git-annex/Remote/Helper/P2P.hs
Joey Hess 62e152f210
incremental checksum on download from ssh or p2p
Checksum as content is received from a remote git-annex repository, rather
than doing it in a second pass.

Not tested at all yet, but I imagine it will work!

Not implemented for any special remotes, and also not implemented for
copies from local remotes. It may be that, for local remotes, it will
suffice to use rsync, rely on its checksumming, and simply return Verified.
(It would still make a checksumming pass when cp is used for COW, I guess.)
2021-02-09 17:03:27 -04:00

77 lines
2.6 KiB
Haskell

{- Helpers for remotes using the git-annex P2P protocol.
-
- Copyright 2016-2021 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE RankNTypes #-}
module Remote.Helper.P2P where
import Annex.Common
import qualified P2P.Protocol as P2P
import P2P.IO
import Types.Remote
import Annex.Content
import Messages.Progress
import Utility.Metered
import Types.NumCopies
import Backend
import Control.Concurrent
-- Runs a Proto action using a connection it sets up.
type ProtoRunner a = P2P.Proto a -> Annex (Maybe a)
-- Runs a Proto action using a ClosableConnection.
type ProtoConnRunner c = forall a. P2P.Proto a -> ClosableConnection c -> Annex (ClosableConnection c, Maybe a)
-- Runs an Annex action with a connection from the pool, adding it back to
-- the pool when done.
type WithConn a c = (ClosableConnection c -> Annex (ClosableConnection c, a)) -> Annex a
store :: (MeterUpdate -> ProtoRunner Bool) -> Key -> AssociatedFile -> MeterUpdate -> Annex ()
store runner k af p = do
let sizer = KeySizer k (fmap (toRawFilePath . fst) <$> prepSendAnnex k)
metered (Just p) sizer $ \_ p' ->
runner p' (P2P.put k af p') >>= \case
Just True -> return ()
Just False -> giveup "transfer failed"
Nothing -> remoteUnavail
retrieve :: VerifyConfig -> (MeterUpdate -> ProtoRunner (Bool, Verification)) -> Key -> AssociatedFile -> FilePath -> MeterUpdate -> Annex Verification
retrieve verifyconfig runner k af dest p = do
iv <- startVerifyKeyContentIncrementally verifyconfig k
metered (Just p) k $ \m p' ->
runner p' (P2P.get dest k iv af m p') >>= \case
Just (True, v) -> return v
Just (False, _) -> giveup "transfer failed"
Nothing -> remoteUnavail
remove :: ProtoRunner Bool -> Key -> Annex ()
remove runner k = runner (P2P.remove k) >>= \case
Just True -> return ()
Just False -> giveup "removing content from remote failed"
Nothing -> remoteUnavail
checkpresent :: ProtoRunner Bool -> Key -> Annex Bool
checkpresent runner k = maybe remoteUnavail return =<< runner (P2P.checkPresent k)
lock :: WithConn a c -> ProtoConnRunner c -> UUID -> Key -> (VerifiedCopy -> Annex a) -> Annex a
lock withconn connrunner u k callback = withconn $ \conn -> do
connv <- liftIO $ newMVar conn
let runproto d p = do
c <- liftIO $ takeMVar connv
(c', mr) <- connrunner p c
liftIO $ putMVar connv c'
return (fromMaybe d mr)
r <- P2P.lockContentWhile runproto k go
conn' <- liftIO $ takeMVar connv
return (conn', r)
where
go False = giveup "can't lock content"
go True = withVerifiedCopy LockedCopy u (return True) callback
remoteUnavail :: a
remoteUnavail = giveup "can't connect to remote"