1 files changed, 80 insertions, 0 deletions
diff --git a/src/PlaylistUpdate.cxx b/src/PlaylistUpdate.cxx
new file mode 100644
index 000000000..0e72ef671
--- /dev/null
+++ b/src/PlaylistUpdate.cxx
@@ -0,0 +1,80 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "Playlist.hxx"
+#include "DatabaseGlue.hxx"
+#include "DatabasePlugin.hxx"
+#include "Song.hxx"
+#include "tag/Tag.hxx"
+#include "Idle.hxx"
+#include "util/Error.hxx"
+
+static bool
+UpdatePlaylistSong(const Database &db, Song &song)
+{
+	if (!song.IsInDatabase() || !song.IsDetached())
+		/* only update Songs instances that are "detached"
+		   from the Database */
+		return false;
+
+	Song *original = db.GetSong(song.uri, IgnoreError());
+	if (original == nullptr)
+		/* not found - shouldn't happen, because the update
+		   thread should ensure that all stale Song instances
+		   have been purged */
+		return false;
+
+	if (original->mtime == song.mtime) {
+		/* not modified */
+		db.ReturnSong(original);
+		return false;
+	}
+
+	song.mtime = original->mtime;
+
+	if (original->tag != nullptr)
+		song.ReplaceTag(Tag(*original->tag));
+
+	db.ReturnSong(original);
+	return true;
+}
+
+void
+playlist::DatabaseModified()
+{
+	const Database *db = GetDatabase();
+	if (db == nullptr)
+		/* how can this ever happen? */
+		return;
+
+	bool modified = false;
+
+	for (unsigned i = 0, n = queue.GetLength(); i != n; ++i) {
+		if (UpdatePlaylistSong(*db, queue.Get(i))) {
+			queue.ModifyAtPosition(i);
+			modified = true;
+		}
+	}
+
+	if (modified) {
+		queue.IncrementVersion();
+		idle_add(IDLE_PLAYLIST);
+	}
+}