git-annex/Logs/Transfer.hs
Joey Hess c784ef4586 unify exception handling into Utility.Exception
Removed old extensible-exceptions, only needed for very old ghc.

Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.

Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.

However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.

Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
2014-08-07 22:03:29 -04:00

322 lines
10 KiB
Haskell

{- git-annex transfer information files and lock files
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Logs.Transfer where
import Common.Annex
import Annex.Perms
import qualified Git
import Types.Key
import Utility.Metered
import Utility.Percentage
import Utility.QuickCheck
import Utility.PID
#ifdef mingw32_HOST_OS
import Utility.WinLock
#endif
import Data.Time.Clock
import Data.Time.Clock.POSIX
import Data.Time
import System.Locale
import Control.Concurrent
{- Enough information to uniquely identify a transfer, used as the filename
- of the transfer information file. -}
data Transfer = Transfer
{ transferDirection :: Direction
, transferUUID :: UUID
, transferKey :: Key
}
deriving (Eq, Ord, Read, Show)
{- Information about a Transfer, stored in the transfer information file.
-
- Note that the associatedFile may not correspond to a file in the local
- git repository. It's some file, possibly relative to some directory,
- of some repository, that was acted on to initiate the transfer.
-}
data TransferInfo = TransferInfo
{ startedTime :: Maybe POSIXTime
, transferPid :: Maybe PID
, transferTid :: Maybe ThreadId
, transferRemote :: Maybe Remote
, bytesComplete :: Maybe Integer
, associatedFile :: Maybe FilePath
, transferPaused :: Bool
}
deriving (Show, Eq, Ord)
stubTransferInfo :: TransferInfo
stubTransferInfo = TransferInfo Nothing Nothing Nothing Nothing Nothing Nothing False
data Direction = Upload | Download
deriving (Eq, Ord, Read, Show)
showLcDirection :: Direction -> String
showLcDirection Upload = "upload"
showLcDirection Download = "download"
readLcDirection :: String -> Maybe Direction
readLcDirection "upload" = Just Upload
readLcDirection "download" = Just Download
readLcDirection _ = Nothing
describeTransfer :: Transfer -> TransferInfo -> String
describeTransfer t info = unwords
[ show $ transferDirection t
, show $ transferUUID t
, fromMaybe (key2file $ transferKey t) (associatedFile info)
, show $ bytesComplete info
]
{- Transfers that will accomplish the same task. -}
equivilantTransfer :: Transfer -> Transfer -> Bool
equivilantTransfer t1 t2
| transferDirection t1 == Download && transferDirection t2 == Download &&
transferKey t1 == transferKey t2 = True
| otherwise = t1 == t2
percentComplete :: Transfer -> TransferInfo -> Maybe Percentage
percentComplete (Transfer { transferKey = key }) info =
percentage <$> keySize key <*> Just (fromMaybe 0 $ bytesComplete info)
{- 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. -}
mkProgressUpdater :: Transfer -> TransferInfo -> Annex (MeterUpdate, FilePath, MVar Integer)
mkProgressUpdater t info = do
tfile <- fromRepo $ transferFile t
_ <- tryNonAsync $ createAnnexDirectory $ takeDirectory tfile
mvar <- liftIO $ newMVar 0
return (liftIO . updater tfile mvar, tfile, mvar)
where
updater tfile mvar b = modifyMVar_ mvar $ \oldbytes -> do
let newbytes = fromBytesProcessed b
if newbytes - oldbytes >= mindelta
then do
let info' = info { bytesComplete = Just newbytes }
_ <- tryIO $ writeTransferInfoFile info' tfile
return newbytes
else return oldbytes
{- The minimum change in bytesComplete that is worth
- updating a transfer info file for is 1% of the total
- keySize, rounded down. -}
mindelta = case keySize (transferKey t) of
Just sz -> sz `div` 100
Nothing -> 100 * 1024 -- arbitrarily, 100 kb
startTransferInfo :: Maybe FilePath -> IO TransferInfo
startTransferInfo file = TransferInfo
<$> (Just . utcTimeToPOSIXSeconds <$> getCurrentTime)
#ifndef mingw32_HOST_OS
<*> pure Nothing -- pid not stored in file, so omitted for speed
#else
<*> (Just <$> getPID)
#endif
<*> pure Nothing -- tid ditto
<*> pure Nothing -- not 0; transfer may be resuming
<*> pure Nothing
<*> pure file
<*> pure False
{- If a transfer is still running, returns its TransferInfo. -}
checkTransfer :: Transfer -> Annex (Maybe TransferInfo)
checkTransfer t = do
tfile <- fromRepo $ transferFile t
#ifndef mingw32_HOST_OS
mode <- annexFileMode
mfd <- liftIO $ catchMaybeIO $
openFd (transferLockFile tfile) ReadOnly (Just mode) defaultFileFlags
case mfd of
Nothing -> return Nothing -- failed to open file; not running
Just fd -> do
locked <- liftIO $
getLock fd (WriteLock, AbsoluteSeek, 0, 0)
liftIO $ closeFd fd
case locked of
Nothing -> return Nothing
Just (pid, _) -> liftIO $ catchDefaultIO Nothing $
readTransferInfoFile (Just pid) tfile
#else
v <- liftIO $ lockShared $ transferLockFile tfile
liftIO $ case v of
Nothing -> catchDefaultIO Nothing $
readTransferInfoFile Nothing tfile
Just lockhandle -> do
dropLock lockhandle
void $ tryIO $ removeFile $ transferLockFile tfile
return Nothing
#endif
{- Gets all currently running transfers. -}
getTransfers :: Annex [(Transfer, TransferInfo)]
getTransfers = do
transfers <- mapMaybe parseTransferFile . concat <$> findfiles
infos <- mapM checkTransfer transfers
return $ map (\(t, Just i) -> (t, i)) $
filter running $ zip transfers infos
where
findfiles = liftIO . mapM dirContentsRecursive
=<< mapM (fromRepo . transferDir) [Download, Upload]
running (_, i) = isJust i
{- Gets failed transfers for a given remote UUID. -}
getFailedTransfers :: UUID -> Annex [(Transfer, TransferInfo)]
getFailedTransfers u = catMaybes <$> (liftIO . getpairs =<< concat <$> findfiles)
where
getpairs = mapM $ \f -> do
let mt = parseTransferFile f
mi <- readTransferInfoFile Nothing f
return $ case (mt, mi) of
(Just t, Just i) -> Just (t, i)
_ -> Nothing
findfiles = liftIO . mapM dirContentsRecursive
=<< mapM (fromRepo . failedTransferDir u) [Download, Upload]
clearFailedTransfers :: UUID -> Annex [(Transfer, TransferInfo)]
clearFailedTransfers u = do
failed <- getFailedTransfers u
mapM_ (removeFailedTransfer . fst) failed
return failed
removeFailedTransfer :: Transfer -> Annex ()
removeFailedTransfer t = do
f <- fromRepo $ failedTransferFile t
liftIO $ void $ tryIO $ removeFile f
recordFailedTransfer :: Transfer -> TransferInfo -> Annex ()
recordFailedTransfer t info = do
failedtfile <- fromRepo $ failedTransferFile t
createAnnexDirectory $ takeDirectory failedtfile
liftIO $ writeTransferInfoFile info failedtfile
{- The transfer information file to use for a given Transfer. -}
transferFile :: Transfer -> Git.Repo -> FilePath
transferFile (Transfer direction u key) r = transferDir direction r
</> filter (/= '/') (fromUUID u)
</> keyFile key
{- The transfer information file to use to record a failed Transfer -}
failedTransferFile :: Transfer -> Git.Repo -> FilePath
failedTransferFile (Transfer direction u key) r = failedTransferDir u direction r
</> keyFile key
{- The transfer lock file corresponding to a given transfer info file. -}
transferLockFile :: FilePath -> FilePath
transferLockFile infofile = let (d,f) = splitFileName infofile in
combine d ("lck." ++ f)
{- Parses a transfer information filename to a Transfer. -}
parseTransferFile :: FilePath -> Maybe Transfer
parseTransferFile file
| "lck." `isPrefixOf` takeFileName file = Nothing
| otherwise = case drop (length bits - 3) bits of
[direction, u, key] -> Transfer
<$> readLcDirection direction
<*> pure (toUUID u)
<*> fileKey key
_ -> Nothing
where
bits = splitDirectories file
writeTransferInfoFile :: TransferInfo -> FilePath -> IO ()
writeTransferInfoFile info tfile = writeFileAnyEncoding tfile $
writeTransferInfo info
{- File format is a header line containing the startedTime and any
- bytesComplete value. Followed by a newline and the associatedFile.
-
- On unix, the transferPid is not included; instead it is obtained
- by looking at the process that locks the file.
-
- On windows, the transferPid is included, as a second line.
-}
writeTransferInfo :: TransferInfo -> String
writeTransferInfo info = unlines
[ (maybe "" show $ startedTime info) ++
(maybe "" (\b -> ' ' : show b) (bytesComplete info))
#ifdef mingw32_HOST_OS
, maybe "" show (transferPid info)
#endif
, fromMaybe "" $ associatedFile info -- comes last; arbitrary content
]
readTransferInfoFile :: Maybe PID -> FilePath -> IO (Maybe TransferInfo)
readTransferInfoFile mpid tfile = catchDefaultIO Nothing $
readTransferInfo mpid <$> readFileStrictAnyEncoding tfile
readTransferInfo :: Maybe PID -> String -> Maybe TransferInfo
readTransferInfo mpid s = TransferInfo
<$> time
#ifdef mingw32_HOST_OS
<*> pure (if isJust mpid then mpid else mpid')
#else
<*> pure mpid
#endif
<*> pure Nothing
<*> pure Nothing
<*> bytes
<*> pure (if null filename then Nothing else Just filename)
<*> pure False
where
#ifdef mingw32_HOST_OS
(firstline, otherlines) = separate (== '\n') s
(secondline, rest) = separate (== '\n') otherlines
mpid' = readish secondline
#else
(firstline, rest) = separate (== '\n') s
#endif
filename
| end rest == "\n" = beginning rest
| otherwise = rest
bits = split " " firstline
numbits = length bits
time = if numbits > 0
then Just <$> parsePOSIXTime =<< headMaybe bits
else pure Nothing -- not failure
bytes = if numbits > 1
then Just <$> readish =<< headMaybe (drop 1 bits)
else pure Nothing -- not failure
parsePOSIXTime :: String -> Maybe POSIXTime
parsePOSIXTime s = utcTimeToPOSIXSeconds
<$> parseTime defaultTimeLocale "%s%Qs" s
{- The directory holding transfer information files for a given Direction. -}
transferDir :: Direction -> Git.Repo -> FilePath
transferDir direction r = gitAnnexTransferDir r </> showLcDirection direction
{- The directory holding failed transfer information files for a given
- Direction and UUID -}
failedTransferDir :: UUID -> Direction -> Git.Repo -> FilePath
failedTransferDir u direction r = gitAnnexTransferDir r
</> "failed"
</> showLcDirection direction
</> filter (/= '/') (fromUUID u)
instance Arbitrary TransferInfo where
arbitrary = TransferInfo
<$> arbitrary
<*> arbitrary
<*> pure Nothing -- cannot generate a ThreadID
<*> pure Nothing -- remote not needed
<*> arbitrary
-- associated file cannot be empty (but can be Nothing)
<*> arbitrary `suchThat` (/= Just "")
<*> arbitrary
prop_read_write_transferinfo :: TransferInfo -> Bool
prop_read_write_transferinfo info
| isJust (transferRemote info) = True -- remote not stored
| isJust (transferTid info) = True -- tid not stored
| otherwise = Just (info { transferPaused = False }) == info'
where
info' = readTransferInfo (transferPid info) (writeTransferInfo info)