Main: move global variables to struct Instance

More preparations for multi-player support.

src/Instance.hxx

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2003-2013 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.
+ */
+
+#ifndef MPD_INSTANCE_HXX
+#define MPD_INSTANCE_HXX
+
+#include "check.h"
+
+class ClientList;
+struct Partition;
+struct song;
+
+struct Instance {
+	ClientList *client_list;
+
+	Partition *partition;
+
+	void DeleteSong(const song &song);
+
+	/**
+	 * The database has been modified.  Propagate the change to
+	 * all subsystems.
+	 */
+	void DatabaseModified();
+
+	/**
+	 * A tag in the play queue has been modified.  Propagate the
+	 * change to all subsystems.
+	 */
+	void TagModified();
+
+	/**
+	 * Synchronize the player with the play queue.
+	 */
+	void SyncWithPlayer();
+};
+
+#endif