#68 - rewritten timer logic on the session - we're using 3 timers now…

… instead of 1.

src/transport.coffee

@@ -5,6 +5,7 @@
 # ***** END LICENSE BLOCK *****
 
 stream = require('stream')
+events = require('events')
 uuid = require('node-uuid')
 utils = require('./utils')
 
@@ -60,23 +61,97 @@ SockJSConnection.prototype.__defineGetter__ 'readyState', ->
 
 MAP = {}
 
+class Timeout
+    constructor: (callback, @delay) ->
+        @missed = 0
+        @doTimeout = =>
+            @missed += 1
+            # 1. reschedule
+            if @delay
+                @tref = setTimeout(@doTimeout, @delay)
+            # 2. call
+            if callback
+                callback(@missed)
+
+    start: () ->
+        @missed = 0
+        if @tref
+            clearTimeout(@tref)
+        if @delay
+            @tref = setTimeout(@doTimeout, @delay)
+
+    stop: () ->
+        if @tref
+            clearTimeout(@tref)
+            @tref = null
+
+    poke: () ->
+        @stop()
+        @start()
+
+
+class SessionTimer extends events.EventEmitter
+    constructor: (session, disconnect_delay, send_delay, recv_delay) ->
+        doPollTimeout = (m) =>
+            console.log('doPollTimeout',m);
+            session.doPollTimeout(m)
+        doSendTimeout = (m) =>
+            console.log('doSendTimeout',m);
+            session.doSendTimeout(m)
+        doRecvTimeout = (m) =>
+            console.log('doRecvTimeout',m);
+            session.doRecvTimeout(m)
+        @no_poll_tref = new Timeout(doPollTimeout, disconnect_delay)
+        @send_tref    = new Timeout(doSendTimeout, send_delay)
+        @recv_tref    = new Timeout(doRecvTimeout, recv_delay)
+        @no_poll_tref.start()
+        @recv_tref.start()
+        console.log('timer: start')
+
+    poll_start: () ->
+        console.log('timer: poll start')
+        @no_poll_tref.stop()
+        @send_tref.start()
+        @recv_tref.poke()
+
+    poll_end: () ->
+        console.log('timer: poll end')
+        @no_poll_tref.start()
+        @send_tref.stop()
+
+    send: () ->
+        console.log('timer: send')
+        @send_tref.poke()
+
+    recv: () ->
+        console.log('timer: recv')
+        @recv_tref.poke()
+
+    close: () ->
+        console.log('timer: close')
+        @no_poll_tref.stop()
+        @send_tref.stop()
+        @recv_tref.stop()
+
+
 class Session
     constructor: (@session_id, server) ->
-        @server_heartbeat_interval = server.options.server_heartbeat_interval
-        @client_heartbeat_reply    = server.options.client_heartbeat_reply
-        @client_heartbeat_count    = false
-        @disconnect_delay = server.options.disconnect_delay
+        @client_heartbeat_reply = server.options.client_heartbeat_reply
         @prefix = server.options.prefix
         @send_buffer = []
         @is_closing = false
         @readyState = Transport.CONNECTING
         if @session_id
             MAP[@session_id] = @
-        @timeout_cb = =>
-            @didTimeout()
-        @heartbeat_cb = =>
-            @doHeartbeat()
-        @to_tref = setTimeout(@timeout_cb, @disconnect_delay)
+        if server.options.client_heartbeat_reply
+            # We want the 'h' frame to fire just before the empty data
+            # "a[]" frame - to save bandwidth. After "h", "a[]" is
+            # spurious.
+            recv_delay = server.options.server_heartbeat_interval - 2
+        @timer = new SessionTimer(@,
+                                  server.options.disconnect_delay,
+                                  server.options.server_heartbeat_interval,
+                                  recv_delay)
         @connection = new SockJSConnection(@)
         @emit_open = =>
             @emit_open = null
@@ -87,19 +162,16 @@ class Session
             recv.doSendFrame(closeFrame(2010, "Another connection still open"))
             recv.didClose()
             return
-        if @to_tref
-            clearTimeout(@to_tref)
-            @to_tref = null
+        @connection.emit('poll')
+        @timer.poll_start()
         if @readyState is Transport.CLOSING
             recv.doSendFrame(@close_frame)
             recv.didClose()
-            @to_tref = setTimeout(@timeout_cb, @disconnect_delay)
+            @timer.poll_end()
             return
 
-        @client_heartbeat_count = 0
-        @connection.emit('poll')
         # Registering. From now on 'unregister' is responsible for
-        # setting the timer.
+        # calling poll_end.
         @recv = recv
         @recv.session = @
 
@@ -142,48 +214,50 @@ class Session
             @connection.headers = headers
 
     unregister: ->
-        @recv.session = null
-        @recv = null
-        if @to_tref
-            clearTimeout(@to_tref)
-        @to_tref = setTimeout(@timeout_cb, @disconnect_delay)
+        @recv = @recv.session = null
+        @timer.poll_end()
 
     tryFlush: ->
         if @send_buffer.length > 0
             [sb, @send_buffer] = [@send_buffer, []]
             @recv.doSendBulk(sb)
-
-        if @to_tref
-            clearTimeout(@to_tref)
-        @to_tref = setTimeout(@heartbeat_cb, @server_heartbeat_interval)
+            @timer.send()
         return
 
-    doHeartbeat: ->
-        @client_heartbeat_count += 1
-        console.log('heartbeat', @client_heartbeat_count)
-        if @client_heartbeat_reply and @client_heartbeat_count is 2
+    doSendTimeout: ->
+        @sendEmptyFrame()
+
+    doRecvTimeout: (missed) ->
+        if not @client_heartbeat_reply
+            return
+        if missed is 1
+            @sendHeartbeat()
+        else if missed is 2
             console.log("Heartbeat missed")
             @close(1006, "Heartbeat missed")
-        else if @sendHeartbeat()
-            @to_tref = setTimeout(@heartbeat_cb, @server_heartbeat_interval)
 
     sendHeartbeat: ->
         if not @recv
             return false
         @recv.doSendFrame("h")
+        @timer.send()
         return true
 
+    sendEmptyFrame: ->
+        if not @recv
+            return false
+        @recv.doSendFrame("a[]")
+        @timer.send()
+        return true
 
-    didTimeout: ->
-        if @to_tref
-            clearTimeout(@to_tref)
-            @to_tref = null
+    doPollTimeout: ->
         if @readyState isnt Transport.CONNECTING and
            @readyState isnt Transport.OPEN and
            @readyState isnt Transport.CLOSING
             throw Error('INVALID_STATE_ERR')
         if @recv
             throw Error('RECV_STILL_THERE')
+        @timer.close()
         @readyState = Transport.CLOSED
         # Node streaming API is broken. Reader defines 'close' and 'end'
         # but Writer defines only 'close'. 'End' isn't optional though.
@@ -202,7 +276,7 @@ class Session
                     @connection.emit('data', msg)
             else
                 @connection.emit('heartbeat')
-                @client_heartbeat_count = 0
+            @timer.recv()
         return
 
     send: (payload) ->
@@ -263,7 +337,7 @@ class GenericReceiver
         session = @session
         @didClose(status, reason)
         if session
-            session.didTimeout()
+            session.doPollTimeout()
 
     didClose: (status, reason) ->
         if @thingy