The chromoting client logs connection statistics to the server.

remoting/webapp/me2mom/debug_log.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * Module to support logging debug messages.
  */
 
 'use strict';
@@ skipping 20 matching lines @@
 remoting.DebugLog.prototype.MAX_DEBUG_LOG_SIZE = 1000;
 
 /**
  * JID for the remoting bot which is used to bridge communication between
  * the Talk network and the Remoting directory service.
  */
 remoting.DebugLog.prototype.REMOTING_DIRECTORY_SERVICE_BOT =
     'remoting@bot.talk.google.com';
 
 /**
+ * The host attributes in a log entry.
+ *
+ * @private
+ */
+remoting.DebugLog.prototype.LOG_ENTRY_HOST_ATTRIBUTES_ =
+    'cpu,os-name,browser-version,webapp-version';
+
+/**
+ * The id attribute in a log entry.
+ *
+ * @private
+ */
+remoting.DebugLog.prototype.LOG_ENTRY_ID_ATTRIBUTE_ = 'id';
+
+/**
  * Add the given message to the debug log.
  *
  * @param {number} indentLevel The indention level for this message.
  * @param {string} message The debug info to add to the log.
  */
 remoting.DebugLog.prototype.logIndent = function(indentLevel, message) {
   // Remove lines from top if we've hit our max log size.
   if (this.logElement.childNodes.length == this.MAX_DEBUG_LOG_SIZE) {
     this.logElement.removeChild(this.logElement.firstChild);
   }
@@ skipping 32 matching lines @@
     debugLog.hidden = true;
   }
 };
 
 /**
  * Update the statistics panel.
  * @param {Object.<string, number>} stats The connection statistics.
  */
 remoting.DebugLog.prototype.updateStatistics = function(stats) {
   var units = '';
-  var videoBandwidth = stats['video_bandwidth'];
+  var videoBandwidth = stats[remoting.ClientSession.STATS_KEY_VIDEO_BANDWIDTH];
   if (videoBandwidth < 1024) {
     units = 'Bps';
   } else if (videoBandwidth < 1048576) {
     units = 'KiBps';
     videoBandwidth = videoBandwidth / 1024;
   } else if (videoBandwidth < 1073741824) {
     units = 'MiBps';
     videoBandwidth = videoBandwidth / 1048576;
   } else {
     units = 'GiBps';
     videoBandwidth = videoBandwidth / 1073741824;
   }
 
   var statistics = document.getElementById('statistics');
   this.statsElement.innerText =
       'Bandwidth: ' + videoBandwidth.toFixed(2) + units +
       ', Frame Rate: ' +
-          (stats['video_frame_rate'] ?
-           stats['video_frame_rate'].toFixed(2) + ' fps' : 'n/a') +
-      ', Capture: ' + stats['capture_latency'].toFixed(2) + 'ms' +
-      ', Encode: ' + stats['encode_latency'].toFixed(2) + 'ms' +
-      ', Decode: ' + stats['decode_latency'].toFixed(2) + 'ms' +
-      ', Render: ' + stats['render_latency'].toFixed(2) + 'ms' +
-      ', Latency: ' + stats['roundtrip_latency'].toFixed(2) + 'ms';
+          (stats[remoting.ClientSession.STATS_KEY_VIDEO_FRAME_RATE] ?
+           stats[remoting.ClientSession.STATS_KEY_VIDEO_FRAME_RATE].toFixed(2)
+              + ' fps' : 'n/a') +
+      ', Capture: ' +
+      stats[remoting.ClientSession.STATS_KEY_CAPTURE_LATENCY].toFixed(2) +
+      'ms' +
+      ', Encode: ' +
+      stats[remoting.ClientSession.STATS_KEY_ENCODE_LATENCY].toFixed(2) +
+      'ms' +
+      ', Decode: ' +
+      stats[remoting.ClientSession.STATS_KEY_DECODE_LATENCY].toFixed(2) +
+      'ms' +
+      ', Render: ' +
+      stats[remoting.ClientSession.STATS_KEY_RENDER_LATENCY].toFixed(2) +
+      'ms' +
+      ', Latency: ' +
+      stats[remoting.ClientSession.STATS_KEY_ROUNDTRIP_LATENCY].toFixed(2) +
+      'ms';
 };
 
 /**
  * Check for the debug toggle hot-key.
  *
  * @param {Event} event The keyboard event.
  * @return {void} Nothing.
  */
 remoting.DebugLog.onKeydown = function(event) {
   var element = /** @type {Element} */ (event.target);
@@ skipping 528 matching lines @@
       var log = child;
       if (log.childNodes.length != 1) {
         return false;
       }
       if (!this.verifyAttributes(log, 'xmlns:gr')) {
         return false;
       }
 
       /** @type {Node} */
       var entry = log.childNodes[0];
-      if (!this.verifyAttributes(entry, 'role,event-name,session-state,cpu,' +
-                                 'os-name,browser-version,webapp-version,id')) {
-        return false;
-      }
       var role = entry.getAttribute('role');
       if (role != 'client') {
         return false;
       }
       var event_name = entry.getAttribute('event-name');
-      if (event_name != 'session-state') {
-        return false;
+      if (event_name == 'session-state') {

[Jamie, 2011/12/09 06:58:34]

This feels unnecessary to me. My understanding of the pretty-printing code is
that it does all this checking because the XML comes from somewhere we don't
control (or at least, that the web-app doesn't control). Isn't this stuff
generated elsewhere in the web-app? Would it be simpler to log it at source, and
skip pretty-printing it here altogether?

[simonmorris, 2011/12/09 18:40:36]

Done.

+        if (!this.verifyAttributes(entry,
+            'role,event-name,session-state,' +
+            this.LOG_ENTRY_HOST_ATTRIBUTES_ + ',' +
+            this.LOG_ENTRY_ID_ATTRIBUTE_)) {
+          return false;
+        }
+        var session_state = entry.getAttribute('session-state');
+        this.prettyIqHeading(action, '?', 'log session-state ' + session_state,
+                             null);
+        this.prettyLogEntryHostAttributes(entry);
+        this.prettyLogEntryIdAttribute(entry);
+        return true;
+      } else if (event_name == 'connection-statistics') {
+        if (!this.verifyAttributes(entry,
+            'role,event-name,video-bandwidth,capture-latency,encode-latency,' +
+            'decode-latency,render-latency,roundtrip-latency,' +
+            this.LOG_ENTRY_HOST_ATTRIBUTES_ + ',' +
+            this.LOG_ENTRY_ID_ATTRIBUTE_)) {
+          return false;
+        }
+        this.prettyIqHeading(action, '?', 'log connection-statistics', null);
+        var video_bandwidth = entry.getAttribute('video-bandwidth');
+        if (video_bandwidth) {
+          this.logIndent(1, 'video bandwidth: ' + video_bandwidth);
+        }
+        var capture_latency = entry.getAttribute('capture-latency');
+        if (capture_latency) {
+          this.logIndent(1, 'capture latency: ' + capture_latency);
+        }
+        var encode_latency = entry.getAttribute('encode-latency');
+        if (encode_latency) {
+          this.logIndent(1, 'encode latency: ' + encode_latency);
+        }
+        var decode_latency = entry.getAttribute('decode-latency');
+        if (decode_latency) {
+          this.logIndent(1, 'decode latency: ' + decode_latency);
+        }
+        var render_latency = entry.getAttribute('render-latency');
+        if (render_latency) {
+          this.logIndent(1, 'render latency: ' + render_latency);
+        }
+        var roundtrip_latency = entry.getAttribute('roundtrip-latency');
+        if (roundtrip_latency) {
+          this.logIndent(1, 'roundtrip latency: ' + roundtrip_latency);
+        }
+        this.prettyLogEntryHostAttributes(entry);
+        this.prettyLogEntryIdAttribute(entry);
+        return true;
       }
-      var session_state = entry.getAttribute('session-state');
-      this.prettyIqHeading(action, '?', 'log session-state ' + session_state,
-                           null);
-
-      var os_name = entry.getAttribute('os-name');
-      var cpu = entry.getAttribute('cpu');
-      var browser_version = entry.getAttribute('browser-version');
-      var webapp_version = entry.getAttribute('webapp-version');
-      this.logIndent(1, os_name + ' ' + cpu + ' Chromium_v' + browser_version +
-                     ' Chromoting_v' + webapp_version);
-      var remoting_id = entry.getAttribute('id');
-      if (remoting_id) {
-        this.logIndent(1, 'id: ' + remoting_id);
-      }
-      return true;
+      return false;
     }
   }
   return false;
-}
+};
+
+/**
+ * Print out the host attributes in a log entry.
+ *
+ * @private
+ * @param {Node} entry
+ */
+remoting.DebugLog.prototype.prettyLogEntryHostAttributes = function(entry) {
+  var os_name = entry.getAttribute('os-name');
+  var cpu = entry.getAttribute('cpu');
+  var browser_version = entry.getAttribute('browser-version');
+  var webapp_version = entry.getAttribute('webapp-version');
+  this.logIndent(1, os_name + ' ' + cpu + ' Chromium_v' + browser_version +
+                       ' Chromoting_v' + webapp_version);
+};
+
+/**
+ * Print out the id attribute in a log entry.
+ *
+ * @private
+ * @param {Node} entry
+ */
+remoting.DebugLog.prototype.prettyLogEntryIdAttribute = function(entry) {
+  var remoting_id = entry.getAttribute('id');
+  if (remoting_id) {
+    this.logIndent(1, 'id: ' + remoting_id);
+  }
+};
 
 /**
  * Print out an iq 'error'-type node.
  *
  * @param {string} action String describing action (send/receive).
  * @param {NodeList} iq_list Node containing the 'error' xml.
  *
  * @return {boolean} True if the data was logged successfully.
  */
 remoting.DebugLog.prototype.prettyIqError = function(action, iq_list) {
@@ skipping 112 matching lines @@
 remoting.DebugLog.prototype.logIq = function(send, message) {
   if (!this.prettyIq(send, message)) {
     // Fall back to showing the raw stanza.
     var prefix = (send ? 'Sending Iq: ' : 'Receiving Iq: ');
     this.log(prefix + message);
   }
 };
 
 /** @type {remoting.DebugLog} */
 remoting.debug = null;