/* * Copyright (C) 2003-2011 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. */ /** \file * * This header declares the db_plugin class. It describes a * plugin API for databases of song metadata. */ #ifndef MPD_DB_PLUGIN_H #define MPD_DB_PLUGIN_H #include <glib.h> #include <assert.h> #include <stdbool.h> struct config_param; struct db_selection; struct db_visitor; struct db { const struct db_plugin *plugin; }; struct db_plugin { const char *name; /** * Allocates and configures a database. */ struct db *(*init)(const struct config_param *param, GError **error_r); /** * Free instance data. */ void (*finish)(struct db *db); /** * Open the database. Read it into memory if applicable. */ bool (*open)(struct db *db, GError **error_r); /** * Close the database, free allocated memory. */ void (*close)(struct db *db); /** * Look up a song (including tag data) in the database. * * @param the URI of the song within the music directory * (UTF-8) */ struct song *(*get_song)(struct db *db, const char *uri, GError **error_r); /** * Visit the selected entities. */ bool (*visit)(struct db *db, const struct db_selection *selection, const struct db_visitor *visitor, void *ctx, GError **error_r); }; G_GNUC_MALLOC static inline struct db * db_plugin_new(const struct db_plugin *plugin, const struct config_param *param, GError **error_r) { assert(plugin != NULL); assert(plugin->init != NULL); assert(plugin->finish != NULL); assert(plugin->get_song != NULL); assert(plugin->visit != NULL); assert(error_r == NULL || *error_r == NULL); struct db *db = plugin->init(param, error_r); assert(db == NULL || db->plugin == plugin); assert(db != NULL || error_r == NULL || *error_r != NULL); return db; } static inline void db_plugin_free(struct db *db) { assert(db != NULL); assert(db->plugin != NULL); assert(db->plugin->finish != NULL); db->plugin->finish(db); } static inline bool db_plugin_open(struct db *db, GError **error_r) { assert(db != NULL); assert(db->plugin != NULL); return db->plugin->open != NULL ? db->plugin->open(db, error_r) : true; } static inline void db_plugin_close(struct db *db) { assert(db != NULL); assert(db->plugin != NULL); if (db->plugin->close != NULL) db->plugin->close(db); } static inline struct song * db_plugin_get_song(struct db *db, const char *uri, GError **error_r) { assert(db != NULL); assert(db->plugin != NULL); assert(db->plugin->get_song != NULL); assert(uri != NULL); return db->plugin->get_song(db, uri, error_r); } static inline bool db_plugin_visit(struct db *db, const struct db_selection *selection, const struct db_visitor *visitor, void *ctx, GError **error_r) { assert(db != NULL); assert(db->plugin != NULL); assert(selection != NULL); assert(visitor != NULL); assert(error_r == NULL || *error_r == NULL); return db->plugin->visit(db, selection, visitor, ctx, error_r); } #endif