/* * Copyright (C) 2003-2009 The Music Player Daemon Project * http://www.musicpd.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* * This is the sticker database library. It is the backend of all the * sticker code in MPD. * * "Stickers" are pieces of information attached to existing MPD * objects (e.g. song files, directories, albums). Clients can create * arbitrary name/value pairs. MPD itself does not assume any special * meaning in them. * * The goal is to allow clients to share additional (possibly dynamic) * information about songs, which is neither stored on the client (not * available to other clients), nor stored in the song files (MPD has * no write access). * * Client developers should create a standard for common sticker * names, to ensure interoperability. * * Examples: song ratings; statistics; deferred tag writes; lyrics; * ... * */ #ifndef STICKER_H #define STICKER_H #include <glib.h> #include <stdbool.h> struct sticker; /** * Opens the sticker database (if path is not NULL). * * @param error_r location to store the error occuring, or NULL to * ignore errors * @return true on success, false on error */ bool sticker_global_init(const char *path, GError **error_r); /** * Close the sticker database. */ void sticker_global_finish(void); /** * Returns true if the sticker database is configured and available. */ bool sticker_enabled(void); /** * Returns one value from an object's sticker record. The caller must * free the return value with g_free(). */ char * sticker_load_value(const char *type, const char *uri, const char *name); /** * Sets a sticker value in the specified object. Overwrites existing * values. */ bool sticker_store_value(const char *type, const char *uri, const char *name, const char *value); /** * Deletes a sticker from the database. All sticker values of the * specified object are deleted. */ bool sticker_delete(const char *type, const char *uri); /** * Deletes a sticker value. Fails if no sticker with this name * exists. */ bool sticker_delete_value(const char *type, const char *uri, const char *name); /** * Frees resources held by the sticker object. * * @param sticker the sticker object to be freed */ void sticker_free(struct sticker *sticker); /** * Determines a single value in a sticker. * * @param sticker the sticker object * @param name the name of the sticker * @return the sticker value, or NULL if none was found */ const char * sticker_get_value(const struct sticker *sticker, const char *name); /** * Iterates over all sticker items in a sticker. * * @param sticker the sticker object * @param func a callback function * @param user_data an opaque pointer for the callback function */ void sticker_foreach(const struct sticker *sticker, void (*func)(const char *name, const char *value, gpointer user_data), gpointer user_data); /** * Loads the sticker for the specified resource. * * @param type the resource type, e.g. "song" * @param uri the URI of the resource, e.g. the song path * @return a sticker object, or NULL on error or if there is no sticker */ struct sticker * sticker_load(const char *type, const char *uri); /** * Finds stickers with the specified name below the specified URI. * * @param type the resource type, e.g. "song" * @param base_uri the URI prefix of the resources, or NULL if all * resources should be searched * @param name the name of the sticker * @return true on success (even if no sticker was found), false on * failure */ bool sticker_find(const char *type, const char *base_uri, const char *name, void (*func)(const char *uri, const char *value, gpointer user_data), gpointer user_data); #endif