score.c: Use the new OSL_DONT_FREE flag for the aft column.
[paraslash.git] / 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 "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 * \sa osl_compare_function.
35 */
36 static int score_compare(const struct osl_object *obj1, const struct osl_object *obj2)
37 {
38 int d1 = *(int*)obj1->data;
39 int d2 = *(int*)obj2->data;
40 int ret = NUM_COMPARE(d2, d1);
41
42 if (ret)
43 return ret;
44 return NUM_COMPARE(obj2->data, obj1->data);
45 }
46
47 /**
48 * The score table consists of two columns: The \a aft_row column contains
49 * pointers to the rows of the audio file table, and the score column contains
50 * the current score of the audio file associated with that row.
51 */
52 enum score_table_columns {
53 /** The row of the audio file. */
54 SCORECOL_AFT_ROW,
55 /** The score */
56 SCORECOL_SCORE,
57 /** This table has two columns */
58 NUM_SCORE_COLUMNS
59 };
60
61 static struct osl_column_description score_cols[] = {
62 [SCORECOL_AFT_ROW] = {
63 .storage_type = OSL_NO_STORAGE,
64 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE | OSL_UNIQUE | OSL_DONT_FREE,
65 .name = "aft_row",
66 .compare_function = ptr_compare,
67 .data_size = sizeof(void *)
68 },
69 [SCORECOL_SCORE] = {
70 .storage_type = OSL_NO_STORAGE,
71 .storage_flags = OSL_RBTREE | OSL_FIXED_SIZE,
72 .name = "score",
73 .compare_function = score_compare,
74 .data_size = sizeof(long)
75 }
76 };
77
78 static struct osl_table_description score_table_desc = {
79 .name = "score",
80 .num_columns = NUM_SCORE_COLUMNS,
81 .flags = 0,
82 .column_descriptions = score_cols
83 };
84
85 /**
86 * Compute the number of files in score table.
87 *
88 * \param num Result is returned here.
89 *
90 * \return Positive on success, negative on errors.
91 *
92 * \sa osl_get_num_rows().
93 */
94 int get_num_admissible_files(unsigned *num)
95 {
96 return osl_get_num_rows(score_table, num);
97 }
98
99 /**
100 * Get the score of the audio file associated with given row of the score table.
101 *
102 * \param score_row Pointer to the row in the score table.
103 * \param score Result is returned here on success.
104 *
105 * On errors (negative return value) the content of \a score is undefined.
106 *
107 * \return The return value of the underlying call to osl_get_object().
108 */
109 static int get_score_of_row(void *score_row, long *score)
110 {
111 struct osl_object obj;
112 int ret = osl_get_object(score_table, score_row, SCORECOL_SCORE, &obj);
113
114 if (ret >= 0)
115 *score = *(long *)obj.data;
116 return ret;
117 }
118
119 /**
120 * Add an entry to the table of admissible files.
121 *
122 * \param aft_row The audio file to be added.
123 * \param score The score for this file.
124 *
125 * \return The return value of the underlying call to osl_add_row().
126 */
127 int score_add(const struct osl_row *aft_row, long score)
128 {
129 int ret;
130 struct osl_object score_objs[NUM_SCORE_COLUMNS];
131 size_t size;
132
133 assert(aft_row);
134 size = score_table_desc.column_descriptions[SCORECOL_AFT_ROW].data_size;
135 score_objs[SCORECOL_AFT_ROW].data = aft_row;
136 score_objs[SCORECOL_AFT_ROW].size = size;
137
138 size = score_table_desc.column_descriptions[SCORECOL_SCORE].data_size;
139 score_objs[SCORECOL_SCORE].data = para_malloc(size);
140 score_objs[SCORECOL_SCORE].size = size;
141 *(int *)(score_objs[SCORECOL_SCORE].data) = score;
142
143 // PARA_DEBUG_LOG("adding %p\n", *(void **) (score_objs[SCORECOL_AFT_ROW].data));
144 ret = osl_add_row(score_table, score_objs);
145 if (ret < 0) {
146 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
147 free(score_objs[SCORECOL_SCORE].data);
148 }
149 return ret;
150 }
151
152 static int get_nth_score(unsigned n, long *score)
153 {
154 struct osl_row *row;
155 int ret = osl_get_nth_row(score_table, SCORECOL_SCORE, n, &row);
156
157 if (ret < 0)
158 return ret;
159 return get_score_of_row(row, score);
160 }
161
162 /**
163 * Replace a row of the score table.
164 *
165 * \param aft_row Determines the audio file to change.
166 * \param percent The position to re-insert the audio file.
167 *
168 * The percent parameter must be between \p 0 and 100 and. A value of zero
169 * means to re-insert the audio file into the score table with a score lower
170 * than any other admissible file.
171 *
172 * \return Positive on success, negative on errors. Possible errors: Errors
173 * returned by osl_get_row(), get_num_admissible_files(), osl_get_nth_row(),
174 * osl_get_object(), osl_update_object().
175 */
176 int score_update(const struct osl_row *aft_row, long percent)
177 {
178 struct osl_row *row;
179 long new_score;
180 unsigned n, new_pos;
181 struct osl_object obj = {.data = aft_row, .size = sizeof(aft_row)};
182 int ret = osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row);
183
184 if (ret < 0)
185 return ret;
186 ret = get_num_admissible_files(&n);
187 if (ret < 0)
188 return ret;
189 new_pos = 1 + (n - 1) * percent / 100;
190 ret = get_nth_score(new_pos, &new_score);
191 if (ret < 0)
192 return ret;
193 new_score--;
194 obj.size = sizeof(long);
195 obj.data = para_malloc(obj.size);
196 *(long *)obj.data = new_score;
197 PARA_DEBUG_LOG("new score: %ld, rank %u/%u\n", new_score, new_pos, n);
198 return osl_update_object(score_table, row, SCORECOL_SCORE, &obj);
199 }
200
201 /**
202 * Given an admissible file, get the corresponding row in the aft and the score.
203 *
204 * \param score_row Determines the admissible file.
205 * \param score Result pointer.
206 * \param aft_row Result pointer.
207 *
208 * \return Negative on errors, positive on success. Possible errors: Errors
209 * returned by osl_get_object().
210 */
211 int get_score_and_aft_row(struct osl_row *score_row, long *score,
212 struct osl_row **aft_row)
213 {
214 struct osl_object obj;
215 int ret = get_score_of_row(score_row, score);
216
217 if (ret < 0)
218 return ret;
219 ret = osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj);
220 if (ret < 0)
221 return ret;
222 *aft_row = obj.data;
223 return 1;
224 }
225
226 static int get_score_row_from_aft_row(const struct osl_row *aft_row,
227 struct osl_row **score_row)
228 {
229 struct osl_object obj = {.data = aft_row, .size = sizeof(aft_row)};
230 return osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, score_row);
231
232 }
233
234 /**
235 * Loop over all files in the score table.
236 *
237 * \param data A pointer to arbitrary data.
238 * \param func Function to be called for each admissible file.
239 *
240 * \return The return value of the underlying call to osl_rbtree_loop().
241 *
242 * This is used for the ls command. The \a data parameter is passed as the
243 * second argument to \a func.
244 *
245 * \sa admissible_file_loop_reverse().
246 */
247 int admissible_file_loop(void *data, osl_rbtree_loop_func *func)
248 {
249 return osl_rbtree_loop(score_table, SCORECOL_SCORE, data, func);
250 }
251
252 /**
253 * Loop over all files in the score table in reverse order.
254 *
255 * \param data As in admissible_file_loop().
256 * \param func As in admissible_file_loop().
257 *
258 * \return Same return value as admissible_file_loop().
259 *
260 * \sa admissible_file_loop(), osl_rbtree_loop_reverse().
261 */
262 int admissible_file_loop_reverse(void *data, osl_rbtree_loop_func *func)
263 {
264 return osl_rbtree_loop_reverse(score_table, SCORECOL_SCORE, data, func);
265 }
266
267 /**
268 * Get the admissible audio file with highest score.
269 *
270 * \param aft_row Points to the row in the aft of the "best" audio file.
271 * \param score Highest score value in the score table.
272 *
273 * \return Positive on success, negative on errors. Possible errors: Errors
274 * returned by osl_rbtree_last_row(), osl_get_object().
275 */
276 int score_get_best(struct osl_row **aft_row, long *score)
277 {
278 struct osl_row *row;
279 struct osl_object obj;
280 int ret = osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row);
281
282 if (ret < 0)
283 return ret;
284 ret = osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj);
285 if (ret < 0)
286 return ret;
287 *aft_row = obj.data;
288 return get_score_of_row(row, score);
289 }
290
291 /**
292 * Remove an entry from the rbtree of admissible files.
293 *
294 * \param aft_row The file which is no longer admissible.
295 *
296 * \return Positive on success, negative on errors. Possible errors:
297 * Errors returned by osl_get_row() and osl_del_row().
298 *
299 * \sa score_add(), score_shutdown().
300 */
301 int score_delete(const struct osl_row *aft_row)
302 {
303 struct osl_row *score_row;
304 int ret = get_score_row_from_aft_row(aft_row, &score_row);
305
306 if (ret < 0)
307 return ret;
308 return osl_del_row(score_table, score_row);
309 }
310
311 /**
312 * Find out whether an audio file is contained in the score table.
313 *
314 * \param aft_row The row of the audio file table.
315 * \param rank Result pointer
316 *
317 * \return Positive, if \a aft_row belongs to the audio file table,
318 * zero if not, negative on errors. If \a aft_row was found, and \a rank
319 * is not \p NULL, the rank of \a aft_row is returned in \a rank.
320 */
321 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank)
322 {
323 struct osl_row *score_row;
324 int ret = get_score_row_from_aft_row(aft_row, &score_row);
325
326 if (ret == -E_RB_KEY_NOT_FOUND)
327 return 0;
328 if (ret < 0)
329 return ret;
330 if (!rank)
331 return 1;
332 ret = osl_get_rank(score_table, score_row, SCORECOL_SCORE, rank);
333 if (ret < 0)
334 return ret;
335 return 1;
336 }
337
338 /* Close the score table. */
339 static void score_close(void)
340 {
341 osl_close_table(score_table, OSL_FREE_VOLATILE);
342 score_table = NULL;
343 }
344
345 /**
346 * Open the score table.
347 *
348 * \param dir Unused.
349 *
350 * \return The return value of the underlying call to osl_open_table().
351 */
352 static int score_open(__a_unused const char *dir)
353 {
354 score_table_desc.dir = NULL; /* this table has only volatile columns */
355 return osl_open_table(&score_table_desc, &score_table);
356 }
357
358 /**
359 * Remove all entries from the score table, but keep the table open.
360 *
361 * \return Standard.
362 */
363 int clear_score_table(void)
364 {
365 score_close();
366 return score_open(NULL);
367 }
368
369 static int score_event_handler(__a_unused enum afs_events event,
370 __a_unused struct para_buffer *pb, __a_unused void *data)
371 {
372 return 1;
373 }
374
375 /**
376 * Initialize the scoring subsystem.
377 *
378 * \param t The members of \a t are filled in by the function.
379 */
380 void score_init(struct afs_table *t)
381 {
382 t->name = score_table_desc.name;
383 t->open = score_open;
384 t->close = score_close;
385 t->event_handler = score_event_handler;
386 }