--- a/src/http/ngx_http_variables.h
+++ b/src/http/ngx_http_variables.h
@@ -63,6 +63,19 @@ ngx_int_t ngx_http_variables_add_core_va
 ngx_int_t ngx_http_variables_init_vars(ngx_conf_t *cf);
 
 
+typedef struct {
+    ngx_rbtree_node_t             node;
+    size_t                        len;
+    ngx_http_variable_value_t    *value;
+} ngx_http_variable_value_node_t;
+
+
+void ngx_http_variable_value_rbtree_insert(ngx_rbtree_node_t *temp,
+    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel);
+ngx_http_variable_value_t *ngx_http_variable_value_lookup(ngx_rbtree_t *rbtree,
+    ngx_str_t *name, uint32_t hash);
+
+
 extern ngx_http_variable_value_t  ngx_http_variable_null_value;
 extern ngx_http_variable_value_t  ngx_http_variable_true_value;