factor out RemoteLog

RemoteLog.hs

@@ -0,0 +1,97 @@
+{- git-annex remote log
+ - 
+ - Copyright 2011 Joey Hess <joey@kitenet.net>
+ - 
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module RemoteLog (
+	remoteLog,
+	readRemoteLog,
+	configSet,
+	keyValToConfig,
+	configToKeyVal,
+
+	prop_idempotent_configEscape
+) where
+
+import Data.List
+import qualified Data.Map as M
+import Data.Maybe
+import Data.Char
+
+import qualified Branch
+import Types
+import Types.Remote
+import UUID
+
+{- 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
+	m <- readRemoteLog
+	Branch.change remoteLog $ unlines $ sort $
+		map toline $ M.toList $ M.insert u c m
+	where
+		toline (u', c') = u' ++ " " ++ (unwords $ configToKeyVal c')
+
+{- Map of remotes by uuid containing key/value config maps. -}
+readRemoteLog :: Annex (M.Map UUID RemoteConfig)
+readRemoteLog = return . remoteLogParse =<< Branch.get remoteLog
+
+remoteLogParse :: String -> M.Map UUID RemoteConfig
+remoteLogParse s =
+	M.fromList $ catMaybes $ map parseline $ filter (not . null) $ lines s
+	where
+		parseline l
+			| length w > 2 = Just (u, c)
+			| otherwise = Nothing
+			where
+				w = words l
+				u = w !! 0
+				c = keyValToConfig $ tail w
+
+{- 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 = (>>= 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 = if ok
+				then chr (read num) : unescape rest
+				else '&' : unescape s
+			where
+				num = takeWhile isNumber s
+				r = drop (length num) s
+				rest = drop 1 r
+				ok = not (null num) && 
+					not (null r) && r !! 0 == ';'
+
+{- for quickcheck -}
+prop_idempotent_configEscape :: String -> Bool
+prop_idempotent_configEscape s = s == (configUnEscape $ configEscape s)