xmpp buddy list tracking

Assistant/XMPP/Client.hs

@@ -0,0 +1,84 @@
+{- xmpp client support
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Assistant.XMPP.Client where
+
+import Assistant.Common
+import Utility.FileMode
+import Utility.SRV
+
+import Network.Protocol.XMPP
+import Network
+import Control.Concurrent
+import qualified Data.Text as T
+import Control.Exception (SomeException)
+
+{- Everything we need to know to connect to an XMPP server. -}
+data XMPPCreds = XMPPCreds
+	{ xmppUsername :: T.Text
+	, xmppPassword :: T.Text
+	, xmppHostname :: HostName
+	, xmppPort :: Int
+	, xmppJID :: T.Text
+	}
+	deriving (Read, Show)
+
+connectXMPP :: XMPPCreds -> (JID -> XMPP a) -> IO (Either SomeException ())
+connectXMPP c a = case parseJID (xmppJID c) of
+	Nothing -> error "bad JID"
+	Just jid -> connectXMPP' jid c a
+
+{- Do a SRV lookup, but if it fails, fall back to the cached xmppHostname. -}
+connectXMPP' :: JID -> XMPPCreds -> (JID -> XMPP a) -> IO (Either SomeException ())
+connectXMPP' jid c a = go =<< lookupSRV srvrecord
+  where
+	srvrecord = mkSRVTcp "xmpp-client" $
+		T.unpack $ strDomain $ jidDomain jid
+	serverjid = JID Nothing (jidDomain jid) Nothing
+
+	go [] = run (xmppHostname c)
+			(PortNumber $ fromIntegral $ xmppPort c)
+			(a jid)
+	go ((h,p):rest) = do
+		{- Try each SRV record in turn, until one connects,
+		 - at which point the MVar will be full. -}
+		mv <- newEmptyMVar
+		r <- run h p $ do
+			liftIO $ putMVar mv ()
+			a jid
+		ifM (isEmptyMVar mv) (go rest, return r)
+
+	{- Async exceptions are let through so the XMPP thread can
+	 - be killed. -}
+	run h p a' = tryNonAsync $
+		runClientError (Server serverjid h p) jid
+			(xmppUsername c) (xmppPassword c) (void a')
+
+{- XMPP runClient, that throws errors rather than returning an Either -}
+runClientError :: Server -> JID -> T.Text -> T.Text -> XMPP a -> IO a
+runClientError s j u p x = either (error . show) return =<< runClient s j u p x
+
+getXMPPCreds :: Annex (Maybe XMPPCreds)
+getXMPPCreds = do
+	f <- xmppCredsFile
+	s <- liftIO $ catchMaybeIO $ readFile f
+	return $ readish =<< s
+
+setXMPPCreds :: XMPPCreds -> Annex ()
+setXMPPCreds creds = do
+	f <- xmppCredsFile
+	liftIO $ do
+		h <- openFile f WriteMode
+		modifyFileMode f $ removeModes
+			[groupReadMode, otherReadMode]
+		hPutStr h (show creds)
+		hClose h	
+
+xmppCredsFile :: Annex FilePath
+xmppCredsFile = do
+	dir <- fromRepo gitAnnexCredsDir
+	return $ dir </> "notify-xmpp"