Implements choosing from a list of possible BOSH addresses.

app.js

@@ -46,7 +46,7 @@ function init() {
 }
 
 /**
- * If we have HTTP endpoint for getting confgi.json configured we're going to
+ * If we have an HTTP endpoint for getting config.json configured we're going to
  * read it and override properties from config.js and interfaceConfig.js.
  * If there is no endpoint we'll just continue with initialization.
  * Keep in mind that if the endpoint has been configured and we fail to obtain
@@ -54,9 +54,11 @@ function init() {
  * will be displayed to the user.
  */
 function obtainConfigAndInit() {
+    var roomName = APP.UI.getRoomNode();
+
     if (config.configLocation) {
         APP.configFetch.obtainConfig(
-            config.configLocation, APP.UI.getRoomNode(),
+            config.configLocation, roomName,
             // Get config result callback
             function(success, error) {
                 if (success) {
@@ -71,6 +73,9 @@ function obtainConfigAndInit() {
                 }
             });
     } else {
+        require("./modules/config/BoshAddressChoice").chooseAddress(
+            config, roomName);
+
         init();
     }
 }

modules/config/BoshAddressChoice.js

@@ -0,0 +1,44 @@
+var jssha = require('jssha');
+
+module.exports = {
+    /**
+     * Looks for a list of possible BOSH addresses in 'config.boshList' and
+     * sets the value of 'config.bosh' based on that list and 'roomName'.
+     * @param config the configuration object.
+     * @param roomName the name of the room/conference.
+     */
+    chooseAddress: function(config, roomName) {
+        if (!roomName || !config.boshList || !Array.isArray(config.boshList) ||
+            !config.boshList.length) {
+            return;
+        }
+
+        // This implements the actual choice of an entry in the list based on
+        // roomName. Please consider the implications for existing deployments
+        // before introducing changes.
+        var hash = (new jssha(roomName, 'TEXT')).getHash('SHA-1', 'HEX');
+        var n = parseInt("0x"+hash.substr(-6));
+        var idx = n % config.boshList.length;
+        var attemptFirstAddress;
+
+        config.bosh = config.boshList[idx];
+        console.log('Setting config.bosh to ' + config.bosh +
+            ' (idx=' + idx + ')');
+
+        if (config.boshAttemptFirstList &&
+            Array.isArray(config.boshAttemptFirstList) &&
+            config.boshAttemptFirstList.length > 0) {
+
+            idx = n % config.boshAttemptFirstList.length;
+            attemptFirstAddress = config.boshAttemptFirstList[idx];
+
+            if (attemptFirstAddress != config.bosh) {
+                config.boshAttemptFirst = attemptFirstAddress;
+                console.log('Setting config.boshAttemptFirst=' +
+                    attemptFirstAddress + ' (idx=' + idx + ')');
+            } else {
+                console.log('Not setting boshAttemptFirst, address matches.');
+            }
+        }
+    }
+};