git-annex/Logs/UUID.hs
Joey Hess ed79596b75 noop
2012-04-21 23:32:33 -04:00

89 lines
2.6 KiB
Haskell

{- git-annex uuids
-
- Each git repository used by git-annex has an annex.uuid setting that
- uniquely identifies that repository.
-
- UUIDs of remotes are cached in git config, using keys named
- remote.<name>.annex-uuid
-
- uuid.log stores a list of known uuids, and their descriptions.
-
- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.UUID (
describeUUID,
recordUUID,
uuidMap
) where
import qualified Data.Map as M
import Data.Time.Clock.POSIX
import Common.Annex
import qualified Annex.Branch
import Logs.UUIDBased
import qualified Annex.UUID
{- Filename of uuid.log. -}
logfile :: FilePath
logfile = "uuid.log"
{- Records a description for a uuid in the log. -}
describeUUID :: UUID -> String -> Annex ()
describeUUID uuid desc = do
ts <- liftIO getPOSIXTime
Annex.Branch.change logfile $
showLog id . changeLog ts uuid 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 (Date $ newertime v) fixedvalue)
| otherwise = (k, v)
where
kuuid = fromUUID k
isbad = not (isuuid kuuid) && 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 (Date d) _) = d + minimumPOSIXTimeSlice
newertime (LogEntry Unknown _) = minimumPOSIXTimeSlice
minimumPOSIXTimeSlice = 0.000001
isuuid s = length s == 36 && length (split "-" s) == 5
{- Records the uuid in the log, if it's not already there. -}
recordUUID :: UUID -> Annex ()
recordUUID u = go . M.lookup u =<< uuidMap
where
go (Just "") = set
go Nothing = set
go _ = noop
set = describeUUID u ""
{- Read the uuidLog into a simple Map.
-
- The UUID of the current repository is included explicitly, since
- it may not have been described and so otherwise would not appear. -}
uuidMap :: Annex (M.Map UUID String)
uuidMap = do
m <- (simpleMap . parseLog Just) <$> Annex.Branch.get logfile
u <- Annex.UUID.getUUID
return $ M.insertWith' preferold u "" m
where
preferold = flip const