* tower.c: Cache repeated lookups of a single tower element. This

[pspp-builds.git] / src / libpspp / tower.h

diff --git a/src/libpspp/tower.h b/src/libpspp/tower.h
index e0ee12a758229bef02e9ae934c0437ee44b3a6bc..5a4c08e204f714aa334c054a73db8867518594f3 100644 (file)
--- a/src/libpspp/tower.h
+++ b/src/libpspp/tower.h
@@ -74,7 +74,9 @@ tower_node_get_height (const struct tower_node *node)
 /* A tower. */
 struct tower 
   {
-    struct abt abt;              /* Tree. */
+    struct abt abt;                   /* Tree. */
+    struct tower_node *cache;         /* Cache node. */
+    unsigned long int cache_bottom;   /* Height of cache's bottom. */
   };
 
 void tower_init (struct tower *);