ZooKeeper: Make reduction of data optional in LiveList.get().

If we need the raw list of objects so that we can know what objects can
be deleted etc. then we'll need to disable the reduction.

r2/r2/lib/zookeeper.py

@@ -91,16 +91,20 @@ def __init__(self, client, root, map_fn=None, reduce_fn=lambda L: L,
 
             @client.ChildrenWatch(root)
             def watcher(children):
-                self.data = self._normalize_children(children)
+                self.data = self._normalize_children(children, reduce=True)
 
     def _nodepath(self, item):
         escaped = urllib.quote(str(item), safe=":")
         return os.path.join(self.root, escaped)
 
-    def _normalize_children(self, children):
+    def _normalize_children(self, children, reduce):
         unquoted = (urllib.unquote(c) for c in children)
         mapped = map(self.map_fn, unquoted)
-        return list(self.reduce_fn(mapped))
+
+        if reduce:
+            return list(self.reduce_fn(mapped))
+        else:
+            return list(mapped)
 
     def add(self, item):
         path = self._nodepath(item)
@@ -114,9 +118,9 @@ def remove(self, item):
         except NoNodeException:
             raise ValueError("not in list")
 
-    def get(self):
+    def get(self, reduce=True):
         children = self.client.get_children(self.root)
-        return self._normalize_children(children)
+        return self._normalize_children(children, reduce)
 
     def __iter__(self):
         if not self.is_watching: