Merge topic branch t/ff-compat into master
[paraslash.git] / afs.h
1 /* Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
2
3 /** \file afs.h Exported symbols of the audio file selector. */
4
5 /** Audio file selector data stored in the audio file table. */
6 struct afs_info {
7 /** Seconds since the epoch. */
8 uint64_t last_played;
9 /** Bit field of set attributes. */
10 uint64_t attributes;
11 /** Counts how many times the file was selected. */
12 uint32_t num_played;
13 /** Image blob associated with this file (foreign key). */
14 uint32_t image_id;
15 /** Lyrics blob associated with this file (foreign key). */
16 uint32_t lyrics_id;
17 /** Mp3, ogg, ... */
18 uint8_t audio_format_id;
19 /** Amplification value. */
20 uint8_t amp;
21 };
22
23 /**
24 * Events caused by changes to an afs table.
25 *
26 * Whenever an afs table changes, an event is generated which causes afs to
27 * call the event handlers of all other tables. For example, if an audio file
28 * is added, the event handler of the mood table checks the new file for
29 * admissibility.
30 */
31 enum afs_events {
32 /** An attribute was added. */
33 ATTRIBUTE_ADD,
34 /** An attribute was renamed. */
35 ATTRIBUTE_RENAME,
36 /** An attribute was removed. */
37 ATTRIBUTE_REMOVE,
38 /** The afs info struct of an audio file changed. */
39 AFSI_CHANGE,
40 /** The afh info struct of an audio file changed. */
41 AFHI_CHANGE,
42 /** An audio file was renamed. */
43 AUDIO_FILE_RENAME,
44 /** An audio file was added. */
45 AUDIO_FILE_ADD,
46 /** An audio file is about to be removed. */
47 AUDIO_FILE_REMOVE,
48 /** A new blob was added. */
49 BLOB_ADD,
50 /** A blob was renamed. */
51 BLOB_RENAME,
52 /** A blob is about to be removed. */
53 BLOB_REMOVE,
54 };
55
56 /**
57 * Used as data for \ref afs_event() for events of type \p ATTRIBUTE_ADD.
58 */
59 struct rmatt_event_data {
60 /** The name of the attribute being added. */
61 const char *name;
62 /** Its bit number. */
63 unsigned char bitnum;
64 };
65
66 /**
67 * Used as data for \ref afs_event() for events of type \p ATTRIBUTE_AFSI_CHANGE.
68 */
69 struct afsi_change_event_data {
70 /** Pointer to the row that has changed. */
71 struct osl_row *aft_row;
72 /** Afs info before the change. */
73 struct afs_info *old_afsi;
74 };
75
76 /** Methods for table startup/shutdown and event handling. */
77 struct afs_table_operations {
78 /** Gets called on startup and on SIGHUP. */
79 int (*open)(const char *base_dir);
80 /** Gets called on shutdown and on SIGHUP. */
81 void (*close)(void);
82 /** Called from the init command. */
83 int (*create)(const char *);
84 /** Handle events generated by other tables. See enum \ref afs_events. */
85 int (*event_handler)(enum afs_events event, struct para_buffer *pb,
86 void *data);
87 };
88
89 /** How audio files are selected by afs. */
90 enum play_mode {
91 /** Admissible files are determined by a mood definition. */
92 PLAY_MODE_MOOD,
93 /** All listed files are admissible. */
94 PLAY_MODE_PLAYLIST,
95 };
96
97 /**
98 * Codes used for communication between the server and the afs process.
99 *
100 * Before forking the afs child, para_server creates a bidirectional pipe
101 * through which both processes communicate. Usually para_server requests a new
102 * audio file in order to start streaming or when the end of the current audio file
103 * has been reached. The afs process responds to such a request by sending
104 * back an eight byte buffer. The first four bytes is the uint32_t
105 * representation of the code, usually \p NEXT_AUDIO_FILE if an admissible
106 * audio file was found, successfully opened and verified. The other four bytes
107 * represent the shared memory id of the shared memory area that contains
108 * details about the audio file to be streamed next. The open file descriptor
109 * of that file is also passed from afs to para_server through the same pipe.
110 */
111 enum afs_server_code {
112 /** An audio file was successfully opened. */
113 NEXT_AUDIO_FILE,
114 /** No admissible audio file was found. */
115 NO_ADMISSIBLE_FILES,
116 };
117
118 /** Flags passed to for_each_matching_row(). */
119 enum pattern_match_flags {
120 /** Loop in reverse order. */
121 PM_REVERSE_LOOP = 1,
122 /** If no pattern is given, loop over all rows. */
123 PM_NO_PATTERN_MATCHES_EVERYTHING = 2,
124 /** If the data in match_column is the empty string, skip this row. */
125 PM_SKIP_EMPTY_NAME = 4,
126 };
127
128 /** Structure passed to for_each_matching_row(). */
129 struct pattern_match_data {
130 /** Loop over all rows in this table. */
131 struct osl_table *table;
132 /** Determines the loop order. Must be an rbtree column. */
133 unsigned loop_col_num;
134 /** Data from this column is matched against the given patterns. */
135 unsigned match_col_num;
136 /** \see \ref pattern_match_flags. */
137 unsigned pm_flags;
138 /** This value is passed verbatim to fnmatch(). */
139 int fnmatch_flags;
140 /** Obtained by deserializing the query buffer in the callback. */
141 struct lls_parse_result *lpr;
142 /** Do not try to match the first inputs of lpr */
143 unsigned input_skip;
144 /** Data pointer passed to the action function. */
145 void *data;
146 /** Gets increased by one for each match. */
147 unsigned num_matches;
148 /** For each matching row, this function will be called. */
149 int (*action)(struct osl_table *table, struct osl_row *row, const char *name, void *data);
150 };
151
152 /** Arguments passed to each afs callback. */
153 struct afs_callback_arg {
154 /** The local socket connecting afs and the command handler. */
155 int fd;
156 /** Callback-specific data. */
157 struct osl_object query;
158 /** Will be written on band SBD_OUTPUT, fully buffered. */
159 struct para_buffer pbout;
160 /**
161 * Convenience pointer for the deserialized parse result.
162 *
163 * Most afs command handlers call \ref send_lls_callback_request() to
164 * serialize the parse result of the subcommand and pass it to the
165 * callback. In afs context a pointer to the deserialized parse result
166 * is stored here.
167 */
168 struct lls_parse_result *lpr;
169 };
170
171 /**
172 * The "top half" of an afs command.
173 *
174 * Afs command handlers run as a process which is not related to the afs
175 * process, i.e. they can not change the address space of afs directly.
176 * Therefore afs commands typically consist of two functions: The command
177 * handler and the corresponding callback function that runs in afs context.
178 *
179 * \sa \ref send_callback_request().
180 */
181 typedef int afs_callback(struct afs_callback_arg *aca);
182
183 /**
184 * Dispatch the output of an afs callback.
185 *
186 * Some AFS callbacks need to send data back to the command handler. Pointers
187 * to this type of function are passed to \ref send_callback_request() and
188 * related functions to dispatch the data in the command handler process. Most
189 * (but not all) afs commands pass \ref afs_cb_result_handler(), which sends
190 * the output of the callback to the connected client.
191 */
192 typedef int callback_result_handler(struct osl_object *result, uint8_t band, void *private);
193 int afs_cb_result_handler(struct osl_object *result, uint8_t band, void *private);
194 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size);
195
196 /** Structure passed to the AFS max_size handler. */
197 struct afs_max_size_handler_data {
198 /** Local socket connecting the command handler and the AFS process. */
199 int fd;
200 /** The sideband designator for this data packet. */
201 uint8_t band;
202 };
203
204 /**
205 * Standard max_size handler for AFS commands.
206 *
207 * \param buf Contains (part of) the AFS command output.
208 * \param size The number of bytes in \a buf.
209 * \param private Pointer to a \ref afs_max_size_handler_data structure.
210 *
211 * Whenever the output of an AFS command exceeds the maximal size of a shared
212 * memory area, the max size handler of the para_buffer which holds the command
213 * output is called with \a private being a pointer to a structure of type
214 * afs_max_size_handler_data.
215 *
216 * \return The return value of the underlying call to \ref
217 * pass_buffer_as_shm().
218 */
219 _static_inline_ int afs_max_size_handler(char *buf, size_t size, void *private)
220 {
221 struct afs_max_size_handler_data *amshd = private;
222 return pass_buffer_as_shm(amshd->fd, amshd->band, buf, size);
223 }
224
225 __noreturn void afs_init(int socket_fd);
226 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
227 void *data);
228 int send_callback_request(afs_callback *f, struct osl_object *query,
229 callback_result_handler *result_handler,
230 void *private_result_data);
231 int send_lls_callback_request(afs_callback *f,
232 const struct lls_command * const cmd,
233 struct lls_parse_result *lpr, void *private_result_data);
234 __printf_2_3 void afs_error(const struct afs_callback_arg *aca,
235 const char *fmt,...);
236 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2);
237 int for_each_matching_row(struct pattern_match_data *pmd);
238
239 /* score */
240 extern const struct afs_table_operations score_ops;
241 int score_loop(osl_rbtree_loop_func *func, void *data);
242 int score_get_best(struct osl_row **aft_row, long *score);
243 int get_score_and_aft_row(struct osl_row *score_row, long *score, struct osl_row **aft_row);
244 int score_add(const struct osl_row *row, long score);
245 int score_update(const struct osl_row *aft_row, long new_score);
246 int score_delete(const struct osl_row *aft_row);
247 void score_clear(void);
248 bool row_belongs_to_score_table(const struct osl_row *aft_row);
249
250 /* attribute */
251 extern const struct afs_table_operations attr_ops;
252 void get_attribute_bitmap(const uint64_t *atts, char *buf); /* needed by com_ls() */
253 int get_attribute_bitnum_by_name(const char *att_name, unsigned char *bitnum);
254 int get_attribute_text(uint64_t *atts, const char *delim, char **text);
255 int attribute_check_callback(struct afs_callback_arg *aca);
256
257 /* aft */
258 extern const struct afs_table_operations aft_ops;
259 int aft_get_row_of_path(const char *path, struct osl_row **row);
260 int aft_check_attributes(uint64_t att_mask, struct para_buffer *pb);
261 int open_and_update_audio_file(int *fd);
262 int load_afd(int shmid, struct audio_file_data *afd);
263 int get_afsi_of_row(const struct osl_row *row, struct afs_info *afsi);
264 int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi);
265 int get_audio_file_path_of_row(const struct osl_row *row, char **path);
266 int audio_file_loop(void *private_data, osl_rbtree_loop_func *func);
267 int aft_check_callback(struct afs_callback_arg *aca);
268 void free_status_items(void);
269
270 /* mood */
271 int mood_load(const char *mood_name, char **msg);
272 void mood_unload(void);
273 int mood_check_callback(struct afs_callback_arg *aca);
274
275 /* playlist */
276 int playlist_load(const char *name, char **msg);
277 void playlist_unload(void);
278 int playlist_check_callback(struct afs_callback_arg *aca);
279
280 /** evaluates to 1 if x < y, to -1 if x > y and to 0 if x == y */
281 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
282
283
284 /** Define exported functions and a table pointer for an osl blob table. */
285 #define DECLARE_BLOB_SYMBOLS(table_name, cmd_prefix) \
286 int cmd_prefix ## _get_name_by_id(uint32_t id, char **name); \
287 int cmd_prefix ## _get_def_by_id(uint32_t id, struct osl_object *def); \
288 int cmd_prefix ## _get_def_by_name(const char *name, struct osl_object *def); \
289 int cmd_prefix ## _get_name_and_def_by_row(const struct osl_row *row, \
290 char **name, struct osl_object *def); \
291 int table_name ##_event_handler(enum afs_events event, \
292 struct para_buffer *pb, void *data); \
293 extern struct osl_table *table_name ## _table; \
294 extern const struct afs_table_operations table_name ## _ops;
295
296 /** \cond blob_symbols */
297 DECLARE_BLOB_SYMBOLS(lyrics, lyr);
298 DECLARE_BLOB_SYMBOLS(images, img);
299 DECLARE_BLOB_SYMBOLS(moods, mood);
300 DECLARE_BLOB_SYMBOLS(playlists, pl);
301 /** \endcond blob_symbols */
302
303 /** The columns of an abstract blob table. */
304 enum blob_table_columns {
305 /** The identifier, a positive integer that never repeats. */
306 BLOBCOL_ID,
307 /** The unique name of the blob. */
308 BLOBCOL_NAME,
309 /** The actual blob contents. */
310 BLOBCOL_DEF,
311 /** A blob table has that many columns. */
312 NUM_BLOB_COLUMNS
313 };