1 files changed, 89 insertions, 0 deletions
diff --git a/src/db/update/InotifyQueue.cxx b/src/db/update/InotifyQueue.cxx
new file mode 100644
index 000000000..013200f98
--- /dev/null
+++ b/src/db/update/InotifyQueue.cxx
@@ -0,0 +1,89 @@
+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "InotifyQueue.hxx"
+#include "InotifyDomain.hxx"
+#include "Service.hxx"
+#include "Log.hxx"
+
+#include <string.h>
+
+/**
+ * Wait this long after the last change before calling
+ * update_enqueue().  This increases the probability that updates can
+ * be bundled.
+ */
+static constexpr unsigned INOTIFY_UPDATE_DELAY_S = 5;
+
+void
+InotifyQueue::OnTimeout()
+{
+	unsigned id;
+
+	while (!queue.empty()) {
+		const char *uri_utf8 = queue.front().c_str();
+
+		id = update.Enqueue(uri_utf8, false);
+		if (id == 0) {
+			/* retry later */
+			ScheduleSeconds(INOTIFY_UPDATE_DELAY_S);
+			return;
+		}
+
+		FormatDebug(inotify_domain, "updating '%s' job=%u",
+			    uri_utf8, id);
+
+		queue.pop_front();
+	}
+}
+
+static bool
+path_in(const char *path, const char *possible_parent)
+{
+	size_t length = strlen(possible_parent);
+
+	return path[0] == 0 ||
+		(memcmp(possible_parent, path, length) == 0 &&
+		 (path[length] == 0 || path[length] == '/'));
+}
+
+void
+InotifyQueue::Enqueue(const char *uri_utf8)
+{
+	ScheduleSeconds(INOTIFY_UPDATE_DELAY_S);
+
+	for (auto i = queue.begin(), end = queue.end(); i != end;) {
+		const char *current_uri = i->c_str();
+
+		if (path_in(uri_utf8, current_uri))
+			/* already enqueued */
+			return;
+
+		if (path_in(current_uri, uri_utf8))
+			/* existing path is a sub-path of the new
+			   path; we can dequeue the existing path and
+			   update the new path instead */
+			i = queue.erase(i);
+		else
+			++i;
+	}
+
+	queue.emplace_back(uri_utf8);
+}