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|
{- git-remote-daemon utilities
-
- Copyright 2014-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module RemoteDaemon.Common
( liftAnnex
, inLocalRepo
, checkShouldFetch
, ConnectionStatus(..)
, robustConnection
) where
import qualified Annex
import Annex.Common
import RemoteDaemon.Types
import qualified Git
import Annex.CatFile
import Utility.ThreadScheduler
import Control.Concurrent
-- Runs an Annex action. Long-running actions should be avoided,
-- since only one liftAnnex can be running at a time, across all
-- transports.
liftAnnex :: TransportHandle -> Annex a -> IO a
liftAnnex (TransportHandle _ annexstate) a = do
st <- takeMVar annexstate
(r, st') <- Annex.run st a
putMVar annexstate st'
return r
inLocalRepo :: TransportHandle -> (Git.Repo -> IO a) -> IO a
inLocalRepo (TransportHandle (LocalRepo g) _) a = a g
-- Check if some shas should be fetched from the remote,
-- and presumably later merged.
checkShouldFetch :: RemoteGitConfig -> TransportHandle -> [Git.Sha] -> IO Bool
checkShouldFetch gc transporthandle shas
| remoteAnnexPull gc = checkNewShas transporthandle shas
| otherwise = return False
-- Check if any of the shas are actally new in the local git repo,
-- to avoid unnecessary fetching.
checkNewShas :: TransportHandle -> [Git.Sha] -> IO Bool
checkNewShas transporthandle = check
where
check [] = return True
check (r:rs) = maybe (check rs) (const $ return False)
=<< liftAnnex transporthandle (catObjectDetails r)
data ConnectionStatus = ConnectionStopping | ConnectionClosed
{- Make connection robust, retrying on error, with exponential backoff. -}
robustConnection :: Int -> IO ConnectionStatus -> IO ()
robustConnection backoff a =
caught =<< a `catchNonAsync` (const $ return ConnectionClosed)
where
caught ConnectionStopping = return ()
caught ConnectionClosed = do
threadDelaySeconds (Seconds backoff)
robustConnection increasedbackoff a
increasedbackoff
| b2 > maxbackoff = maxbackoff
| otherwise = b2
where
b2 = backoff * 2
maxbackoff = 3600 -- one hour
|
