63 lines
1.8 KiB
Haskell
63 lines
1.8 KiB
Haskell
{- exception handling in the git-annex monad
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-
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- Note that when an Annex action fails and the exception is handled
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- by these functions, any changes the action has made to the
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- AnnexState are retained. This works because the Annex monad
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- internally stores the AnnexState in a MVar.
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-
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- Copyright 2011-2014 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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{-# LANGUAGE PackageImports #-}
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{-# LANGUAGE ScopedTypeVariables #-}
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module Annex.Exception (
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bracketIO,
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bracketAnnex,
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tryAnnex,
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tryAnnexIO,
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throwAnnex,
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catchAnnex,
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catchNonAsyncAnnex,
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tryNonAsyncAnnex,
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) where
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import qualified Control.Monad.Catch as M
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import Control.Exception
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import Common.Annex
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{- Runs an Annex action, with setup and cleanup both in the IO monad. -}
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bracketIO :: IO v -> (v -> IO b) -> (v -> Annex a) -> Annex a
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bracketIO setup cleanup = M.bracket (liftIO setup) (liftIO . cleanup)
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bracketAnnex :: Annex v -> (v -> Annex b) -> (v -> Annex a) -> Annex a
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bracketAnnex = M.bracket
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{- try in the Annex monad -}
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tryAnnex :: Annex a -> Annex (Either SomeException a)
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tryAnnex = M.try
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{- try in the Annex monad, but only catching IO exceptions -}
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tryAnnexIO :: Annex a -> Annex (Either IOException a)
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tryAnnexIO = M.try
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{- throw in the Annex monad -}
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throwAnnex :: Exception e => e -> Annex a
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throwAnnex = M.throwM
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{- catch in the Annex monad -}
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catchAnnex :: Exception e => Annex a -> (e -> Annex a) -> Annex a
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catchAnnex = M.catch
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{- catchs all exceptions except for async exceptions -}
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catchNonAsyncAnnex :: Annex a -> (SomeException -> Annex a) -> Annex a
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catchNonAsyncAnnex a onerr = a `M.catches`
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[ M.Handler (\ (e :: AsyncException) -> throwAnnex e)
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, M.Handler (\ (e :: SomeException) -> onerr e)
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]
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tryNonAsyncAnnex :: Annex a -> Annex (Either SomeException a)
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tryNonAsyncAnnex a = (Right <$> a) `catchNonAsyncAnnex` (return . Left)
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