git-annex/Annex/BranchState.hs
2011-12-12 17:38:46 -04:00

56 lines
1.5 KiB
Haskell

{- git-annex branch state management
-
- Runtime state about the git-annex branch, including a small read cache.
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.BranchState where
import Common.Annex
import Types.BranchState
import qualified Annex
getState :: Annex BranchState
getState = Annex.getState Annex.branchstate
setState :: BranchState -> Annex ()
setState state = Annex.changeState $ \s -> s { Annex.branchstate = state }
setCache :: FilePath -> String -> Annex ()
setCache file content = do
state <- getState
setState state { cachedFile = Just file, cachedContent = content }
getCache :: FilePath -> Annex (Maybe String)
getCache file = getState >>= go
where
go state
| cachedFile state == Just file =
return $ Just $ cachedContent state
| otherwise = return Nothing
invalidateCache :: Annex ()
invalidateCache = do
state <- getState
setState state { cachedFile = Nothing, cachedContent = "" }
{- Runs an action to update the branch, if it's not been updated before
- in this run of git-annex. -}
runUpdateOnce :: Annex () -> Annex ()
runUpdateOnce a = unlessM (branchUpdated <$> getState) $ do
a
disableUpdate
{- Avoids updating the branch. A useful optimisation when the branch
- is known to have not changed, or git-annex won't be relying on info
- from it. -}
disableUpdate :: Annex ()
disableUpdate = Annex.changeState setupdated
where
setupdated s = s { Annex.branchstate = new }
where
new = old { branchUpdated = True }
old = Annex.branchstate s