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         /**
 165          * Convenience pointer for the deserialized parse result.
 166          *
 167          * Most afs command handlers call \ref send_lls_callback_request() to
 168          * serialize the parse result of the subcommand and pass it to the
 169          * callback. In afs context a pointer to the deserialized parse result
 170          * is stored here.
 171          */
 172         struct lls_parse_result *lpr;
 173 };
 174
 175 /**
 176  * Afs command handlers run as a process which is not related to the afs
 177  * process, i.e. they can not change the address space of afs directly.
 178  * Therefore afs commands typically consist of two functions: The command
 179  * handler and the corresponding callback function that runs in afs context.
 180  *
 181  * \sa \ref send_callback_request().
 182  */
 183 typedef int afs_callback(struct afs_callback_arg *aca);
 184
 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.
 189  */
 190 typedef int callback_result_handler(struct osl_object *result, uint8_t band, void *private);
 191 int afs_cb_result_handler(struct osl_object *result, uint8_t band, void *private);
 192 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size);
 193
 194 /** Structure passed to the AFS max_size handler. */
 195 struct afs_max_size_handler_data {
 196         /** Local socket connecting the command handler and the AFS process. */
 197         int fd;
 198         /** The sideband designator for this data packet. */
 199         uint8_t band;
 200 };
 201
 202 /**
 203  * Standard max_size handler for AFS commands.
 204  *
 205  * \param buf Contains (part of) the AFS command output.
 206  * \param size The number of bytes in \a buf.
 207  * \param private Pointer to a \ref afs_max_size_handler_data structure.
 208  *
 209  * Whenever the output of an AFS command exceeds the maximal size of a shared
 210  * memory area, the max size handler of the para_buffer which holds the command
 211  * output is called with \a private being a pointer to a structure of type
 212  * afs_max_size_handler_data.
 213  *
 214  * \return The return value of the underlying call to \ref
 215  *  pass_buffer_as_shm().
 216  */
 217 _static_inline_ int afs_max_size_handler(char *buf, size_t size, void *private)
 218 {
 219         struct afs_max_size_handler_data *amshd = private;
 220         return pass_buffer_as_shm(amshd->fd, amshd->band, buf, size);
 221 }
 222
 223 __noreturn void afs_init(int socket_fd);
 224 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
 225         void *data);
 226 int send_callback_request(afs_callback *f, struct osl_object *query,
 227                 callback_result_handler *result_handler,
 228                 void *private_result_data);
 229 int send_lls_callback_request(afs_callback *f,
 230                 const struct lls_command * const cmd,
 231                 struct lls_parse_result *lpr, void *private_result_data);
 232 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2);
 233 int for_each_matching_row(struct pattern_match_data *pmd);
 234
 235 /* score */
 236 void score_init(struct afs_table *t);
 237 int admissible_file_loop(void *data, osl_rbtree_loop_func *func);
 238 int score_get_best(struct osl_row **aft_row, long *score);
 239 int get_score_and_aft_row(struct osl_row *score_row, long *score, struct osl_row **aft_row);
 240 int score_add(const struct osl_row *row, long score);
 241 int score_update(const struct osl_row *aft_row, long new_score);
 242 int get_num_admissible_files(unsigned *num);
 243 int score_delete(const struct osl_row *aft_row);
 244 int clear_score_table(void);
 245 int row_belongs_to_score_table(const struct osl_row *aft_row, unsigned *rank);
 246
 247 /* attribute */
 248 void attribute_init(struct afs_table *t);
 249 void get_attribute_bitmap(const uint64_t *atts, char *buf); /* needed by com_ls() */
 250 int get_attribute_bitnum_by_name(const char *att_name, unsigned char *bitnum);
 251 int get_attribute_text(uint64_t *atts, const char *delim, char **text);
 252 int attribute_check_callback(struct afs_callback_arg *aca);
 253
 254 /* aft */
 255 void aft_init(struct afs_table *t);
 256 int aft_get_row_of_path(const char *path, struct osl_row **row);
 257 int aft_check_attributes(uint64_t att_mask, struct para_buffer *pb);
 258 int open_and_update_audio_file(int *fd);
 259 int load_afd(int shmid, struct audio_file_data *afd);
 260 int get_afsi_of_row(const struct osl_row *row, struct afs_info *afsi);
 261 int get_afhi_of_row(const struct osl_row *row, struct afh_info *afhi);
 262 int get_audio_file_path_of_row(const struct osl_row *row, char **path);
 263 int audio_file_loop(void *private_data, osl_rbtree_loop_func *func);
 264 int aft_check_callback(struct afs_callback_arg *aca);
 265 void free_status_items(void);
 266
 267 /* playlist */
 268 int playlist_open(const char *name);
 269 void playlist_close(void);
 270 int playlist_check_callback(struct afs_callback_arg *aca);
 271
 272 /** evaluates to 1 if x < y, to -1 if x > y and to 0 if x == y */
 273 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
 274
 275
 276 /** Define exported functions and a table pointer for an osl blob table. */
 277 #define DECLARE_BLOB_SYMBOLS(table_name, cmd_prefix) \
 278         void table_name ## _init(struct afs_table *t); \
 279         int cmd_prefix ## _get_name_by_id(uint32_t id, char **name); \
 280         int cmd_prefix ## _get_def_by_id(uint32_t id, struct osl_object *def); \
 281         int cmd_prefix ## _get_def_by_name(char *name, struct osl_object *def); \
 282         int cmd_prefix ## _get_name_and_def_by_row(const struct osl_row *row, \
 283                 char **name, struct osl_object *def); \
 284         int table_name ##_event_handler(enum afs_events event, \
 285                 struct para_buffer *pb, void *data); \
 286         extern struct osl_table *table_name ## _table;
 287
 288 /** \cond blob_symbols */
 289 DECLARE_BLOB_SYMBOLS(lyrics, lyr);
 290 DECLARE_BLOB_SYMBOLS(images, img);
 291 DECLARE_BLOB_SYMBOLS(moods, mood);
 292 DECLARE_BLOB_SYMBOLS(playlists, pl);
 293 /** \endcond blob_symbols */
 294
 295 /** The columns of an abstract blob table. */
 296 enum blob_table_columns {
 297         /** The identifier, a positive integer that never repeats. */
 298         BLOBCOL_ID,
 299         /** The unique name of the blob. */
 300         BLOBCOL_NAME,
 301         /** The actual blob contents. */
 302         BLOBCOL_DEF,
 303         /** A blob table has that many columns. */
 304         NUM_BLOB_COLUMNS
 305 };