score.c

   1 /*
   2  * Copyright (C) 2007-2013 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         long d1 = *(long *)obj1->data;
  42         long d2 = *(long *)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         *(long *)(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 0 and 100. A value of zero means to
 172  * re-insert the audio file into the score table with a score lower than any
 173  * other admissible file.
 174  *
 175  * \return Positive on success, negative on errors.
 176  */
 177 int score_update(const struct osl_row *aft_row, long percent)
 178 {
 179         struct osl_row *row;
 180         long new_score;
 181         unsigned n, new_pos;
 182         struct osl_object obj = {.data = (struct osl_row *)aft_row,
 183                 .size = sizeof(aft_row)};
 184         int ret = osl(osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row));
 185
 186         if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND)) /* not an error */
 187                 return 1;
 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_DEBUG_LOG("new score: %ld, rank %u/%u\n", new_score, new_pos, n);
 202         return osl(osl_update_object(score_table, row, SCORECOL_SCORE, &obj));
 203 }
 204
 205 /**
 206  * Given an admissible file, get the corresponding row in the aft and the score.
 207  *
 208  * \param score_row Determines the admissible file.
 209  * \param score Result pointer.
 210  * \param aft_row Result pointer.
 211  *
 212  * \return Negative on errors, positive on success. Possible errors: Errors
 213  * returned by osl_get_object().
 214  */
 215 int get_score_and_aft_row(struct osl_row *score_row, long *score,
 216                 struct osl_row **aft_row)
 217 {
 218         struct osl_object obj;
 219         int ret = get_score_of_row(score_row, score);
 220
 221         if (ret < 0)
 222                 return ret;
 223         ret = osl(osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj));
 224         if (ret < 0)
 225                 return ret;
 226         *aft_row = obj.data;
 227         return 1;
 228 }
 229
 230 static int get_score_row_from_aft_row(const struct osl_row *aft_row,
 231                 struct osl_row **score_row)
 232 {
 233         struct osl_object obj = {.data = (struct osl_row *)aft_row,
 234                 .size = sizeof(aft_row)};
 235         return osl(osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, score_row));
 236 }
 237
 238 /**
 239  * Loop over all files in the score table.
 240  *
 241  * \param data A pointer to arbitrary data.
 242  * \param func Function to be called for each admissible file.
 243  *
 244  * \return The return value of the underlying call to osl_rbtree_loop().
 245  *
 246  * This is used for the ls command. The \a data parameter is passed as the
 247  * second argument to \a func.
 248  *
 249  * \sa admissible_file_loop_reverse().
 250  */
 251 int admissible_file_loop(void *data, osl_rbtree_loop_func *func)
 252 {
 253         return osl(osl_rbtree_loop(score_table, SCORECOL_SCORE, data, func));
 254 }
 255
 256 /**
 257  * Loop over all files in the score table in reverse order.
 258  *
 259  * \param data As in admissible_file_loop().
 260  * \param func As in admissible_file_loop().
 261  *
 262  * \return Same return value as admissible_file_loop().
 263  *
 264  * \sa admissible_file_loop(), osl_rbtree_loop_reverse().
 265  */
 266 int admissible_file_loop_reverse(void *data, osl_rbtree_loop_func *func)
 267 {
 268         return osl(osl_rbtree_loop_reverse(score_table, SCORECOL_SCORE, data, func));
 269 }
 270
 271 /**
 272  * Get the admissible audio file with highest score.
 273  *
 274  * \param aft_row Points to the row in the aft of the "best" audio file.
 275  * \param score Highest score value in the score table.
 276  *
 277  * \return Positive on success, negative on errors. Possible errors: Errors
 278  * returned by osl_rbtree_last_row(), osl_get_object().
 279  */
 280 int score_get_best(struct osl_row **aft_row, long *score)
 281 {
 282         struct osl_row *row;
 283         struct osl_object obj;
 284         int ret = osl(osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row));
 285
 286         if (ret < 0)
 287                 return ret;
 288         ret = osl(osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj));
 289         if (ret < 0)
 290                 return ret;
 291         *aft_row = obj.data;
 292         return get_score_of_row(row, score);
 293 }
 294
 295 /**
 296  * Remove an entry from the rbtree of admissible files.
 297  *
 298  * \param aft_row The file which is no longer admissible.
 299  *
 300  * \return Positive on success, negative on errors. Possible errors:
 301  * Errors returned by osl_get_row() and osl_del_row().
 302  *
 303  * \sa score_add(), score_shutdown().
 304  */
 305 int score_delete(const struct osl_row *aft_row)
 306 {
 307         struct osl_row *score_row;
 308         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 309
 310         if (ret < 0)
 311                 return ret;
 312         return osl(osl_del_row(score_table, score_row));
 313 }
 314
 315 /**
 316  * Find out whether an audio file is contained in the score table.
 317  *
 318  * \param aft_row The row of the audio file table.
 319  * \param rank Result pointer
 320  *
 321  * \return Positive, if \a aft_row belongs to the audio file table,
 322  * zero if not, negative on errors. If \a aft_row was found, and \a rank
 323  * is not \p NULL, the rank of \a aft_row is returned in \a rank.
 324  */
 325 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank)
 326 {
 327         struct osl_row *score_row;
 328         int ret = get_score_row_from_aft_row(aft_row, &score_row);
 329
 330         if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
 331                 return 0;
 332         if (ret < 0)
 333                 return ret;
 334         if (!rank)
 335                 return 1;
 336         ret = osl(osl_get_rank(score_table, score_row, SCORECOL_SCORE, rank));
 337         if (ret < 0)
 338                 return ret;
 339         return 1;
 340 }
 341
 342 /* Close the score table. */
 343 static void score_close(void)
 344 {
 345         osl_close_table(score_table, OSL_FREE_VOLATILE);
 346         score_table = NULL;
 347 }
 348
 349 /**
 350  * Open the score table.
 351  *
 352  * \param dir Unused.
 353  *
 354  * \return The return value of the underlying call to osl_open_table().
 355  */
 356 static int score_open(__a_unused const char *dir)
 357 {
 358         score_table_desc.dir = NULL; /* this table has only volatile columns */
 359         return osl(osl_open_table(&score_table_desc, &score_table));
 360 }
 361
 362 /**
 363  * Remove all entries from the score table, but keep the table open.
 364  *
 365  * \return Standard.
 366  */
 367 int clear_score_table(void)
 368 {
 369         score_close();
 370         return score_open(NULL);
 371 }
 372
 373 static int score_event_handler(__a_unused enum afs_events event,
 374                 __a_unused struct para_buffer *pb, __a_unused void *data)
 375 {
 376         return 1;
 377 }
 378
 379 /**
 380  * Initialize the scoring subsystem.
 381  *
 382  * \param t The members of \a t are filled in by the function.
 383  */
 384 void score_init(struct afs_table *t)
 385 {
 386         t->name = score_table_desc.name;
 387         t->open = score_open;
 388         t->close = score_close;
 389         t->event_handler = score_event_handler;
 390 }