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