git-annex/Logs/UUID.hs
2019-01-03 11:37:02 -04:00

81 lines
2.5 KiB
Haskell

{- git-annex uuid log
-
- uuid.log stores a list of known uuids, and their descriptions.
-
- Copyright 2010-2012 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.UUID (
uuidLog,
describeUUID,
uuidDescMap,
uuidDescMapLoad
) where
import Types.UUID
import Annex.Common
import Annex.VectorClock
import qualified Annex
import qualified Annex.Branch
import Logs
import Logs.UUIDBased
import qualified Annex.UUID
import qualified Data.Map.Strict as M
{- Records a description for a uuid in the log. -}
describeUUID :: UUID -> UUIDDesc -> Annex ()
describeUUID uuid desc = do
c <- liftIO currentVectorClock
Annex.Branch.change uuidLog $
showLog id . changeLog c uuid (fromUUIDDesc desc) . fixBadUUID . parseLog Just
{- Temporarily here to fix badly formatted uuid logs generated by
- versions 3.20111105 and 3.20111025.
-
- Those logs contain entries with the UUID and description flipped.
- Due to parsing, if the description is multiword, only the first
- will be taken to be the UUID. So, if the UUID of an entry does
- not look like a UUID, and the last word of the description does,
- flip them back.
-}
fixBadUUID :: Log String -> Log String
fixBadUUID = M.fromList . map fixup . M.toList
where
fixup (k, v)
| isbad = (fixeduuid, LogEntry (newertime v) fixedvalue)
| otherwise = (k, v)
where
kuuid = fromUUID k
isbad = not (isuuid kuuid) && not (null ws) && isuuid lastword
ws = words $ value v
lastword = Prelude.last ws
fixeduuid = toUUID lastword
fixedvalue = unwords $ kuuid: Prelude.init ws
-- For the fixed line to take precidence, it should be
-- slightly newer, but only slightly.
newertime (LogEntry (VectorClock c) _) = VectorClock (c + minimumPOSIXTimeSlice)
newertime (LogEntry Unknown _) = VectorClock minimumPOSIXTimeSlice
minimumPOSIXTimeSlice = 0.000001
isuuid s = length s == 36 && length (splitc '-' s) == 5
{- The map is cached for speed. -}
uuidDescMap :: Annex UUIDDescMap
uuidDescMap = maybe uuidDescMapLoad return =<< Annex.getState Annex.uuiddescmap
{- Read the uuidLog into a simple Map.
-
- The UUID of the current repository is included explicitly, since
- it may not have been described and otherwise would not appear. -}
uuidDescMapLoad :: Annex UUIDDescMap
uuidDescMapLoad = do
m <- (simpleMap . parseLog (Just . UUIDDesc . encodeBS))
<$> Annex.Branch.get uuidLog
u <- Annex.UUID.getUUID
let m' = M.insertWith preferold u mempty m
Annex.changeState $ \s -> s { Annex.uuiddescmap = Just m' }
return m'
where
preferold = flip const