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     } list; /**< Possible choices */
 101     const char **list_text; /**< Human-readable names for list values */
 102     void *owner; /**< Origin run-time linker module handle */
 103 };
 104
 105 /**
 106  * Gets a configuration item type
 107  *
 108  * This function checks the type of configuration item by name.
 109  * \param name Configuration item name
 110  * \return The configuration item type or 0 if not found.
 111  */
 112 VLC_API int config_GetType(const char *name) VLC_USED;
 113
 114 /**
 115  * Gets an integer configuration item.
 116  *
 117  * This function retrieves the current value of a configuration item of
 118  * integral type (\ref CONFIG_ITEM_INTEGER and \ref CONFIG_ITEM_BOOL).
 119  *
 120  * \warning The behaviour is undefined if the configuration item exists but is
 121  * not of integer or boolean type.
 122  *
 123  * \param name Configuration item name
 124  * \return The configuration item value or -1 if not found.
 125  * \bug A legitimate integer value of -1 cannot be distinguished from an error.
 126  */
 127 VLC_API int64_t config_GetInt(const char *name) VLC_USED;
 128
 129 /**
 130  * Sets an integer configuration item.
 131  *
 132  * This function changes the current value of a configuration item of
 133  * integral type (\ref CONFIG_ITEM_INTEGER and \ref CONFIG_ITEM_BOOL).
 134  *
 135  * \warning The behaviour is undefined if the configuration item exists but is
 136  * not of integer or boolean type.
 137  *
 138  * \note If no configuration item by the specified exist, the function has no
 139  * effects.
 140  *
 141  * \param name Configuration item name
 142  * \param val New value
 143  */
 144 VLC_API void config_PutInt(const char *name, int64_t val);
 145
 146 /**
 147  * Gets an floating point configuration item.
 148  *
 149  * This function retrieves the current value of a configuration item of
 150  * floating point type (\ref CONFIG_ITEM_FLOAT).
 151  *
 152  * \warning The behaviour is undefined if the configuration item exists but is
 153  * not of floating point type.
 154  *
 155  * \param name Configuration item name
 156  * \return The configuration item value or -1 if not found.
 157  * \bug A legitimate floating point value of -1 cannot be distinguished from an
 158  * error.
 159  */
 160 VLC_API float config_GetFloat(const char *name) VLC_USED;
 161
 162 /**
 163  * Sets an floating point configuration item.
 164  *
 165  * This function changes the current value of a configuration item of
 166  * floating point type (\ref CONFIG_ITEM_FLOAT).
 167  *
 168  * \warning The behaviour is undefined if the configuration item exists but is
 169  * not of floating point type.
 170  *
 171  * \note If no configuration item by the specified exist, the function has no
 172  * effects.
 173  *
 174  * \param name Configuration item name
 175  * \param val New value
 176  */
 177 VLC_API void config_PutFloat(const char *name, float val);
 178
 179 /**
 180  * Gets an string configuration item.
 181  *
 182  * This function retrieves the current value of a configuration item of
 183  * string type (\ref CONFIG_ITEM_STRING).
 184  *
 185  * \note The caller must free() the returned pointer (if non-NULL), which is a
 186  * duplicate of the current value. It is not safe to return a pointer to the
 187  * current value internally as it can be modified at any time by any other
 188  * thread.
 189  *
 190  * \warning The behaviour is undefined if the configuration item exists but is
 191  * not of string type.
 192  *
 193  * \param name Configuration item name
 194  * \return Normally, a heap-allocated copy of the configuration item value.
 195  * If the value is the empty string, if the configuration does not exist,
 196  * or if an error occurs, NULL is returned.
 197  * \bug The empty string value cannot be distinguished from an error.
 198  */
 199 VLC_API char *config_GetPsz(const char *name) VLC_USED VLC_MALLOC;
 200
 201 /**
 202  * Sets an string configuration item.
 203  *
 204  * This function changes the current value of a configuration item of
 205  * string type (e.g. \ref CONFIG_ITEM_STRING).
 206  *
 207  * \warning The behaviour is undefined if the configuration item exists but is
 208  * not of a string type.
 209  *
 210  * \note If no configuration item by the specified exist, the function has no
 211  * effects.
 212  *
 213  * \param name Configuration item name
 214  * \param val New value (will be copied)
 215  * \bug This function allocates memory but errors cannot be detected.
 216  */
 217 VLC_API void config_PutPsz(const char *name, const char *val);
 218
 219 /**
 220  * Enumerates integer configuration choices.
 221  *
 222  * Determines a list of suggested values for an integer configuration item.
 223  * \param values pointer to a table of integer values [OUT]
 224  * \param texts pointer to a table of descriptions strings [OUT]
 225  * \return number of choices, or -1 on error
 226  * \note the caller is responsible for calling free() on all descriptions and
 227  * on both tables. In case of error, both pointers are set to NULL.
 228  */
 229 VLC_API ssize_t config_GetIntChoices(const char *, int64_t **values,
 230                                      char ***texts) VLC_USED;
 231
 232 /**
 233  * Determines a list of suggested values for a string configuration item.
 234  * \param values pointer to a table of value strings [OUT]
 235  * \param texts pointer to a table of descriptions strings [OUT]
 236  * \return number of choices, or -1 on error
 237  * \note the caller is responsible for calling free() on all values, on all
 238  * descriptions and on both tables.
 239  * In case of error, both pointers are set to NULL.
 240  */
 241 VLC_API ssize_t config_GetPszChoices(const char *,
 242                                      char ***values, char ***texts) VLC_USED;
 243
 244 VLC_API int config_SaveConfigFile( vlc_object_t * );
 245 #define config_SaveConfigFile(a) config_SaveConfigFile(VLC_OBJECT(a))
 246
 247 /**
 248  * Resets the configuration.
 249  *
 250  * This function resets all configuration items to their respective
 251  * compile-time default value.
 252  */
 253 VLC_API void config_ResetAll(void);
 254
 255 /**
 256  * Looks up a configuration item.
 257  *
 258  * This function looks for the internal representation of a configuration item.
 259  * Where possible, this should be avoided in favor of more specific function
 260  * calls.
 261  *
 262  * \param name Configuration item name
 263  * \return The internal structure, or NULL if not found.
 264  */
 265 VLC_API module_config_t *config_FindConfig(const char *name) VLC_USED;
 266
 267 /**
 268  * System directory identifiers
 269  */
 270 typedef enum vlc_system_dir
 271 {
 272     VLC_PKG_DATA_DIR, /**< Package-specific architecture-independent read-only
 273                            data directory (e.g. /usr/local/data/vlc). */
 274     VLC_PKG_LIB_DIR, /**< Package-specific architecture-dependent read-only
 275                           data directory (e.g. /usr/local/lib/vlc). */
 276     VLC_PKG_LIBEXEC_DIR, /**< Package-specific executable read-only directory
 277                               (e.g. /usr/local/libexec/vlc). */
 278     VLC_PKG_INCLUDE_DIR_RESERVED,
 279     VLC_SYSDATA_DIR, /**< Global architecture-independent read-only
 280                           data directory (e.g. /usr/local/data).
 281                           Available only on some platforms. */
 282     VLC_LIB_DIR, /**< Global architecture-dependent read-only directory
 283                       (e.g. /usr/local/lib). */
 284     VLC_LIBEXEC_DIR, /**< Global executable read-only directory
 285                           (e.g. /usr/local/libexec). */
 286     VLC_INCLUDE_DIR_RESERVED,
 287     VLC_LOCALE_DIR, /**< Base directory for package read-only locale data. */
 288 } vlc_sysdir_t;
 289
 290 /**
 291  * Gets an installation directory.
 292  *
 293  * This function determines one of the installation directory.
 294  *
 295  * @param dir identifier of the directory (see \ref vlc_sysdir_t)
 296  * @param filename name of a file or other object within the directory
 297  *                 (or NULL to obtain the plain directory)
 298  *
 299  * @return a heap-allocated string (use free() to release it), or NULL on error
 300  */
 301 VLC_API char *config_GetSysPath(vlc_sysdir_t dir, const char *filename)
 302 VLC_USED VLC_MALLOC;
 303
 304 typedef enum vlc_user_dir
 305 {
 306     VLC_HOME_DIR, /* User's home */
 307     VLC_CONFIG_DIR, /* VLC-specific configuration directory */
 308     VLC_USERDATA_DIR, /* VLC-specific data directory */
 309     VLC_CACHE_DIR, /* VLC-specific user cached data directory */
 310     /* Generic directories (same as XDG) */
 311     VLC_DESKTOP_DIR=0x80,
 312     VLC_DOWNLOAD_DIR,
 313     VLC_TEMPLATES_DIR,
 314     VLC_PUBLICSHARE_DIR,
 315     VLC_DOCUMENTS_DIR,
 316     VLC_MUSIC_DIR,
 317     VLC_PICTURES_DIR,
 318     VLC_VIDEOS_DIR,
 319 } vlc_userdir_t;
 320
 321 VLC_API char * config_GetUserDir( vlc_userdir_t ) VLC_USED VLC_MALLOC;
 322
 323 VLC_API void config_AddIntf(const char *);
 324 VLC_API void config_RemoveIntf(const char *);
 325 VLC_API bool config_ExistIntf(const char *) VLC_USED;
 326
 327 /****************************************************************************
 328  * config_chain_t:
 329  ****************************************************************************/
 330 struct config_chain_t
 331 {
 332     config_chain_t *p_next;     /**< Pointer on the next config_chain_t element */
 333
 334     char        *psz_name;      /**< Option name */
 335     char        *psz_value;     /**< Option value */
 336 };
 337
 338 /**
 339  * This function will
 340  * - create all options in the array ppsz_options (var_Create).
 341  * - parse the given linked list of config_chain_t and set the value (var_Set).
 342  *
 343  * The option names will be created by adding the psz_prefix prefix.
 344  */
 345 VLC_API void config_ChainParse( vlc_object_t *, const char *psz_prefix, const char *const *ppsz_options, const config_chain_t * );
 346 #define config_ChainParse( a, b, c, d ) config_ChainParse( VLC_OBJECT(a), b, c, d )
 347
 348 /**
 349  * This function will parse a configuration string (psz_opts) and
 350  * - set all options for this module in a chained list (*pp_cfg)
 351  * - returns a pointer on the next module if any.
 352  *
 353  * The string format is
 354  *   module{option=*,option=*}
 355  *
 356  * The options values are unescaped using config_StringUnescape.
 357  */
 358 VLC_API const char *config_ChainParseOptions( config_chain_t **pp_cfg, const char *ppsz_opts );
 359
 360 /**
 361  * This function will parse a configuration string (psz_string) and
 362  * - set the module name (*ppsz_name)
 363  * - set all options for this module in a chained list (*pp_cfg)
 364  * - returns a pointer on the next module if any.
 365  *
 366  * The string format is
 367  *   module{option=*,option=*}[:modulenext{option=*,...}]
 368  *
 369  * The options values are unescaped using config_StringUnescape.
 370  */
 371 VLC_API char *config_ChainCreate( char **ppsz_name, config_chain_t **pp_cfg, const char *psz_string ) VLC_USED VLC_MALLOC;
 372
 373 /**
 374  * This function will release a linked list of config_chain_t
 375  * (Including the head)
 376  */
 377 VLC_API void config_ChainDestroy( config_chain_t * );
 378
 379 /**
 380  * This function will duplicate a linked list of config_chain_t
 381  */
 382 VLC_API config_chain_t * config_ChainDuplicate( const config_chain_t * ) VLC_USED VLC_MALLOC;
 383
 384 /**
 385  * This function will unescape a string in place and will return a pointer on
 386  * the given string.
 387  * No memory is allocated by it (unlike config_StringEscape).
 388  * If NULL is given as parameter nothing will be done (NULL will be returned).
 389  *
 390  * The following sequences will be unescaped (only one time):
 391  * \\ \' and \"
 392  */
 393 VLC_API char * config_StringUnescape( char *psz_string );
 394
 395 /**
 396  * This function will escape a string that can be unescaped by
 397  * config_StringUnescape.
 398  * The returned value is allocated by it. You have to free it once you
 399  * do not need it anymore (unlike config_StringUnescape).
 400  * If NULL is given as parameter nothing will be done (NULL will be returned).
 401  *
 402  * The escaped characters are ' " and \
 403  */
 404 VLC_API char * config_StringEscape( const char *psz_string ) VLC_USED VLC_MALLOC;
 405
 406 # ifdef __cplusplus
 407 }
 408 # endif
 409
 410 /** @} */
 411
 412 #endif /* _VLC_CONFIGURATION_H */