remove message and presence channels (use stanza channel instead)

rename forkSession to dupSession

examples/EchoClient.hs

@@ -26,35 +26,40 @@ import           Network.Xmpp.IM
 -- Server and authentication details.
 host     = "localhost"
 port     = PortNumber 5222
-realm    = "host.com"
+realm    = "server.com"
 username = "echo"
 password = "pwd"
 resource = Just "bot"
 
 -- | Automatically accept all subscription requests from other entities
 autoAccept :: Session -> IO ()
-autoAccept context = forever $ do
-  st <- waitForPresence isPresenceSubscribe context
+autoAccept session = forever $ do
+  st <- waitForPresence isPresenceSubscribe session
   let Just friend = presenceFrom st
-  sendPresence (presenceSubscribed friend) context
+  sendPresence (presenceSubscribed friend) session
   printf "Hello %s !" (show friend)
 
 main :: IO ()
 main = do
-    con <- simpleConnect
-               host
-               port
-               realm
-               username
-               password
-               resource
-    putStrLn "connected"
-    sendPresence presenceOnline con
-    _thread <- forkIO $ autoAccept con
-    forever $ do -- echo all messages back to the user
-        msg <- getMessage con
+    sess <- simpleConnect
+                host
+                port
+                realm
+                username
+                password
+                resource
+    -- We won't be able to receive stanzas before we set out status to online
+    sendPresence presenceOnline sess
+    putStrLn "Connected."
+    -- We want to see all incoming stanzas in the auto-accept thread as well.
+    sess' <- dupSession sess
+    _thread <- forkIO $ autoAccept sess'
+    forever $ do
+        -- Echo all messages back to the user.
+        msg <- getMessage sess
+        sendMessage (answerIM (bodies msg) [] msg) sess
+        -- Print the received message to the screen.
         let sender = show . fromJust $ messageFrom msg
         let contents = maybe "nothing" Text.unpack $ body msg
-        printf "%s sayd \"%s\"\n" sender contents
-        sendMessage (answerIM (bodies msg) [] msg) con
+        printf "%s says \"%s\"\n" sender contents
     return ()

source/Network/Xmpp.hs

@@ -78,7 +78,7 @@ module Network.Xmpp
   --    presence, or IQ stanza. The particular allowable values for the 'type'
   --    attribute vary depending on whether the stanza is a message, presence,
   --    or IQ stanza.
-  , getStanzaChan
+  --
   -- ** Messages
   -- | The /message/ stanza is a /push/ mechanism whereby one entity
   -- pushes information to another entity, similar to the communications that
@@ -144,7 +144,7 @@ module Network.Xmpp
   , iqRequestPayload
   , iqResultPayload
   -- * Threads
-  , forkSession
+  , dupSession
   -- * Miscellaneous
   , LangTag(..)
   , exampleParams

source/Network/Xmpp/Concurrent/Channels.hs

@@ -34,38 +34,17 @@ import           Network.Xmpp.Pickle
 import           Network.Xmpp.Types
 import           Text.XML.Stream.Elements
 
-toChans :: TChan (Either MessageError Message)
-        -> TChan (Either PresenceError Presence)
-        -> TChan Stanza
+toChans :: TChan Stanza
         -> TVar IQHandlers
         -> Stanza
         -> IO ()
-toChans messageC presenceC stanzaC iqHands sta = atomically $ do
+toChans stanzaC iqHands sta = atomically $ do
         writeTChan stanzaC sta
-        void $ readTChan stanzaC -- sic
         case sta of
-            MessageS  m -> do writeTChan messageC $ Right m
-                              _ <- readTChan messageC -- Sic!
-                              return ()
-                           -- this may seem ridiculous, but to prevent
-                           -- the channel from filling up we
-                           -- immedtiately remove the
-                           -- Stanza we just put in. It will still be
-                           -- available in duplicates.
-            MessageErrorS m -> do writeTChan messageC $ Left m
-                                  _ <- readTChan messageC
-                                  return ()
-            PresenceS      p -> do
-                             writeTChan presenceC $ Right p
-                             _ <- readTChan presenceC
-                             return ()
-            PresenceErrorS p ->  do
-                                   writeTChan presenceC $ Left p
-                                   _ <- readTChan presenceC
-                                   return ()
             IQRequestS     i -> handleIQRequest iqHands i
             IQResultS      i -> handleIQResponse iqHands (Right i)
             IQErrorS       i -> handleIQResponse iqHands (Left i)
+            _                -> return ()
   where
     -- If the IQ request has a namespace, send it through the appropriate channel.
     handleIQRequest :: TVar IQHandlers -> IQRequest -> STM ()
@@ -94,17 +73,13 @@ toChans messageC presenceC stanzaC iqHands sta = atomically $ do
 -- | Creates and initializes a new Xmpp context.
 newSession :: Connection -> IO Session
 newSession con = do
-    messageC <- newTChanIO
-    presenceC <- newTChanIO
     outC <- newTChanIO
-    stanzaC <- newTChanIO
+    stanzaChan <- newTChanIO
     iqHandlers <- newTVarIO (Map.empty, Map.empty)
     eh <- newTVarIO $ EventHandlers { connectionClosedHandler = \_ -> return () }
-    let stanzaHandler = toChans messageC presenceC stanzaC iqHandlers
+    let stanzaHandler = toChans stanzaChan iqHandlers
     (kill, wLock, conState, readerThread) <- startThreadsWith stanzaHandler eh con
     writer <- forkIO $ writeWorker outC wLock
-    workermCh <- newIORef $ Nothing
-    workerpCh <- newIORef $ Nothing
     idRef <- newTVarIO 1
     let getId = atomically $ do
             curId <- readTVar idRef
@@ -118,11 +93,7 @@ newSession con = do
                        , stopThreads = kill >> killThread writer
                        }
     return $ Session { context = cont
-                     , mShadow = messageC
-                     , pShadow = presenceC
-                     , sShadow = stanzaC
-                     , messagesRef = workermCh
-                     , presenceRef = workerpCh
+                     , stanzaCh = stanzaChan
                      , outCh = outC
                      , iqHandlers = iqHandlers
                      }

source/Network/Xmpp/Concurrent/Channels/Basic.hs

@@ -2,21 +2,15 @@
 module Network.Xmpp.Concurrent.Channels.Basic where
 
 import Control.Concurrent.STM
-import Data.IORef
 import Network.Xmpp.Concurrent.Channels.Types
 import Network.Xmpp.Types
 
--- | Get a duplicate of the stanza channel
-getStanzaChan :: Session -> IO (TChan Stanza)
-getStanzaChan session = atomically $ dupTChan (sShadow session)
-
 -- | Send a stanza to the server.
 sendStanza :: Stanza -> Session -> IO ()
 sendStanza a session = atomically $ writeTChan (outCh session) a
 
--- | Create a forked session object
-forkSession :: Session -> IO Session
-forkSession session = do
-    mCH' <- newIORef Nothing
-    pCH' <- newIORef Nothing
-    return $ session {messagesRef = mCH' , presenceRef = pCH'}
+-- | Create a new session object with the inbound channel duplicated
+dupSession :: Session -> IO Session
+dupSession session = do
+    stanzaCh' <- atomically $ dupTChan (stanzaCh session)
+    return $ session {stanzaCh = stanzaCh'}

source/Network/Xmpp/Concurrent/Channels/Message.hs

@@ -8,30 +8,15 @@ import Network.Xmpp.Types
 import Network.Xmpp.Concurrent.Types
 import Network.Xmpp.Concurrent.Channels.Basic
 
--- | Get the inbound stanza channel, duplicates from master if necessary. Please
--- note that once duplicated it will keep filling up, call 'dropMessageChan' to
--- allow it to be garbage collected.
-getMessageChan :: Session -> IO (TChan (Either MessageError Message))
-getMessageChan session = do
-    mCh <- readIORef . messagesRef $ session
-    case mCh of
-        Nothing -> do
-            mCh' <- atomically $ dupTChan (mShadow session)
-            writeIORef (messagesRef session) (Just mCh')
-            return mCh'
-        Just mCh' -> return mCh'
-
--- | Drop the local end of the inbound stanza channel from our context so it can
--- be GC-ed.
-dropMessageChan :: Session -> IO ()
-dropMessageChan session = writeIORef (messagesRef session) Nothing
-
 -- | Read an element from the inbound stanza channel, acquiring a copy of the
 -- channel as necessary.
 pullMessage :: Session -> IO (Either MessageError Message)
 pullMessage session = do
-    c <- getMessageChan session
-    atomically $ readTChan c
+    stanza <- atomically . readTChan $ stanzaCh session
+    case stanza of
+        MessageS m -> return $ Right m
+        MessageErrorS e -> return $ Left e
+        _ -> pullMessage session
 
 -- | Get the next received message
 getMessage :: Session -> IO Message

source/Network/Xmpp/Concurrent/Channels/Presence.hs

@@ -8,29 +8,15 @@ import Network.Xmpp.Types
 import Network.Xmpp.Concurrent.Types
 import Network.Xmpp.Concurrent.Channels.Basic
 
--- | Analogous to 'getMessageChan'.
-getPresenceChan :: Session -> IO (TChan (Either PresenceError Presence))
-getPresenceChan session = do
-    pCh <- readIORef $ (presenceRef session)
-    case pCh of
-        Nothing -> do
-            pCh' <- atomically $ dupTChan (pShadow session)
-            writeIORef (presenceRef session) (Just pCh')
-            return pCh'
-        Just pCh' -> return pCh'
-
-
--- | Analogous to 'dropMessageChan'.
-dropPresenceChan :: Session -> IO ()
-dropPresenceChan session = writeIORef (presenceRef session) Nothing
-
-
 -- | Read an element from the inbound stanza channel, acquiring a copy of the
 -- channel as necessary.
 pullPresence :: Session -> IO (Either PresenceError Presence)
 pullPresence session = do
-    c <- getPresenceChan session
-    atomically $ readTChan c
+    stanza <- atomically . readTChan $ stanzaCh session
+    case stanza of
+        PresenceS p -> return $ Right p
+        PresenceErrorS e -> return $ Left e
+        _ -> pullPresence session
 
 -- | Pulls a (non-error) presence and returns it if the given predicate returns
 -- @True@.

source/Network/Xmpp/Concurrent/Channels/Types.hs

@@ -11,18 +11,7 @@ import           Network.Xmpp.Types
 -- | An XMPP session context
 data Session = Session
     { context :: Context
-      -- The original master channels that the reader puts stanzas
-      -- into. These are cloned by @get{STanza,Message,Presence}Chan
-      -- on demand when first used by the thread and are stored in the
-      -- {message,presence}Ref fields below.
-    , mShadow :: TChan (Either MessageError Message)
-    , pShadow :: TChan (Either PresenceError Presence)
-    , sShadow :: TChan Stanza -- All stanzas
-      -- The cloned copies of the original/shadow channels. They are
-      -- thread-local (as opposed to the shadow channels) and contains all
-      -- stanzas received after the cloning of the shadow channels.
-    , messagesRef :: IORef (Maybe (TChan (Either MessageError Message)))
-    , presenceRef :: IORef (Maybe (TChan (Either PresenceError Presence)))
+    , stanzaCh :: TChan Stanza -- All stanzas
     , outCh :: TChan Stanza
     , iqHandlers :: TVar IQHandlers
       -- Writing lock, so that only one thread could write to the stream at any