git-annex/Command/TransferKeys.hs
Joey Hess b40df4f0d0 reorganize numcopies code (no behavior changes)
Move stuff into Logs.NumCopies. Add a NumCopies newtype.

Better names for various serialization classes that are specific to one
thing or another.
2014-01-21 16:08:59 -04:00

139 lines
3.7 KiB
Haskell

{- git-annex command, used internally by assistant
-
- Copyright 2012, 2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE TypeSynonymInstances, FlexibleInstances #-}
module Command.TransferKeys where
import Common.Annex
import Command
import Annex.Content
import Logs.Location
import Logs.Transfer
import qualified Remote
import Types.Key
import GHC.IO.Handle
data TransferRequest = TransferRequest Direction Remote Key AssociatedFile
def :: [Command]
def = [command "transferkeys" paramNothing seek
SectionPlumbing "transfers keys"]
seek :: CommandSeek
seek = withNothing start
start :: CommandStart
start = withHandles $ \(readh, writeh) -> do
runRequests readh writeh runner
stop
where
runner (TransferRequest direction remote key file)
| direction == Upload =
upload (Remote.uuid remote) key file forwardRetry $ \p -> do
ok <- Remote.storeKey remote key file p
when ok $
Remote.logStatus remote key InfoPresent
return ok
| otherwise = download (Remote.uuid remote) key file forwardRetry $ \p ->
getViaTmp key $ \t -> Remote.retrieveKeyFile remote key file t p
{- stdin and stdout are connected with the caller, to be used for
- communication with it. But doing a transfer might involve something
- that tries to read from stdin, or write to stdout. To avoid that, close
- stdin, and duplicate stderr to stdout. Return two new handles
- that are duplicates of the original (stdin, stdout). -}
withHandles :: ((Handle, Handle) -> Annex a) -> Annex a
withHandles a = do
readh <- liftIO $ hDuplicate stdin
writeh <- liftIO $ hDuplicate stdout
liftIO $ do
nullh <- openFile devNull ReadMode
nullh `hDuplicateTo` stdin
stderr `hDuplicateTo` stdout
a (readh, writeh)
runRequests
:: Handle
-> Handle
-> (TransferRequest -> Annex Bool)
-> Annex ()
runRequests readh writeh a = do
liftIO $ do
hSetBuffering readh NoBuffering
fileEncoding readh
fileEncoding writeh
go =<< readrequests
where
go (d:u:k:f:rest) = do
case (deserialize d, deserialize u, deserialize k, deserialize f) of
(Just direction, Just uuid, Just key, Just file) -> do
mremote <- Remote.remoteFromUUID uuid
case mremote of
Nothing -> sendresult False
Just remote -> sendresult =<< a
(TransferRequest direction remote key file)
_ -> sendresult False
go rest
go [] = noop
go [""] = noop
go v = error $ "transferkeys protocol error: " ++ show v
readrequests = liftIO $ split fieldSep <$> hGetContents readh
sendresult b = liftIO $ do
hPutStrLn writeh $ serialize b
hFlush writeh
sendRequest :: Transfer -> AssociatedFile -> Handle -> IO ()
sendRequest t f h = do
hPutStr h $ intercalate fieldSep
[ serialize (transferDirection t)
, serialize (transferUUID t)
, serialize (transferKey t)
, serialize f
, "" -- adds a trailing null
]
hFlush h
readResponse :: Handle -> IO Bool
readResponse h = fromMaybe False . deserialize <$> hGetLine h
fieldSep :: String
fieldSep = "\0"
class TCSerialized a where
serialize :: a -> String
deserialize :: String -> Maybe a
instance TCSerialized Bool where
serialize True = "1"
serialize False = "0"
deserialize "1" = Just True
deserialize "0" = Just False
deserialize _ = Nothing
instance TCSerialized Direction where
serialize Upload = "u"
serialize Download = "d"
deserialize "u" = Just Upload
deserialize "d" = Just Download
deserialize _ = Nothing
instance TCSerialized AssociatedFile where
serialize (Just f) = f
serialize Nothing = ""
deserialize "" = Just Nothing
deserialize f = Just $ Just f
instance TCSerialized UUID where
serialize = fromUUID
deserialize = Just . toUUID
instance TCSerialized Key where
serialize = key2file
deserialize = file2key