69 lines
1.8 KiB
Haskell
69 lines
1.8 KiB
Haskell
{- git-annex concurrent state
|
|
-
|
|
- Copyright 2015 Joey Hess <id@joeyh.name>
|
|
-
|
|
- Licensed under the GNU GPL version 3 or higher.
|
|
-}
|
|
|
|
module Annex.Concurrent where
|
|
|
|
import Annex.Common
|
|
import Annex
|
|
import Annex.CatFile
|
|
import Annex.CheckAttr
|
|
import Annex.HashObject
|
|
import Annex.CheckIgnore
|
|
import qualified Annex.Queue
|
|
|
|
import qualified Data.Map as M
|
|
|
|
{- Allows forking off a thread that uses a copy of the current AnnexState
|
|
- to run an Annex action.
|
|
-
|
|
- The returned IO action can be used to start the thread.
|
|
- It returns an Annex action that must be run in the original
|
|
- calling context to merge the forked AnnexState back into the
|
|
- current AnnexState.
|
|
-}
|
|
forkState :: Annex a -> Annex (IO (Annex a))
|
|
forkState a = do
|
|
st <- dupState
|
|
return $ do
|
|
(ret, newst) <- run st a
|
|
return $ do
|
|
mergeState newst
|
|
return ret
|
|
|
|
{- Returns a copy of the current AnnexState that is safe to be
|
|
- used when forking off a thread.
|
|
-
|
|
- After an Annex action is run using this AnnexState, it
|
|
- should be merged back into the current Annex's state,
|
|
- by calling mergeState.
|
|
-}
|
|
dupState :: Annex AnnexState
|
|
dupState = do
|
|
st <- Annex.getState id
|
|
-- avoid sharing eg, open file handles
|
|
return $ st
|
|
{ Annex.workers = []
|
|
, Annex.catfilehandles = M.empty
|
|
, Annex.checkattrhandle = Nothing
|
|
, Annex.checkignorehandle = Nothing
|
|
}
|
|
|
|
{- Merges the passed AnnexState into the current Annex state.
|
|
- Also closes various handles in it. -}
|
|
mergeState :: AnnexState -> Annex ()
|
|
mergeState st = do
|
|
st' <- liftIO $ snd <$> run st closehandles
|
|
forM_ (M.toList $ Annex.cleanup st') $
|
|
uncurry addCleanup
|
|
Annex.Queue.mergeFrom st'
|
|
changeState $ \s -> s { errcounter = errcounter s + errcounter st' }
|
|
where
|
|
closehandles = do
|
|
catFileStop
|
|
checkAttrStop
|
|
hashObjectStop
|
|
checkIgnoreStop
|