build: Compile with -Wdiscarded-qualifiers.
[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 /** Function pointers for table handling. */
77 struct afs_table {
78 /** Initializes the other pointers in this struct. */
79 void (*init)(struct afs_table *t);
80 /** The name of this table. */
81 const char *name;
82 /** Gets called on startup and on \p SIGHUP. */
83 int (*open)(const char *base_dir);
84 /** Gets called on shutdown and on \p SIGHUP. */
85 void (*close)(void);
86 /** Called by the \a init afs command. */
87 int (*create)(const char *);
88 /** Handles afs events. */
89 int (*event_handler)(enum afs_events event, struct para_buffer *pb,
90 void *data);
91 };
92
93 /** How audio files are selected by afs. */
94 enum play_mode {
95 /** Admissible files are determined by a mood definition. */
96 PLAY_MODE_MOOD,
97 /** All listed files are admissible. */
98 PLAY_MODE_PLAYLIST,
99 };
100
101 /**
102 * Codes used for communication between the server and the afs process.
103 *
104 * Before forking the afs child, para_server creates a bidirectional pipe
105 * through which both processes communicate. Usually para_server requests a new
106 * audio file in order to start streaming or when the end of the current audio file
107 * has been reached. The afs process responds to such a request by sending
108 * back an eight byte buffer. The first four bytes is the uint32_t
109 * representation of the code, usually \p NEXT_AUDIO_FILE if an admissible
110 * audio file was found, successfully opened and verified. The other four bytes
111 * represent the shared memory id of the shared memory area that contains
112 * details about the audio file to be streamed next. The open file descriptor
113 * of that file is also passed from afs to para_server through the same pipe.
114 */
115 enum afs_server_code {
116 /** An audio file was successfully opened. */
117 NEXT_AUDIO_FILE,
118 /** No admissible audio file was found. */
119 NO_ADMISSIBLE_FILES,
120 };
121
122 /** Flags passed to for_each_matching_row(). */
123 enum pattern_match_flags {
124 /** Loop in reverse order. */
125 PM_REVERSE_LOOP = 1,
126 /** If no pattern is given, loop over all rows. */
127 PM_NO_PATTERN_MATCHES_EVERYTHING = 2,
128 /** If the data in match_column is the empty string, skip this row. */
129 PM_SKIP_EMPTY_NAME = 4,
130 };
131
132 /** Structure passed to for_each_matching_row(). */
133 struct pattern_match_data {
134 /** Loop over all rows in this table. */
135 struct osl_table *table;
136 /** Determines the loop order. Must be an rbtree column. */
137 unsigned loop_col_num;
138 /** Data from this column is matched against the given patterns. */
139 unsigned match_col_num;
140 /** \see \ref pattern_match_flags. */
141 unsigned pm_flags;
142 /** This value is passed verbatim to fnmatch(). */
143 int fnmatch_flags;
144 /** Obtained by deserializing the query buffer in the callback. */
145 struct lls_parse_result *lpr;
146 /** Do not try to match the first inputs of lpr */
147 unsigned input_skip;
148 /** Data pointer passed to the action function. */
149 void *data;
150 /** Gets increased by one for each match. */
151 unsigned num_matches;
152 /** For each matching row, this function will be called. */
153 int (*action)(struct osl_table *table, struct osl_row *row, const char *name, void *data);
154 };
155
156 /** Arguments passed to each afs callback. */
157 struct afs_callback_arg {
158 /** The local socket connecting afs and the command handler. */
159 int fd;
160 /** Callback-specific data. */
161 struct osl_object query;
162 /** Will be written on band SBD_OUTPUT, fully buffered. */
163 struct para_buffer pbout;
164 struct lls_parse_result *lpr;
165 };
166
167 /**
168 * Afs command handlers run as a process which is not related to the afs
169 * process, i.e. they can not change the address space of afs directly.
170 * Therefore afs commands typically consist of two functions: The command
171 * handler and the corresponding callback function that runs in afs context.
172 *
173 * \sa \ref send_callback_request().
174 */
175 typedef int afs_callback(struct afs_callback_arg *aca);
176
177 /**
178 * Some AFS callbacks need to send data back to the command handler. Pointers
179 * to this type of function are passed to \ref send_callback_request() and
180 * related functions to dispatch the data in the command handler process.
181 */
182 typedef int callback_result_handler(struct osl_object *result, uint8_t band, void *private);
183 int afs_cb_result_handler(struct osl_object *result, uint8_t band, void *private);
184 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size);
185
186 /** Structure passed to the AFS max_size handler. */
187 struct afs_max_size_handler_data {
188 /** Local socket connecting the command handler and the AFS process. */
189 int fd;
190 /** The sideband designator for this data packet. */
191 uint8_t band;
192 };
193
194 /**
195 * Standard max_size handler for AFS commands.
196 *
197 * \param buf Contains (part of) the AFS command output.
198 * \param size The number of bytes in \a buf.
199 * \param private Pointer to a \ref afs_max_size_handler_data structure.
200 *
201 * Whenever the output of an AFS command exceeds the maximal size of a shared
202 * memory area, the max size handler of the para_buffer which holds the command
203 * output is called with \a private being a pointer to a structure of type
204 * afs_max_size_handler_data.
205 *
206 * \return The return value of the underlying call to \ref
207 * pass_buffer_as_shm().
208 */
209 _static_inline_ int afs_max_size_handler(char *buf, size_t size, void *private)
210 {
211 struct afs_max_size_handler_data *amshd = private;
212 return pass_buffer_as_shm(amshd->fd, amshd->band, buf, size);
213 }
214
215 __noreturn void afs_init(int socket_fd);
216 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
217 void *data);
218 int send_callback_request(afs_callback *f, struct osl_object *query,
219 callback_result_handler *result_handler,
220 void *private_result_data);
221 int send_lls_callback_request(afs_callback *f,
222 const struct lls_command * const cmd,
223 struct lls_parse_result *lpr, 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
227 /* score */
228 void score_init(struct afs_table *t);
229 int admissible_file_loop(void *data, osl_rbtree_loop_func *func);
230 int score_get_best(struct osl_row **aft_row, long *score);
231 int get_score_and_aft_row(struct osl_row *score_row, long *score, struct osl_row **aft_row);
232 int score_add(const struct osl_row *row, long score);
233 int score_update(const struct osl_row *aft_row, long new_score);
234 int get_num_admissible_files(unsigned *num);
235 int score_delete(const struct osl_row *aft_row);
236 int clear_score_table(void);
237 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank);
238
239 /* attribute */
240 void attribute_init(struct afs_table *t);
241 void get_attribute_bitmap(const uint64_t *atts, char *buf); /* needed by com_ls() */
242 int get_attribute_bitnum_by_name(const char *att_name, unsigned char *bitnum);
243 int get_attribute_text(uint64_t *atts, const char *delim, char **text);
244 int attribute_check_callback(struct afs_callback_arg *aca);
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 aft_check_attributes(uint64_t att_mask, struct para_buffer *pb);
250 int open_and_update_audio_file(struct audio_file_data *afd);
251 int load_afd(int shmid, struct audio_file_data *afd);
252 int get_afsi_of_row(const struct osl_row *row, struct afs_info *afsi);
253 int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi);
254 int get_audio_file_path_of_row(const struct osl_row *row, char **path);
255 int audio_file_loop(void *private_data, osl_rbtree_loop_func *func);
256 int aft_check_callback(struct afs_callback_arg *aca);
257
258 /* playlist */
259 int playlist_open(const char *name);
260 void playlist_close(void);
261 int playlist_check_callback(struct afs_callback_arg *aca);
262
263 /** evaluates to 1 if x < y, to -1 if x > y and to 0 if x == y */
264 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
265
266
267 /** Define exported functions and a table pointer for an osl blob table. */
268 #define DECLARE_BLOB_SYMBOLS(table_name, cmd_prefix) \
269 void table_name ## _init(struct afs_table *t); \
270 int cmd_prefix ## _get_name_by_id(uint32_t id, char **name); \
271 int cmd_prefix ## _get_def_by_id(uint32_t id, struct osl_object *def); \
272 int cmd_prefix ## _get_def_by_name(char *name, struct osl_object *def); \
273 int cmd_prefix ## _get_name_and_def_by_row(const struct osl_row *row, \
274 char **name, struct osl_object *def); \
275 int table_name ##_event_handler(enum afs_events event, \
276 struct para_buffer *pb, void *data); \
277 extern struct osl_table *table_name ## _table;
278
279 DECLARE_BLOB_SYMBOLS(lyrics, lyr);
280 DECLARE_BLOB_SYMBOLS(images, img);
281 DECLARE_BLOB_SYMBOLS(moods, mood);
282 DECLARE_BLOB_SYMBOLS(playlists, pl);
283
284 /** The columns of an abstract blob table. */
285 enum blob_table_columns {
286 /** The identifier, a positive integer that never repeats. */
287 BLOBCOL_ID,
288 /** The unique name of the blob. */
289 BLOBCOL_NAME,
290 /** The actual blob contents. */
291 BLOBCOL_DEF,
292 /** A blob table has that many columns. */
293 NUM_BLOB_COLUMNS
294 };