1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
|
{- git-annex vector clocks
-
- We don't have a way yet to keep true distributed vector clocks.
- The next best thing is a timestamp.
-
- Copyright 2017-2020 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Types.VectorClock where
import Data.Time.Clock.POSIX
import Control.Applicative
import Prelude
import Utility.QuickCheck
-- | Some very old logs did not have any time stamp at all;
-- Unknown is used for those.
data VectorClock = Unknown | VectorClock POSIXTime
deriving (Eq, Ord, Show)
-- Unknown is oldest.
prop_VectorClock_sane :: Bool
prop_VectorClock_sane = Unknown < VectorClock 1
instance Arbitrary VectorClock where
arbitrary = VectorClock <$> arbitrary
|