git-annex/Logs/Difference.hs
Joey Hess ba3825441c rework Differences data type
Eliminated complexity and future proofed. The most important change is that
all functions over Difference are now total; any Difference that can be
expressed should be handled. Avoids needs for sanity checking of inputs,
and version skew with the future.

Also, the difference.log now serializes a [Difference], not a Differences.
This saves space and keeps it simpler.

Note that [Difference] might contain conflicting differences (eg,
[Version5, Version6]. In this case, one of them needs to consistently win
over the others, probably based on Ord.
2015-01-28 13:50:02 -04:00

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1.2 KiB
Haskell

{- git-annex difference log
-
- Copyright 2015 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.Difference (
recordDifferences,
recordedDifferences,
recordedDifferencesFor,
module Logs.Difference.Pure
) where
import Data.Monoid
import Data.Time.Clock.POSIX
import qualified Data.Map as M
import Common.Annex
import Types.Difference
import qualified Annex.Branch
import Logs
import Logs.UUIDBased
import Logs.Difference.Pure
recordDifferences :: Differences -> UUID -> Annex ()
recordDifferences (Differences differences) uuid = do
ts <- liftIO getPOSIXTime
Annex.Branch.change differenceLog $
showLog id . changeLog ts uuid (show differences) . parseLog Just
recordDifferences UnknownDifferences _ = return ()
-- Map of UUIDs that have Differences recorded.
-- If a new version of git-annex has added a Difference this version
-- doesn't know about, it will contain UnknownDifferences.
recordedDifferences :: Annex (M.Map UUID Differences)
recordedDifferences = parseDifferencesLog <$> Annex.Branch.get differenceLog
recordedDifferencesFor :: UUID -> Annex Differences
recordedDifferencesFor u = fromMaybe mempty . M.lookup u
<$> recordedDifferences