per-proxypair Snowflake ID generation instead of just one for the Broker (#11)

proxy/broker.coffee

@@ -12,21 +12,16 @@ STATUS_GATEWAY_TIMEOUT = 504
 MESSAGE_TIMEOUT = 'Timed out waiting for a client offer.'
 MESSAGE_UNEXPECTED = 'Unexpected status.'
 
-genSnowflakeID = ->
-  Math.random().toString(36).substring(2)
-
 # Represents a broker running remotely.
 class Broker
 
   clients: 0
-  id: null
 
   # When interacting with the Broker, snowflake must generate a unique session
   # ID so the Broker can keep track of which signalling channel it's speaking
   # to.
   constructor: (@url) ->
     @clients = 0
-    @id = genSnowflakeID()
     # Ensure url has the right protocol + trailing slash.
     @url = 'http://' + @url if 0 == @url.indexOf('localhost', 0)
     @url = 'https://' + @url if 0 != @url.indexOf('http', 0)
@@ -37,7 +32,7 @@ class Broker
   # waits for a response containing some client offer that the Broker chooses
   # for this proxy..
   # TODO: Actually support multiple clients.
-  getClientOffer: =>
+  getClientOffer: (id) =>
     new Promise (fulfill, reject) =>
       xhr = new XMLHttpRequest()
       xhr.onreadystatechange = ->
@@ -53,12 +48,12 @@ class Broker
             snowflake.ui.setStatus ' failure. Please refresh.'
             reject MESSAGE_UNEXPECTED
       @_xhr = xhr  # Used by spec to fake async Broker interaction
-      @_postRequest xhr, 'proxy', @id
+      @_postRequest id, xhr, 'proxy', id
 
   # Assumes getClientOffer happened, and a WebRTC SDP answer has been generated.
   # Sends it back to the broker, which passes it to back to the original client.
-  sendAnswer: (answer) ->
-    dbg @id + ' - Sending answer back to broker...\n'
+  sendAnswer: (id, answer) ->
+    dbg id + ' - Sending answer back to broker...\n'
     dbg answer.sdp
     xhr = new XMLHttpRequest()
     xhr.onreadystatechange = ->
@@ -73,14 +68,14 @@ class Broker
           dbg 'Broker ERROR: Unexpected ' + xhr.status +
               ' - ' + xhr.statusText
           snowflake.ui.setStatus ' failure. Please refresh.'
-    @_postRequest xhr, 'answer', JSON.stringify(answer)
+    @_postRequest id, xhr, 'answer', JSON.stringify(answer)
 
   # urlSuffix for the broker is different depending on what action
   # is desired.
-  _postRequest: (xhr, urlSuffix, payload) =>
+  _postRequest: (id, xhr, urlSuffix, payload) =>
     try
       xhr.open 'POST', @url + urlSuffix
-      xhr.setRequestHeader('X-Session-ID', @id)
+      xhr.setRequestHeader('X-Session-ID', id)
     catch err
       ###
       An exception happens here when, for example, NoScript allows the domain