--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/dancres/blitz/disk/Syncable.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,23 @@
+package org.dancres.blitz.disk;
+
+/**
+   Those involved in storage management should implement this interface and
+   register with Disk.  This facilitates, checkpointing and clean shutdown
+   of Blitz.
+ */
+public interface Syncable {
+    /**
+       When called, the instance should synchronize all "dirtied" state to
+       disk - i.e. if no further operations were carried out and the JVM
+       was stopped, recovery wouldn't be necessary because the disk contains
+       an accurate copy of the memory state at the point when sync() was
+       invoked.
+     */
+    public void sync() throws Exception;
+
+    /**
+       When called, the instance should close and release any files it is
+       currently using.
+     */
+    public void close() throws Exception;
+}