                 mi->logical_not = 0;
 377         for (i = 0; mood_methods[i].parser; i++) {
 378                 if (strcmp(*w, mood_methods[i].name))
 379                         continue;
 380                 break;
 381         }
 382         ret = -E_MOOD_SYNTAX;
 383         if (!mood_methods[i].parser)
 384                 goto out;
 385         ret = mood_methods[i].parser(num_words - 1 - (w - argv), w,
 386                 &mi->parser_data);
 387         if (ret < 0)
 388                 goto out;
 389         mi->method = &mood_methods[i];
 390 success:
 391         if (mlpd->m) {
 392                 if (mlt == ML_ACCEPT)
 393                         para_list_add(&mi->mood_item_node, &mlpd->m->accept_list);
 394                 else if (mlt == ML_DENY)
 395                         para_list_add(&mi->mood_item_node, &mlpd->m->deny_list);
 396                 else
 397                         para_list_add(&mi->mood_item_node, &mlpd->m->score_list);
 398         }
 399         PARA_DEBUG_LOG("%s entry added, method: %p\n", mlt == ML_ACCEPT? "accept" :
 400                 (mlt == ML_DENY? "deny" : "score"), mi->method);
 401         ret = 1;
 402 out:
 403         free_argv(argv);
 404         if (mi && (ret < 0 || !mlpd->m)) { /* mi was not added to any list */
 405                 free(mi->parser_data);
 406                 free(mi);
 407         }
 408         return ret;
 409 }
 410
 411 static int load_mood(const struct osl_row *mood_row, struct mood **m,
 412                 char **errmsg)
 413 {
 414         char *mood_name;
 415         struct osl_object mood_def;
 416         struct mood_line_parser_data mlpd = {.line_num = 0};
 417         int ret;
 418
 419         *m = NULL;
 420         ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
 421         if (ret < 0) {
 422                 if (errmsg)
 423                         *errmsg = make_message(
 424                                 "could not read mood definition");
 425                 return ret;
 426         }
 427         assert(*mood_name);
 428         mlpd.m = alloc_new_mood(mood_name);
 429         ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
 430                 parse_mood_line, &mlpd);
 431         if (ret < 0) {
 432                 PARA_INFO_LOG("opening version 2 mood %s\n", mlpd.m->name);
 433                 ret = mp_init(mood_def.data, mood_def.size, &mlpd.m->parser_context,
 434                         errmsg);
 435                 if (ret < 0)
 436                         destroy_mood(mlpd.m);
 437         } else {
 438                 PARA_WARNING_LOG("loaded version 1 mood %s\n", mlpd.m->name);
 439                 PARA_WARNING_LOG("please convert to version 2\n");
 440                 ret = 1;
 441         }
 442         osl_close_disk_object(&mood_def);
 443         if (ret >= 0)
 444                 *m = mlpd.m;
 445         return ret;
 446 }
 447
 448 static int check_mood(struct osl_row *mood_row, void *data)
 449 {
 450         struct para_buffer *pb = data;
 451         char *mood_name;
 452         struct osl_object mood_def;
 453         struct mood_line_parser_data mlpd = {.line_num = 0};
 454
 455         int ret = mood_get_name_and_def_by_row(mood_row, &mood_name, &mood_def);
 456
 457         if (ret < 0) {
 458                 para_printf(pb, "cannot read mood\n");
 459                 return ret;
 460         }
 461         if (!*mood_name) /* ignore dummy row */
 462                 goto out;
 463         ret = for_each_line(FELF_READ_ONLY, mood_def.data, mood_def.size,
 464                 parse_mood_line, &mlpd);
 465         if (ret < 0) {
 466                 char *errmsg;
 467                 struct mood *m = alloc_new_mood("check");
 468                 ret = mp_init(mood_def.data, mood_def.size, &m->parser_context,
 469                         &errmsg);
 470                 if (ret < 0) {
 471                         para_printf(pb, "%s: %s\n", mood_name, errmsg);
 472                         free(errmsg);
 473                         para_printf(pb, "%s\n", para_strerror(-ret));
 474                 } else
 475                         destroy_mood(m);
 476         } else {
 477                 para_printf(pb, "%s: v1 mood, please convert to v2\n",
 478                         mood_name);
 479
 480         }
 481         ret = 1; /* don't fail the loop on invalid mood definitions */
 482 out:
 483         osl_close_disk_object(&mood_def);
 484         return ret;
 485 }
 486
 487 /**
 488  * Check all moods for syntax errors.
 489  *
 490  * \param aca Only ->pbout is used for diagnostics.
 491  *
 492  * \return Negative on fatal errors. Inconsistent mood definitions are not
 493  * considered an error.
 494  */
 495 int mood_check_callback(struct afs_callback_arg *aca)
 496 {
 497         para_printf(&aca->pbout, "checking moods...\n");
 498         return osl(osl_rbtree_loop(moods_table, BLOBCOL_ID, &aca->pbout,
 499                 check_mood));
 500 }
 501
 502 static int64_t normalized_value(int64_t x, int64_t n, int64_t sum, int64_t qd)
 503 {
 504         if (!n || !qd)
 505                 return 0;
 506         return 100 * (n * x - sum) / (int64_t)int_sqrt(n) / (int64_t)int_sqrt(qd);
 507 }
 508
 509 static long compute_score(struct afs_info *afsi, long mood_score)
 510 {
 511         mood_score -= normalized_value(afsi->num_played, statistics.num,
 512                 statistics.num_played_sum, statistics.num_played_qd);
 513         mood_score -= normalized_value(afsi->last_played, statistics.num,
 514                 statistics.last_played_sum, statistics.last_played_qd);
 515         return mood_score / 3;
 516 }
 517
 518 static int add_afs_statistics(const struct osl_row *row)
 519 {
 520         uint64_t n, x, s, q;
 521         struct afs_info afsi;
 522         int ret;
 523
 524         ret = get_afsi_of_row(row, &afsi);
 525         if (ret < 0)
 526                 return ret;
 527         n = statistics.num;
 528         x = afsi.last_played;
 529         s = statistics.last_played_sum;
 530         if (n > 0) {
 531                 q = (x > s / n)? x - s / n : s / n - x;
 532                 statistics.last_played_qd += q * q * n / (n + 1);
 533         }
 534         statistics.last_played_sum += x;
 535
 536         x = afsi.num_played;
 537         s = statistics.num_played_sum;
 538         if (n > 0) {
 539                 q = (x > s / n)? x - s / n : s / n - x;
 540                 statistics.num_played_qd += q * q * n / (n + 1);
 541         }
 542         statistics.num_played_sum += x;
 543         statistics.num++;
 544         return 1;
 545 }
 546
 547 static int del_afs_statistics(const struct osl_row *row)
 548 {
 549         uint64_t n, s, q, a, new_s;
 550         struct afs_info afsi;
 551         int ret;
 552         ret = get_afsi_of_row(row, &afsi);
 553         if (ret < 0)
 554                 return ret;
 555         n = statistics.num;
 556         assert(n);
 557         if (n == 1) {
 558                 memset(&statistics, 0, sizeof(statistics));
 559                 return 1;
 560         }
 561
 562         s = statistics.last_played_sum;
 563         q = statistics.last_played_qd;
 564         a = afsi.last_played;
 565         new_s = s - a;
 566         statistics.last_played_sum = new_s;
 567         statistics.last_played_qd = q + s * s / n - a * a
 568                 - new_s * new_s / (n - 1);
 569
 570         s = statistics.num_played_sum;
 571         q = statistics.num_played_qd;
 572         a = afsi.num_played;
 573         new_s = s - a;
 574         statistics.num_played_sum = new_s;
 575         statistics.num_played_qd = q + s * s / n - a * a
 576                 - new_s * new_s / (n - 1);
 577
 578         statistics.num--;
 579         return 1;
 580 }
 581
 582 /*
 583  * At mood open time we determine the set of admissible files for the given
 584  * mood. The mood score of each admissible file is computed by adding up all
 585  * mood item scores. Next, we update the afs statistics and append a struct
 586  * admissible_file_info to a temporary array.
 587  *
 588  * When all files have been processed in this way, the final score of each
 589  * admissible file is computed by adding the dynamic score (which depends on
 590  * the afs_statistics and the current time) to the mood score. Finally, all
 591  * audio files in the temporary array are added to the score table and the
 592  * array is freed.
 593  */
 594 struct admissible_file_info
 595 {
 596         /** The admissible audio file. */
 597         struct osl_row *aft_row;
 598         /** Its score. */
 599         long score;
 600 };
 601
 602 /** The temporary array of admissible files. */
 603 struct admissible_array {
 604         /** Files are admissible wrt. this mood. */
 605         struct mood *m;
 606         /** The size of the array */
 607         unsigned size;
 608         /** Pointer to the array of admissible files. */
 609         struct admissible_file_info *array;
 610 };
 611
 612 /**
 613  * Add an entry to the array of admissible files.
 614  *
 615  * \param aft_row The audio file to be added.
 616  * \param private_data Pointer to a struct admissible_file_info.
 617  *
 618  * \return 1 if row admissible, 0 if not, negative on errors.
 619  */
 620 static int add_if_admissible(struct osl_row *aft_row, void *data)
 621 {
 622         struct admissible_array *aa = data;
 623         int ret;
 624         long score = 0;
 625
 626         ret = row_is_admissible(aft_row, aa->m, &score);
 627         if (ret <= 0)
 628                 return ret;
 629         if (statistics.num >= aa->size) {
 630                 aa->size *= 2;
 631                 aa->size += 100;
 632                 aa->array = para_realloc(aa->array,
 633                         aa->size * sizeof(struct admissible_file_info));
 634         }
 635         aa->array[statistics.num].aft_row = aft_row;
 636         aa->array[statistics.num].score = score;
 637         ret = add_afs_statistics(aft_row);
 638         if (ret < 0)
 639                 return ret;
 640         return 1;
 641 }
 642
 643 /**
 644  * Compute the new quadratic deviation in case one element changes.
 645  *
 646  * \param n Number of elements.
 647  * \param old_qd The quadratic deviation before the change.
 648  * \param old_val The value that was replaced.
 649  * \param new_val The replacement value.
 650  * \param old_sum The sum of all elements before the update.
 651  *
 652  * \return The new quadratic deviation resulting from replacing old_val
 653  * by new_val.
 654  *
 655  * Given n real numbers a_1, ..., a_n, their sum S = a_1 + ... + a_n,
 656  * their quadratic deviation
 657  *
 658  * q = (a_1 - S/n)^2 + ... + (a_n - S/n)^2,
 659  *
 660  * and a real number b, the quadratic deviation q' of a_1,...a_{n-1}, b (ie.
 661  * the last number a_n was replaced by b) may be computed in O(1) time in terms
 662  * of n, q, a_n, b, and S as
 663  *
 664  *      q' = q + d * s - (2 * S + d) * d / n
 665  *         = q + d * (s - 2 * S / n - d /n),
 666  *
 667  * where d = b - a_n, and s = b + a_n.
 668  *
 669  * Example: n = 3, a_1 = 3, a_2 = 5, a_3 = 7, b = 10. Then S = 15, q = 8, d = 3,
 670  * s = 17, so
 671  *
 672  *      q + d * s - (2 * S + d) * d / n = 8 + 51 - 33 = 26,
 673  *
 674  * which equals q' = (3 - 6)^2 + (5 - 6)^2 + (10 - 6)^2.
 675  *
 676  */
 677 _static_inline_ int64_t update_quadratic_deviation(int64_t n, int64_t old_qd,
 678                 int64_t old_val, int64_t new_val, int64_t old_sum)
 679 {
 680         int64_t delta = new_val - old_val;
 681         int64_t sigma = new_val + old_val;
 682         return old_qd + delta * (sigma - 2 * old_sum / n - delta / n);
 683 }
 684
 685 static int update_afs_statistics(struct afs_info *old_afsi,
 686                 struct afs_info *new_afsi)
 687 {
 688         unsigned n;
 689         int ret = get_num_admissible_files(&n);
 690
 691         if (ret < 0)
 692                 return ret;
 693         assert(n);
 694
 695         statistics.last_played_qd = update_quadratic_deviation(n,
 696                 statistics.last_played_qd, old_afsi->last_played,
 697                 new_afsi->last_played, statistics.last_played_sum);
 698         statistics.last_played_sum += new_afsi->last_played - old_afsi->last_played;
 699
 700         statistics.num_played_qd = update_quadratic_deviation(n,
 701                 statistics.num_played_qd, old_afsi->num_played,
 702                 new_afsi->num_played, statistics.num_played_sum);
 703         statistics.num_played_sum += new_afsi->num_played - old_afsi->num_played;
 704         return 1;
 705 }
 706
 707 static int add_to_score_table(const struct osl_row *aft_row, long mood_score)
 708 {
 709         long score;
 710         struct afs_info afsi;
 711         int ret = get_afsi_of_row(aft_row, &afsi);
 712
 713         if (ret < 0)
 714                 return ret;
 715         score = compute_score(&afsi, mood_score);
 716         return score_add(aft_row, score);
 717 }
 718
 719 static int delete_from_statistics_and_score_table(const struct osl_row *aft_row)
 720 {
 721         int ret = del_afs_statistics(aft_row);
 722         if (ret < 0)
 723                 return ret;
 724         return score_delete(aft_row);
 725 }
 726
 727 /**
 728  * Delete one entry from the statistics and from the score table.
 729  *
 730  * \param aft_row The audio file which is no longer admissible.
 731  *
 732  * \return Positive on success, negative on errors.
 733  *
 734  * \sa \ref score_delete().
 735  */
 736 static int mood_delete_audio_file(const struct osl_row *aft_row)
 737 {
 738         int ret;
 739
 740         ret = row_belongs_to_score_table(aft_row, NULL);
 741         if (ret < 0)
 742                 return ret;
 743         if (!ret) /* not admissible, nothing to do */
 744                 return 1;
 745         return delete_from_statistics_and_score_table(aft_row);
 746 }
 747
 748 /**
 749  * Compute the new score of an audio file wrt. the current mood.
 750  *
 751  * \param aft_row Determines the audio file.
 752  * \param old_afsi The audio file selector info before updating.
 753  *
 754  * The \a old_afsi argument may be \p NULL which indicates that no changes to
 755  * the audio file info were made.
 756  *
 757  * \return Positive on success, negative on errors.
 758  */
 759 static int mood_update_audio_file(const struct osl_row *aft_row,
 760                 struct afs_info *old_afsi)
 761 {
 762         long score, percent;
 763         int ret, is_admissible, was_admissible = 0;
 764         struct afs_info afsi;
 765         unsigned rank;
 766
 767         if (!current_mood)
 768                 return 1; /* nothing to do */
 769         ret = row_belongs_to_score_table(aft_row, &rank);
 770         if (ret < 0)
 771                 return ret;
 772         was_admissible = ret;
 773         ret = row_is_admissible(aft_row, current_mood, &score);
 774         if (ret < 0)
 775                 return ret;
 776         is_admissible = (ret > 0);
 777         if (!was_admissible && !is_admissible)
 778                 return 1;
 779         if (was_admissible && !is_admissible)
 780                 return delete_from_statistics_and_score_table(aft_row);
 781         if (!was_admissible && is_admissible) {
 782                 ret = add_afs_statistics(aft_row);
 783                 if (ret < 0)
 784                         return ret;
 785                 return add_to_score_table(aft_row, score);
 786         }
 787         /* update score */
 788         ret = get_afsi_of_row(aft_row, &afsi);
 789         if (ret < 0)
 790                 return ret;
 791         if (old_afsi) {
 792                 ret = update_afs_statistics(old_afsi, &afsi);
 793                 if (ret < 0)
 794                         return ret;
 795         }
 796         score = compute_score(&afsi, score);
 797         PARA_DEBUG_LOG("score: %li\n", score);
 798         percent = (score + 100) / 3;
 799         if (percent > 100)
 800                 percent = 100;
 801         else if (percent < 0)
 802                 percent = 0;
 803         PARA_DEBUG_LOG("moving from rank %u to %li%%\n", rank, percent);
 804         return score_update(aft_row, percent);
 805 }
 806
 807 static void log_statistics(void)
 808 {
 809         unsigned n = statistics.num;
 810         int mean_days, sigma_days;
 811         /*
 812          * We can not use the "now" pointer from sched.c here because we are
 813          * called before schedule(), which initializes "now".
 814          */
 815         struct timeval rnow;
 816
 817         assert(current_mood);
 818         PARA_NOTICE_LOG("loaded mood %s\n", current_mood->name?
 819                 current_mood->name : "(dummy)");
 820         if (!n) {
 821                 PARA_WARNING_LOG("no admissible files\n");
 822                 return;
 823         }
 824         PARA_NOTICE_LOG("%u admissible files\n", statistics.num);
 825         clock_get_realtime(&rnow);
 826         mean_days = (rnow.tv_sec - statistics.last_played_sum / n) / 3600 / 24;
 827         sigma_days = int_sqrt(statistics.last_played_qd / n) / 3600 / 24;
 828         PARA_NOTICE_LOG("last_played mean/sigma: %d/%d days\n", mean_days, sigma_days);
 829         PARA_NOTICE_LOG("num_played mean/sigma: %llu/%llu\n",
 830                 (long long unsigned)statistics.num_played_sum / n,
 831                 (long long unsigned)int_sqrt(statistics.num_played_qd / n));
 832 }
 833
 834 /**
 835  * Close the current mood.
 836  *
 837  * Frees all resources of the current mood.
 838  */
 839 void close_current_mood(void)
 840 {
 841         destroy_mood(current_mood);
 842         current_mood = NULL;
 843         memset(&statistics, 0, sizeof(statistics));
 844 }
 845
 846 /**
 847  * Change the current mood.
 848  *
 849  * \param mood_name The name of the mood to open.
 850  * \param errmsg Error description is returned here.
 851  *
 852  * If \a mood_name is \a NULL, load the dummy mood that accepts every audio file
 853  * and uses a scoring method based only on the \a last_played information.
 854  *
 855  * The errmsg pointer may be NULL, in which case no error message will be
 856  * returned. If a non-NULL pointer is given, the caller must free *errmsg.
 857  *
 858  * If there is already an open mood, it will be closed first.
 859  *
 860  * \return Positive on success, negative on errors. Loading the dummy mood
 861  * always succeeds.
 862  *
 863  * \sa struct \ref afs_info::last_played, \ref mp_eval_row().
 864  */
 865 int change_current_mood(const char *mood_name, char **errmsg)
 866 {
 867         int i, ret;
 868         struct admissible_array aa = {
 869                 .size = 0,
 870                 .array = NULL
 871         };
 872
 873         if (mood_name) {
 874                 struct mood *m;
 875                 struct osl_row *row;
 876                 struct osl_object obj = {
 877                         .data = (char *)mood_name,
 878                         .size = strlen(mood_name) + 1
 879                 };
 880                 ret = osl(osl_get_row(moods_table, BLOBCOL_NAME, &obj, &row));
 881                 if (ret < 0) {
 882                         if (errmsg)
 883                                 *errmsg = make_message("no such mood: %s",
 884                                         mood_name);
 885                         return ret;
 886                 }
 887                 ret = load_mood(row, &m, errmsg);
 888                 if (ret < 0)
 889                         return ret;
 890                 close_current_mood();
 891                 current_mood = m;
 892         } else { /* load dummy mood */
 893                 close_current_mood();
 894                 current_mood = alloc_new_mood(NULL);
 895         }
 896         aa.m = current_mood;
 897         PARA_NOTICE_LOG("computing statistics of admissible files\n");
 898         ret = audio_file_loop(&aa, add_if_admissible);
 899         if (ret < 0) {
 900                 if (errmsg)
 901                         *errmsg = make_message("audio file loop failed");
 902                 return ret;
 903         }
 904         for (i = 0; i < statistics.num; i++) {
 905                 struct admissible_file_info *a = aa.array + i;
 906                 ret = add_to_score_table(a->aft_row, a->score);
 907                 if (ret < 0) {
 908                         if (errmsg)
 909                                 *errmsg = make_message(
 910                                         "could not add row to score table");
 911                         goto out;
 912                 }
 913         }
 914         log_statistics();
 915         ret = statistics.num;
 916 out:
 917         free(aa.array);
 918         return ret;
 919 }
 920
 921 /*
 922  * Close and re-open the current mood.
 923  *
 924  * This function is called on events which render the current list of
 925  * admissible files useless, for example if an attribute is removed from the
 926  * attribute table.
 927  *
 928  * If no mood is currently open, the function returns success.
 929  */
 930 static int reload_current_mood(void)
 931 {
 932         int ret;
 933         char *mood_name = NULL;
 934
 935         ret = clear_score_table();
 936         if (ret < 0)
 937                 return ret;
 938         if (!current_mood)
 939                 return 1;
 940         PARA_NOTICE_LOG("reloading %s\n", current_mood->name?
 941                 current_mood->name : "(dummy)");
 942         if (current_mood->name)
 943                 mood_name = para_strdup(current_mood->name);
 944         close_current_mood();
 945         ret = change_current_mood(mood_name, NULL);
 946         free(mood_name);
 947         return ret;
 948 }
 949
 950 /**
 951  * Notification callback for the moods table.
 952  *
 953  * \param event Type of the event just occurred.
 954  * \param pb Unused.
 955  * \param data Its type depends on the event.
 956  *
 957  * This function performs actions required due to the occurrence of the given
 958  * event. Possible actions include reload of the current mood and update of the
 959  * score of an audio file.
 960  *
 961  * \return Standard.
 962  */
 963 int moods_event_handler(enum afs_events event, __a_unused struct para_buffer *pb,
 964                 void *data)
 965 {
 966         if (!current_mood)
 967                 return 0;
 968         switch (event) {
 969         /*
 970          * The three blob events might change the set of admissible files,
 971          * so we must reload the score list.
 972          */
 973         case BLOB_RENAME:
 974         case BLOB_REMOVE:
 975         case BLOB_ADD:
 976                 if (data == moods_table || data == playlists_table)
 977                         return 1; /* no reload necessary for these */
 978                 return reload_current_mood();
 979         /* these also require reload of the score table */
 980         case ATTRIBUTE_ADD:
 981         case ATTRIBUTE_REMOVE:
 982         case ATTRIBUTE_RENAME:
 983                 return reload_current_mood();
 984         /* changes to the aft only require to re-examine the audio file */
 985         case AFSI_CHANGE: {
 986                 struct afsi_change_event_data *aced = data;
 987                 return mood_update_audio_file(aced->aft_row, aced->old_afsi);
 988                 }
 989         case AFHI_CHANGE:
 990         case AUDIO_FILE_RENAME:
 991         case AUDIO_FILE_ADD:
 992                 return mood_update_audio_file(data, NULL);
 993         case AUDIO_FILE_REMOVE:
 994                 return mood_delete_audio_file(data);
 995         default:
 996                 return 1;
 997         }
 998 }