more refactor

Core.hs

@@ -0,0 +1,87 @@
+{- git-annex core functions -}
+
+module Core where
+
+import System.IO
+import System.Directory
+import Control.Monad.State (liftIO)
+import Control.Exception
+import CmdLine
+import Types
+import BackendList
+import Locations
+import UUID
+import qualified GitRepo as Git
+import qualified Annex
+
+{- Create and returns an Annex state object. 
+ - Examines and prepares the git repo.
+ -}
+start :: IO AnnexState
+start = do
+	g <- Git.repoFromCwd
+	let s = Annex.new g
+	(_,s') <- Annex.run s (prep g)
+	return s'
+	where
+		prep g = do
+			-- setup git and read its config; update state
+			g' <- liftIO $ Git.configRead g
+			Annex.gitRepoChange g'
+			liftIO $ gitSetup g'
+			Annex.backendsChange $ parseBackendList $
+				Git.configGet g' "annex.backends" ""
+			prepUUID
+
+{- Processes each param in the list by dispatching the handler function
+ - for the user-selection operation mode. Catches exceptions, not stopping
+ - if some error out, and propigates an overall error status at the end.
+ -
+ - This runs in the IO monad, not in the Annex monad. It seems that
+ - exceptions can only be caught in the IO monad, not in a stacked monad;
+ - or more likely I missed an easy way to do it. So, I have to laboriously
+ - thread AnnexState through this function.
+ -}
+tryRun :: AnnexState -> Mode -> [String] -> IO ()
+tryRun state mode params = tryRun' state mode 0 0 params
+tryRun' state mode errnum oknum [] = do
+	if (errnum > 0)
+		then error $ (show errnum) ++ " failed ; " ++ show (oknum) ++ " ok"
+		else return ()
+tryRun' state mode errnum oknum (f:fs) = do
+	result <- try
+		(Annex.run state (dispatch mode f))::IO (Either SomeException ((), AnnexState))
+	case (result) of
+		Left err -> do
+			showErr err
+			tryRun' state mode (errnum + 1) oknum fs
+		Right (_,state') -> tryRun' state' mode errnum (oknum + 1) fs
+
+{- Exception pretty-printing. -}
+showErr e = do
+	hPutStrLn stderr $ "git-annex: " ++ (show e)
+	return ()
+
+{- Sets up a git repo for git-annex. May be called repeatedly. -}
+gitSetup :: Git.Repo -> IO ()
+gitSetup repo = do
+	-- configure git to use union merge driver on state files
+	exists <- doesFileExist attributes
+	if (not exists)
+		then do
+			writeFile attributes $ attrLine ++ "\n"
+			commit
+		else do
+			content <- readFile attributes
+			if (all (/= attrLine) (lines content))
+				then do
+					appendFile attributes $ attrLine ++ "\n"
+					commit
+				else return ()
+	where
+		attrLine = stateLoc ++ "/*.log merge=union"
+		attributes = Git.attributes repo
+		commit = do
+			Git.run repo ["add", attributes]
+			Git.run repo ["commit", "-m", "git-annex setup", 
+					attributes]