git-annex/Logs/Remote.hs
Joey Hess c7c2015435 add ConfigMonitor thread
Monitors git-annex branch for changes, which are noticed by the Merger
thread whenever the branch ref is changed (either due to an incoming push,
or a local change), and refreshes cached config values for modified config
files.

Rate limited to run no more often than once per minute. This is important
because frequent git-annex branch changes happen when files are being
added, or transferred, etc.

A primary use case is that, when preferred content changes are made,
and get pushed to remotes, the remotes start honoring those settings.
Other use cases include propigating repository description and trust
changes to remotes, and learning when a remote has added a new special
remote, so the webapp can present the GUI to enable that special remote
locally.

Also added a uuid.log cache. All other config files already had caches.
2012-10-20 16:43:35 -04:00

88 lines
2.2 KiB
Haskell

{- git-annex remote log
-
- Copyright 2011 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Logs.Remote (
remoteLog,
readRemoteLog,
configSet,
keyValToConfig,
configToKeyVal,
prop_idempotent_configEscape
) where
import qualified Data.Map as M
import Data.Time.Clock.POSIX
import Data.Char
import Common.Annex
import qualified Annex.Branch
import Types.Remote
import Logs.UUIDBased
{- Filename of remote.log. -}
remoteLog :: FilePath
remoteLog = "remote.log"
{- Adds or updates a remote's config in the log. -}
configSet :: UUID -> RemoteConfig -> Annex ()
configSet u c = do
ts <- liftIO getPOSIXTime
Annex.Branch.change remoteLog $
showLog showConfig . changeLog ts u c . parseLog parseConfig
{- Map of remotes by uuid containing key/value config maps. -}
readRemoteLog :: Annex (M.Map UUID RemoteConfig)
readRemoteLog = simpleMap . parseLog parseConfig <$> Annex.Branch.get remoteLog
parseConfig :: String -> Maybe RemoteConfig
parseConfig = Just . keyValToConfig . words
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_idempotent_configEscape :: String -> Bool
prop_idempotent_configEscape s = s == (configUnEscape . configEscape) s