git-annex/Utility/Exception.hs
Joey Hess e213ef310f git-annex (5.20140717) unstable; urgency=high
* Fix minor FD leak in journal code. Closes: #754608
  * direct: Fix handling of case where a work tree subdirectory cannot
    be written to due to permissions.
  * migrate: Avoid re-checksumming when migrating from hashE to hash backend.
  * uninit: Avoid failing final removal in some direct mode repositories
    due to file modes.
  * S3: Deal with AWS ACL configurations that do not allow creating or
    checking the location of a bucket, but only reading and writing content to
    it.
  * resolvemerge: New plumbing command that runs the automatic merge conflict
    resolver.
  * Deal with change in git 2.0 that made indirect mode merge conflict
    resolution leave behind old files.
  * sync: Fix git sync with local git remotes even when they don't have an
    annex.uuid set. (The assistant already did so.)
  * Set gcrypt-publish-participants when setting up a gcrypt repository,
    to avoid unncessary passphrase prompts.
    This is a security/usability tradeoff. To avoid exposing the gpg key
    ids who can decrypt the repository, users can unset
    gcrypt-publish-participants.
  * Install nautilus hooks even when ~/.local/share/nautilus/ does not yet
    exist, since it is not automatically created for Gnome 3 users.
  * Windows: Move .vbs files out of git\bin, to avoid that being in the
    PATH, which caused some weird breakage. (Thanks, divB)
  * Windows: Fix locking issue that prevented the webapp starting
    (since 5.20140707).

# imported from the archive
2014-07-17 11:27:25 -04:00

59 lines
1.8 KiB
Haskell

{- Simple IO exception handling (and some more)
-
- Copyright 2011-2012 Joey Hess <joey@kitenet.net>
-
- License: BSD-2-clause
-}
{-# LANGUAGE ScopedTypeVariables #-}
module Utility.Exception where
import Control.Exception
import qualified Control.Exception as E
import Control.Applicative
import Control.Monad
import System.IO.Error (isDoesNotExistError)
import Utility.Data
{- Catches IO errors and returns a Bool -}
catchBoolIO :: IO Bool -> IO Bool
catchBoolIO = catchDefaultIO False
{- Catches IO errors and returns a Maybe -}
catchMaybeIO :: IO a -> IO (Maybe a)
catchMaybeIO a = catchDefaultIO Nothing $ Just <$> a
{- Catches IO errors and returns a default value. -}
catchDefaultIO :: a -> IO a -> IO a
catchDefaultIO def a = catchIO a (const $ return def)
{- Catches IO errors and returns the error message. -}
catchMsgIO :: IO a -> IO (Either String a)
catchMsgIO a = either (Left . show) Right <$> tryIO a
{- catch specialized for IO errors only -}
catchIO :: IO a -> (IOException -> IO a) -> IO a
catchIO = E.catch
{- try specialized for IO errors only -}
tryIO :: IO a -> IO (Either IOException a)
tryIO = try
{- Catches all exceptions except for async exceptions.
- This is often better to use than catching them all, so that
- ThreadKilled and UserInterrupt get through.
-}
catchNonAsync :: IO a -> (SomeException -> IO a) -> IO a
catchNonAsync a onerr = a `catches`
[ Handler (\ (e :: AsyncException) -> throw e)
, Handler (\ (e :: SomeException) -> onerr e)
]
tryNonAsync :: IO a -> IO (Either SomeException a)
tryNonAsync a = (Right <$> a) `catchNonAsync` (return . Left)
{- Catches only DoesNotExist exceptions, and lets all others through. -}
tryWhenExists :: IO a -> IO (Maybe a)
tryWhenExists a = eitherToMaybe <$>
tryJust (guard . isDoesNotExistError) a