1 files changed, 114 insertions, 0 deletions
diff --git a/src/db/SongSort.cxx b/src/db/SongSort.cxx
new file mode 100644
index 000000000..dcea033b6
--- /dev/null
+++ b/src/db/SongSort.cxx
@@ -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.
+ */
+
+#include "config.h"
+#include "SongSort.hxx"
+#include "Song.hxx"
+#include "tag/Tag.hxx"
+
+extern "C" {
+#include "util/list_sort.h"
+}
+
+#include <glib.h>
+
+#include <stdlib.h>
+
+static int
+compare_utf8_string(const char *a, const char *b)
+{
+	if (a == nullptr)
+		return b == nullptr ? 0 : -1;
+
+	if (b == nullptr)
+		return 1;
+
+	return g_utf8_collate(a, b);
+}
+
+/**
+ * Compare two string tag values, ignoring case.  Either one may be
+ * nullptr.
+ */
+static int
+compare_string_tag_item(const Tag &a, const Tag &b,
+			TagType type)
+{
+	return compare_utf8_string(a.GetValue(type),
+				   b.GetValue(type));
+}
+
+/**
+ * Compare two tag values which should contain an integer value
+ * (e.g. disc or track number).  Either one may be nullptr.
+ */
+static int
+compare_number_string(const char *a, const char *b)
+{
+	long ai = a == nullptr ? 0 : strtol(a, nullptr, 10);
+	long bi = b == nullptr ? 0 : strtol(b, nullptr, 10);
+
+	if (ai <= 0)
+		return bi <= 0 ? 0 : -1;
+
+	if (bi <= 0)
+		return 1;
+
+	return ai - bi;
+}
+
+static int
+compare_tag_item(const Tag &a, const Tag &b, TagType type)
+{
+	return compare_number_string(a.GetValue(type),
+				     b.GetValue(type));
+}
+
+/* Only used for sorting/searchin a songvec, not general purpose compares */
+static int
+song_cmp(gcc_unused void *priv, struct list_head *_a, struct list_head *_b)
+{
+	const Song *a = (const Song *)_a;
+	const Song *b = (const Song *)_b;
+	int ret;
+
+	/* first sort by album */
+	ret = compare_string_tag_item(a->tag, b->tag, TAG_ALBUM);
+	if (ret != 0)
+		return ret;
+
+	/* then sort by disc */
+	ret = compare_tag_item(a->tag, b->tag, TAG_DISC);
+	if (ret != 0)
+		return ret;
+
+	/* then by track number */
+	ret = compare_tag_item(a->tag, b->tag, TAG_TRACK);
+	if (ret != 0)
+		return ret;
+
+	/* still no difference?  compare file name */
+	return g_utf8_collate(a->uri, b->uri);
+}
+
+void
+song_list_sort(struct list_head *songs)
+{
+	list_sort(nullptr, songs, song_cmp);
+}