more efficient data type for ChangeChan

Making this a tset of lists of Changes, rather than a tset of Changes
makes refilling it, in batch mode, much more efficient. Rather than needing
to add every Change it's collected one at a time, it can add them in one
fast batch operation.

It would be more efficient yet to use a Set, but that would need an Eq
instance for InodeCache.

Assistant/Changes.hs

@@ -28,17 +28,17 @@ pendingAddChange f = Just <$> (PendingAddChange <$> liftIO getCurrentTime <*> pu
 {- Gets all unhandled changes.
  - Blocks until at least one change is made. -}
 getChanges :: Assistant [Change]
-getChanges = (atomically . getTSet) <<~ changeChan
+getChanges = fmap concat $ (atomically . getTSet) <<~ changeChan
 
 {- Gets all unhandled changes, without blocking. -}
 getAnyChanges :: Assistant [Change]
-getAnyChanges = (atomically . readTSet) <<~ changeChan
+getAnyChanges = fmap concat $ (atomically . readTSet) <<~ changeChan
 
 {- Puts unhandled changes back into the channel.
  - Note: Original order is not preserved. -}
 refillChanges :: [Change] -> Assistant ()
-refillChanges cs = (atomically . flip putTSet cs) <<~ changeChan
+refillChanges cs = (atomically . flip putTSet1 cs) <<~ changeChan
 
 {- Records a change in the channel. -}
 recordChange :: Change -> Assistant ()
-recordChange c = (atomically . flip putTSet1 c) <<~ changeChan
+recordChange c = (atomically . flip putTSet1 [c]) <<~ changeChan

Assistant/Types/Changes.hs

@@ -22,7 +22,7 @@ changeInfoKey (AddKeyChange k) = Just k
 changeInfoKey (LinkChange (Just k)) = Just k
 changeInfoKey _ = Nothing
 
-type ChangeChan = TSet Change
+type ChangeChan = TSet [Change]
 
 newChangeChan :: IO ChangeChan
 newChangeChan = atomically newTSet