From: Martin Mares <mj@ucw.cz>
Date: Mon, 30 Jun 2014 15:02:17 +0000 (+0200)
Subject: Redblack: Added search_up
X-Git-Tag: v6.1~5
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=ec6703bb4d58e504fde8ea8429f9b26ab6632696;p=libucw.git

Redblack: Added search_up
---

diff --git a/ucw/redblack.h b/ucw/redblack.h
index ece0d079..a77ee777 100644
--- a/ucw/redblack.h
+++ b/ucw/redblack.h
@@ -71,6 +71,9 @@
  *  TREE_WANT_SEARCH_DOWN node *search_down(key) -- find either the node with
  *                      specified value, or if it does not exist, the node
  *                      with nearest smaller value.
+ *  TREE_WANT_SEARCH_UP	node *search_up(key) -- find either the node with
+ *                      specified value, or if it does not exist, the node
+ *                      with nearest greater value.
  *  TREE_WANT_BOUNDARY	node *boundary(uint direction) -- finds smallest
  *			(direction==0) or largest (direction==1) node.
  *  TREE_WANT_ADJACENT	node *adjacent(node *, uint direction) -- finds next
@@ -480,6 +483,29 @@ TREE_STATIC P(node) * P(search_down) (T *t, TREE_KEY_DECL)
 }
 #endif
 
+#ifdef TREE_WANT_SEARCH_UP
+TREE_STATIC P(node) * P(search_up) (T *t, TREE_KEY_DECL)
+{
+	P(node) *last_left=NULL;
+	P(bucket) *node=t->root;
+	while(node)
+	{
+		int cmp;
+		cmp = P(cmp) (TREE_KEY(), TREE_KEY(node->n.));
+		if (cmp == 0)
+			return &node->n;
+		else if (cmp > 0)
+			node=P(tree_son) (node, 1);
+		else
+		{
+			last_left=&node->n;
+			node=P(tree_son) (node, 0);
+		}
+	}
+	return last_left;
+}
+#endif
+
 #ifdef TREE_WANT_BOUNDARY
 TREE_STATIC P(node) * P(boundary) (T *t, uint direction)
 {
@@ -1053,6 +1079,7 @@ do											\
 #undef TREE_WANT_FIND_NEXT
 #undef TREE_WANT_SEARCH
 #undef TREE_WANT_SEARCH_DOWN
+#undef TREE_WANT_SEARCH_UP
 #undef TREE_WANT_BOUNDARY
 #undef TREE_WANT_ADJACENT
 #undef TREE_WANT_NEW