refactoring

This is groundwork for using git-annex transferkeys to run transfers,
in order to allow stalled transfers to be interrupted and retried.

The new upload and download are closer to what git-annex transferkeys
does, so the plan is to make them use it.

Then things that were left using upload' and download' won't recover
from stalls. Notably, that includes import and export. But
at least get/move/copy will be able to. (Also the assistant hopefully,
but not yet.)

This commit was sponsored by Jake Vosloo on Patreon.

Command/AddUrl.hs

@@ -332,7 +332,7 @@ downloadWeb addunlockedmatcher o url urlinfo file =
 			let cleanuptmp = pruneTmpWorkDirBefore tmp (liftIO . removeWhenExistsWith R.removeLink)
 			showNote "using youtube-dl"
 			Transfer.notifyTransfer Transfer.Download url $
-				Transfer.download webUUID mediakey (AssociatedFile Nothing) Transfer.noRetry $ \p ->
+				Transfer.download' webUUID mediakey (AssociatedFile Nothing) Transfer.noRetry $ \p ->
 					youtubeDl url (fromRawFilePath workdir) p >>= \case
 						Right (Just mediafile) -> do
 							cleanuptmp
@@ -396,7 +396,7 @@ downloadWith' downloader dummykey u url afile =
 	checkDiskSpaceToGet dummykey Nothing $ do
 		tmp <- fromRepo $ gitAnnexTmpObjectLocation dummykey
 		ok <- Transfer.notifyTransfer Transfer.Download url $
-			Transfer.download u dummykey afile Transfer.stdRetry $ \p -> do
+			Transfer.download' u dummykey afile Transfer.stdRetry $ \p -> do
 				createAnnexDirectory (parentDir tmp)
 				downloader (fromRawFilePath tmp) p
 		if ok

Command/Export.hs

@@ -283,7 +283,7 @@ performExport r db ek af contentsha loc allfilledvar = do
 	sent <- tryNonAsync $ case ek of
 		AnnexKey k -> ifM (inAnnex k)
 			( notifyTransfer Upload af $
-				upload (uuid r) k af stdRetry $ \pm -> do
+				upload' (uuid r) k af stdRetry $ \pm -> do
 					let rollback = void $
 						performUnexport r db [ek] loc
 					sendAnnex k rollback $ \f ->

Command/Get.hs

@@ -9,7 +9,6 @@ module Command.Get where
 
 import Command
 import qualified Remote
-import Annex.Content
 import Annex.Transfer
 import Annex.NumCopies
 import Annex.Wanted
@@ -114,10 +113,6 @@ getKey' key afile = dispatch
 		| Remote.hasKeyCheap r =
 			either (const False) id <$> Remote.hasKey r key
 		| otherwise = return True
-	docopy r witness = getViaTmp (Remote.retrievalSecurityPolicy r) (RemoteVerify r) key afile $ \dest ->
-		download (Remote.uuid r) key afile stdRetry
-			(\p -> do
-				showAction $ "from " ++ Remote.name r
-				Remote.verifiedAction $
-					Remote.retrieveKeyFile r key afile (fromRawFilePath dest) p
-			) witness
+	docopy r witness = do
+		showAction $ "from " ++ Remote.name r
+		download r key afile stdRetry witness

Command/Move.hs

@@ -142,8 +142,7 @@ toPerform dest removewhen key afile fastcheck isthere = do
 		Right False -> logMove srcuuid destuuid False key $ \deststartedwithcopy -> do
 			showAction $ "to " ++ Remote.name dest
 			ok <- notifyTransfer Upload afile $
-				upload (Remote.uuid dest) key afile stdRetry $
-					Remote.action . Remote.storeKey dest key afile
+				upload dest key afile stdRetry
 			if ok
 				then finish deststartedwithcopy $
 					Remote.logStatus dest key InfoPresent
@@ -223,10 +222,8 @@ fromPerform src removewhen key afile = do
 			then dispatch removewhen deststartedwithcopy True
 			else dispatch removewhen deststartedwithcopy =<< get
   where
-	get = notifyTransfer Download afile $ 
-		download (Remote.uuid src) key afile stdRetry $ \p ->
-			getViaTmp (Remote.retrievalSecurityPolicy src) (RemoteVerify src) key afile $ \t ->
-				Remote.verifiedAction $ Remote.retrieveKeyFile src key afile (fromRawFilePath t) p
+	get = notifyTransfer Download afile $
+		download src key afile stdRetry
 	
 	dispatch _ _ False = stop -- failed
 	dispatch RemoveNever _ True = next $ return True -- copy complete

Command/TransferKey.hs

@@ -51,7 +51,7 @@ start o (_, key) = startingCustomOutput key $ case fromToOptions o of
 
 toPerform :: Key -> AssociatedFile -> Remote -> CommandPerform
 toPerform key file remote = go Upload file $
-	upload (uuid remote) key file stdRetry $ \p -> do
+	upload' (uuid remote) key file stdRetry $ \p -> do
 		tryNonAsync (Remote.storeKey remote key file p) >>= \case
 			Right () -> do
 				Remote.logStatus remote key InfoPresent
@@ -62,7 +62,7 @@ toPerform key file remote = go Upload file $
 
 fromPerform :: Key -> AssociatedFile -> Remote -> CommandPerform
 fromPerform key file remote = go Upload file $
-	download (uuid remote) key file stdRetry $ \p ->
+	download' (uuid remote) key file stdRetry $ \p ->
 		getViaTmp (retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t ->
 			tryNonAsync (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p) >>= \case
 				Right v -> return (True, v)	

Command/TransferKeys.hs

@@ -49,7 +49,7 @@ start = do
   where
 	runner (TransferRequest direction _ keydata file) remote
 		| direction == Upload = notifyTransfer direction file $
-			upload (Remote.uuid remote) key file stdRetry $ \p -> do
+			upload' (Remote.uuid remote) key file stdRetry $ \p -> do
 				tryNonAsync (Remote.storeKey remote key file p) >>= \case
 					Left e -> do
 						warning (show e)
@@ -58,7 +58,7 @@ start = do
 						Remote.logStatus remote key InfoPresent
 						return True
 		| otherwise = notifyTransfer direction file $
-			download (Remote.uuid remote) key file stdRetry $ \p ->
+			download' (Remote.uuid remote) key file stdRetry $ \p ->
 				getViaTmp (Remote.retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t -> do
 					r <- tryNonAsync (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p) >>= \case
 						Left e -> do