score.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 score.c Scoring functions to determine the audio file streaming order. */
   8 #include <regex.h>
   9 #include <osl.h>
  10
  11 #include "para.h"
  12 #include "error.h"
  13 #include "string.h"
  14 #include "afh.h"
  15 #include "afs.h"
  16 #include "list.h"
  17
  18 static struct osl_table *score_table;
  19
  20 static int ptr_compare(const struct osl_object *obj1, const struct osl_object *obj2)
  21 {
  22         void *d1 = *(void **)obj1->data;
  23         void *d2 = *(void **)obj2->data;
  24         return NUM_COMPARE(d1, d2);
  25 }
  26
  27 /**
  28  * Compare the score of two audio files
  29  *
  30  * \param obj1 Pointer to the first score object.
  31  * \param obj2 Pointer to the second score object.
  32  *
  33  * This function first compares the score values as usual integers. If they compare as
  34  * equal, the address of \a obj1 and \a obj2 are compared. So this compare function
  35  * returns zero if and only if \a obj1 and \a obj2 point to the same memory area.
  36  *
  37  * \sa osl_compare_function.
  38  */
  39 static int score_compare(const struct osl_object *obj1, const struct osl_object *obj2)
  40 {
  41         int d1 = *(int*)obj1->data;
  42         int d2 = *(int*)obj2->data;
  43         int ret = NUM_COMPARE(d2, d1);
  44
  45         if (ret)
  46                 return ret;
  47         return NUM_COMPARE(obj2->data, obj1->data);
  48 }
  49
  50 /**
  51  * The score table consists of two columns: The \a aft_row column contains
  52  * pointers to the rows of the audio file table,  and the score column contains
  53  * the current score of the audio file associated with that row.
  54  */
  55 enum score_table_columns {
  56         /** The row of the audio file. */
  57         SCORECOL_AFT_ROW,
  58         /** The score */
  59         SCORECOL_SCORE,
  60         /** This table has two columns */
  61         NUM_SCORE_COLUMNS
  62 };
  63
  64 static struct osl_column_description score_cols[] = {
  65         [SCORECOL_AFT_ROW] = {
  66                 .storage_type = OSL_NO_STORAGE,
  67                 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE | OSL_DONT_FREE,
  68                 .name = "aft_row",
  69                 .compare_function = ptr_compare,
  70                 .data_size = sizeof(void *)
  71         },
  72         [SCORECOL_SCORE] = {
  73                 .storage_type = OSL_NO_STORAGE,
  74                 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE,
  75                 .name = "score",
  76                 .compare_function = score_compare,
  77                 .data_size = sizeof(long)
  78         }
  79 };
  80
  81 static struct osl_table_description score_table_desc = {
  82         .name = "score",
  83         .num_columns = NUM_SCORE_COLUMNS,
  84         .flags = 0,
  85         .column_descriptions = score_cols
  86 };
  87
  88 /**
  89  * Compute the number of files in score table.
  90  *
  91  * \param num Result is returned here.
  92  *
  93  * \return Positive on success, negative on errors.
  94  *
  95  * \sa osl_get_num_rows().
  96  */
  97 int get_num_admissible_files(unsigned *num)
  98 {
  99         return osl(osl_get_num_rows(score_table, num));
 100 }
 101
 102 /**
 103  * Get the score of the audio file associated with given row of the score table.
 104  *
 105  * \param score_row Pointer to the row in the score table.
 106  * \param score Result is returned here on success.
 107  *
 108  * On errors (negative return value) the content of \a score is undefined.
 109  *
 110  * \return The return value of the underlying call to osl_get_object().
 111  */
 112 static int get_score_of_row(void *score_row, long *score)
 113 {
 114         struct osl_object obj;
 115         int ret = osl(osl_get_object(score_table, score_row, SCORECOL_SCORE, &obj));
 116
 117         if (ret >= 0)
 118                 *score = *(long *)obj.data;
 119         return ret;
 120 }
 121
 122 /**
 123  * Add an entry to the table of admissible files.
 124  *
 125  * \param aft_row The audio file to be added.
 126  * \param score The score for this file.
 127  *
 128  * \return The return value of the underlying call to osl_add_row().
 129  */
 130 int score_add(const struct osl_row *aft_row, long score)
 131 {
 132         int ret;
 133         struct osl_object score_objs[NUM_SCORE_COLUMNS];
 134         size_t size;
 135
 136         assert(aft_row);
 137         size = score_table_desc.column_descriptions[SCORECOL_AFT_ROW].data_size;
 138         score_objs[SCORECOL_AFT_ROW].data = (struct osl_row *)aft_row;
 139         score_objs[SCORECOL_AFT_ROW].size = size;
 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(osl_add_row(score_table, score_objs));
 148         if (ret < 0) {
 149                 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 150                 free(score_objs[SCORECOL_SCORE].data);
 151         }
 152         return ret;
 153 }
 154
 155 static int get_nth_score(unsigned n, long *score)
 156 {
 157         struct osl_row *row;
 158         int ret = osl(osl_get_nth_row(score_table, SCORECOL_SCORE, n, &row));
 159
 160         if (ret < 0)
 161                 return ret;
 162         return get_score_of_row(row, score);
 163 }
 164
 165 /**
 166  * Replace a row of the score table.
 167  *
 168  * \param aft_row Determines the audio file to change.
 169  * \param percent The position to re-insert the audio file.
 170  *
 171  * The percent parameter must be between \p 0 and 100 and. A value of zero
 172  * means to re-insert the audio file into the score table with a score lower
 173  * than any other admissible file.
 174  *
 175  * \return Positive on success, negative on errors. Possible errors: Errors
 176  * returned by osl_get_row(), get_num_admissible_files(), osl_get_nth_row(),
 177  * osl_get_object(), osl_update_object().
 178  */
 179 int score_update(const struct osl_row *aft_row, long percent)
 180 {
 181         struct osl_row *row;
 182         long new_score;
 183         unsigned n, new_pos;
 184         struct osl_object obj = {.data = (struct osl_row *)aft_row,
 185                 .size = sizeof(aft_row)};
 186         int ret = osl(osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row));
 187
 188         if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND)) /* not an error */
 189                 return 1;
 190         if (ret < 0)
 191                 return ret;
 192         ret = get_num_admissible_files(&n);
 193         if (ret < 0)
 194                 return ret;
 195         new_pos = 1 + (n - 1) * percent / 100;
 196         ret = get_nth_score(new_pos, &new_score);
 197         if (ret < 0)
 198                 return ret;
 199         new_score--;
 200         obj.size = sizeof(long);
 201         obj.data = para_malloc(obj.size);
 202         *(long *)obj.data = new_score;
 203         PARA_DEBUG_LOG("new score: %ld, rank %u/%u\n", new_score, new_pos, n);
 204         return osl(osl_update_object(score_table, row, SCORECOL_SCORE, &obj));
 205 }
 206
 207 /**
 208  * Given an admissible file, get the corresponding row in the aft and the score.
 209  *
 210  * \param score_row Determines the admissible file.
 211  * \param score Result pointer.
 212  * \param aft_row Result pointer.
 213  *
 214  * \return Negative on errors, positive on success. Possible errors: Errors
 215  * returned by osl_get_object().
 216  */
 217 int get_score_and_aft_row(struct osl_row *score_row, long *score,
 218                 struct osl_row **aft_row)
 219 {
 220         struct osl_object obj;
 221         int ret = get_score_of_row(score_row, score);
 222
 223         if (ret < 0)
 224                 return ret;
 225         ret = osl(osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj));
 226         if (ret < 0)
 227                 return ret;
 228         *aft_row = obj.data;
 229         return 1;
 230 }
 231
 232 static int get_score_row_from_aft_row(const struct osl_row *aft_row,
 233                 struct osl_row **score_row)
 234 {
 235         struct osl_object obj = {.data = (struct osl_row *)aft_row,
 236                 .size = sizeof(aft_row)};
 237         return osl(osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, score_row));
 238 }
 239
 240 /**
 241  * Loop over all files in the score table.
 242  *
 243  * \param data A pointer to arbitrary data.
 244  * \param func Function to be called for each admissible file.
 245  *
 246  * \return The return value of the underlying call to osl_rbtree_loop().
 247  *
 248  * This is used for the ls command. The \a data parameter is passed as the
 249  * second argument to \a func.
 250  *
 251  * \sa admissible_file_loop_reverse().
 252  */
 253 int admissible_file_loop(void *data, osl_rbtree_loop_func *func)
 254 {
 255         return osl(osl_rbtree_loop(score_table, SCORECOL_SCORE, data, func));
 256 }
 257
 258 /**
 259  * Loop over all files in the score table in reverse order.
 260  *
 261  * \param data As in admissible_file_loop().
 262  * \param func As in admissible_file_loop().
 263  *
 264  * \return Same return value as admissible_file_loop().
 265  *
 266  * \sa admissible_file_loop(), osl_rbtree_loop_reverse().
 267  */
 268 int admissible_file_loop_reverse(void *data, osl_rbtree_loop_func *func)
 269 {
 270         return osl(osl_rbtree_loop_reverse(score_table, SCORECOL_SCORE, data, func));
 271 }
 272
 273 /**
 274  * Get the admissible audio file with highest score.
 275  *
 276  * \param aft_row Points to the row in the aft of the "best" audio file.
 277  * \param score Highest score value in the score table.
 278  *
 279  * \return Positive on success, negative on errors. Possible errors: Errors
 280  * returned by osl_rbtree_last_row(), osl_get_object().
 281  */
 282 int score_get_best(struct osl_row **aft_row, long *score)
 283 {
 284         struct osl_row *row;
 285         struct osl_object obj;
 286         int ret = osl(osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row));
 287
 288         if (ret < 0)
 289                 return ret;
 290         ret = osl(osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj));
 291         if (ret < 0)
 292                 return ret;
 293         *aft_row = obj.data;
 294         return get_score_of_row(row, score);
 295 }
 296
 297 /**
 298  * Remove an entry from the rbtree of admissible files.
 299  *
 300  * \param aft_row The file which is no longer admissible.
 301  *
 302  * \return Positive on success, negative on errors. Possible errors:
 303  * Errors returned by osl_get_row() and osl_del_row().
 304  *
 305  * \sa score_add(), score_shutdown().
 306  */
 307 int score_delete(const struct osl_row *aft_row)
 308 {
 309         struct osl_row *score_row;
 310         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 311
 312         if (ret < 0)
 313                 return ret;
 314         return osl(osl_del_row(score_table, score_row));
 315 }
 316
 317 /**
 318  * Find out whether an audio file is contained in the score table.
 319  *
 320  * \param aft_row The row of the audio file table.
 321  * \param rank Result pointer
 322  *
 323  * \return Positive, if \a aft_row belongs to the audio file table,
 324  * zero if not, negative on errors. If \a aft_row was found, and \a rank
 325  * is not \p NULL, the rank of \a aft_row is returned in \a rank.
 326  */
 327 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank)
 328 {
 329         struct osl_row *score_row;
 330         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 331
 332         if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
 333                 return 0;
 334         if (ret < 0)
 335                 return ret;
 336         if (!rank)
 337                 return 1;
 338         ret = osl(osl_get_rank(score_table, score_row, SCORECOL_SCORE, rank));
 339         if (ret < 0)
 340                 return ret;
 341         return 1;
 342 }
 343
 344 /* Close the score table. */
 345 static void score_close(void)
 346 {
 347         osl_close_table(score_table, OSL_FREE_VOLATILE);
 348         score_table = NULL;
 349 }
 350
 351 /**
 352  * Open the score table.
 353  *
 354  * \param dir Unused.
 355  *
 356  * \return The return value of the underlying call to osl_open_table().
 357  */
 358 static int score_open(__a_unused const char *dir)
 359 {
 360         score_table_desc.dir = NULL; /* this table has only volatile columns */
 361         return osl(osl_open_table(&score_table_desc, &score_table));
 362 }
 363
 364 /**
 365  * Remove all entries from the score table, but keep the table open.
 366  *
 367  * \return Standard.
 368  */
 369 int clear_score_table(void)
 370 {
 371         score_close();
 372         return score_open(NULL);
 373 }
 374
 375 static int score_event_handler(__a_unused enum afs_events event,
 376                 __a_unused struct para_buffer *pb, __a_unused void *data)
 377 {
 378         return 1;
 379 }
 380
 381 /**
 382  * Initialize the scoring subsystem.
 383  *
 384  * \param t The members of \a t are filled in by the function.
 385  */
 386 void score_init(struct afs_table *t)
 387 {
 388         t->name = score_table_desc.name;
 389         t->open = score_open;
 390         t->close = score_close;
 391         t->event_handler = score_event_handler;
 392 }