score.c

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