1 files changed, 156 insertions, 0 deletions
diff --git a/src/db_plugin.h b/src/db_plugin.h
new file mode 100644
index 000000000..1c7e14ede
--- /dev/null
+++ b/src/db_plugin.h
@@ -0,0 +1,156 @@
+/*
+ * 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