git-annex/RemoteDaemon/Common.hs
Joey Hess c2f612292a
start splitting out readonly values from AnnexState
Values in AnnexRead can be read more efficiently, without MVar overhead.
Only a few things have been moved into there, and the performance
increase so far is not likely to be noticable.

This is groundwork for putting more stuff in there, particularly a value
that indicates if debugging is enabled.

The obvious next step is to change option parsing to not run in the
Annex monad to set values in AnnexState, and instead return a pure value
that gets stored in AnnexRead.
2021-04-02 15:51:44 -04:00

71 lines
2 KiB
Haskell

{- git-remote-daemon utilities
-
- Copyright 2014-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL 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 _ stmv rd) a = do
st <- takeMVar stmv
(r, (st', _rd)) <- Annex.run (st, rd) a
putMVar stmv 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