avoid repeatedly searching path to make batch command when running transferkeys

Assistant/TransferSlots.hs

@@ -29,6 +29,7 @@ import qualified Types.Remote as Remote
 import Annex.Content
 import Annex.Wanted
 import Config.Files
+import Utility.Batch
 
 import qualified Data.Map as M 
 import qualified Control.Exception as E
@@ -44,17 +45,17 @@ type TransferGenerator = Assistant (Maybe (Transfer, TransferInfo, Transferrer -
 {- Waits until a transfer slot becomes available, then runs a
  - TransferGenerator, and then runs the transfer action in its own thread. 
  -}
-inTransferSlot :: FilePath -> TransferGenerator -> Assistant ()
-inTransferSlot program gen = do
+inTransferSlot :: FilePath -> BatchCommandMaker -> TransferGenerator -> Assistant ()
+inTransferSlot program batchmaker gen = do
 	flip MSemN.wait 1 <<~ transferSlots
-	runTransferThread program =<< gen
+	runTransferThread program batchmaker =<< gen
 
 {- Runs a TransferGenerator, and its transfer action,
  - without waiting for a slot to become available. -}
-inImmediateTransferSlot :: FilePath -> TransferGenerator -> Assistant ()
-inImmediateTransferSlot program gen = do
+inImmediateTransferSlot :: FilePath -> BatchCommandMaker -> TransferGenerator -> Assistant ()
+inImmediateTransferSlot program batchmaker gen = do
 	flip MSemN.signal (-1) <<~ transferSlots
-	runTransferThread program =<< gen
+	runTransferThread program batchmaker =<< gen
 
 {- Runs a transfer action, in an already allocated transfer slot.
  - Once it finishes, frees the transfer slot.
@@ -66,19 +67,19 @@ inImmediateTransferSlot program gen = do
  - then pausing the thread until a ResumeTransfer exception is raised,
  - then rerunning the action.
  -}
-runTransferThread :: FilePath -> Maybe (Transfer, TransferInfo, Transferrer -> Assistant ()) -> Assistant ()
-runTransferThread _ Nothing = flip MSemN.signal 1 <<~ transferSlots
-runTransferThread program (Just (t, info, a)) = do
+runTransferThread :: FilePath -> BatchCommandMaker -> Maybe (Transfer, TransferInfo, Transferrer -> Assistant ()) -> Assistant ()
+runTransferThread _ _ Nothing = flip MSemN.signal 1 <<~ transferSlots
+runTransferThread program batchmaker (Just (t, info, a)) = do
 	d <- getAssistant id
 	aio <- asIO1 a
-	tid <- liftIO $ forkIO $ runTransferThread' program d aio
+	tid <- liftIO $ forkIO $ runTransferThread' program batchmaker d aio
 	updateTransferInfo t $ info { transferTid = Just tid }
 
-runTransferThread' :: FilePath -> AssistantData -> (Transferrer -> IO ()) -> IO ()
-runTransferThread' program d run = go
+runTransferThread' :: FilePath -> BatchCommandMaker -> AssistantData -> (Transferrer -> IO ()) -> IO ()
+runTransferThread' program batchmaker d run = go
   where
 	go = catchPauseResume $
-		withTransferrer program (transferrerPool d)
+		withTransferrer program batchmaker (transferrerPool d)
 			run
 	pause = catchPauseResume $
 		runEvery (Seconds 86400) noop
@@ -279,7 +280,8 @@ startTransfer t = do
 		liftIO $ throwTo tid ResumeTransfer
 	start info = do
 		program <- liftIO readProgramFile
-		inImmediateTransferSlot program $
+		batchmaker <- liftIO getBatchCommandMaker
+		inImmediateTransferSlot program batchmaker $
 			genTransfer t info
 
 getCurrentTransfers :: Assistant TransferMap