git-annex/Assistant/ScanRemotes.hs
2015-01-21 12:50:09 -04:00

41 lines
1.2 KiB
Haskell

{- git-annex assistant remotes needing scanning
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.ScanRemotes where
import Assistant.Common
import Assistant.Types.ScanRemotes
import qualified Types.Remote as Remote
import Data.Function
import Control.Concurrent.STM
import qualified Data.Map as M
{- Blocks until there is a remote or remotes that need to be scanned.
-
- The list has higher priority remotes listed first. -}
getScanRemote :: Assistant [(Remote, ScanInfo)]
getScanRemote = do
v <- getAssistant scanRemoteMap
liftIO $ atomically $
reverse . sortBy (compare `on` scanPriority . snd) . M.toList
<$> takeTMVar v
{- Adds new remotes that need scanning. -}
addScanRemotes :: Bool -> [Remote] -> Assistant ()
addScanRemotes _ [] = noop
addScanRemotes full rs = do
v <- getAssistant scanRemoteMap
liftIO $ atomically $ do
m <- fromMaybe M.empty <$> tryTakeTMVar v
putTMVar v $ M.unionWith merge (M.fromList $ zip rs (map info rs)) m
where
info r = ScanInfo (-1 * Remote.cost r) full
merge x y = ScanInfo
{ scanPriority = max (scanPriority x) (scanPriority y)
, fullScan = fullScan x || fullScan y
}