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 };