git-annex/Annex/Branch/Transitions.hs
2015-01-21 12:50:09 -04:00

64 lines
2.3 KiB
Haskell

{- git-annex branch transitions
-
- Copyright 2013 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Annex.Branch.Transitions (
FileTransition(..),
getTransitionCalculator
) where
import Logs
import Logs.Transitions
import qualified Logs.UUIDBased as UUIDBased
import qualified Logs.Presence.Pure as Presence
import qualified Logs.Chunk.Pure as Chunk
import Types.TrustLevel
import Types.UUID
import qualified Data.Map as M
import Data.Default
data FileTransition
= ChangeFile String
| RemoveFile
| PreserveFile
type TransitionCalculator = FilePath -> String -> TrustMap -> FileTransition
getTransitionCalculator :: Transition -> Maybe TransitionCalculator
getTransitionCalculator ForgetGitHistory = Nothing
getTransitionCalculator ForgetDeadRemotes = Just dropDead
dropDead :: FilePath -> String -> TrustMap -> FileTransition
dropDead f content trustmap = case getLogVariety f of
Just UUIDBasedLog
-- Don't remove the dead repo from the trust log,
-- because git remotes may still exist, and they need
-- to still know it's dead.
| f == trustLog -> PreserveFile
| otherwise -> ChangeFile $ UUIDBased.showLog id $ dropDeadFromMapLog trustmap id $ UUIDBased.parseLog Just content
Just NewUUIDBasedLog -> ChangeFile $
UUIDBased.showLogNew id $ dropDeadFromMapLog trustmap id $ UUIDBased.parseLogNew Just content
Just (ChunkLog _) -> ChangeFile $
Chunk.showLog $ dropDeadFromMapLog trustmap fst $ Chunk.parseLog content
Just (PresenceLog _) ->
let newlog = Presence.compactLog $ dropDeadFromPresenceLog trustmap $ Presence.parseLog content
in if null newlog
then RemoveFile
else ChangeFile $ Presence.showLog newlog
Just OtherLog -> PreserveFile
Nothing -> PreserveFile
dropDeadFromMapLog :: Ord k => TrustMap -> (k -> UUID) -> M.Map k v -> M.Map k v
dropDeadFromMapLog trustmap getuuid = M.filterWithKey $ \k _v -> notDead trustmap getuuid k
{- Presence logs can contain UUIDs or other values. Any line that matches
- a dead uuid is dropped; any other values are passed through. -}
dropDeadFromPresenceLog :: TrustMap -> [Presence.LogLine] -> [Presence.LogLine]
dropDeadFromPresenceLog trustmap = filter $ notDead trustmap (toUUID . Presence.info)
notDead :: TrustMap -> (v -> UUID) -> v -> Bool
notDead trustmap a v = M.findWithDefault def (a v) trustmap /= DeadTrusted