git-annex/Logs/Remote.hs
Joey Hess c3975ff3b4
sameas RemoteConfig inheritance
I found a way to avoid inheritance complicating anything outside of
Logs.Remote. It seems fine to require all inherited values to be
inherited and not set in the sameas remote's config. Since inherited
values will be used for stuff like encryption and perhaps chunking, which
control the actual content stored on the remote, it seems likely that
there will not be any reason to need them to vary between two remotes
that access the same underlying data store.

The newer version of containers is free; the minimum ghc version is
bundled with a newer version than that.
2019-10-10 15:58:22 -04:00

131 lines
3.8 KiB
Haskell

{- git-annex remote log
-
- Copyright 2011-2019 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Logs.Remote (
remoteLog,
readRemoteLog,
configSet,
keyValToConfig,
configToKeyVal,
showConfig,
prop_isomorphic_configEscape,
prop_parse_show_Config,
) where
import Annex.Common
import qualified Annex.Branch
import Types.Remote
import Logs
import Logs.UUIDBased
import Annex.SpecialRemote.Config
import qualified Data.Map as M
import Data.Char
import qualified Data.Attoparsec.ByteString.Lazy as A
import Data.ByteString.Builder
{- Adds or updates a remote's config in the log. -}
configSet :: UUID -> RemoteConfig -> Annex ()
configSet u cfg = do
c <- liftIO currentVectorClock
Annex.Branch.change remoteLog $
buildLogOld (byteString . encodeBS . showConfig)
. changeLog c u (removeSameasInherited cfg)
. parseLogOld remoteConfigParser
{- Map of remotes by uuid containing key/value config maps. -}
readRemoteLog :: Annex (M.Map UUID RemoteConfig)
readRemoteLog = addSameasInherited
. simpleMap
. parseLogOld remoteConfigParser
<$> Annex.Branch.get remoteLog
{- Each RemoteConfig that has a sameas-uuid inherits some fields
- from it. Such fields can only be set by inheritance; the RemoteConfig
- cannot provide values from them. -}
addSameasInherited :: M.Map UUID RemoteConfig -> M.Map UUID RemoteConfig
addSameasInherited m = M.map go m
where
go c = case toUUID <$> M.lookup sameasUUIDField c of
Nothing -> c
Just sameasuuid -> case M.lookup sameasuuid m of
Nothing -> c
Just parentc ->
M.withoutKeys c sameasInherits
`M.union`
M.restrictKeys parentc sameasInherits
{- Remove any fields inherited from a sameas-uuid. -}
removeSameasInherited :: RemoteConfig -> RemoteConfig
removeSameasInherited c = case M.lookup sameasUUIDField c of
Nothing -> c
Just _ -> M.restrictKeys c sameasInherits
remoteConfigParser :: A.Parser RemoteConfig
remoteConfigParser = keyValToConfig . words . decodeBS <$> A.takeByteString
showConfig :: RemoteConfig -> String
showConfig = unwords . configToKeyVal
{- Given Strings like "key=value", generates a RemoteConfig. -}
keyValToConfig :: [String] -> RemoteConfig
keyValToConfig ws = M.fromList $ map (/=/) ws
where
(/=/) s = (k, v)
where
k = takeWhile (/= '=') s
v = configUnEscape $ drop (1 + length k) s
configToKeyVal :: M.Map String String -> [String]
configToKeyVal m = map toword $ sort $ M.toList m
where
toword (k, v) = k ++ "=" ++ configEscape v
configEscape :: String -> String
configEscape = concatMap escape
where
escape c
| isSpace c || c `elem` "&" = "&" ++ show (ord c) ++ ";"
| otherwise = [c]
configUnEscape :: String -> String
configUnEscape = unescape
where
unescape [] = []
unescape (c:rest)
| c == '&' = entity rest
| otherwise = c : unescape rest
entity s
| not (null num) && ";" `isPrefixOf` r =
chr (Prelude.read num) : unescape rest
| otherwise =
'&' : unescape s
where
num = takeWhile isNumber s
r = drop (length num) s
rest = drop 1 r
{- for quickcheck -}
prop_isomorphic_configEscape :: String -> Bool
prop_isomorphic_configEscape s = s == (configUnEscape . configEscape) s
prop_parse_show_Config :: RemoteConfig -> Bool
prop_parse_show_Config c
-- whitespace and '=' are not supported in config keys
| any (\k -> any isSpace k || elem '=' k) (M.keys c) = True
| any (any excluded) (M.keys c) = True
| any (any excluded) (M.elems c) = True
| otherwise = A.parseOnly remoteConfigParser (encodeBS $ showConfig c) ~~ Right c
where
normalize v = sort . M.toList <$> v
a ~~ b = normalize a == normalize b
-- limit to ascii alphanumerics for simplicity; characters not
-- allowed by the current character set in the config may not
-- round-trip in an identical representation due to the use of the
-- filesystem encoding.
excluded ch = not (isAlphaNum ch) || not (isAscii ch)