--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -1633,3 +1633,87 @@ ngx_http_variables_init_vars(ngx_conf_t 
 
     return NGX_OK;
 }
+
+
+void
+ngx_http_variable_value_rbtree_insert(ngx_rbtree_node_t *temp,
+    ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel)
+{
+    ngx_rbtree_node_t               **p;
+    ngx_http_variable_value_node_t   *vvn, *vvt;
+
+    for ( ;; ) {
+
+        vvn = (ngx_http_variable_value_node_t *) node;
+        vvt = (ngx_http_variable_value_node_t *) temp;
+
+        if (node->key != temp->key) {
+
+            p = (node->key < temp->key) ? &temp->left : &temp->right;
+
+        } else if (vvn->len != vvt->len) {
+
+            p = (vvn->len < vvt->len) ? &temp->left : &temp->right;
+
+        } else {
+            p = (ngx_memcmp(vvn->value->data, vvt->value->data, vvn->len) < 0)
+                 ? &temp->left : &temp->right;
+        }
+
+        if (*p == sentinel) {
+            break;
+        }
+
+        temp = *p;
+    }
+
+    *p = node;
+    node->parent = temp;
+    node->left = sentinel;
+    node->right = sentinel;
+    ngx_rbt_red(node);
+}
+
+
+ngx_http_variable_value_t *
+ngx_http_variable_value_lookup(ngx_rbtree_t *rbtree, ngx_str_t *val,
+    uint32_t hash)
+{
+    ngx_int_t                        rc;
+    ngx_rbtree_node_t               *node, *sentinel;
+    ngx_http_variable_value_node_t  *vvn;
+
+    node = rbtree->root;
+    sentinel = rbtree->sentinel;
+
+    while (node != sentinel) {
+
+        vvn = (ngx_http_variable_value_node_t *) node;
+
+        if (hash != node->key) {
+            node = (hash < node->key) ? node->left : node->right;
+            continue;
+        }
+
+        if (val->len != vvn->len) {
+            node = (val->len < vvn->len) ? node->left : node->right;
+            continue;
+        }
+
+        rc = ngx_memcmp(val->data, vvn->value->data, val->len);
+
+        if (rc < 0) {
+            node = node->left;
+            continue;
+        }
+
+        if (rc > 0) {
+            node = node->right;
+            continue;
+        }
+
+        return vvn->value;
+    }
+
+    return NULL;
+}

--- 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;