1 files changed, 7 insertions, 0 deletions
diff --git a/delta.h b/delta.h
index 7b3f86d..40ccf5a 100644
--- a/delta.h
+++ b/delta.h
@@ -24,6 +24,13 @@ create_delta_index(const void *buf, unsigned long bufsize);
 extern void free_delta_index(struct delta_index *index);
 
 /*
+ * sizeof_delta_index: returns memory usage of delta index
+ *
+ * Given pointer must be what create_delta_index() returned, or NULL.
+ */
+extern unsigned long sizeof_delta_index(struct delta_index *index);
+
+/*
  * create_delta: create a delta from given index for the given buffer
  *
  * This function may be called multiple times with different buffers using