git-annex/Annex/Exception.hs
Joey Hess bf86b5ca16 improve robustness of fromDirect and replaceFile
Made fromDirect check that a file in the tree has good content (and is not
a broken symlink either) before copying it to another file that has the
same key.

Made replaceFile clean up the temp file if the action that creates it, or
the file replacement action fails.
2013-05-25 15:06:02 -04:00

36 lines
1.1 KiB
Haskell

{- exception handling in the git-annex monad
-
- Note that when an Annex action fails and the exception is handled
- by these functions, any changes the action has made to the
- AnnexState are retained. This works because the Annex monad
- internally stores the AnnexState in a MVar.
-
- Copyright 2011-2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Exception (
bracketIO,
tryAnnex,
throw,
catchAnnex,
) where
import Prelude hiding (catch)
import "MonadCatchIO-transformers" Control.Monad.CatchIO (bracket, try, throw, catch)
import Control.Exception hiding (handle, try, throw, bracket, catch)
import Common.Annex
{- Runs an Annex action, with setup and cleanup both in the IO monad. -}
bracketIO :: IO v -> (v -> IO b) -> (v -> Annex a) -> Annex a
bracketIO setup cleanup go = bracket (liftIO setup) (liftIO . cleanup) go
{- try in the Annex monad -}
tryAnnex :: Annex a -> Annex (Either SomeException a)
tryAnnex = try
{- catch in the Annex monad -}
catchAnnex :: Exception e => Annex a -> (e -> Annex a) -> Annex a
catchAnnex = catch