git-annex/CmdLine/Action.hs
Joey Hess c784ef4586 unify exception handling into Utility.Exception
Removed old extensible-exceptions, only needed for very old ghc.

Made webdav use Utility.Exception, to work after some changes in DAV's
exception handling.

Removed Annex.Exception. Mostly this was trivial, but note that
tryAnnex is replaced with tryNonAsync and catchAnnex replaced with
catchNonAsync. In theory that could be a behavior change, since the former
caught all exceptions, and the latter don't catch async exceptions.

However, in practice, nothing in the Annex monad uses async exceptions.
Grepping for throwTo and killThread only find stuff in the assistant,
which does not seem related.

Command.Add.undo is changed to accept a SomeException, and things
that use it for rollback now catch non-async exceptions, rather than
only IOExceptions.
2014-08-07 22:03:29 -04:00

69 lines
2 KiB
Haskell

{- git-annex command-line actions
-
- Copyright 2010-2014 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE BangPatterns #-}
module CmdLine.Action where
import Common.Annex
import qualified Annex
import Types.Command
import qualified Annex.Queue
type CommandActionRunner = CommandStart -> CommandCleanup
{- Runs a command, starting with the check stage, and then
- the seek stage. Finishes by printing the number of commandActions that
- failed. -}
performCommandAction :: Command -> CmdParams -> Annex ()
performCommandAction Command { cmdseek = seek, cmdcheck = c, cmdname = name } params = do
mapM_ runCheck c
Annex.changeState $ \s -> s { Annex.errcounter = 0 }
seek params
showerrcount =<< Annex.getState Annex.errcounter
where
showerrcount 0 = noop
showerrcount cnt = error $ name ++ ": " ++ show cnt ++ " failed"
{- Runs one of the actions needed to perform a command.
- Individual actions can fail without stopping the whole command,
- including by throwing IO errors (but other errors terminate the whole
- command).
-
- This should only be run in the seek stage. -}
commandAction :: CommandActionRunner
commandAction a = account =<< tryIO go
where
go = do
Annex.Queue.flushWhenFull
callCommandAction a
account (Right True) = return True
account (Right False) = incerr
account (Left err) = do
showErr err
showEndFail
incerr
incerr = do
Annex.changeState $ \s ->
let ! c = Annex.errcounter s + 1
! s' = s { Annex.errcounter = c }
in s'
return False
{- Runs a single command action through the start, perform and cleanup
- stages, without catching errors. Useful if one command wants to run
- part of another command. -}
callCommandAction :: CommandActionRunner
callCommandAction = start
where
start = stage $ maybe skip perform
perform = stage $ maybe failure cleanup
cleanup = stage $ status
stage = (=<<)
skip = return True
failure = showEndFail >> return False
status r = showEndResult r >> return r