From fac10ea799fe9b6158d74f66d6ad46536d38a545 Mon Sep 17 00:00:00 2001
From: Patrick McHardy <kaber@trash.net>
Date: Wed, 18 Mar 2009 04:55:00 +0100
Subject: Initial commit

---
 include/rbtree.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 include/rbtree.h

(limited to 'include/rbtree.h')

diff --git a/include/rbtree.h b/include/rbtree.h
new file mode 100644
index 00000000..26b6b44a
--- /dev/null
+++ b/include/rbtree.h
@@ -0,0 +1,98 @@
+/*
+ * Red Black Trees
+ * (C) 1999  Andrea Arcangeli <andrea@suse.de>
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef	_RBTREE_H
+#define	_RBTREE_H
+
+#include <stddef.h>
+
+struct rb_node
+{
+	unsigned long  rb_parent_color;
+#define	RB_RED		0
+#define	RB_BLACK	1
+	struct rb_node *rb_right;
+	struct rb_node *rb_left;
+};
+
+struct rb_root
+{
+	struct rb_node *rb_node;
+};
+
+#define rb_parent(r)   ((struct rb_node *)((r)->rb_parent_color & ~3))
+#define rb_color(r)   ((r)->rb_parent_color & 1)
+#define rb_is_red(r)   (!rb_color(r))
+#define rb_is_black(r) rb_color(r)
+#define rb_set_red(r)  do { (r)->rb_parent_color &= ~1; } while (0)
+#define rb_set_black(r)  do { (r)->rb_parent_color |= 1; } while (0)
+
+static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p)
+{
+	rb->rb_parent_color = (rb->rb_parent_color & 3) | (unsigned long)p;
+}
+static inline void rb_set_color(struct rb_node *rb, int color)
+{
+	rb->rb_parent_color = (rb->rb_parent_color & ~1) | color;
+}
+
+#define RB_ROOT	(struct rb_root) { NULL, }
+#define	rb_entry(ptr, type, member) container_of(ptr, type, member)
+
+#define RB_EMPTY_ROOT(root)	((root)->rb_node == NULL)
+#define RB_EMPTY_NODE(node)	(rb_parent(node) == node)
+#define RB_CLEAR_NODE(node)	(rb_set_parent(node, node))
+
+extern void rb_insert_color(struct rb_node *, struct rb_root *);
+extern void rb_erase(struct rb_node *, struct rb_root *);
+
+/* Find logical next and previous nodes in a tree */
+extern struct rb_node *rb_next(struct rb_node *);
+extern struct rb_node *rb_prev(struct rb_node *);
+extern struct rb_node *rb_first(struct rb_root *);
+extern struct rb_node *rb_last(struct rb_root *);
+
+/* Fast replacement of a single node without remove/rebalance/add/rebalance */
+extern void rb_replace_node(struct rb_node *victim, struct rb_node *new, 
+			    struct rb_root *root);
+
+static inline void rb_link_node(struct rb_node * node, struct rb_node * parent,
+				struct rb_node ** rb_link)
+{
+	node->rb_parent_color = (unsigned long )parent;
+	node->rb_left = node->rb_right = NULL;
+
+	*rb_link = node;
+}
+
+#define rb_for_each_entry(pos, root, member) \
+	for ((pos) = (root)->rb_node ? \
+			rb_entry(rb_first(root), typeof(*pos), member) : NULL; \
+	     (pos) != NULL; \
+	     (pos) = rb_entry(rb_next(&(pos)->member), typeof(*pos), member))
+
+#define rb_for_each_entry_safe(pos, node, next, root, member) \
+	for ((node) = rb_first(root); \
+	     (pos)  = (node) ? rb_entry((node), typeof(*pos), member) : NULL, \
+	     (next) = (node) ? rb_next(node) : NULL, \
+	     (pos) != NULL; \
+	     (node) = (next))
+
+#endif	/* _RBTREE_H */
-- 
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