git-annex/Assistant/Threads/TransferWatcher.hs
Joey Hess a1b1b5ef52 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.
2013-10-26 16:58:16 -04:00

98 lines
3 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.DaemonStatus
import Assistant.TransferSlots
import Logs.Transfer
import Utility.DirWatcher
import Utility.DirWatcher.Types
import qualified Remote
import Control.Concurrent
{- This thread watches for changes to the gitAnnexTransferDir,
- and updates the DaemonStatus's map of ongoing transfers. -}
transferWatcherThread :: NamedThread
transferWatcherThread = namedThread "TransferWatcher" $ do
dir <- liftAnnex $ gitAnnexTransferDir <$> gitRepo
liftIO $ createDirectoryIfMissing True dir
let hook a = Just <$> asIO2 (runHandler a)
addhook <- hook onAdd
delhook <- hook onDel
modifyhook <- hook onModify
errhook <- hook onErr
let hooks = mkWatchHooks
{ addHook = addhook
, delHook = delhook
, modifyHook = modifyhook
, errHook = errhook
}
void $ liftIO $ watchDir dir (const False) hooks id
debug ["watching for transfers"]
type Handler = FilePath -> Assistant ()
{- Runs an action handler.
-
- Exceptions are ignored, otherwise a whole thread could be crashed.
-}
runHandler :: Handler -> FilePath -> Maybe FileStatus -> Assistant ()
runHandler handler file _filestatus =
either (liftIO . print) (const noop) =<< tryIO <~> handler file
{- Called when there's an error with inotify. -}
onErr :: Handler
onErr = error
{- Called when a new transfer information file is written. -}
onAdd :: Handler
onAdd file = case parseTransferFile file of
Nothing -> noop
Just t -> go t =<< liftAnnex (checkTransfer t)
where
go _ Nothing = noop -- transfer already finished
go t (Just info) = do
debug [ "transfer starting:", describeTransfer t info ]
r <- liftAnnex $ Remote.remoteFromUUID $ transferUUID t
updateTransferInfo t info { transferRemote = r }
{- 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 file = case parseTransferFile file of
Nothing -> noop
Just t -> go t =<< liftIO (readTransferInfoFile Nothing file)
where
go _ Nothing = noop
go t (Just newinfo) = alterTransferInfo t $
\i -> i { 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 file = case parseTransferFile file of
Nothing -> noop
Just t -> do
debug [ "transfer finishing:", show t]
minfo <- removeTransfer t
finished <- asIO2 finishedTransfer
void $ liftIO $ forkIO $ do
{- XXX race workaround delay. The location
- log needs to be updated before finishedTransfer
- runs. -}
threadDelay 10000000 -- 10 seconds
finished t minfo