git-annex/Assistant/Pushes.hs
2012-11-03 14:16:17 -04:00

40 lines
1.2 KiB
Haskell

{- git-annex assistant push tracking
-
- Copyright 2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Pushes where
import Assistant.Common
import Assistant.Types.Pushes
import Control.Concurrent.STM
import Data.Time.Clock
import qualified Data.Map as M
{- Blocks until there are failed pushes.
- Returns Remotes whose pushes failed a given time duration or more ago.
- (This may be an empty list.) -}
getFailedPushesBefore :: NominalDiffTime -> Assistant [Remote]
getFailedPushesBefore duration = do
v <- getAssistant failedPushMap
liftIO $ do
m <- atomically $ readTMVar v
now <- getCurrentTime
return $ M.keys $ M.filter (not . toorecent now) m
where
toorecent now time = now `diffUTCTime` time < duration
{- Modifies the map. -}
changeFailedPushMap :: (PushMap -> PushMap) -> Assistant ()
changeFailedPushMap a = do
v <- getAssistant failedPushMap
liftIO $ atomically $ store v . a . fromMaybe M.empty =<< tryTakeTMVar v
where
{- tryTakeTMVar empties the TMVar; refill it only if
- the modified map is not itself empty -}
store v m
| m == M.empty = noop
| otherwise = putTMVar v $! m