1 files changed, 124 insertions, 0 deletions
diff --git a/src/StateFile.cxx b/src/StateFile.cxx
new file mode 100644
index 00000000..a15eb722
--- /dev/null
+++ b/src/StateFile.cxx
@@ -0,0 +1,124 @@
+/*
+ * 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 "StateFile.hxx"
+#include "OutputState.hxx"
+#include "PlaylistState.hxx"
+#include "TextFile.hxx"
+#include "Partition.hxx"
+#include "Volume.hxx"
+#include "event/Loop.hxx"
+
+#include <glib.h>
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+
+#undef G_LOG_DOMAIN
+#define G_LOG_DOMAIN "state_file"
+
+StateFile::StateFile(Path &&_path, const char *_path_utf8,
+                     Partition &_partition, EventLoop &_loop)
+	:TimeoutMonitor(_loop), path(std::move(_path)), path_utf8(_path_utf8),
+	 partition(_partition),
+	 prev_volume_version(0), prev_output_version(0),
+	 prev_playlist_version(0)
+{
+	ScheduleSeconds(5 * 60);
+}
+
+void
+StateFile::Write()
+{
+	g_debug("Saving state file %s", path_utf8.c_str());
+
+	FILE *fp = FOpen(path, FOpenMode::WriteText);
+	if (G_UNLIKELY(!fp)) {
+		g_warning("failed to create %s: %s",
+			  path_utf8.c_str(), g_strerror(errno));
+		return;
+	}
+
+	save_sw_volume_state(fp);
+	audio_output_state_save(fp);
+	playlist_state_save(fp, &partition.playlist, &partition.pc);
+
+	fclose(fp);
+
+	prev_volume_version = sw_volume_state_get_hash();
+	prev_output_version = audio_output_state_get_version();
+	prev_playlist_version = playlist_state_get_hash(&partition.playlist,
+							&partition.pc);
+}
+
+void
+StateFile::Read()
+{
+	bool success;
+
+	g_debug("Loading state file %s", path_utf8.c_str());
+
+	TextFile file(path);
+	if (file.HasFailed()) {
+		g_warning("failed to open %s: %s",
+			  path_utf8.c_str(), g_strerror(errno));
+		return;
+	}
+
+	const char *line;
+	while ((line = file.ReadLine()) != NULL) {
+		success = read_sw_volume_state(line) ||
+			audio_output_state_read(line) ||
+			playlist_state_restore(line, file, &partition.playlist,
+					       &partition.pc);
+		if (!success)
+			g_warning("Unrecognized line in state file: %s", line);
+	}
+
+	prev_volume_version = sw_volume_state_get_hash();
+	prev_output_version = audio_output_state_get_version();
+	prev_playlist_version = playlist_state_get_hash(&partition.playlist,
+							&partition.pc);
+}
+
+inline void
+StateFile::AutoWrite()
+{
+	if (prev_volume_version == sw_volume_state_get_hash() &&
+	    prev_output_version == audio_output_state_get_version() &&
+	    prev_playlist_version == playlist_state_get_hash(&partition.playlist,
+							     &partition.pc))
+		/* nothing has changed - don't save the state file,
+		   don't spin up the hard disk */
+		return;
+
+	Write();
+}
+
+/**
+ * This function is called every 5 minutes by the GLib main loop, and
+ * saves the state file.
+ */
+bool
+StateFile::OnTimeout()
+{
+	AutoWrite();
+	return true;
+}