Let afs_event() return int.
[paraslash.git] / afs.h
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.h Exported symbols of the audio file selector. */
8
9 #include <regex.h>
10
11 /** Audio file selector data stored in the audio file table. */
12 struct afs_info {
13 /** Seconds since the epoch. */
14 uint64_t last_played;
15 /** Bit field of set attributes. */
16 uint64_t attributes;
17 /** Counts how many times the file was selected. */
18 uint32_t num_played;
19 /** Image blob associated with this file (foreign key). */
20 uint32_t image_id;
21 /** Lyrics blob associated with this file (foreign key). */
22 uint32_t lyrics_id;
23 /** Mp3, ogg, ... */
24 uint8_t audio_format_id;
25 /** Amplification value. */
26 uint8_t amp;
27 };
28
29 /**
30 * Events caused by changes to an afs table.
31 *
32 * Whenever an afs table changes, an event is generated which causes afs to
33 * call the event handlers of all other tables. For example, if an audio file
34 * is added, the event handler of the mood table checks the new file for
35 * admissibility.
36 */
37 enum afs_events {
38 /** An attribute was added. */
39 ATTRIBUTE_ADD,
40 /** An attribute was renamed. */
41 ATTRIBUTE_RENAME,
42 /** An attribute was removed. */
43 ATTRIBUTE_REMOVE,
44 /** The afs info struct of an audio file changed. */
45 AFSI_CHANGE,
46 /** The afh info struct of an audio file changed. */
47 AFHI_CHANGE,
48 /** An audio file was renamed. */
49 AUDIO_FILE_RENAME,
50 /** An audio file was added. */
51 AUDIO_FILE_ADD,
52 /** An audio file is about to be removed. */
53 AUDIO_FILE_REMOVE,
54 /** A new blob was added. */
55 BLOB_ADD,
56 /** A blob was renamed. */
57 BLOB_RENAME,
58 /** A blob is about to be removed. */
59 BLOB_REMOVE,
60 };
61
62 /**
63 * Used as data for \ref afs_event() for events of type \p ATTRIBUTE_ADD.
64 */
65 struct rmatt_event_data {
66 /** The name of the attribute being added. */
67 const char *name;
68 /** Its bit number. */
69 unsigned char bitnum;
70 };
71
72 /**
73 * Used as data for \ref afs_event() for events of type \p ATTRIBUTE_AFSI_CHANGE.
74 */
75 struct afsi_change_event_data {
76 /** Pointer to the row that has changed. */
77 struct osl_row *aft_row;
78 /** Afs info before the change. */
79 struct afs_info *old_afsi;
80 };
81
82 /** Function pointers for table handling. */
83 struct afs_table {
84 /** Initializes the other pointers in this struct. */
85 void (*init)(struct afs_table *t);
86 /** The name of this table. */
87 const char *name;
88 /** Gets called on startup and on \p SIGHUP. */
89 int (*open)(const char *base_dir);
90 /** Gets called on shutdown and on \p SIGHUP. */
91 void (*close)(void);
92 /** Called by the \a init afs command. */
93 int (*create)(const char *);
94 /** Handles afs events. */
95 int (*event_handler)(enum afs_events event, struct para_buffer *pb,
96 void *data);
97 };
98
99 /** How audio files are selected by afs. */
100 enum play_mode {
101 /** Admissible files are determined by a mood definition. */
102 PLAY_MODE_MOOD,
103 /** All listed files are admissible. */
104 PLAY_MODE_PLAYLIST,
105 };
106
107 /**
108 * Codes used for communication between the server and the afs process.
109 *
110 * Before forking the afs child, para_server creates a bidirectional pipe
111 * through which both processes communicate. Usually para_server requests a new
112 * audio file in order to start streaming or when the end of the current audio file
113 * has been reached. The afs process responds to such a request by sending
114 * back an eight byte buffer. The first four bytes is the uint32_t
115 * representation of the code, usually \p NEXT_AUDIO_FILE if an admissible
116 * audio file was found, successfully opened and verified. The other four bytes
117 * represent the shared memory id of the shared memory area that contains
118 * details about the audio file to be streamed next. The open file descriptor
119 * of that file is also passed from afs to para_server through the same pipe.
120 */
121 enum afs_server_code {
122 /** An audio file was successfully opened. */
123 NEXT_AUDIO_FILE,
124 /** No admissible audio file was found. */
125 NO_ADMISSIBLE_FILES,
126 };
127
128 /** Flags passed to for_each_matching_row(). */
129 enum pattern_match_flags {
130 /** Loop in reverse order. */
131 PM_REVERSE_LOOP = 1,
132 /** If no pattern is given, loop over all rows. */
133 PM_NO_PATTERN_MATCHES_EVERYTHING = 2,
134 /** If the data in match_column is the empty string, skip this row. */
135 PM_SKIP_EMPTY_NAME = 4,
136 };
137
138 /** Structure passed to for_each_matching_row(). */
139 struct pattern_match_data {
140 /** Loop over all rows in this table. */
141 struct osl_table *table;
142 /** Determines the loop order. Must be an rbtree column. */
143 unsigned loop_col_num;
144 /** Data from this column is matched against the given patterns. */
145 unsigned match_col_num;
146 /** \see pattern_match_flags. */
147 unsigned pm_flags;
148 /** This value is passed verbatim to fnmatch(). */
149 int fnmatch_flags;
150 /** Null-terminated array of patterns. */
151 struct osl_object patterns;
152 /** Data pointer passed to the action function. */
153 void *data;
154 /** Gets increased by one for each match. */
155 unsigned num_matches;
156 /** For each matching row, this function will be called. */
157 int (*action)(struct osl_table *table, struct osl_row *row, const char *name, void *data);
158 };
159
160
161 /**
162 * Afs command handlers run as a process which is not related to the afs
163 * process, i.e. they can not change the address space of afs directly.
164 * Therefore afs commands typically consist of two functions: The command
165 * handler and the corresponding callback function that runs in afs context.
166 *
167 * \sa send_callback_request().
168 */
169 typedef int callback_function(int fd, const struct osl_object *);
170
171 /**
172 * Callbacks send chunks to data back to the command handler. Pointers to
173 * this type of function are used by \ref send_callback_request and friends
174 * to deal with the data in the command handler process.
175 *
176 * \sa \ref send_callback_request().
177 */
178 typedef int callback_result_handler(struct osl_object *result, uint8_t band, void *private);
179 int afs_cb_result_handler(struct osl_object *result, uint8_t band, void *private);
180 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size);
181
182 /** Structure passed to the AFS max_size handler. */
183 struct afs_max_size_handler_data {
184 /** Local socket connecting the command handler and the AFS process. */
185 int fd;
186 /** The sideband designator for this data packet. */
187 uint8_t band;
188 };
189
190 /**
191 * Standard max_size handler for AFS commands.
192 *
193 * \param buf Contains (part of) the AFS command output.
194 * \param size The number of bytes in \a buf.
195 * \param private Pointer to a \ref afs_max_size_handler_data structure.
196 *
197 * Whenever the output of an AFS command exceeds the maximal size of a shared
198 * memory area, the max size handler of the para_buffer which holds the command
199 * output is called with \a private being a pointer to a structure of type
200 * afs_max_size_handler_data.
201 *
202 * \return The return value of the underlying call to \ref
203 * pass_buffer_as_shm().
204 */
205 _static_inline_ int afs_max_size_handler(char *buf, size_t size, void *private)
206 {
207 struct afs_max_size_handler_data *amshd = private;
208 return pass_buffer_as_shm(amshd->fd, amshd->band, buf, size);
209 }
210
211 __noreturn void afs_init(uint32_t cookie, int socket_fd);
212 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
213 void *data);
214 int send_callback_request(callback_function *f, struct osl_object *query,
215 callback_result_handler *result_handler,
216 void *private_result_data);
217 int send_option_arg_callback_request(struct osl_object *options,
218 int argc, char * const * const argv, callback_function *f,
219 callback_result_handler *result_handler,
220 void *private_result_data);
221 int send_standard_callback_request(int argc, char * const * const argv,
222 callback_function *f, callback_result_handler *result_handler,
223 void *private_result_data);
224 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2);
225 int for_each_matching_row(struct pattern_match_data *pmd);
226 void flush_and_free_pb(struct para_buffer *pb);
227
228 /* score */
229 void score_init(struct afs_table *t);
230 int admissible_file_loop(void *data, osl_rbtree_loop_func *func);
231 int score_get_best(struct osl_row **aft_row, long *score);
232 int get_score_and_aft_row(struct osl_row *score_row, long *score, struct osl_row **aft_row);
233 int score_add(const struct osl_row *row, long score);
234 int score_update(const struct osl_row *aft_row, long new_score);
235 int get_num_admissible_files(unsigned *num);
236 int score_delete(const struct osl_row *aft_row);
237 int clear_score_table(void);
238 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank);
239
240 /* attribute */
241 void attribute_init(struct afs_table *t);
242 void get_attribute_bitmap(const uint64_t *atts, char *buf); /* needed by com_ls() */
243 int get_attribute_bitnum_by_name(const char *att_name, unsigned char *bitnum);
244 int get_attribute_text(uint64_t *atts, const char *delim, char **text);
245
246 /* aft */
247 void aft_init(struct afs_table *t);
248 int aft_get_row_of_path(const char *path, struct osl_row **row);
249 int open_and_update_audio_file(struct audio_file_data *afd);
250 int load_afd(int shmid, struct audio_file_data *afd);
251 int get_afsi_of_row(const struct osl_row *row, struct afs_info *afsi);
252 int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi);
253 int get_audio_file_path_of_row(const struct osl_row *row, char **path);
254 int audio_file_loop(void *private_data, osl_rbtree_loop_func *func);
255 int aft_check_callback(int fd, __a_unused const struct osl_object *query);
256
257 /* playlist */
258 int playlist_open(char *name);
259 void playlist_close(void);
260 int playlist_check_callback(int fd, __a_unused const struct osl_object *query);
261
262 /** evaluates to 1 if x < y, to -1 if x > y and to 0 if x == y */
263 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
264
265
266 /** Define exported functions and a table pointer for an osl blob table. */
267 #define DECLARE_BLOB_SYMBOLS(table_name, cmd_prefix) \
268 void table_name ## _init(struct afs_table *t); \
269 int cmd_prefix ## _get_name_by_id(uint32_t id, char **name); \
270 int cmd_prefix ## _get_def_by_id(uint32_t id, struct osl_object *def); \
271 int cmd_prefix ## _get_def_by_name(char *name, struct osl_object *def); \
272 int cmd_prefix ## _get_name_and_def_by_row(const struct osl_row *row, \
273 char **name, struct osl_object *def); \
274 int table_name ##_event_handler(enum afs_events event, \
275 struct para_buffer *pb, void *data); \
276 extern struct osl_table *table_name ## _table;
277
278 DECLARE_BLOB_SYMBOLS(lyrics, lyr);
279 DECLARE_BLOB_SYMBOLS(images, img);
280 DECLARE_BLOB_SYMBOLS(moods, mood);
281 DECLARE_BLOB_SYMBOLS(playlists, pl);
282
283 /** The columns of an abstract blob table. */
284 enum blob_table_columns {
285 /** The identifier, a positive integer that never repeats. */
286 BLOBCOL_ID,
287 /** The unique name of the blob. */
288 BLOBCOL_NAME,
289 /** The actual blob contents. */
290 BLOBCOL_DEF,
291 /** A blob table has that many columns. */
292 NUM_BLOB_COLUMNS
293 };