The chromoting client logs connection statistics to the server.

remoting/webapp/me2mom/server_log_entry.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
  * A class of server log entries.
  */
 
 'use strict';
@@ skipping 76 matching lines @@
     case remoting.ClientSession.ConnectionError.INCOMPATIBLE_PROTOCOL:
       return 'incompatible-protocol';
     case remoting.ClientSession.ConnectionError.NETWORK_FAILURE:
       return 'network-failure';
     default:
       return 'unknown-' + connectionError;
   }
 }
 
 /** @private */
+remoting.ServerLogEntry.prototype.VALUE_EVENT_NAME_CONNECTION_STATISTICS_ =
+    "connection-statistics";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_VIDEO_BANDWIDTH_ = "video-bandwidth";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_CAPTURE_LATENCY_ = "capture-latency";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_ENCODE_LATENCY_ = "encode-latency";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_DECODE_LATENCY_ = "decode-latency";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_RENDER_LATENCY_ = "render-latency";
+/** @private */
+remoting.ServerLogEntry.prototype.KEY_ROUNDTRIP_LATENCY_ = "roundtrip-latency";

[Jamie, 2011/12/09 19:47:56]

Why not reuse the keys from ClientSession?

[simonmorris, 2011/12/09 21:12:12]

Because I want to be able to look down the list of keys
and verify that they match the keys that the server handles.

Also, I don't want a change in the ClientSession keys
to inadvertently change the keys sent to the server,
which would then be ignored.

+
+/** @private */
 remoting.ServerLogEntry.prototype.KEY_OS_NAME_ = 'os-name';
 /** @private */
 remoting.ServerLogEntry.prototype.VALUE_OS_NAME_WINDOWS_ = 'Windows';
 /** @private */
 remoting.ServerLogEntry.prototype.VALUE_OS_NAME_LINUX_ = 'Linux';
 /** @private */
 remoting.ServerLogEntry.prototype.VALUE_OS_NAME_MAC_ = 'Mac';
 /** @private */
 remoting.ServerLogEntry.prototype.VALUE_OS_NAME_CHROMEOS_ = 'ChromeOS';
 
@@ skipping 28 matching lines @@
 remoting.ServerLogEntry.prototype.toStanza = function() {
   var stanza = '<gr:entry ';
   for (var key in this.dict) {
     stanza += escape(key) + '="' + escape(this.dict[key]) + '" ';
   }
   stanza += '/>';
   return stanza;
 };
 
 /**
+ * Prints this object on the debug log.
+ *
+ * @param {number} indentLevel the indentation level of each field
+ */
+remoting.ServerLogEntry.prototype.toDebugLog = function(indentLevel) {
+  for (var key in this.dict) {
+    remoting.debug.logIndent(indentLevel, key + ': ' + this.dict[key]);
+  }

[Jamie, 2011/12/09 19:47:56]

It might be better to log these on a single line, since they're all closely
related.

[simonmorris, 2011/12/09 21:12:12]

Done.

+};
+
+/**
  * Makes a log entry for a change of client session state.
  *
  * @param {remoting.ClientSession.State} state
  * @param {remoting.ClientSession.ConnectionError} connectionError
  * @return {remoting.ServerLogEntry}
  */
 remoting.ServerLogEntry.prototype.makeClientSessionStateChange =
     function(state, connectionError) {
   var entry = new remoting.ServerLogEntry();
   entry.set(this.KEY_ROLE_, this.VALUE_ROLE_CLIENT_);
   entry.set(this.KEY_EVENT_NAME_, this.VALUE_EVENT_NAME_SESSION_STATE_);
   entry.set(this.KEY_SESSION_STATE_, this.getValueForSessionState(state));
   if (connectionError != remoting.ClientSession.ConnectionError.NONE) {
     entry.set(this.KEY_CONNECTION_ERROR_,
               this.getValueForConnectionError(connectionError));
   }
   return entry;
 };
 
 /**
+ * Makes a log entry for a set of connection statistics.
+ * Returns null if all the statistics were zero.
+ *
+ * @param {remoting.StatsAccumulator} statsAccumulator
+ * @return {?remoting.ServerLogEntry}
+ */
+remoting.ServerLogEntry.prototype.makeStats = function(statsAccumulator) {

[Jamie, 2011/12/09 19:47:56]

I don't think this (or the previous method) belongs in the prototype; they're
basically 'static' factory methods.

[simonmorris, 2011/12/09 21:12:12]

Done.

+  var entry = new remoting.ServerLogEntry();
+  entry.set(this.KEY_ROLE_, this.VALUE_ROLE_CLIENT_);
+  entry.set(this.KEY_EVENT_NAME_, this.VALUE_EVENT_NAME_CONNECTION_STATISTICS_);
+  var nonZero = false;
+  nonZero |= entry.addStatsField(
+      this.KEY_VIDEO_BANDWIDTH_,
+      remoting.ClientSession.STATS_KEY_VIDEO_BANDWIDTH, statsAccumulator);
+  nonZero |= entry.addStatsField(
+      this.KEY_CAPTURE_LATENCY_,
+      remoting.ClientSession.STATS_KEY_CAPTURE_LATENCY, statsAccumulator);
+  nonZero |= entry.addStatsField(
+      this.KEY_ENCODE_LATENCY_,
+      remoting.ClientSession.STATS_KEY_ENCODE_LATENCY, statsAccumulator);
+  nonZero |= entry.addStatsField(
+      this.KEY_DECODE_LATENCY_,
+      remoting.ClientSession.STATS_KEY_DECODE_LATENCY, statsAccumulator);
+  nonZero |= entry.addStatsField(
+      this.KEY_RENDER_LATENCY_,
+      remoting.ClientSession.STATS_KEY_RENDER_LATENCY, statsAccumulator);
+  nonZero |= entry.addStatsField(
+      this.KEY_ROUNDTRIP_LATENCY_,
+      remoting.ClientSession.STATS_KEY_ROUNDTRIP_LATENCY, statsAccumulator);
+  if (nonZero) {
+    return entry;
+  }
+  return null;
+};
+
+/**
+ * Adds one connection statistic to a log entry.
+ *
+ * @private
+ * @param {string} entryKey
+ * @param {string} statsKey
+ * @param {remoting.StatsAccumulator} statsAccumulator
+ * @return {boolean} whether the statistic is non-zero
+ */
+remoting.ServerLogEntry.prototype.addStatsField = function(
+    entryKey, statsKey, statsAccumulator) {
+  var val = statsAccumulator.calcMean(statsKey);
+  this.set(entryKey, val.toString());
+  return (val != 0);
+};
+
+/**
  * Adds an ID field to this log entry.
  *
  * @param {string} id
  */
 remoting.ServerLogEntry.prototype.addIdField = function(id) {
   this.set(this.KEY_ID_, id);
 }
 
 /**
  * Adds fields describing the host to this log entry.
@@ skipping 109 matching lines @@
   }
   return null;
 };
 
 /**
  * Adds a field specifying the webapp version to this log entry.
  */
 remoting.ServerLogEntry.prototype.addWebappVersionField = function() {
   this.set(this.KEY_WEBAPP_VERSION_, chrome.app.getDetails().version);
 };