add desktop notifications

Motivation: Hook scripts for nautilus or other file managers
need to provide the user with feedback that a file is being downloaded.

This commit was sponsored by THM Schoemaker.

Logs/Transfer.hs

@@ -88,108 +88,6 @@ percentComplete :: Transfer -> TransferInfo -> Maybe Percentage
 percentComplete (Transfer { transferKey = key }) info =
 	percentage <$> keySize key <*> Just (fromMaybe 0 $ bytesComplete info)
 
-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
-
-upload :: UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex Bool) -> Annex Bool
-upload u key = runTransfer (Transfer Upload u key)
-
-download :: UUID -> Key -> AssociatedFile -> RetryDecider -> (MeterUpdate -> Annex Bool) -> Annex Bool
-download u key = runTransfer (Transfer Download u key)
-
-{- 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
-
 {- Generates a callback that can be called as transfer progresses to update
  - the transfer info file. Also returns the file it'll be updating, and a
  - MVar that can be used to read the number of bytesComplete. -}