7 files changed, 123 insertions, 97 deletions
diff --git a/lib/assets/javascripts/cable.js.coffee b/lib/assets/javascripts/cable.coffee
index 0bd1757505..476d90ef72 100644
--- a/lib/assets/javascripts/cable.js.coffee
+++ b/lib/assets/javascripts/cable.coffee
@@ -3,6 +3,8 @@
 
 @Cable =
   PING_IDENTIFIER: "_ping"
+  INTERNAL_MESSAGES:
+    SUBSCRIPTION_CONFIRMATION: 'confirm_subscription'
 
   createConsumer: (url) ->
     new Cable.Consumer url
diff --git a/lib/assets/javascripts/cable/connection.coffee b/lib/assets/javascripts/cable/connection.coffee
new file mode 100644
index 0000000000..33159130c7
--- /dev/null
+++ b/lib/assets/javascripts/cable/connection.coffee
@@ -0,0 +1,80 @@
+# Encapsulate the cable connection held by the consumer. This is an internal class not intended for direct user manipulation.
+class Cable.Connection
+  @reopenDelay: 500
+
+  constructor: (@consumer) ->
+    @open()
+
+  send: (data) ->
+    if @isOpen()
+      @webSocket.send(JSON.stringify(data))
+      true
+    else
+      false
+
+  open: =>
+    if @webSocket and not @isState("closed")
+      throw new Error("Existing connection must be closed before opening")
+    else
+      @webSocket = new WebSocket(@consumer.url)
+      @installEventHandlers()
+      true
+
+  close: ->
+    @webSocket?.close()
+
+  reopen: ->
+    if @isState("closed")
+      @open()
+    else
+      try
+        @close()
+      finally
+        setTimeout(@open, @constructor.reopenDelay)
+
+  isOpen: ->
+    @isState("open")
+
+  # Private
+
+  isState: (states...) ->
+    @getState() in states
+
+  getState: ->
+    return state.toLowerCase() for state, value of WebSocket when value is @webSocket?.readyState
+    null
+
+  installEventHandlers: ->
+    for eventName of @events
+      handler = @events[eventName].bind(this)
+      @webSocket["on#{eventName}"] = handler
+    return
+
+  events:
+    message: (event) ->
+      {identifier, message, type} = JSON.parse(event.data)
+
+      if type?
+        switch type
+          when Cable.INTERNAL_MESSAGES.SUBSCRIPTION_CONFIRMATION
+            @consumer.subscriptions.notify(identifier, "connected")
+      else
+        @consumer.subscriptions.notify(identifier, "received", message)
+
+    open: ->
+      @disconnected = false
+      @consumer.subscriptions.reload()
+
+    close: ->
+      @disconnect()
+
+    error: ->
+      @disconnect()
+
+  disconnect: ->
+    return if @disconnected
+    @disconnected = true
+    @consumer.subscriptions.notifyAll("disconnected")
+
+  toJSON: ->
+    state: @getState()
diff --git a/lib/assets/javascripts/cable/connection.js.coffee b/lib/assets/javascripts/cable/connection.js.coffee
deleted file mode 100644
index 464f0c1ff7..0000000000
--- a/lib/assets/javascripts/cable/connection.js.coffee
+++ /dev/null
@@ -1,77 +0,0 @@
-# Encapsulate the cable connection held by the consumer. This is an internal class not intended for direct user manipulation.
-class Cable.Connection
-  constructor: (@consumer) ->
-    @open()
-
-  send: (data) ->
-    if @isOpen()
-      @webSocket.send(JSON.stringify(data))
-      true
-    else
-      false
-
-  open: ->
-    return if @isState("open", "connecting")
-    @webSocket = new WebSocket(@consumer.url)
-    @installEventHandlers()
-
-  close: ->
-    return if @isState("closed", "closing")
-    @webSocket?.close()
-
-  reopen: ->
-    if @isOpen()
-      @closeSilently => @open()
-    else
-      @open()
-
-  isOpen: ->
-    @isState("open")
-
-  # Private
-
-  isState: (states...) ->
-    @getState() in states
-
-  getState: ->
-    return state.toLowerCase() for state, value of WebSocket when value is @webSocket?.readyState
-    null
-
-  closeSilently: (callback = ->) ->
-    @uninstallEventHandlers()
-    @installEventHandler("close", callback)
-    @installEventHandler("error", callback)
-    try
-      @webSocket.close()
-    finally
-      @uninstallEventHandlers()
-
-  installEventHandlers: ->
-    for eventName of @events
-      @installEventHandler(eventName)
-
-  installEventHandler: (eventName, handler) ->
-    handler ?= @events[eventName].bind(this)
-    @webSocket.addEventListener(eventName, handler)
-
-  uninstallEventHandlers: ->
-    for eventName of @events
-      @webSocket.removeEventListener(eventName)
-
-  events:
-    message: (event) ->
-      {identifier, message} = JSON.parse(event.data)
-      @consumer.subscriptions.notify(identifier, "received", message)
-
-    open: ->
-      @consumer.subscriptions.reload()
-
-    close: ->
-      @consumer.subscriptions.notifyAll("disconnected")
-
-    error: ->
-      @consumer.subscriptions.notifyAll("disconnected")
-      @closeSilently()
-
-  toJSON: ->
-    state: @getState()
diff --git a/lib/assets/javascripts/cable/connection_monitor.js.coffee b/lib/assets/javascripts/cable/connection_monitor.coffee
index cac65d9043..bf99dee34d 100644
--- a/lib/assets/javascripts/cable/connection_monitor.js.coffee
+++ b/lib/assets/javascripts/cable/connection_monitor.coffee
@@ -1,15 +1,13 @@
 # Responsible for ensuring the cable connection is in good health by validating the heartbeat pings sent from the server, and attempting
 # revival reconnections if things go astray. Internal class, not intended for direct user manipulation.
 class Cable.ConnectionMonitor
-  identifier: Cable.PING_IDENTIFIER
-
-  pollInterval:
-    min: 2
+  @pollInterval:
+    min: 3
     max: 30
 
-  staleThreshold:
-    startedAt: 4
-    pingedAt: 8
+  @staleThreshold: 6 # Server::Connections::BEAT_INTERVAL * 2 (missed two pings)
+
+  identifier: Cable.PING_IDENTIFIER
 
   constructor: (@consumer) ->
     @consumer.subscriptions.add(this)
@@ -18,6 +16,10 @@ class Cable.ConnectionMonitor
   connected: ->
     @reset()
     @pingedAt = now()
+    delete @disconnectedAt
+
+  disconnected: ->
+    @disconnectedAt = now()
 
   received: ->
     @pingedAt = now()
@@ -30,9 +32,11 @@ class Cable.ConnectionMonitor
     delete @stoppedAt
     @startedAt = now()
     @poll()
+    document.addEventListener("visibilitychange", @visibilityDidChange)
 
   stop: ->
     @stoppedAt = now()
+    document.removeEventListener("visibilitychange", @visibilityDidChange)
 
   poll: ->
     setTimeout =>
@@ -42,20 +46,28 @@ class Cable.ConnectionMonitor
     , @getInterval()
 
   getInterval: ->
-    {min, max} = @pollInterval
-    interval = 4 * Math.log(@reconnectAttempts + 1)
+    {min, max} = @constructor.pollInterval
+    interval = 5 * Math.log(@reconnectAttempts + 1)
     clamp(interval, min, max) * 1000
 
   reconnectIfStale: ->
     if @connectionIsStale()
-      @reconnectAttempts += 1
-      @consumer.connection.reopen()
+      @reconnectAttempts++
+      unless @disconnectedRecently()
+        @consumer.connection.reopen()
 
   connectionIsStale: ->
-    if @pingedAt
-      secondsSince(@pingedAt) > @staleThreshold.pingedAt
-    else
-      secondsSince(@startedAt) > @staleThreshold.startedAt
+    secondsSince(@pingedAt ? @startedAt) > @constructor.staleThreshold
+
+  disconnectedRecently: ->
+    @disconnectedAt and secondsSince(@disconnectedAt) < @constructor.staleThreshold
+
+  visibilityDidChange: =>
+    if document.visibilityState is "visible"
+      setTimeout =>
+        if @connectionIsStale() or not @consumer.connection.isOpen()
+          @consumer.connection.reopen()
+      , 200
 
   toJSON: ->
     interval = @getInterval()
diff --git a/lib/assets/javascripts/cable/consumer.js.coffee b/lib/assets/javascripts/cable/consumer.coffee
index 05a7398e79..05a7398e79 100644
--- a/lib/assets/javascripts/cable/consumer.js.coffee
+++ b/lib/assets/javascripts/cable/consumer.coffee
diff --git a/lib/assets/javascripts/cable/subscription.js.coffee b/lib/assets/javascripts/cable/subscription.coffee
index 5b024d4e15..5b024d4e15 100644
--- a/lib/assets/javascripts/cable/subscription.js.coffee
+++ b/lib/assets/javascripts/cable/subscription.coffee
diff --git a/lib/assets/javascripts/cable/subscriptions.js.coffee b/lib/assets/javascripts/cable/subscriptions.coffee
index fe6975c870..4efb384ee2 100644
--- a/lib/assets/javascripts/cable/subscriptions.js.coffee
+++ b/lib/assets/javascripts/cable/subscriptions.coffee
@@ -9,6 +9,7 @@
 class Cable.Subscriptions
   constructor: (@consumer) ->
     @subscriptions = []
+    @history = []
 
   create: (channelName, mixin) ->
     channel = channelName
@@ -20,13 +21,11 @@ class Cable.Subscriptions
   add: (subscription) ->
     @subscriptions.push(subscription)
     @notify(subscription, "initialized")
-    if @sendCommand(subscription, "subscribe")
-      @notify(subscription, "connected")
+    @sendCommand(subscription, "subscribe")
 
   reload: ->
     for subscription in @subscriptions
-      if @sendCommand(subscription, "subscribe")
-        @notify(subscription, "connected")
+      @sendCommand(subscription, "subscribe")
 
   remove: (subscription) ->
     @subscriptions = (s for s in @subscriptions when s isnt subscription)
@@ -49,6 +48,10 @@ class Cable.Subscriptions
     for subscription in subscriptions
       subscription[callbackName]?(args...)
 
+      if callbackName in ["initialized", "connected", "disconnected"]
+        {identifier} = subscription
+        @record(notification: {identifier, callbackName, args})
+
   sendCommand: (subscription, command) ->
     {identifier} = subscription
     if identifier is Cable.PING_IDENTIFIER
@@ -56,5 +59,11 @@ class Cable.Subscriptions
     else
       @consumer.send({command, identifier})
 
+  record: (data) ->
+    data.time = new Date()
+    @history = @history.slice(-19)
+    @history.push(data)
+
   toJSON: ->
-    subscription.identifier for subscription in @subscriptions
+    history: @history
+    identifiers: (subscription.identifier for subscription in @subscriptions)