--- filebased.py	2008-12-05 15:32:28.000000000 +0100
+++ filebased.py.new	2008-12-05 15:32:37.000000000 +0100
@@ -37,6 +37,21 @@
         self.set(key, value, timeout)
         return True
 
+    def when_cached(self, key, default=0):
+        fname = self._key_to_file(key)
+        rv = default
+        try:
+            rv = os.stat(fname)[8]
+        except (IOError, OSError, EOFError, pickle.PickleError):
+            pass
+        return rv
+		
+    def get_if_newer(self, key, timestamp, default=None):
+        rv = default
+        if self.when_cached(key) > timestamp:
+            rv = self.get(key)
+        return rv
+
     def get(self, key, default=None):
         fname = self._key_to_file(key)
         try: