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 void 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 void 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
 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
 245 /* aft */
 246 void aft_init(struct afs_table *t);
 247 int aft_get_row_of_path(const char *path, struct osl_row **row);
 248 int open_and_update_audio_file(struct osl_row *aft_row, long score,
 249         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 void 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 void 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 };