git-annex/Annex/UUID.hs
Joey Hess 69f2d1dd43
remoteConfig rework
remoteAnnexConfig will avoid bugs like
a3a674d15b

Use now more generic remoteConfig in a couple places that built
non-annex config settings manually before.
2020-02-19 13:45:11 -04:00

124 lines
3.2 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
-
- Copyright 2010-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
{-# LANGUAGE OverloadedStrings #-}
module Annex.UUID (
configkeyUUID,
getUUID,
getRepoUUID,
getUncachedUUID,
isUUIDConfigured,
prepUUID,
genUUID,
genUUIDInNameSpace,
gCryptNameSpace,
removeRepoUUID,
storeUUID,
storeUUIDIn,
setUUID,
webUUID,
bitTorrentUUID,
) where
import Annex.Common
import qualified Annex
import qualified Git
import qualified Git.Config
import Git.Types
import Config
import qualified Data.UUID as U
import qualified Data.UUID.V4 as U4
import qualified Data.UUID.V5 as U5
import Data.String
configkeyUUID :: ConfigKey
configkeyUUID = annexConfig "uuid"
{- Generates a random UUID, that does not include the MAC address. -}
genUUID :: IO UUID
genUUID = toUUID <$> U4.nextRandom
{- Generates a UUID from a given string, using a namespace.
- Given the same namespace, the same string will always result
- in the same UUID. -}
genUUIDInNameSpace :: U.UUID -> String -> UUID
genUUIDInNameSpace namespace = toUUID . U5.generateNamed namespace . s2w8
{- Namespace used for UUIDs derived from git-remote-gcrypt ids. -}
gCryptNameSpace :: U.UUID
gCryptNameSpace = U5.generateNamed U5.namespaceURL $
s2w8 "http://git-annex.branchable.com/design/gcrypt/"
{- Get current repository's UUID. -}
getUUID :: Annex UUID
getUUID = annexUUID <$> Annex.getGitConfig
{- Looks up a remote repo's UUID, caching it in .git/config if
- it's not already. -}
getRepoUUID :: Git.Repo -> Annex UUID
getRepoUUID r = do
c <- toUUID <$> getConfig cachekey ""
let u = getUncachedUUID r
if c /= u && u /= NoUUID
then do
updatecache u
return u
else return c
where
updatecache u = do
g <- gitRepo
when (g /= r) $ storeUUIDIn cachekey u
cachekey = remoteAnnexConfig r "uuid"
removeRepoUUID :: Annex ()
removeRepoUUID = do
unsetConfig configkeyUUID
storeUUID NoUUID
getUncachedUUID :: Git.Repo -> UUID
getUncachedUUID = toUUID . Git.Config.get configkeyUUID ""
-- Does the repo's config have a key for the UUID?
-- True even when the key has no value.
isUUIDConfigured :: Git.Repo -> Bool
isUUIDConfigured = isJust . Git.Config.getMaybe configkeyUUID
{- Make sure that the repo has an annex.uuid setting. -}
prepUUID :: Annex ()
prepUUID = whenM ((==) NoUUID <$> getUUID) $
storeUUID =<< liftIO genUUID
storeUUID :: UUID -> Annex ()
storeUUID u = do
Annex.changeGitConfig $ \c -> c { annexUUID = u }
storeUUIDIn configkeyUUID u
storeUUIDIn :: ConfigKey -> UUID -> Annex ()
storeUUIDIn configfield = setConfig configfield . fromUUID
{- Only sets the configkey in the Repo; does not change .git/config -}
setUUID :: Git.Repo -> UUID -> IO Git.Repo
setUUID r u = do
let s = encodeBS' $ show configkeyUUID ++ "=" ++ fromUUID u
Git.Config.store s r
-- Dummy uuid for the whole web. Do not alter.
webUUID :: UUID
webUUID = UUID (fromString "00000000-0000-0000-0000-000000000001")
-- Dummy uuid for bittorrent. Do not alter.
bitTorrentUUID :: UUID
bitTorrentUUID = UUID (fromString "00000000-0000-0000-0000-000000000002")