git-annex/Logs/Export.hs
Joey Hess bfc9039ead
convert git-annex branch access to ByteStrings and Builders
Most of the individual logs are not converted yet, only presense logs
have an efficient ByteString Builder implemented so far. The rest
convert to and from String.
2019-01-03 13:21:48 -04:00

127 lines
4 KiB
Haskell

{- git-annex export log
-
- Copyright 2017 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.Export where
import qualified Data.Map as M
import Annex.Common
import qualified Annex.Branch
import qualified Git
import Git.Sha
import Git.FilePath
import Logs
import Logs.MapLog
import Annex.UUID
data Exported = Exported
{ exportedTreeish :: Git.Ref
, incompleteExportedTreeish :: [Git.Ref]
}
deriving (Eq, Show)
data ExportParticipants = ExportParticipants
{ exportFrom :: UUID
, exportTo :: UUID
}
deriving (Eq, Ord)
data ExportChange = ExportChange
{ oldTreeish :: [Git.Ref]
, newTreeish :: Git.Ref
}
-- | Get what's been exported to a special remote.
--
-- If the list contains multiple items, there was an export conflict,
-- and different trees were exported to the same special remote.
getExport :: UUID -> Annex [Exported]
getExport remoteuuid = nub . mapMaybe get . M.toList . simpleMap
. parseExportLog
. decodeBL
<$> Annex.Branch.get exportLog
where
get (ep, exported)
| exportTo ep == remoteuuid = Just exported
| otherwise = Nothing
-- | Record a change in what's exported to a special remote.
--
-- This is called before an export begins uploading new files to the
-- remote, but after it's cleaned up any files that need to be deleted
-- from the old treeish.
--
-- Any entries in the log for the oldTreeish will be updated to the
-- newTreeish. This way, when multiple repositories are exporting to
-- the same special remote, there's no conflict as long as they move
-- forward in lock-step.
--
-- Also, the newTreeish is grafted into the git-annex branch. This is done
-- to ensure that it's available later.
recordExport :: UUID -> ExportChange -> Annex ()
recordExport remoteuuid ec = do
c <- liftIO currentVectorClock
u <- getUUID
let ep = ExportParticipants { exportFrom = u, exportTo = remoteuuid }
let exported = Exported (newTreeish ec) []
Annex.Branch.change exportLog $
encodeBL . showExportLog
. changeMapLog c ep exported
. M.mapWithKey (updateothers c u)
. parseExportLog . decodeBL
where
updateothers c u ep le@(LogEntry _ exported@(Exported { exportedTreeish = t }))
| u == exportFrom ep || remoteuuid /= exportTo ep || t `notElem` oldTreeish ec = le
| otherwise = LogEntry c (exported { exportedTreeish = newTreeish ec })
-- | Record the beginning of an export, to allow cleaning up from
-- interrupted exports.
--
-- This is called before any changes are made to the remote.
recordExportBeginning :: UUID -> Git.Ref -> Annex ()
recordExportBeginning remoteuuid newtree = do
c <- liftIO currentVectorClock
u <- getUUID
let ep = ExportParticipants { exportFrom = u, exportTo = remoteuuid }
old <- fromMaybe (Exported emptyTree [])
. M.lookup ep . simpleMap
. parseExportLog
. decodeBL
<$> Annex.Branch.get exportLog
let new = old { incompleteExportedTreeish = nub (newtree:incompleteExportedTreeish old) }
Annex.Branch.change exportLog $
encodeBL . showExportLog
. changeMapLog c ep new
. parseExportLog . decodeBL
Annex.Branch.graftTreeish newtree (asTopFilePath "export.tree")
parseExportLog :: String -> MapLog ExportParticipants Exported
parseExportLog = parseMapLog parseExportParticipants parseExported
showExportLog :: MapLog ExportParticipants Exported -> String
showExportLog = showMapLog formatExportParticipants formatExported
formatExportParticipants :: ExportParticipants -> String
formatExportParticipants ep =
fromUUID (exportFrom ep) ++ ':' : fromUUID (exportTo ep)
parseExportParticipants :: String -> Maybe ExportParticipants
parseExportParticipants s = case separate (== ':') s of
("",_) -> Nothing
(_,"") -> Nothing
(f,t) -> Just $ ExportParticipants
{ exportFrom = toUUID f
, exportTo = toUUID t
}
formatExported :: Exported -> String
formatExported exported = unwords $ map Git.fromRef $
exportedTreeish exported : incompleteExportedTreeish exported
parseExported :: String -> Maybe Exported
parseExported s = case words s of
(et:it) -> Just $ Exported (Git.Ref et) (map Git.Ref it)
_ -> Nothing