1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
3 /** \file score.c Scoring functions to determine the audio file streaming order. */
15 static struct osl_table *score_table;
17 static int ptr_compare(const struct osl_object *obj1, const struct osl_object *obj2)
19 void *d1 = *(void **)obj1->data;
20 void *d2 = *(void **)obj2->data;
21 return NUM_COMPARE(d1, d2);
25 * This function first compares the score values. If they are equal, the
26 * addresses of the two objects are compared. Thus, the function returns
27 * "equal" only if the two objects alias each other, i.e., point to the same
30 static int score_compare(const struct osl_object *obj1, const struct osl_object *obj2)
32 long d1 = *(long *)obj1->data;
33 long d2 = *(long *)obj2->data;
34 int ret = NUM_COMPARE(d2, d1);
38 return NUM_COMPARE(obj2->data, obj1->data);
42 * The score table consists of two columns: The \a aft_row column contains
43 * pointers to the rows of the audio file table, and the score column contains
44 * the current score of the audio file associated with that row.
46 enum score_table_columns {
47 /** The row of the audio file. */
51 /** This table has two columns */
55 static struct osl_column_description score_cols[] = {
56 [SCORECOL_AFT_ROW] = {
57 .storage_type = OSL_NO_STORAGE,
58 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE | OSL_DONT_FREE,
60 .compare_function = ptr_compare,
61 .data_size = sizeof(void *)
64 .storage_type = OSL_NO_STORAGE,
65 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE,
67 .compare_function = score_compare,
68 .data_size = sizeof(long)
72 static struct osl_table_description score_table_desc = {
74 .num_columns = NUM_SCORE_COLUMNS,
76 .column_descriptions = score_cols
79 /* On errors (negative return value) the content of score is undefined. */
80 static int get_score_of_row(struct osl_table *t, void *score_row, long *score)
82 struct osl_object obj;
83 int ret = osl(osl_get_object(t, score_row, SCORECOL_SCORE, &obj));
86 *score = *(long *)obj.data;
91 * Add a (row, score) pair to the score table.
93 * \param aft_row Identifies the audio file to be added.
94 * \param score The score value of the audio file.
95 * \param t NULL means to operate on the currently active table.
97 * \return The return value of the underlying call to osl_add_row().
99 int score_add(const struct osl_row *aft_row, long score, struct osl_table *t)
102 struct osl_object score_objs[NUM_SCORE_COLUMNS];
106 size = score_table_desc.column_descriptions[SCORECOL_AFT_ROW].data_size;
107 score_objs[SCORECOL_AFT_ROW].data = (struct osl_row *)aft_row;
108 score_objs[SCORECOL_AFT_ROW].size = size;
110 size = score_table_desc.column_descriptions[SCORECOL_SCORE].data_size;
111 score_objs[SCORECOL_SCORE].data = alloc(size);
112 score_objs[SCORECOL_SCORE].size = size;
113 *(long *)(score_objs[SCORECOL_SCORE].data) = score;
115 // PARA_DEBUG_LOG("adding %p\n", *(void **) (score_objs[SCORECOL_AFT_ROW].data));
116 ret = osl(osl_add_row(t? t : score_table, score_objs));
118 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
119 free(score_objs[SCORECOL_SCORE].data);
125 * Replace a row of the score table.
127 * \param aft_row Determines the audio file to change.
128 * \param percent The position to re-insert the audio file.
130 * The percent parameter must be between 0 and 100. A value of zero means to
131 * re-insert the audio file into the score table with a score lower than any
132 * other admissible file.
134 * \return Positive on success, negative on errors.
136 int score_update(const struct osl_row *aft_row, long percent)
138 struct osl_row *row, *rrow; /* score row, reference row */
141 struct osl_object obj = {.data = (struct osl_row *)aft_row,
142 .size = sizeof(aft_row)};
143 int ret = osl(osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row));
145 if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND)) /* not an error */
149 ret = osl(osl_get_num_rows(score_table, &n));
152 new_pos = 1 + (n - 1) * percent / 100;
153 ret = osl(osl_get_nth_row(score_table, SCORECOL_SCORE, new_pos, &rrow));
156 ret = get_score_of_row(score_table, rrow, &new_score);
160 obj.size = sizeof(long);
161 obj.data = alloc(obj.size);
162 *(long *)obj.data = new_score;
163 PARA_DEBUG_LOG("new score: %ld, rank %u/%u\n", new_score, new_pos, n);
164 return osl(osl_update_object(score_table, row, SCORECOL_SCORE, &obj));
168 * Given an admissible file, get the corresponding row in the aft and the score.
170 * \param score_row Determines the admissible file.
171 * \param score Result pointer.
172 * \param aft_row Result pointer.
176 int get_score_and_aft_row(struct osl_row *score_row, long *score,
177 struct osl_row **aft_row)
179 struct osl_object obj;
180 int ret = get_score_of_row(score_table, score_row, score);
184 ret = osl(osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj));
191 static int get_score_row_from_aft_row(struct osl_table *t,
192 const struct osl_row *aft_row, struct osl_row **score_row)
194 struct osl_object obj = {.data = (struct osl_row *)aft_row,
195 .size = sizeof(aft_row)};
196 return osl(osl_get_row(t, SCORECOL_AFT_ROW, &obj, score_row));
200 * Call the given function for each row of the score table.
202 * \param func Callback, called once per row.
203 * \param t NULL means to use the currently active score table.
204 * \param data Passed verbatim to the callback.
206 * \return The return value of the underlying call to osl_rbtree_loop(). The
207 * loop terminates early if the callback returns negative.
209 int score_loop(osl_rbtree_loop_func *func, struct osl_table *t, void *data)
211 return osl(osl_rbtree_loop(t? t : score_table, SCORECOL_SCORE, data,
216 * Get the admissible audio file with highest score.
218 * \param aft_row Points to the row in the aft of the "best" audio file.
219 * \param score Highest score value in the score table.
223 int score_get_best(struct osl_row **aft_row, long *score)
226 struct osl_object obj;
227 int ret = osl(osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row));
231 ret = osl(osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj));
235 return get_score_of_row(score_table, row, score);
239 * Remove an entry from the rbtree of admissible files.
241 * \param aft_row The file which is no longer admissible.
245 * \sa \ref score_add().
247 int score_delete(const struct osl_row *aft_row)
249 struct osl_row *score_row;
250 int ret = get_score_row_from_aft_row(score_table, aft_row, &score_row);
254 return osl(osl_del_row(score_table, score_row));
258 * Find out whether an audio file is contained in the score table.
260 * \param aft_row The row of the audio file table.
262 * \return If the lookup operation fails for any other reason than "not found",
263 * the function aborts the current process (afs), since this is considered a
264 * fatal error that should never happen.
266 bool row_belongs_to_score_table(const struct osl_row *aft_row)
268 struct osl_row *score_row;
269 int ret = get_score_row_from_aft_row(score_table, aft_row, &score_row);
271 if (ret == -OSL_ERRNO_TO_PARA_ERROR(E_OSL_RB_KEY_NOT_FOUND))
278 * Free all volatile objects, then close the table.
280 * \param t As returned from \ref score_open().
282 * This either succeeds or terminates the calling process.
284 void score_close(struct osl_table *t)
286 assert(osl_close_table(t? t : score_table, OSL_FREE_VOLATILE) >= 0);
289 static void close_global_table(void)
294 static int open_global_table(__a_unused const char *dir)
296 assert(osl(osl_open_table(&score_table_desc, &score_table)) >= 0);
301 * Allocate a score table instance.
303 * \param result NULL means to open the currently active score table.
305 * Since the score table does no filesystem I/O, this function always succeeds.
306 * \sa \ref score_close().
308 void score_open(struct osl_table **result)
311 assert(osl(osl_open_table(&score_table_desc, result)) >= 0);
313 open_global_table(NULL);
317 * Remove all entries from the score table, but keep the table open.
319 void score_clear(void)
321 close_global_table();
322 open_global_table(NULL);
325 /** The score table stores (aft row, score) pairs in memory. */
326 const struct afs_table_operations score_ops = {
327 .open = open_global_table,
328 .close = close_global_table,