db/simple: create dedicated directory

src/db/plugins/simple/SimpleDatabasePlugin.hxx

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2003-2014 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_SIMPLE_DATABASE_PLUGIN_HXX
+#define MPD_SIMPLE_DATABASE_PLUGIN_HXX
+
+#include "db/Interface.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "db/LightSong.hxx"
+#include "Compiler.h"
+
+#include <cassert>
+
+struct config_param;
+struct Directory;
+struct DatabasePlugin;
+class EventLoop;
+class DatabaseListener;
+
+class SimpleDatabase : public Database {
+	AllocatedPath path;
+	std::string path_utf8;
+
+	Directory *root;
+
+	time_t mtime;
+
+	/**
+	 * A buffer for GetSong().
+	 */
+	mutable LightSong light_song;
+
+#ifndef NDEBUG
+	mutable unsigned borrowed_song_count;
+#endif
+
+	SimpleDatabase();
+
+public:
+	static Database *Create(EventLoop &loop, DatabaseListener &listener,
+				const config_param &param,
+				Error &error);
+
+	gcc_pure
+	Directory *GetRoot() {
+		assert(root != NULL);
+
+		return root;
+	}
+
+	bool Save(Error &error);
+
+	/**
+	 * Returns true if there is a valid database file on the disk.
+	 */
+	bool FileExists() const {
+		return mtime > 0;
+	}
+
+	/* virtual methods from class Database */
+	virtual bool Open(Error &error) override;
+	virtual void Close() override;
+
+	virtual const LightSong *GetSong(const char *uri_utf8,
+					 Error &error) const override;
+	virtual void ReturnSong(const LightSong *song) const;
+
+	virtual bool Visit(const DatabaseSelection &selection,
+			   VisitDirectory visit_directory,
+			   VisitSong visit_song,
+			   VisitPlaylist visit_playlist,
+			   Error &error) const override;
+
+	virtual bool VisitUniqueTags(const DatabaseSelection &selection,
+				     TagType tag_type,
+				     VisitString visit_string,
+				     Error &error) const override;
+
+	virtual bool GetStats(const DatabaseSelection &selection,
+			      DatabaseStats &stats,
+			      Error &error) const override;
+
+	virtual time_t GetUpdateStamp() const override {
+		return mtime;
+	}
+
+private:
+	bool Configure(const config_param &param, Error &error);
+
+	gcc_pure
+	bool Check(Error &error) const;
+
+	bool Load(Error &error);
+};
+
+extern const DatabasePlugin simple_db_plugin;
+
+#endif