score.c

   1 /*
   2  * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file score.c Scoring functions to determine the audio file streaming order. */
   8 #include "para.h"
   9 #include "error.h"
  10 #include "afh.h"
  11 #include "afs.h"
  12 #include "list.h"
  13 #include "string.h"
  14
  15 int mood_compute_score(const void *row, long *score);
  16
  17 static void *score_table;
  18
  19 static int ptr_compare(const struct osl_object *obj1, const struct osl_object *obj2)
  20 {
  21         void *d1 = *(void **)obj1->data;
  22         void *d2 = *(void **)obj2->data;
  23         return NUM_COMPARE(d1, d2);
  24 }
  25
  26 /**
  27  * Compare the score of two audio files
  28  *
  29  * \param obj1 Pointer to the first score object.
  30  * \param obj2 Pointer to the second score object.
  31  *
  32  * This function first compares the score values as usual integers. If they compare as
  33  * equal, the addresss of \a obj1 and \a obj2 are compared. So this compare function
  34  * returns zero if and only if \a obj1 and \a obj2 point to the same memory area.
  35  *
  36  * \sa osl_compare_function.
  37  */
  38 static int score_compare(const struct osl_object *obj1, const struct osl_object *obj2)
  39 {
  40         int d1 = *(int*)obj1->data;
  41         int d2 = *(int*)obj2->data;
  42         int ret = NUM_COMPARE(d2, d1);
  43
  44         if (ret)
  45                 return ret;
  46         return NUM_COMPARE(obj2->data, obj1->data);
  47 }
  48
  49 /**
  50  * The score table consists of two colums: The \a aft_row column contains
  51  * pointers to the rows of the audio file table,  and the score column contains
  52  * the current score of the audio file associated with that row.
  53  */
  54 enum score_table_columns {
  55         /** The row of the audio file. */
  56         SCORECOL_AFT_ROW,
  57         /** The score */
  58         SCORECOL_SCORE,
  59         /** This table has two columns */
  60         NUM_SCORE_COLUMNS
  61 };
  62
  63 static struct osl_column_description score_cols[] = {
  64         [SCORECOL_AFT_ROW] = {
  65                 .storage_type = OSL_NO_STORAGE,
  66                 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE,
  67                 .name = "aft_row",
  68                 .compare_function = ptr_compare,
  69                 .data_size = sizeof(void *)
  70         },
  71         [SCORECOL_SCORE] = {
  72                 .storage_type = OSL_NO_STORAGE,
  73                 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE,
  74                 .name = "score",
  75                 .compare_function = score_compare,
  76                 .data_size = sizeof(long)
  77         }
  78 };
  79
  80 static struct osl_table_description score_table_desc = {
  81         .name = "score",
  82         .num_columns = NUM_SCORE_COLUMNS,
  83         .flags = 0,
  84         .column_descriptions = score_cols
  85 };
  86
  87 /**
  88  * Compute the number of files in score table.
  89  *
  90  * \param num Result is returned here.
  91  *
  92  * \return Positive on success, negative on errors.
  93  *
  94  * \sa osl_get_num_rows().
  95  */
  96 int get_num_admissible_files(unsigned *num)
  97 {
  98         return osl_get_num_rows(score_table, num);
  99 }
 100
 101 /**
 102  * Get the score of the audio file associated with given row of the score table.
 103  *
 104  * \param score_row Pointer to the row in the score table.
 105  * \param score Result is returned here on success.
 106  *
 107  * On errors (negative return value) the content of \a score is undefined.
 108  *
 109  * \return The return value of the underlying call to osl_get_object().
 110  */
 111 static int get_score_of_row(void *score_row, long *score)
 112 {
 113         struct osl_object obj;
 114         int ret = osl_get_object(score_table, score_row, SCORECOL_SCORE, &obj);
 115
 116         if (ret >= 0)
 117                 *score = *(long *)obj.data;
 118         return ret;
 119 }
 120
 121 /**
 122  * Add an entry to the table of admissible files.
 123  *
 124  * \param aft_row The audio file to be added.
 125  * \param score The score for this file.
 126  *
 127  * \return The return value of the underlying call to osl_add_row().
 128  */
 129 int score_add(const struct osl_row *aft_row, long score)
 130 {
 131         int ret;
 132         struct osl_object score_objs[NUM_SCORE_COLUMNS];
 133         size_t size;
 134
 135         assert(aft_row);
 136         size = score_table_desc.column_descriptions[SCORECOL_AFT_ROW].data_size;
 137         score_objs[SCORECOL_AFT_ROW].data = para_malloc(size);
 138         score_objs[SCORECOL_AFT_ROW].size = size;
 139         *(const void **)(score_objs[SCORECOL_AFT_ROW].data) = aft_row;
 140
 141         size = score_table_desc.column_descriptions[SCORECOL_SCORE].data_size;
 142         score_objs[SCORECOL_SCORE].data = para_malloc(size);
 143         score_objs[SCORECOL_SCORE].size = size;
 144         *(int *)(score_objs[SCORECOL_SCORE].data) = score;
 145
 146 //      PARA_DEBUG_LOG("adding %p\n", *(void **) (score_objs[SCORECOL_AFT_ROW].data));
 147         ret = osl_add_row(score_table, score_objs);
 148         if (ret < 0) {
 149                 PARA_ERROR_LOG("failed to add row: %d\n", ret);
 150                 free(score_objs[SCORECOL_AFT_ROW].data);
 151                 free(score_objs[SCORECOL_SCORE].data);
 152         }
 153         return ret;
 154 }
 155
 156 static int get_nth_score(unsigned n, long *score)
 157 {
 158         struct osl_row *row;
 159         int ret = osl_get_nth_row(score_table, SCORECOL_SCORE, n, &row);
 160
 161         if (ret < 0)
 162                 return ret;
 163         return get_score_of_row(row, score);
 164 }
 165
 166 /**
 167  * Replace a row of the score table.
 168  *
 169  * \param aft_row Determines the audio file to change.
 170  * \param percent The position to re-insert the audio file.
 171  *
 172  * The percent paramenter must be between \p 0 and 100 and. A value of zero
 173  * means to re-insert the audio file into the score table with a score lower
 174  * than any other admissible file.
 175  *
 176  * \return Positive on success, negative on errors. Possible errors: Errors
 177  * returned by osl_get_row(), get_num_admissible_files(), osl_get_nth_row(),
 178  * osl_get_object(), osl_update_object().
 179  */
 180 int score_update(const struct osl_row *aft_row, long percent)
 181 {
 182         struct osl_row *row;
 183         long new_score;
 184         unsigned n, new_pos;
 185         struct osl_object obj = {.data = &aft_row, .size = sizeof(void **)};
 186         int ret = osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row);
 187
 188         if (ret < 0)
 189                 return ret;
 190         ret = get_num_admissible_files(&n);
 191         if (ret < 0)
 192                 return ret;
 193         new_pos = 1 + (n - 1) * percent / 100;
 194         ret = get_nth_score(new_pos, &new_score);
 195         if (ret < 0)
 196                 return ret;
 197         new_score--;
 198         obj.size = sizeof(long);
 199         obj.data = para_malloc(obj.size);
 200         *(long *)obj.data = new_score;
 201         PARA_NOTICE_LOG("new score: %ld, position: %u/%u\n", new_score,
 202                 new_pos, n);
 203         return osl_update_object(score_table, row, SCORECOL_SCORE, &obj);
 204 }
 205
 206 /**
 207  * Given an admissible file, get the corresponding row in the aft and the score.
 208  *
 209  * \param score_row Determines the admissible file.
 210  * \param score Result pointer.
 211  * \param aft_row Result pointer.
 212  *
 213  * \return Negative on errors, positive on success. Possible errors: Errors
 214  * returned by osl_get_object().
 215  */
 216 int get_score_and_aft_row(struct osl_row *score_row, long *score,
 217                 struct osl_row **aft_row)
 218 {
 219         struct osl_object obj;
 220         int ret = get_score_of_row(score_row, score);
 221
 222         if (ret < 0)
 223                 return ret;
 224         ret = osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj);
 225         if (ret < 0)
 226                 return ret;
 227         *aft_row = *(void **)obj.data;
 228         return 1;
 229 }
 230
 231 static int get_score_row_from_aft_row(const struct osl_row *aft_row,
 232                 struct osl_row **score_row)
 233 {
 234         struct osl_object obj = {.data = &aft_row, .size = sizeof(void **)};
 235         return osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, score_row);
 236
 237 }
 238
 239 /**
 240  * Loop over all files in the score table.
 241  *
 242  * \param data A pointer to arbitrary data.
 243  * \param func Function to be called for each admissible file.
 244  *
 245  * \return The return value of the underlying call to osl_rbtree_loop().
 246  *
 247  * This is used for the ls command. The \a data parameter is passed as the
 248  * second argument to \a func.
 249  *
 250  * \sa admissible_file_loop_reverse().
 251  */
 252 int admissible_file_loop(void *data, osl_rbtree_loop_func *func)
 253 {
 254         return osl_rbtree_loop(score_table, SCORECOL_SCORE, data, func);
 255 }
 256
 257 /**
 258  * Loop over all files in the score table in reverse order.
 259  *
 260  * \param data As in admissible_file_loop().
 261  * \param func As in admissible_file_loop().
 262  *
 263  * \return Same return value as admissible_file_loop().
 264  *
 265  * \sa admissible_file_loop(), osl_rbtree_loop_reverse().
 266  */
 267 int admissible_file_loop_reverse(void *data, osl_rbtree_loop_func *func)
 268 {
 269         return osl_rbtree_loop_reverse(score_table, SCORECOL_SCORE, data, func);
 270 }
 271
 272 /**
 273  * Get the admissible audio file with highest score.
 274  *
 275  * \param aft_row Points to the row in the aft of the "best" audio file.
 276  * \param score Highest score value in the score table.
 277  *
 278  * \return Positive on success, negative on errors. Possible errors: Errors
 279  * returned by osl_rbtree_last_row(), osl_get_object().
 280  */
 281 int score_get_best(struct osl_row **aft_row, long *score)
 282 {
 283         struct osl_row *row;
 284         struct osl_object obj;
 285         int ret = osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row);
 286
 287         if (ret < 0)
 288                 return ret;
 289         ret = osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj);
 290         if (ret < 0)
 291                 return ret;
 292         *aft_row = *(void **)obj.data;
 293         return get_score_of_row(row, score);
 294 }
 295
 296 /**
 297  * Remove an entry from the rbtree of admissible files.
 298  *
 299  * \param aft_row The file which is no longer admissible.
 300  *
 301  * \return Positive on success, negative on errors. Possible errors:
 302  * Errors returned by osl_get_row() and osl_del_row().
 303  *
 304  * \sa score_add(), score_shutdown().
 305  */
 306 int score_delete(const struct osl_row *aft_row)
 307 {
 308         struct osl_row *score_row;
 309         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 310
 311         if (ret < 0)
 312                 return ret;
 313         return osl_del_row(score_table, score_row);
 314 }
 315
 316 /**
 317  * Find out whether an audio file is contained in the score table.
 318  *
 319  * \param aft_row The row of the audio file table.
 320  *
 321  * \return Positive, if \a aft_row belongs to the audio file table,
 322  * zero if not, negative on errors.
 323  */
 324 int row_belongs_to_score_table(const struct osl_row *aft_row)
 325 {
 326         struct osl_row *score_row;
 327         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 328         if (ret >= 0)
 329                 return 1;
 330         if (ret == -E_RB_KEY_NOT_FOUND)
 331                 return 0;
 332         return ret;
 333 }
 334
 335 /**
 336  * Close the score table.
 337  *
 338  * \param flags Options passed to osl_close_table().
 339  *
 340  * \sa score_init().
 341  */
 342 void score_shutdown(enum osl_close_flags flags)
 343 {
 344         osl_close_table(score_table, flags | OSL_FREE_VOLATILE);
 345 }
 346
 347 /**
 348  * Init the scoring subsystem.
 349  *
 350  * \param ti Gets filled in by the function.
 351  * \param db The database directory.
 352  *
 353  * \return The return value of the underlying call to osl_open_table().
 354  *
 355  * \sa score_shutdown().
 356  */
 357 int score_init(struct table_info *ti, const char *db)
 358 {
 359         score_table_desc.dir = db;
 360         ti->desc = &score_table_desc;
 361         ti->flags = TBLFLAG_SKIP_CREATE;
 362         int ret = osl_open_table(ti->desc, &ti->table);
 363
 364         score_table = ti->table;
 365         return ret;
 366 }