Fix table init.
[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 "afh.h"
11 #include "afs.h"
12 #include "list.h"
13 #include "string.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 addresss 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 colums: 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,
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 = para_malloc(size);
136 score_objs[SCORECOL_AFT_ROW].size = size;
137 *(const void **)(score_objs[SCORECOL_AFT_ROW].data) = aft_row;
138
139 size = score_table_desc.column_descriptions[SCORECOL_SCORE].data_size;
140 score_objs[SCORECOL_SCORE].data = para_malloc(size);
141 score_objs[SCORECOL_SCORE].size = size;
142 *(int *)(score_objs[SCORECOL_SCORE].data) = score;
143
144 // PARA_DEBUG_LOG("adding %p\n", *(void **) (score_objs[SCORECOL_AFT_ROW].data));
145 ret = osl_add_row(score_table, score_objs);
146 if (ret < 0) {
147 PARA_ERROR_LOG("failed to add row: %d\n", ret);
148 free(score_objs[SCORECOL_AFT_ROW].data);
149 free(score_objs[SCORECOL_SCORE].data);
150 }
151 return ret;
152 }
153
154 static int get_nth_score(unsigned n, long *score)
155 {
156 struct osl_row *row;
157 int ret = osl_get_nth_row(score_table, SCORECOL_SCORE, n, &row);
158
159 if (ret < 0)
160 return ret;
161 return get_score_of_row(row, score);
162 }
163
164 /**
165 * Replace a row of the score table.
166 *
167 * \param aft_row Determines the audio file to change.
168 * \param percent The position to re-insert the audio file.
169 *
170 * The percent paramenter must be between \p 0 and 100 and. A value of zero
171 * means to re-insert the audio file into the score table with a score lower
172 * than any other admissible file.
173 *
174 * \return Positive on success, negative on errors. Possible errors: Errors
175 * returned by osl_get_row(), get_num_admissible_files(), osl_get_nth_row(),
176 * osl_get_object(), osl_update_object().
177 */
178 int score_update(const struct osl_row *aft_row, long percent)
179 {
180 struct osl_row *row;
181 long new_score;
182 unsigned n, new_pos;
183 struct osl_object obj = {.data = &aft_row, .size = sizeof(void **)};
184 int ret = osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, &row);
185
186 if (ret < 0)
187 return ret;
188 ret = get_num_admissible_files(&n);
189 if (ret < 0)
190 return ret;
191 new_pos = 1 + (n - 1) * percent / 100;
192 ret = get_nth_score(new_pos, &new_score);
193 if (ret < 0)
194 return ret;
195 new_score--;
196 obj.size = sizeof(long);
197 obj.data = para_malloc(obj.size);
198 *(long *)obj.data = new_score;
199 PARA_DEBUG_LOG("new score: %ld, position: %u/%u\n", new_score,
200 new_pos, n);
201 return osl_update_object(score_table, row, SCORECOL_SCORE, &obj);
202 }
203
204 /**
205 * Given an admissible file, get the corresponding row in the aft and the score.
206 *
207 * \param score_row Determines the admissible file.
208 * \param score Result pointer.
209 * \param aft_row Result pointer.
210 *
211 * \return Negative on errors, positive on success. Possible errors: Errors
212 * returned by osl_get_object().
213 */
214 int get_score_and_aft_row(struct osl_row *score_row, long *score,
215 struct osl_row **aft_row)
216 {
217 struct osl_object obj;
218 int ret = get_score_of_row(score_row, score);
219
220 if (ret < 0)
221 return ret;
222 ret = osl_get_object(score_table, score_row, SCORECOL_AFT_ROW, &obj);
223 if (ret < 0)
224 return ret;
225 *aft_row = *(void **)obj.data;
226 return 1;
227 }
228
229 static int get_score_row_from_aft_row(const struct osl_row *aft_row,
230 struct osl_row **score_row)
231 {
232 struct osl_object obj = {.data = &aft_row, .size = sizeof(void **)};
233 return osl_get_row(score_table, SCORECOL_AFT_ROW, &obj, score_row);
234
235 }
236
237 /**
238 * Loop over all files in the score table.
239 *
240 * \param data A pointer to arbitrary data.
241 * \param func Function to be called for each admissible file.
242 *
243 * \return The return value of the underlying call to osl_rbtree_loop().
244 *
245 * This is used for the ls command. The \a data parameter is passed as the
246 * second argument to \a func.
247 *
248 * \sa admissible_file_loop_reverse().
249 */
250 int admissible_file_loop(void *data, osl_rbtree_loop_func *func)
251 {
252 return osl_rbtree_loop(score_table, SCORECOL_SCORE, data, func);
253 }
254
255 /**
256 * Loop over all files in the score table in reverse order.
257 *
258 * \param data As in admissible_file_loop().
259 * \param func As in admissible_file_loop().
260 *
261 * \return Same return value as admissible_file_loop().
262 *
263 * \sa admissible_file_loop(), osl_rbtree_loop_reverse().
264 */
265 int admissible_file_loop_reverse(void *data, osl_rbtree_loop_func *func)
266 {
267 return osl_rbtree_loop_reverse(score_table, SCORECOL_SCORE, data, func);
268 }
269
270 /**
271 * Get the admissible audio file with highest score.
272 *
273 * \param aft_row Points to the row in the aft of the "best" audio file.
274 * \param score Highest score value in the score table.
275 *
276 * \return Positive on success, negative on errors. Possible errors: Errors
277 * returned by osl_rbtree_last_row(), osl_get_object().
278 */
279 int score_get_best(struct osl_row **aft_row, long *score)
280 {
281 struct osl_row *row;
282 struct osl_object obj;
283 int ret = osl_rbtree_last_row(score_table, SCORECOL_SCORE, &row);
284
285 if (ret < 0)
286 return ret;
287 ret = osl_get_object(score_table, row, SCORECOL_AFT_ROW, &obj);
288 if (ret < 0)
289 return ret;
290 *aft_row = *(void **)obj.data;
291 return get_score_of_row(row, score);
292 }
293
294 /**
295 * Remove an entry from the rbtree of admissible files.
296 *
297 * \param aft_row The file which is no longer admissible.
298 *
299 * \return Positive on success, negative on errors. Possible errors:
300 * Errors returned by osl_get_row() and osl_del_row().
301 *
302 * \sa score_add(), score_shutdown().
303 */
304 int score_delete(const struct osl_row *aft_row)
305 {
306 struct osl_row *score_row;
307 int ret = get_score_row_from_aft_row(aft_row, &score_row);
308
309 if (ret < 0)
310 return ret;
311 return osl_del_row(score_table, score_row);
312 }
313
314 /**
315 * Find out whether an audio file is contained in the score table.
316 *
317 * \param aft_row The row of the audio file table.
318 *
319 * \return Positive, if \a aft_row belongs to the audio file table,
320 * zero if not, negative on errors.
321 */
322 int row_belongs_to_score_table(const struct osl_row *aft_row)
323 {
324 struct osl_row *score_row;
325 int ret = get_score_row_from_aft_row(aft_row, &score_row);
326 if (ret >= 0)
327 return 1;
328 if (ret == -E_RB_KEY_NOT_FOUND)
329 return 0;
330 return ret;
331 }
332
333 /**
334 * Close the score table.
335 *
336 * \param flags Options passed to osl_close_table().
337 *
338 * \sa score_init().
339 */
340 void score_shutdown(enum osl_close_flags flags)
341 {
342 osl_close_table(score_table, flags | OSL_FREE_VOLATILE);
343 score_table = NULL;
344 }
345
346 /**
347 * Init the scoring subsystem.
348 *
349 * \param ti Gets filled in by the function.
350 * \param db The database directory.
351 *
352 * \return The return value of the underlying call to osl_open_table().
353 *
354 * \sa score_shutdown().
355 */
356 int score_init(struct table_info *ti, const char *db)
357 {
358 score_table_desc.dir = db;
359 ti->desc = &score_table_desc;
360 ti->flags = TBLFLAG_SKIP_CREATE;
361 return osl_open_table(ti->desc, &score_table);
362 }