git-annex/Assistant/Changes.hs
Joey Hess 362ed9f0e3 use DList for the transfer queue
Some nice efficiency gains here for list appending, although mostly
the small size of the transfer queue makes them irrelivant.
2013-04-25 01:33:44 -04:00

47 lines
1.5 KiB
Haskell

{- git-annex assistant change tracking
-
- Copyright 2012-2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Assistant.Changes where
import Assistant.Common
import Assistant.Types.Changes
import Utility.TList
import Data.Time.Clock
import Control.Concurrent.STM
{- Handlers call this when they made a change that needs to get committed. -}
madeChange :: FilePath -> ChangeInfo -> Assistant (Maybe Change)
madeChange f t = Just <$> (Change <$> liftIO getCurrentTime <*> pure f <*> pure t)
noChange :: Assistant (Maybe Change)
noChange = return Nothing
{- Indicates an add needs to be done, but has not started yet. -}
pendingAddChange :: FilePath -> Assistant (Maybe Change)
pendingAddChange f = Just <$> (PendingAddChange <$> liftIO getCurrentTime <*> pure f)
{- Gets all unhandled changes.
- Blocks until at least one change is made. -}
getChanges :: Assistant [Change]
getChanges = (atomically . getTList) <<~ changePool
{- Gets all unhandled changes, without blocking. -}
getAnyChanges :: Assistant [Change]
getAnyChanges = (atomically . takeTList) <<~ changePool
{- Puts unhandled changes back into the pool.
- Note: Original order is not preserved. -}
refillChanges :: [Change] -> Assistant ()
refillChanges cs = (atomically . flip appendTList cs) <<~ changePool
{- Records a change to the pool. -}
recordChange :: Change -> Assistant ()
recordChange c = (atomically . flip snocTList c) <<~ changePool
recordChanges :: [Change] -> Assistant ()
recordChanges = refillChanges