add a function to return the first entry that is stored in a tree where

the key is an array of uint32_t

(This used to be ctdb commit 99553397aade4f1c4d17ef14dad406934958c80a)

ctdb/common/rb_tree.c

@@ -962,6 +962,43 @@ trbt_traversearray32(trbt_tree_t *tree, uint32_t keylen,
 }
 
 
+/* this function will return the first node in a tree where
+   the key is an array of uint32_t
+*/
+void *
+trbt_findfirstarray32(trbt_tree_t *tree, uint32_t keylen)
+{
+	trbt_node_t *node;
+
+	if (keylen < 1) {
+		return NULL;
+	}
+	
+	if (tree == NULL) {
+		return NULL;
+	}
+
+	node=tree->root;
+	if (node == NULL) {
+		return NULL;
+	}
+
+	while (node->left) {
+		node = node->left;
+	}
+
+	/* we found our node so return the data */
+	if (keylen == 1) {
+		return node->data;
+	}
+
+	/* we are still traversing subtrees so find the first node in the
+	   next level of trees
+	*/
+	return trbt_findfirstarray32(node->data, keylen-1);
+}
+
+
 #if 0
 static void printtree(trbt_node_t *node, int levels)
 {

ctdb/common/rb_tree.h

@@ -76,3 +76,7 @@ void *trbt_lookuparray32(trbt_tree_t *tree, uint32_t keylen, uint32_t *key);
 
 /* Traverse a tree with a key based on an array of uint32 */
 void trbt_traversearray32(trbt_tree_t *tree, uint32_t keylen, void (*callback)(void *param, void *data), void *param);
+
+/* Lookup the first node in the tree with a key based on an array of uint32 
+   and return a pointer to data or NULL */
+void *trbt_findfirstarray32(trbt_tree_t *tree, uint32_t keylen);

ctdb/tests/rb_test.c

@@ -301,6 +301,7 @@ int main(int argc, const char *argv[])
 	printf("\niterations passed:%d\n", i);
 	trbt_traversearray32(tree, 3, random_traverse, NULL);
 	printf("\n");
+	printf("first node: %s\n", (char *)trbt_findfirstarray32(tree, 3));
 
 
 	printf("\ndeleting all entries\n");