1 files changed, 82 insertions, 0 deletions
diff --git a/rbtree-utils.c b/rbtree-utils.c
new file mode 100644
index 00000000..7371bbb4
--- /dev/null
+++ b/rbtree-utils.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2014 Facebook.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include "rbtree-utils.h"
+
+int rb_insert(struct rb_root *root, struct rb_node *node,
+	      rb_compare_nodes comp)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	int ret;
+
+	while(*p) {
+		parent = *p;
+
+		ret = comp(parent, node);
+		if (ret < 0)
+			p = &(*p)->rb_left;
+		else if (ret > 0)
+			p = &(*p)->rb_right;
+		else
+			return -EEXIST;
+	}
+
+	rb_link_node(node, parent, p);
+	rb_insert_color(node, root);
+	return 0;
+}
+
+struct rb_node *rb_search(struct rb_root *root, void *key, rb_compare_keys comp,
+			  struct rb_node **next_ret)
+{
+	struct rb_node *n = root->rb_node;
+	struct rb_node *parent = NULL;
+	int ret = 0;
+
+	while(n) {
+		parent = n;
+
+		ret = comp(n, key);
+		if (ret < 0)
+			n = n->rb_left;
+		else if (ret > 0)
+			n = n->rb_right;
+		else
+			return n;
+	}
+
+	if (!next_ret)
+		return NULL;
+
+	if (parent && ret > 0)
+		parent = rb_next(parent);
+
+	*next_ret = parent;
+	return NULL;
+}
+
+void rb_free_nodes(struct rb_root *root, rb_free_node free_node)
+{
+	struct rb_node *node;
+
+	while ((node = rb_first(root))) {
+		rb_erase(node, root);
+		free_node(node);
+	}
+}