1 files changed, 431 insertions, 0 deletions
diff --git a/assets/js/message-bus.js b/assets/js/message-bus.js
new file mode 100644
index 0000000..0a1d4a0
--- /dev/null
+++ b/assets/js/message-bus.js
@@ -0,0 +1,431 @@
+/*jshint bitwise: false*/
+(function(global, document, undefined) {
+  'use strict';
+  var previousMessageBus = global.MessageBus;
+
+  // http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
+  var callbacks, clientId, failCount, shouldLongPoll, queue, responseCallbacks, uniqueId, baseUrl;
+  var me, started, stopped, longPoller, pollTimeout, paused, later, jQuery, interval, chunkedBackoff;
+
+  uniqueId = function() {
+    return 'xxxxxxxxxxxx4xxxyxxxxxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+      var r, v;
+      r = Math.random() * 16 | 0;
+      v = c === 'x' ? r : (r & 0x3 | 0x8);
+      return v.toString(16);
+    });
+  };
+
+  clientId = uniqueId();
+  responseCallbacks = {};
+  callbacks = [];
+  queue = [];
+  interval = null;
+  failCount = 0;
+  baseUrl = "/";
+  paused = false;
+  later = [];
+  chunkedBackoff = 0;
+  jQuery = global.jQuery;
+  var hiddenProperty;
+
+  (function(){
+    var prefixes = ["","webkit","ms"];
+    for(var i=0; i<prefixes.length; i++) {
+      var prefix = prefixes[i];
+      var check = prefix + (prefix === "" ? "hidden" : "Hidden");
+      if(document[check] !== undefined ){
+        hiddenProperty = check;
+      }
+    }
+  })();
+
+  var isHidden = function() {
+    if (hiddenProperty !== undefined){
+      return document[hiddenProperty];
+    } else {
+      return !document.hasFocus;
+    }
+  };
+
+  var hasonprogress = (new XMLHttpRequest()).onprogress === null;
+  var allowChunked = function(){
+    return me.enableChunkedEncoding && hasonprogress;
+  };
+
+  shouldLongPoll = function() {
+    return me.alwaysLongPoll || !isHidden();
+  };
+
+  var totalAjaxFailures = 0;
+  var totalAjaxCalls = 0;
+  var lastAjax;
+
+  var processMessages = function(messages) {
+    var gotData = false;
+    if (!messages) return false; // server unexpectedly closed connection
+
+    for (var i=0; i<messages.length; i++) {
+      var message = messages[i];
+      gotData = true;
+      for (var j=0; j<callbacks.length; j++) {
+        var callback = callbacks[j];
+        if (callback.channel === message.channel) {
+          callback.last_id = message.message_id;
+          try {
+            callback.func(message.data, message.global_id, message.message_id);
+          }
+          catch(e){
+            if(console.log) {
+              console.log("MESSAGE BUS FAIL: callback " + callback.channel +  " caused exception " + e.message);
+            }
+          }
+        }
+        if (message.channel === "/__status") {
+          if (message.data[callback.channel] !== undefined) {
+            callback.last_id = message.data[callback.channel];
+          }
+        }
+      }
+    }
+
+    return gotData;
+  };
+
+  var reqSuccess = function(messages) {
+    failCount = 0;
+    if (paused) {
+      if (messages) {
+        for (var i=0; i<messages.length; i++) {
+          later.push(messages[i]);
+        }
+      }
+    } else {
+      return processMessages(messages);
+    }
+    return false;
+  };
+
+  longPoller = function(poll,data){
+    var gotData = false;
+    var aborted = false;
+    lastAjax = new Date();
+    totalAjaxCalls += 1;
+    data.__seq = totalAjaxCalls;
+
+    var longPoll = shouldLongPoll() && me.enableLongPolling;
+    var chunked = longPoll && allowChunked();
+    if (chunkedBackoff > 0) {
+      chunkedBackoff--;
+      chunked = false;
+    }
+
+    var headers = {
+      'X-SILENCE-LOGGER': 'true'
+    };
+    for (var name in me.headers){
+      headers[name] = me.headers[name];
+    }
+
+    if (!chunked){
+      headers["Dont-Chunk"] = 'true';
+    }
+
+    var dataType = chunked ? "text" : "json";
+
+    var handle_progress = function(payload, position) {
+
+      var separator = "\r\n|\r\n";
+      var endChunk = payload.indexOf(separator, position);
+
+      if (endChunk === -1) {
+        return position;
+      }
+
+      var chunk = payload.substring(position, endChunk);
+      chunk = chunk.replace(/\r\n\|\|\r\n/g, separator);
+
+      try {
+        reqSuccess(JSON.parse(chunk));
+      } catch(e) {
+        if (console.log) {
+          console.log("FAILED TO PARSE CHUNKED REPLY");
+          console.log(data);
+        }
+      }
+
+      return handle_progress(payload, endChunk + separator.length);
+    }
+
+    var disableChunked = function(){
+      if (me.longPoll) {
+        me.longPoll.abort();
+        chunkedBackoff = 30;
+      }
+    };
+
+    var setOnProgressListener = function(xhr) {
+      var position = 0;
+      // if it takes longer than 3000 ms to get first chunk, we have some proxy
+      // this is messing with us, so just backoff from using chunked for now
+      var chunkedTimeout = setTimeout(disableChunked,3000);
+      xhr.onprogress = function () {
+        clearTimeout(chunkedTimeout);
+        if(xhr.getResponseHeader('Content-Type') === 'application/json; charset=utf-8') {
+          // not chunked we are sending json back
+          chunked = false;
+          return;
+        }
+        position = handle_progress(xhr.responseText, position);
+      }
+    };
+    if (!me.ajax){
+      throw new Error("Either jQuery or the ajax adapter must be loaded");
+    }
+    var req = me.ajax({
+      url: me.baseUrl + "message-bus/" + me.clientId + "/poll" + (!longPoll ? "?dlp=t" : ""),
+      data: data,
+      cache: false,
+      async: true,
+      dataType: dataType,
+      type: 'POST',
+      headers: headers,
+      messageBus: {
+        chunked: chunked,
+        onProgressListener: function(xhr) {
+          var position = 0;
+          // if it takes longer than 3000 ms to get first chunk, we have some proxy
+          // this is messing with us, so just backoff from using chunked for now
+          var chunkedTimeout = setTimeout(disableChunked,3000);
+          return xhr.onprogress = function () {
+            clearTimeout(chunkedTimeout);
+            if(xhr.getResponseHeader('Content-Type') === 'application/json; charset=utf-8') {
+              chunked = false; // not chunked, we are sending json back
+            } else {
+              position = handle_progress(xhr.responseText, position);
+            }
+          }
+        }
+      },
+      xhr: function() {
+        var xhr = jQuery.ajaxSettings.xhr();
+        if (!chunked) {
+          return xhr;
+        }
+        this.messageBus.onProgressListener(xhr);
+        return xhr;
+      },
+      success: function(messages) {
+         if (!chunked) {
+           // we may have requested text so jQuery will not parse
+           if (typeof(messages) === "string") {
+             messages = JSON.parse(messages);
+           }
+           gotData = reqSuccess(messages);
+         }
+       },
+      error: function(xhr, textStatus, err) {
+        if(textStatus === "abort") {
+          aborted = true;
+        } else {
+          failCount += 1;
+          totalAjaxFailures += 1;
+        }
+      },
+      complete: function() {
+        var interval;
+        try {
+          if (gotData || aborted) {
+            interval = 100;
+          } else {
+            interval = me.callbackInterval;
+            if (failCount > 2) {
+              interval = interval * failCount;
+            } else if (!shouldLongPoll()) {
+              interval = me.backgroundCallbackInterval;
+            }
+            if (interval > me.maxPollInterval) {
+              interval = me.maxPollInterval;
+            }
+
+            interval -= (new Date() - lastAjax);
+
+            if (interval < 100) {
+              interval = 100;
+            }
+          }
+        } catch(e) {
+          if(console.log && e.message) {
+            console.log("MESSAGE BUS FAIL: " + e.message);
+          }
+        }
+
+        pollTimeout = setTimeout(function(){pollTimeout=null; poll();}, interval);
+        me.longPoll = null;
+      }
+    });
+
+    return req;
+  };
+
+  me = {
+    enableChunkedEncoding: true,
+    enableLongPolling: true,
+    callbackInterval: 15000,
+    backgroundCallbackInterval: 60000,
+    maxPollInterval: 3 * 60 * 1000,
+    callbacks: callbacks,
+    clientId: clientId,
+    alwaysLongPoll: false,
+    baseUrl: baseUrl,
+    headers: {},
+    ajax: (jQuery && jQuery.ajax),
+    noConflict: function(){
+      global.MessageBus = global.MessageBus.previousMessageBus;
+      return this;
+    },
+    diagnostics: function(){
+      console.log("Stopped: " + stopped + " Started: " + started);
+      console.log("Current callbacks");
+      console.log(callbacks);
+      console.log("Total ajax calls: " + totalAjaxCalls + " Recent failure count: " + failCount + " Total failures: " + totalAjaxFailures);
+      console.log("Last ajax call: " + (new Date() - lastAjax) / 1000  + " seconds ago") ;
+    },
+
+    pause: function() {
+      paused = true;
+    },
+
+    resume: function() {
+      paused = false;
+      processMessages(later);
+      later = [];
+    },
+
+    stop: function() {
+      stopped = true;
+      started = false;
+    },
+
+    // Start polling
+    start: function() {
+      var poll, delayPollTimeout;
+
+      if (started) return;
+      started = true;
+      stopped = false;
+
+      poll = function() {
+        var data;
+
+        if(stopped) {
+          return;
+        }
+
+        if (callbacks.length === 0) {
+          if(!delayPollTimeout) {
+            delayPollTimeout = setTimeout(function(){ delayPollTimeout = null; poll();}, 500);
+          }
+          return;
+        }
+
+        data = {};
+        for (var i=0;i<callbacks.length;i++) {
+          data[callbacks[i].channel] = callbacks[i].last_id;
+        }
+
+        me.longPoll = longPoller(poll,data);
+      };
+
+
+      // monitor visibility, issue a new long poll when the page shows
+      if(document.addEventListener && 'hidden' in document){
+        me.visibilityEvent = global.document.addEventListener('visibilitychange', function(){
+          if(!document.hidden && !me.longPoll && pollTimeout){
+            clearTimeout(pollTimeout);
+            pollTimeout = null;
+            poll();
+          }
+        });
+      }
+
+      poll();
+    },
+
+    "status": function() {
+      if (paused) {
+         return "paused";
+      } else if (started) {
+         return "started";
+      } else if (stopped) {
+        return "stopped";
+      } else {
+        throw "Cannot determine current status";
+      }
+    },
+
+    // Subscribe to a channel
+    subscribe: function(channel, func, lastId) {
+
+      if(!started && !stopped){
+        me.start();
+      }
+
+      if (typeof(lastId) !== "number" || lastId < -1){
+        lastId = -1;
+      }
+      callbacks.push({
+        channel: channel,
+        func: func,
+        last_id: lastId
+      });
+      if (me.longPoll) {
+        me.longPoll.abort();
+      }
+
+      return func;
+    },
+
+    // Unsubscribe from a channel
+    unsubscribe: function(channel, func) {
+      // TODO allow for globbing in the middle of a channel name
+      // like /something/*/something
+      // at the moment we only support globbing /something/*
+      var glob;
+      if (channel.indexOf("*", channel.length - 1) !== -1) {
+        channel = channel.substr(0, channel.length - 1);
+        glob = true;
+      }
+
+      var removed = false;
+
+      for (var i=callbacks.length-1; i>=0; i--) {
+
+        var callback = callbacks[i];
+        var keep;
+
+        if (glob) {
+          keep = callback.channel.substr(0, channel.length) !== channel;
+        } else {
+          keep = callback.channel !== channel;
+        }
+
+        if(!keep && func && callback.func !== func){
+          keep = true;
+        }
+
+        if (!keep) {
+          callbacks.splice(i,1);
+          removed = true;
+        }
+      }
+
+      if (removed && me.longPoll) {
+        me.longPoll.abort();
+      }
+
+      return removed;
+    }
+  };
+  global.MessageBus = me;
+})(window, document);