--- a/src/core/ngx_string.h
+++ b/src/core/ngx_string.h
@@ -13,17 +13,28 @@
 
 
 typedef struct {
-    size_t     len;
-    u_char    *data;
+    size_t      len;
+    u_char     *data;
 } ngx_str_t;
 
 
 typedef struct {
-    ngx_str_t  key;
-    ngx_str_t  value;
+    ngx_str_t   key;
+    ngx_str_t   value;
 } ngx_keyval_t;
 
 
+typedef struct {
+    unsigned    len:29;
+
+    unsigned    valid:1;
+    unsigned    no_cachable:1;
+    unsigned    not_found:1;
+
+    u_char     *data;
+} ngx_variable_value_t;
+
+
 #define ngx_string(str)     { sizeof(str) - 1, (u_char *) str }
 #define ngx_null_string     { 0, NULL }