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Diffstat (limited to 'Annex/Transfer.hs')
| -rw-r--r-- | Annex/Transfer.hs | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/Annex/Transfer.hs b/Annex/Transfer.hs new file mode 100644 index 000000000..dac32e752 --- /dev/null +++ b/Annex/Transfer.hs @@ -0,0 +1,178 @@ +{- git-annex transfers + - + - Copyright 2012-2014 Joey Hess <joey@kitenet.net> + - + - Licensed under the GNU GPL version 3 or higher. + -} + +{-# LANGUAGE CPP #-} + +module Annex.Transfer ( + module X, + upload, + download, + runTransfer, + notifyTransfer, + NotifyWitness, + noRetry, + forwardRetry, +) where + +import qualified Annex +import Logs.Transfer as X +import Annex.Perms +import Annex.Exception +import Utility.Metered +#ifdef WITH_DBUS_NOTIFICATIONS +import Common.Annex +import Types.DesktopNotify +import qualified DBus.Notify as Notify +import qualified DBus.Client +#endif +#ifdef mingw32_HOST_OS +import Utility.WinLock +#endif + +import Control.Concurrent + +upload :: UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex Bool) -> NotifyWitness -> Annex Bool +upload u key f d a _witness = runTransfer (Transfer Upload u key) f d a + +download :: UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex Bool) -> NotifyWitness -> Annex Bool +download u key f d a _witness = runTransfer (Transfer Download u key) f d a + +{- Runs a transfer action. Creates and locks the lock file while the + - action is running, and stores info in the transfer information + - file. + - + - If the transfer action returns False, the transfer info is + - left in the failedTransferDir. + - + - If the transfer is already in progress, returns False. + - + - An upload can be run from a read-only filesystem, and in this case + - no transfer information or lock file is used. + -} +runTransfer :: Transfer -> Maybe FilePath -> RetryDecider -> (MeterUpdate -> Annex Bool) -> Annex Bool +runTransfer t file shouldretry a = do + info <- liftIO $ startTransferInfo file + (meter, tfile, metervar) <- mkProgressUpdater t info + mode <- annexFileMode + (fd, inprogress) <- liftIO $ prep tfile mode info + if inprogress + then do + showNote "transfer already in progress" + return False + else do + ok <- retry info metervar $ + bracketIO (return fd) (cleanup tfile) (const $ a meter) + unless ok $ recordFailedTransfer t info + return ok + where +#ifndef mingw32_HOST_OS + prep tfile mode info = do + mfd <- catchMaybeIO $ + openFd (transferLockFile tfile) ReadWrite (Just mode) + defaultFileFlags { trunc = True } + case mfd of + Nothing -> return (Nothing, False) + Just fd -> do + locked <- catchMaybeIO $ + setLock fd (WriteLock, AbsoluteSeek, 0, 0) + if isNothing locked + then return (Nothing, True) + else do + void $ tryIO $ writeTransferInfoFile info tfile + return (mfd, False) +#else + prep tfile _mode info = do + v <- catchMaybeIO $ lockExclusive (transferLockFile tfile) + case v of + Nothing -> return (Nothing, False) + Just Nothing -> return (Nothing, True) + Just (Just lockhandle) -> do + void $ tryIO $ writeTransferInfoFile info tfile + return (Just lockhandle, False) +#endif + cleanup _ Nothing = noop + cleanup tfile (Just lockhandle) = do + void $ tryIO $ removeFile tfile +#ifndef mingw32_HOST_OS + void $ tryIO $ removeFile $ transferLockFile tfile + closeFd lockhandle +#else + {- Windows cannot delete the lockfile until the lock + - is closed. So it's possible to race with another + - process that takes the lock before it's removed, + - so ignore failure to remove. + -} + dropLock lockhandle + void $ tryIO $ removeFile $ transferLockFile tfile +#endif + retry oldinfo metervar run = do + v <- tryAnnex run + case v of + Right b -> return b + Left _ -> do + b <- getbytescomplete metervar + let newinfo = oldinfo { bytesComplete = Just b } + if shouldretry oldinfo newinfo + then retry newinfo metervar run + else return False + getbytescomplete metervar + | transferDirection t == Upload = + liftIO $ readMVar metervar + | otherwise = do + f <- fromRepo $ gitAnnexTmpObjectLocation (transferKey t) + liftIO $ catchDefaultIO 0 $ + fromIntegral . fileSize <$> getFileStatus f + +type RetryDecider = TransferInfo -> TransferInfo -> Bool + +noRetry :: RetryDecider +noRetry _ _ = False + +{- Retries a transfer when it fails, as long as the failed transfer managed + - to send some data. -} +forwardRetry :: RetryDecider +forwardRetry old new = bytesComplete old < bytesComplete new + +-- Witness that notification has happened. +data NotifyWitness = NotifyWitness + +{- Wrap around an action that performs a transfer, which may run multiple + - attempts, and displays notification when supported. -} +notifyTransfer :: Direction -> Maybe FilePath -> (NotifyWitness -> Annex Bool) -> Annex Bool +notifyTransfer _ Nothing a = a NotifyWitness +notifyTransfer direction (Just f) a = do +#ifdef WITH_DBUS_NOTIFICATIONS + wanted <- Annex.getState Annex.desktopnotify + let action = if direction == Upload then "uploading" else "downloading" + let basedesc = action ++ " " ++ f + let startdesc = "started " ++ basedesc + let enddesc = "finished " ++ basedesc + if (notifyStart wanted || notifyFinish wanted) + then do + client <- liftIO DBus.Client.connectSession + let mknote desc = Notify.blankNote + { Notify.appName = "git-annex" + , Notify.body = Just $ Notify.Text desc + , Notify.hints = + [ Notify.Category Notify.Transfer + , Notify.Urgency Notify.Low + , Notify.SuppressSound True + ] + } + startnotification <- liftIO $ if notifyStart wanted + then Just <$> Notify.notify client (mknote startdesc) + else pure Nothing + r <- a NotifyWitness + when (notifyFinish wanted) $ liftIO $ void $ maybe + (Notify.notify client $ mknote enddesc) + (\n -> Notify.replace client n $ mknote enddesc) + startnotification + return r + else a NotifyWitness +#else + a NotifyWitness +#endif |