git-annex/Assistant/Threads/TransferWatcher.hs

123 lines
4 KiB
Haskell

{- git-annex assistant transfer watching thread
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Threads.TransferWatcher where
import Assistant.Common
import Assistant.ThreadedMonad
import Assistant.DaemonStatus
import Assistant.TransferQueue
import Assistant.Drop
import Annex.Content
import Logs.Transfer
import Utility.DirWatcher
import Utility.Types.DirWatcher
import qualified Remote
thisThread :: ThreadName
thisThread = "TransferWatcher"
{- This thread watches for changes to the gitAnnexTransferDir,
- and updates the DaemonStatus's map of ongoing transfers. -}
transferWatcherThread :: ThreadState -> DaemonStatusHandle -> TransferQueue -> NamedThread
transferWatcherThread st dstatus transferqueue = thread $ do
g <- runThreadState st gitRepo
let dir = gitAnnexTransferDir g
createDirectoryIfMissing True dir
let hook a = Just $ runHandler st dstatus transferqueue a
let hooks = mkWatchHooks
{ addHook = hook onAdd
, delHook = hook onDel
, modifyHook = hook onModify
, errHook = hook onErr
}
void $ watchDir dir (const False) hooks id
debug thisThread ["watching for transfers"]
where
thread = NamedThread thisThread
type Handler = ThreadState -> DaemonStatusHandle -> TransferQueue -> FilePath -> Maybe FileStatus -> IO ()
{- Runs an action handler.
-
- Exceptions are ignored, otherwise a whole thread could be crashed.
-}
runHandler :: ThreadState -> DaemonStatusHandle -> TransferQueue -> Handler -> FilePath -> Maybe FileStatus -> IO ()
runHandler st dstatus transferqueue handler file filestatus = void $
either print (const noop) =<< tryIO go
where
go = handler st dstatus transferqueue file filestatus
{- Called when there's an error with inotify. -}
onErr :: Handler
onErr _ _ _ msg _ = error msg
{- Called when a new transfer information file is written. -}
onAdd :: Handler
onAdd st dstatus _ file _ = case parseTransferFile file of
Nothing -> noop
Just t -> go t =<< runThreadState st (checkTransfer t)
where
go _ Nothing = noop -- transfer already finished
go t (Just info) = do
debug thisThread
[ "transfer starting:"
, show t
]
r <- headMaybe . filter (sameuuid t)
<$> runThreadState st Remote.remoteList
updateTransferInfo dstatus t info
{ transferRemote = r }
sameuuid t r = Remote.uuid r == transferUUID t
{- Called when a transfer information file is updated.
-
- The only thing that should change in the transfer info is the
- bytesComplete, so that's the only thing updated in the DaemonStatus. -}
onModify :: Handler
onModify _ dstatus _ file _ = do
case parseTransferFile file of
Nothing -> noop
Just t -> go t =<< readTransferInfoFile Nothing file
where
go _ Nothing = noop
go t (Just newinfo) = alterTransferInfo dstatus t $ \info ->
info { bytesComplete = bytesComplete newinfo }
{- This thread can only watch transfer sizes when the DirWatcher supports
- tracking modificatons to files. -}
watchesTransferSize :: Bool
watchesTransferSize = modifyTracked
{- Called when a transfer information file is removed. -}
onDel :: Handler
onDel st dstatus transferqueue file _ = case parseTransferFile file of
Nothing -> noop
Just t -> do
debug thisThread
[ "transfer finishing:"
, show t
]
minfo <- removeTransfer dstatus t
finishedTransfer st dstatus transferqueue t minfo
{- Queue uploads of files we successfully downloaded, spreading them
- out to other reachable remotes.
-
- Also, downloading a file may have caused a remote to not want it,
- so drop it from the remote. -}
finishedTransfer :: ThreadState -> DaemonStatusHandle -> TransferQueue -> Transfer -> Maybe TransferInfo -> IO ()
finishedTransfer st dstatus transferqueue t (Just info)
| transferDirection t == Download = runThreadState st $
whenM (inAnnex $ transferKey t) $ do
handleRemoteDrops dstatus
(transferKey t) (associatedFile info)
queueTransfersMatching (/= transferUUID t)
Later transferqueue dstatus
(transferKey t) (associatedFile info) Upload
| otherwise = noop
finishedTransfer _ _ _ _ _ = noop