include/vlc_configuration.h

   1 /*****************************************************************************
   2  * vlc_configuration.h : configuration management module
   3  * This file describes the programming interface for the configuration module.
   4  * It includes functions allowing to declare, get or set configuration options.
   5  *****************************************************************************
   6  * Copyright (C) 1999-2006 VLC authors and VideoLAN
   7  *
   8  * Authors: Gildas Bazin <gbazin@videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #ifndef VLC_CONFIGURATION_H
  26 #define VLC_CONFIGURATION_H 1
  27
  28 /**
  29  * \defgroup config User settings
  30  * \ingroup interface
  31  * VLC provides a simple name-value dictionary for user settings.
  32  *
  33  * Those settings are per-user per-system - they are shared by all LibVLC
  34  * instances in a single process, and potentially other processes as well.
  35  *
  36  * Each name-value pair is called a configuration item.
  37  * @{
  38  */
  39
  40 /**
  41  * \file
  42  * This file describes the programming interface for the configuration module.
  43  * It includes functions allowing to declare, get or set configuration options.
  44  */
  45
  46 #include <sys/types.h>  /* for ssize_t */
  47
  48 # ifdef __cplusplus
  49 extern "C" {
  50 # endif
  51
  52 struct config_category_t
  53 {
  54     int         i_id;
  55     const char *psz_name;
  56     const char *psz_help;
  57 };
  58
  59 typedef union
  60 {
  61     char       *psz;
  62     int64_t     i;
  63     float       f;
  64 } module_value_t;
  65
  66 typedef int (*vlc_string_list_cb)(const char *, char ***, char ***);
  67 typedef int (*vlc_integer_list_cb)(const char *, int64_t **, char ***);
  68
  69 /**
  70  * Configuration item
  71  *
  72  * This is the internal reprensation of a configuration item.
  73  * See also config_FindConfig().
  74  */
  75 struct module_config_t
  76 {
  77     uint8_t     i_type; /**< Configuration type */
  78     char        i_short; /**< Optional short option name */
  79     unsigned    b_internal:1; /**< Hidden from preferences and help */
  80     unsigned    b_unsaveable:1; /**< Not stored in configuration */
  81     unsigned    b_safe:1; /**< Safe for web plugins and playlist files */
  82     unsigned    b_removed:1; /**< Obsolete */
  83
  84     const char *psz_type; /**< Configuration subtype */
  85     const char *psz_name; /**< Option name */
  86     const char *psz_text; /**< Short comment on the configuration option */
  87     const char *psz_longtext; /**< Long comment on the configuration option */
  88
  89     module_value_t value; /**< Current value */
  90     module_value_t orig; /**< Default value */
  91     module_value_t min; /**< Minimum value (for scalars only) */
  92     module_value_t max; /**< Maximum value (for scalars only) */
  93
  94     /* Values list */
  95     uint16_t list_count; /**< Choices count */
  96     union
  97     {
  98         const char **psz; /**< Table of possible string choices */
  99         const int  *i; /**< Table of possible integer choices */
 100         vlc_string_list_cb psz_cb; /**< Callback to enumerate string choices */
 101         vlc_integer_list_cb i_cb; /**< Callback to enumerate integer choices */
 102     } list; /**< Possible choices */
 103     const char **list_text; /**< Human-readable names for list values */
 104     const char *list_cb_name; /**< Symbol name of the enumeration callback */
 105     void *owner; /**< Origin run-time linker module handle */
 106 };
 107
 108 /**
 109  * Gets a configuration item type
 110  *
 111  * This function checks the type of configuration item by name.
 112  * \param name Configuration item name
 113  * \return The configuration item type or 0 if not found.
 114  */
 115 VLC_API int config_GetType(const char *name) VLC_USED;
 116
 117 /**
 118  * Gets an integer configuration item.
 119  *
 120  * This function retrieves the current value of a configuration item of
 121  * integral type (\ref CONFIG_ITEM_INTEGER and \ref CONFIG_ITEM_BOOL).
 122  *
 123  * \warning The behaviour is undefined if the configuration item exists but is
 124  * not of integer or boolean type.
 125  *
 126  * \param name Configuration item name
 127  * \return The configuration item value or -1 if not found.
 128  * \bug A legitimate integer value of -1 cannot be distinguished from an error.
 129  */
 130 VLC_API int64_t config_GetInt(const char *name) VLC_USED;
 131
 132 /**
 133  * Sets an integer configuration item.
 134  *
 135  * This function changes the current value of a configuration item of
 136  * integral type (\ref CONFIG_ITEM_INTEGER and \ref CONFIG_ITEM_BOOL).
 137  *
 138  * \warning The behaviour is undefined if the configuration item exists but is
 139  * not of integer or boolean type.
 140  *
 141  * \note If no configuration item by the specified exist, the function has no
 142  * effects.
 143  *
 144  * \param name Configuration item name
 145  * \param val New value
 146  */
 147 VLC_API void config_PutInt(const char *name, int64_t val);
 148
 149 /**
 150  * Gets an floating point configuration item.
 151  *
 152  * This function retrieves the current value of a configuration item of
 153  * floating point type (\ref CONFIG_ITEM_FLOAT).
 154  *
 155  * \warning The behaviour is undefined if the configuration item exists but is
 156  * not of floating point type.
 157  *
 158  * \param name Configuration item name
 159  * \return The configuration item value or -1 if not found.
 160  * \bug A legitimate floating point value of -1 cannot be distinguished from an
 161  * error.
 162  */
 163 VLC_API float config_GetFloat(const char *name) VLC_USED;
 164
 165 /**
 166  * Sets an integer configuration item.
 167  *
 168  * This function changes the current value of a configuration item of
 169  * integral type (\ref CONFIG_ITEM_FLOAT).
 170  *
 171  * \warning The behaviour is undefined if the configuration item exists but is
 172  * not of floating point type.
 173  *
 174  * \note If no configuration item by the specified exist, the function has no
 175  * effects.
 176  *
 177  * \param name Configuration item name
 178  * \param val New value
 179  */
 180 VLC_API void config_PutFloat(const char *name, float val);
 181
 182 /**
 183  * Gets an string configuration item.
 184  *
 185  * This function retrieves the current value of a configuration item of
 186  * string type (\ref CONFIG_ITEM_STRING).
 187  *
 188  * \note The caller must free() the returned pointer (if non-NULL), which is a
 189  * duplicate of the current value. It is not safe to return a pointer to the
 190  * current value internally as it can be modified at any time by any other
 191  * thread.
 192  *
 193  * \warning The behaviour is undefined if the configuration item exists but is
 194  * not of floating point type.
 195  *
 196  * \param name Configuration item name
 197  * \return Normally, a heap-allocated copy of the configuration item value.
 198  * If the value is the empty string, if the configuration does not exist,
 199  * or if an error occurs, NULL is returned.
 200  * \bug The empty string value cannot be distinguished from an error.
 201  */
 202 VLC_API char *config_GetPsz(const char *name) VLC_USED VLC_MALLOC;
 203
 204 /**
 205  * Sets an string configuration item.
 206  *
 207  * This function changes the current value of a configuration item of
 208  * string type (e.g. \ref CONFIG_ITEM_STRING).
 209  *
 210  * \warning The behaviour is undefined if the configuration item exists but is
 211  * not of a string type.
 212  *
 213  * \note If no configuration item by the specified exist, the function has no
 214  * effects.
 215  *
 216  * \param name Configuration item name
 217  * \param val New value (will be copied)
 218  * \bug This function allocates memory but errors cannot be detected.
 219  */
 220 VLC_API void config_PutPsz(const char *name, const char *val);
 221
 222 /**
 223  * Enumerates integer configuration choices.
 224  *
 225  * Determines a list of suggested values for an integer configuration item.
 226  * \param values pointer to a table of integer values [OUT]
 227  * \param texts pointer to a table of descriptions strings [OUT]
 228  * \return number of choices, or -1 on error
 229  * \note the caller is responsible for calling free() on all descriptions and
 230  * on both tables. In case of error, both pointers are set to NULL.
 231  */
 232 VLC_API ssize_t config_GetIntChoices(const char *, int64_t **values,
 233                                      char ***texts) VLC_USED;
 234
 235 /**
 236  * Determines a list of suggested values for a string configuration item.
 237  * \param values pointer to a table of value strings [OUT]
 238  * \param texts pointer to a table of descriptions strings [OUT]
 239  * \return number of choices, or -1 on error
 240  * \note the caller is responsible for calling free() on all values, on all
 241  * descriptions and on both tables.
 242  * In case of error, both pointers are set to NULL.
 243  */
 244 VLC_API ssize_t config_GetPszChoices(const char *,
 245                                      char ***values, char ***texts) VLC_USED;
 246
 247 VLC_API int config_SaveConfigFile( vlc_object_t * );
 248 #define config_SaveConfigFile(a) config_SaveConfigFile(VLC_OBJECT(a))
 249
 250 /**
 251  * Resets the configuration.
 252  *
 253  * This function resets all configuration items to their respective
 254  * compile-time default value.
 255  */
 256 VLC_API void config_ResetAll(void);
 257
 258 /**
 259  * Looks up a configuration item.
 260  *
 261  * This function looks for the internal representation of a configuration item.
 262  * Where possible, this should be avoided in favor of more specific function
 263  * calls.
 264  *
 265  * \param name Configuration item name
 266  * \return The internal structure, or NULL if not found.
 267  */
 268 VLC_API module_config_t *config_FindConfig(const char *name) VLC_USED;
 269
 270 /**
 271  * System directory identifiers
 272  */
 273 typedef enum vlc_system_dir
 274 {
 275     VLC_PKG_DATA_DIR, /**< Package-specific architecture-independent read-only
 276                            data directory (e.g. /usr/local/data/vlc). */
 277     VLC_PKG_LIB_DIR, /**< Package-specific architecture-dependent read-only
 278                           data directory (e.g. /usr/local/lib/vlc). */
 279     VLC_PKG_LIBEXEC_DIR, /**< Package-specific executable read-only directory
 280                               (e.g. /usr/local/libexec/vlc). */
 281     VLC_PKG_INCLUDE_DIR_RESERVED,
 282     VLC_SYSDATA_DIR, /**< Global architecture-independent read-only
 283                           data directory (e.g. /usr/local/data).
 284                           Available only on some platforms. */
 285     VLC_LIB_DIR, /**< Global architecture-dependent read-only directory
 286                       (e.g. /usr/local/lib). */
 287     VLC_LIBEXEC_DIR, /**< Global executable read-only directory
 288                           (e.g. /usr/local/libexec). */
 289     VLC_INCLUDE_DIR_RESERVED,
 290     VLC_LOCALE_DIR, /**< Base directory for package read-only locale data. */
 291 } vlc_sysdir_t;
 292
 293 /**
 294  * Gets an installation directory.
 295  *
 296  * This function determines one of the installation directory.
 297  *
 298  * @param dir identifier of the directory (see \ref vlc_sysdir_t)
 299  * @param filename name of a file or other object within the directory
 300  *                 (or NULL to obtain the plain directory)
 301  *
 302  * @return a heap-allocated string (use free() to release it), or NULL on error
 303  */
 304 VLC_API char *config_GetSysPath(vlc_sysdir_t dir, const char *filename)
 305 VLC_USED VLC_MALLOC;
 306
 307 typedef enum vlc_user_dir
 308 {
 309     VLC_HOME_DIR, /* User's home */
 310     VLC_CONFIG_DIR, /* VLC-specific configuration directory */
 311     VLC_USERDATA_DIR, /* VLC-specific data directory */
 312     VLC_CACHE_DIR, /* VLC-specific user cached data directory */
 313     /* Generic directories (same as XDG) */
 314     VLC_DESKTOP_DIR=0x80,
 315     VLC_DOWNLOAD_DIR,
 316     VLC_TEMPLATES_DIR,
 317     VLC_PUBLICSHARE_DIR,
 318     VLC_DOCUMENTS_DIR,
 319     VLC_MUSIC_DIR,
 320     VLC_PICTURES_DIR,
 321     VLC_VIDEOS_DIR,
 322 } vlc_userdir_t;
 323
 324 VLC_API char * config_GetUserDir( vlc_userdir_t ) VLC_USED VLC_MALLOC;
 325
 326 VLC_API void config_AddIntf(const char *);
 327 VLC_API void config_RemoveIntf(const char *);
 328 VLC_API bool config_ExistIntf(const char *) VLC_USED;
 329
 330 /****************************************************************************
 331  * config_chain_t:
 332  ****************************************************************************/
 333 struct config_chain_t
 334 {
 335     config_chain_t *p_next;     /**< Pointer on the next config_chain_t element */
 336
 337     char        *psz_name;      /**< Option name */
 338     char        *psz_value;     /**< Option value */
 339 };
 340
 341 /**
 342  * This function will
 343  * - create all options in the array ppsz_options (var_Create).
 344  * - parse the given linked list of config_chain_t and set the value (var_Set).
 345  *
 346  * The option names will be created by adding the psz_prefix prefix.
 347  */
 348 VLC_API void config_ChainParse( vlc_object_t *, const char *psz_prefix, const char *const *ppsz_options, config_chain_t * );
 349 #define config_ChainParse( a, b, c, d ) config_ChainParse( VLC_OBJECT(a), b, c, d )
 350
 351 /**
 352  * This function will parse a configuration string (psz_opts) and
 353  * - set all options for this module in a chained list (*pp_cfg)
 354  * - returns a pointer on the next module if any.
 355  *
 356  * The string format is
 357  *   module{option=*,option=*}
 358  *
 359  * The options values are unescaped using config_StringUnescape.
 360  */
 361 VLC_API const char *config_ChainParseOptions( config_chain_t **pp_cfg, const char *ppsz_opts );
 362
 363 /**
 364  * This function will parse a configuration string (psz_string) and
 365  * - set the module name (*ppsz_name)
 366  * - set all options for this module in a chained list (*pp_cfg)
 367  * - returns a pointer on the next module if any.
 368  *
 369  * The string format is
 370  *   module{option=*,option=*}[:modulenext{option=*,...}]
 371  *
 372  * The options values are unescaped using config_StringUnescape.
 373  */
 374 VLC_API char *config_ChainCreate( char **ppsz_name, config_chain_t **pp_cfg, const char *psz_string ) VLC_USED VLC_MALLOC;
 375
 376 /**
 377  * This function will release a linked list of config_chain_t
 378  * (Including the head)
 379  */
 380 VLC_API void config_ChainDestroy( config_chain_t * );
 381
 382 /**
 383  * This function will duplicate a linked list of config_chain_t
 384  */
 385 VLC_API config_chain_t * config_ChainDuplicate( const config_chain_t * ) VLC_USED VLC_MALLOC;
 386
 387 /**
 388  * This function will unescape a string in place and will return a pointer on
 389  * the given string.
 390  * No memory is allocated by it (unlike config_StringEscape).
 391  * If NULL is given as parameter nothing will be done (NULL will be returned).
 392  *
 393  * The following sequences will be unescaped (only one time):
 394  * \\ \' and \"
 395  */
 396 VLC_API char * config_StringUnescape( char *psz_string );
 397
 398 /**
 399  * This function will escape a string that can be unescaped by
 400  * config_StringUnescape.
 401  * The returned value is allocated by it. You have to free it once you
 402  * do not need it anymore (unlike config_StringUnescape).
 403  * If NULL is given as parameter nothing will be done (NULL will be returned).
 404  *
 405  * The escaped characters are ' " and \
 406  */
 407 VLC_API char * config_StringEscape( const char *psz_string ) VLC_USED VLC_MALLOC;
 408
 409 # ifdef __cplusplus
 410 }
 411 # endif
 412
 413 /** @} */
 414
 415 #endif /* _VLC_CONFIGURATION_H */