git-annex/Logs/ContentIdentifier.hs
Joey Hess 6280af2901
generate more compact git-annex branch for imports
Especially from borg, where the content identifier logs
all end up being the same identical file!

But also, for other imports, the location tracking logs can,
in some cases, be identical files.

Bonus optimisation: Avoid looking up (and parsing when set)
GIT_ANNEX_VECTOR_CLOCK env var every time a log is written to.
Although the lookup does happen at startup even when no
log will be written now.
2020-12-23 15:25:16 -04:00

52 lines
1.6 KiB
Haskell

{- Remote content identifier logs.
-
- Copyright 2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.ContentIdentifier (
module X,
recordContentIdentifier,
getContentIdentifiers,
) where
import Annex.Common
import Logs
import Logs.MapLog
import Types.Import
import Types.RemoteState
import qualified Annex.Branch
import Logs.ContentIdentifier.Pure as X
import qualified Annex
import qualified Data.Map as M
import Data.List.NonEmpty (NonEmpty(..))
import qualified Data.List.NonEmpty as NonEmpty
-- | Records a remote's content identifier and the key that it corresponds to.
--
-- A remote may use multiple content identifiers for the same key over time,
-- so ones that were recorded before are preserved.
recordContentIdentifier :: RemoteStateHandle -> ContentIdentifier -> Key -> Annex ()
recordContentIdentifier (RemoteStateHandle u) cid k = do
c <- currentVectorClock
config <- Annex.getGitConfig
Annex.Branch.maybeChange (remoteContentIdentifierLogFile config k) $
addcid c . parseLog
where
addcid c v
| cid `elem` l = Nothing -- no change needed
| otherwise = Just $ buildLog $
changeMapLog c u (cid :| l) v
where
m = simpleMap v
l = contentIdentifierList (M.lookup u m)
-- | Get all known content identifiers for a key.
getContentIdentifiers :: Key -> Annex [(RemoteStateHandle, [ContentIdentifier])]
getContentIdentifiers k = do
config <- Annex.getGitConfig
map (\(u, l) -> (RemoteStateHandle u, NonEmpty.toList l) )
. M.toList . simpleMap . parseLog
<$> Annex.Branch.get (remoteContentIdentifierLogFile config k)