moved code out of webapp

No code changes, aside from some changes to lifting in code that turned out
to be able to run in Assistant rather than Handler.

1 files changed, 199 insertions, 0 deletions

diff --git a/Assistant/TransferSlots.hs b/Assistant/TransferSlots.hs
index 81a778a0a..36d557c3d 100644
--- a/Assistant/TransferSlots.hs
+++ b/Assistant/TransferSlots.hs
@@ -13,11 +13,27 @@ import Assistant.Types.TransferSlots
 import Assistant.DaemonStatus
 import Assistant.TransferrerPool
 import Assistant.Types.TransferrerPool
+import Assistant.Types.TransferQueue
+import Assistant.TransferQueue
+import Assistant.Alert
+import Assistant.Alert.Utility
+import Assistant.Commits
+import Assistant.Drop
 import Logs.Transfer
+import Logs.Location
+import qualified Git
+import qualified Remote
+import qualified Types.Remote as Remote
+import Annex.Content
+import Annex.Wanted
+import Config.Files
 
+import qualified Data.Map as M 
 import qualified Control.Exception as E
 import Control.Concurrent
 import qualified Control.Concurrent.MSemN as MSemN
+import System.Posix.Signals (signalProcessGroup, sigTERM, sigKILL)
+import System.Posix.Process (getProcessGroupIDOf)
 
 type TransferGenerator = Assistant (Maybe (Transfer, TransferInfo, Transferrer -> Assistant ()))
 
@@ -76,3 +92,186 @@ runTransferThread' program d run = go
 			_ -> done
 	done = runAssistant d $ 
 		flip MSemN.signal 1 <<~ transferSlots
+
+{- By the time this is called, the daemonstatus's currentTransfers map should
+ - already have been updated to include the transfer. -}
+genTransfer :: Transfer -> TransferInfo -> TransferGenerator
+genTransfer t info = case (transferRemote info, associatedFile info) of
+	(Just remote, Just file) 
+		| Git.repoIsLocalUnknown (Remote.repo remote) -> do
+			-- optimisation for removable drives not plugged in
+			liftAnnex $ recordFailedTransfer t info
+			void $ removeTransfer t
+			return Nothing
+		| otherwise -> ifM (liftAnnex $ shouldTransfer t info)
+			( do
+				debug [ "Transferring:" , describeTransfer t info ]
+				notifyTransfer
+				return $ Just (t, info, go remote file)
+			, do
+				debug [ "Skipping unnecessary transfer:",
+					describeTransfer t info ]
+				void $ removeTransfer t
+				finishedTransfer t (Just info)
+				return Nothing
+			)
+	_ -> return Nothing
+  where
+	direction = transferDirection t
+	isdownload = direction == Download
+
+	{- Alerts are only shown for successful transfers.
+	 - Transfers can temporarily fail for many reasons,
+	 - so there's no point in bothering the user about
+	 - those. The assistant should recover.
+	 -
+	 - After a successful upload, handle dropping it from
+	 - here, if desired. In this case, the remote it was
+	 - uploaded to is known to have it.
+	 -
+	 - Also, after a successful transfer, the location
+	 - log has changed. Indicate that a commit has been
+	 - made, in order to queue a push of the git-annex
+	 - branch out to remotes that did not participate
+	 - in the transfer.
+	 -
+	 - If the process failed, it could have crashed,
+	 - so remove the transfer from the list of current
+	 - transfers, just in case it didn't stop
+	 - in a way that lets the TransferWatcher do its
+	 - usual cleanup. However, first check if something else is
+	 - running the transfer, to avoid removing active transfers.
+	 -}
+	go remote file transferrer = ifM (liftIO $ performTransfer transferrer t $ associatedFile info)
+		( do
+			void $ addAlert $ makeAlertFiller True $
+				transferFileAlert direction True file
+			unless isdownload $
+				handleDrops
+					("object uploaded to " ++ show remote)
+					True (transferKey t)
+					(associatedFile info)
+					(Just remote)
+			void recordCommit
+		, whenM (liftAnnex $ isNothing <$> checkTransfer t) $
+			void $ removeTransfer t
+		)
+
+{- Called right before a transfer begins, this is a last chance to avoid
+ - unnecessary transfers.
+ -
+ - For downloads, we obviously don't need to download if the already
+ - have the object.
+ -
+ - Smilarly, for uploads, check if the remote is known to already have
+ - the object.
+ -
+ - Also, uploads get queued to all remotes, in order of cost.
+ - This may mean, for example, that an object is uploaded over the LAN
+ - to a locally paired client, and once that upload is done, a more
+ - expensive transfer remote no longer wants the object. (Since
+ - all the clients have it already.) So do one last check if this is still
+ - preferred content.
+ -
+ - We'll also do one last preferred content check for downloads. An
+ - example of a case where this could be needed is if a download is queued
+ - for a file that gets moved out of an archive directory -- but before
+ - that download can happen, the file is put back in the archive.
+ -}
+shouldTransfer :: Transfer -> TransferInfo -> Annex Bool
+shouldTransfer t info
+	| transferDirection t == Download =
+		(not <$> inAnnex key) <&&> wantGet True file
+	| transferDirection t == Upload = case transferRemote info of
+		Nothing -> return False
+		Just r -> notinremote r
+			<&&> wantSend True file (Remote.uuid r)
+	| otherwise = return False
+  where
+	key = transferKey t
+	file = associatedFile info
+
+	{- Trust the location log to check if the remote already has
+	 - the key. This avoids a roundtrip to the remote. -}
+	notinremote r = notElem (Remote.uuid r) <$> loggedLocations key
+
+{- Queue uploads of files downloaded to us, spreading them
+ - out to other reachable remotes.
+ -
+ - Downloading a file may have caused a remote to not want it;
+ - so check for drops from remotes.
+ -
+ - Uploading a file may cause the local repo, or some other remote to not
+ - want it; handle that too.
+ -}
+finishedTransfer :: Transfer -> Maybe TransferInfo -> Assistant ()
+finishedTransfer t (Just info)
+	| transferDirection t == Download =
+		whenM (liftAnnex $ inAnnex $ transferKey t) $ do
+			dodrops False
+			queueTransfersMatching (/= transferUUID t)
+				"newly received object"
+				Later (transferKey t) (associatedFile info) Upload
+	| otherwise = dodrops True
+  where
+	dodrops fromhere = handleDrops
+		("drop wanted after " ++ describeTransfer t info)
+		fromhere (transferKey t) (associatedFile info) Nothing
+finishedTransfer _ _ = noop
+
+{- Pause a running transfer. -}
+pauseTransfer :: Transfer -> Assistant ()
+pauseTransfer = cancelTransfer True
+
+{- Cancel a running transfer. -}
+cancelTransfer :: Bool -> Transfer -> Assistant ()
+cancelTransfer pause t = do
+	m <- getCurrentTransfers
+	unless pause $
+		{- remove queued transfer -}
+		void $ dequeueTransfers $ equivilantTransfer t
+	{- stop running transfer -}
+	maybe noop stop (M.lookup t m)
+  where
+	stop info = do
+		{- When there's a thread associated with the
+		 - transfer, it's signaled first, to avoid it
+		 - displaying any alert about the transfer having
+		 - failed when the transfer process is killed. -}
+		liftIO $ maybe noop signalthread $ transferTid info
+		liftIO $ maybe noop killproc $ transferPid info
+		if pause
+			then void $ alterTransferInfo t $
+				\i -> i { transferPaused = True }
+			else void $ removeTransfer t
+	signalthread tid
+		| pause = throwTo tid PauseTransfer
+		| otherwise = killThread tid
+	{- In order to stop helper processes like rsync,
+	 - kill the whole process group of the process running the transfer. -}
+	killproc pid = void $ tryIO $ do
+		g <- getProcessGroupIDOf pid
+		void $ tryIO $ signalProcessGroup sigTERM g
+		threadDelay 50000 -- 0.05 second grace period
+		void $ tryIO $ signalProcessGroup sigKILL g
+
+{- Start or resume a transfer. -}
+startTransfer :: Transfer -> Assistant ()
+startTransfer t = do
+	m <- getCurrentTransfers
+	maybe startqueued go (M.lookup t m)
+  where
+	go info = maybe (start info) resume $ transferTid info
+	startqueued = do
+		is <- map snd <$> getMatchingTransfers (== t)
+		maybe noop start $ headMaybe is
+	resume tid = do
+		alterTransferInfo t $ \i -> i { transferPaused = False }
+		liftIO $ throwTo tid ResumeTransfer
+	start info = do
+		program <- liftIO readProgramFile
+		inImmediateTransferSlot program $
+			genTransfer t info
+
+getCurrentTransfers :: Assistant TransferMap
+getCurrentTransfers = currentTransfers <$> getDaemonStatus