diff -r 176736afa886 -r 8d38eab2777a mercurial/peer.py
--- a/mercurial/peer.py	Wed Mar 02 14:18:43 2016 -0500
+++ b/mercurial/peer.py	Tue Mar 01 18:39:25 2016 -0500
@@ -41,6 +41,14 @@
     def submit(self):
         raise NotImplementedError()
 
+class iterbatcher(batcher):
+
+    def submit(self):
+        raise NotImplementedError()
+
+    def results(self):
+        raise NotImplementedError()
+
 class localbatch(batcher):
     '''performs the queued calls directly'''
     def __init__(self, local):
@@ -50,6 +58,19 @@
         for name, args, opts, resref in self.calls:
             resref.set(getattr(self.local, name)(*args, **opts))
 
+class localiterbatcher(iterbatcher):
+    def __init__(self, local):
+        super(iterbatcher, self).__init__()
+        self.local = local
+
+    def submit(self):
+        # submit for a local iter batcher is a noop
+        pass
+
+    def results(self):
+        for name, args, opts, resref in self.calls:
+            yield getattr(self.local, name)(*args, **opts)
+
 def batchable(f):
     '''annotation for batchable methods
 
@@ -91,6 +112,14 @@
     def batch(self):
         return localbatch(self)
 
+    def iterbatch(self):
+        """Batch requests but allow iterating over the results.
+
+        This is to allow interleaving responses with things like
+        progress updates for clients.
+        """
+        return localiterbatcher(self)
+
     def capable(self, name):
         '''tell whether repo supports named capability.
         return False if not supported.