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.

Annex/Action.hs

@@ -6,6 +6,8 @@
  -}
 
 module Annex.Action (
+	action,
+	verifiedAction,
 	startup,
 	shutdown,
 	stopCoProcesses,
@@ -21,6 +23,22 @@ import Annex.CheckAttr
 import Annex.HashObject
 import Annex.CheckIgnore
 
+{- Runs an action that may throw exceptions, catching and displaying them. -}
+action :: Annex () -> Annex Bool
+action a = tryNonAsync a >>= \case
+	Right () -> return True
+	Left e -> do
+		warning (show e)
+		return False
+
+verifiedAction :: Annex Verification -> Annex (Bool, Verification)
+verifiedAction a = tryNonAsync a >>= \case
+	Right v -> return (True, v)
+	Left e -> do
+		warning (show e)
+		return (False, UnVerified)
+
+
 {- Actions to perform each time ran. -}
 startup :: Annex ()
 startup = return ()

Annex/Import.hs

@@ -466,7 +466,7 @@ importKeys remote importtreeconfig importcontent importablecontents = do
 				return (Just (k', ok))
 			checkDiskSpaceToGet k Nothing $
 				notifyTransfer Download af $
-					download (Remote.uuid remote) k af stdRetry $ \p' ->
+					download' (Remote.uuid remote) k af stdRetry $ \p' ->
 						withTmp k $ downloader p'
 			
 	-- The file is small, so is added to git, so while importing
@@ -520,7 +520,7 @@ importKeys remote importtreeconfig importcontent importablecontents = do
 				return Nothing
 		checkDiskSpaceToGet tmpkey Nothing $
 			notifyTransfer Download af $
-				download (Remote.uuid remote) tmpkey af stdRetry $ \p ->
+				download' (Remote.uuid remote) tmpkey af stdRetry $ \p ->
 					withTmp tmpkey $ \tmpfile ->
 						metered (Just p) tmpkey $
 							const (rundownload tmpfile)

Annex/Transfer.hs

@@ -10,8 +10,10 @@
 module Annex.Transfer (
 	module X,
 	upload,
+	upload',
 	alwaysUpload,
 	download,
+	download',
 	runTransfer,
 	alwaysRunTransfer,
 	noRetry,
@@ -24,7 +26,9 @@ import qualified Annex
 import Logs.Transfer as X
 import Types.Transfer as X
 import Annex.Notification as X
+import Annex.Content
 import Annex.Perms
+import Annex.Action
 import Utility.Metered
 import Utility.ThreadScheduler
 import Annex.LockPool
@@ -42,16 +46,28 @@ import qualified Data.Map.Strict as M
 import qualified System.FilePath.ByteString as P
 import Data.Ord
 
-upload :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
-upload u key f d a _witness = guardHaveUUID u $ 
+upload :: Remote -> Key -> AssociatedFile -> RetryDecider -> NotifyWitness -> Annex Bool
+upload r key f d = upload' (Remote.uuid r) key f d $
+	action . Remote.storeKey r key f
+
+upload' :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
+upload' u key f d a _witness = guardHaveUUID u $ 
 	runTransfer (Transfer Upload u (fromKey id key)) f d a
 
 alwaysUpload :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
 alwaysUpload u key f d a _witness = guardHaveUUID u $ 
 	alwaysRunTransfer (Transfer Upload u (fromKey id key)) f d a
 
-download :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
-download u key f d a _witness = guardHaveUUID u $
+download :: Remote -> Key -> AssociatedFile -> RetryDecider -> NotifyWitness -> Annex Bool
+download r key f d witness =
+	getViaTmp (Remote.retrievalSecurityPolicy r) (RemoteVerify r) key f $ \dest ->
+		download' (Remote.uuid r) key f d (go dest) witness
+  where
+	go dest p = verifiedAction $
+		Remote.retrieveKeyFile r key f (fromRawFilePath dest) p
+
+download' :: Observable v => UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> NotifyWitness -> Annex v
+download' u key f d a _witness = guardHaveUUID u $
 	runTransfer (Transfer Download u (fromKey id key)) f d a
 
 guardHaveUUID :: Observable v => UUID -> Annex v -> Annex v
@@ -81,7 +97,7 @@ alwaysRunTransfer :: Observable v => Transfer -> AssociatedFile -> RetryDecider
 alwaysRunTransfer = runTransfer' True
 
 runTransfer' :: Observable v => Bool -> Transfer -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex v) -> Annex v
-runTransfer' ignorelock t afile retrydecider transferaction = enteringStage TransferStage $ debugLocks $ checkSecureHashes t $ do
+runTransfer' ignorelock t afile retrydecider transferaction = enteringStage TransferStage $ debugLocks $ preCheckSecureHashes t $ do
 	info <- liftIO $ startTransferInfo afile
 	(meter, tfile, createtfile, metervar) <- mkProgressUpdater t info
 	mode <- annexFileMode
@@ -180,8 +196,8 @@ runTransfer' ignorelock t afile retrydecider transferaction = enteringStage Tran
  - still contains content using an insecure hash, remotes will likewise
  - tend to be configured to reject it, so Upload is also prevented.
  -}
-checkSecureHashes :: Observable v => Transfer -> Annex v -> Annex v
-checkSecureHashes t a = ifM (isCryptographicallySecure (transferKey t))
+preCheckSecureHashes :: Observable v => Transfer -> Annex v -> Annex v
+preCheckSecureHashes t a = ifM (isCryptographicallySecure (transferKey t))
 	( a
 	, ifM (annexSecureHashesOnly <$> Annex.getGitConfig)
 		( do

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
+	docopy r witness = do
 		showAction $ "from " ++ Remote.name r
-				Remote.verifiedAction $
-					Remote.retrieveKeyFile r key afile (fromRawFilePath dest) p
-			) witness
+		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
@@ -224,9 +223,7 @@ fromPerform src removewhen key afile = do
 			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
+		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

P2P/Annex.hs

@@ -75,7 +75,7 @@ runLocal runst runner a = case a of
 		let rsp = RetrievalAllKeysSecure
 		v <- tryNonAsync $ do
 			let runtransfer ti = 
-				Right <$> transfer download k af (\p ->
+				Right <$> transfer download' k af (\p ->
 					getViaTmp rsp DefaultVerify k af $ \tmp ->
 						storefile (fromRawFilePath tmp) o l getb validitycheck p ti)
 			let fallback = return $ Left $

Remote.hs

@@ -70,6 +70,7 @@ import Annex.Common
 import Types.Remote
 import qualified Annex
 import Annex.UUID
+import Annex.Action
 import Logs.UUID
 import Logs.Trust
 import Logs.Location hiding (logStatus)
@@ -82,21 +83,6 @@ import Config.DynamicConfig
 import Git.Types (RemoteName, ConfigKey(..), fromConfigValue)
 import Utility.Aeson
 
-{- Runs an action that may throw exceptions, catching and displaying them. -}
-action :: Annex () -> Annex Bool
-action a = tryNonAsync a >>= \case
-	Right () -> return True
-	Left e -> do
-		warning (show e)
-		return False
-
-verifiedAction :: Annex Verification -> Annex (Bool, Verification)
-verifiedAction a = tryNonAsync a >>= \case
-	Right v -> return (True, v)
-	Left e -> do
-		warning (show e)
-		return (False, UnVerified)
-
 {- Map from UUIDs of Remotes to a calculated value. -}
 remoteMap :: (Remote -> v) -> Annex (M.Map UUID v)
 remoteMap mkv = remoteMap' mkv (pure . mkk)