Use OP_MSG to kill cursors

Author: darycabrera

Database/MongoDB/Query.hs

@@ -1648,7 +1648,10 @@ nextBatch (Cursor fcol batchSize var) = liftDB $ modifyMVar var $ \dBatch -> do
       (0, _)      -> return (emptyBatch, resultDocs)
       (_, Just 0) -> do
         pipe <- asks mongoPipe
-        liftIOE ConnectionFailure $ P.send pipe [KillCursors [cid]]
+        let sd = P.serverData pipe
+        if maxWireVersion sd < opMsgOnlyWireVersion
+          then liftIOE ConnectionFailure $ P.send pipe [KillCursors [cid]]
+          else liftIOE ConnectionFailure $ P.sendOpMsg pipe [Kc (P.KillC (KillCursors [cid]) fcol)] (Just MoreToCome) []
         return (emptyBatch, resultDocs)
       (_, _)      -> (, resultDocs) <$> getNextBatch
 
@@ -1710,11 +1713,14 @@ rest :: MonadIO m => Cursor -> Action m [Document]
 rest c = loop (next c)
 
 closeCursor :: MonadIO m => Cursor -> Action m ()
-closeCursor (Cursor _ _ var) = liftDB $ modifyMVar var $ \dBatch -> do
+closeCursor (Cursor fcol _ var) = liftDB $ modifyMVar var $ \dBatch -> do
     Batch _ cid _ <- fulfill dBatch
     unless (cid == 0) $ do
       pipe <- asks mongoPipe
-      liftIOE ConnectionFailure $ P.send pipe [KillCursors [cid]]
+      let sd = P.serverData pipe
+      if maxWireVersion sd < opMsgOnlyWireVersion
+        then liftIOE ConnectionFailure $ P.send pipe [KillCursors [cid]]
+        else liftIOE ConnectionFailure $ P.sendOpMsg pipe [Kc (P.KillC (KillCursors [cid]) fcol)] (Just MoreToCome) []
     return (return $ Batch (Just 0) 0 [], ())
 
 isCursorClosed :: MonadIO m => Cursor -> Action m Bool