tools/perf/page_sets/webrtc_track_peerconnections.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This file overwrites the webkitRTCPeerConnection constructor with a
   6 // new constructor which tracks all created connections. It does this by
   7 // periodically gathering statistics on all connections, using the WebRTC
   8 // statistics API. All reports are gathered into window.peerConnectionReports,
   9 // which contains one list per connection. In each list there is a number of
  10 // report batches, which in turn contains metric names mapped to values.
  11
  12 window.peerConnectionReports = [];
  13
  14 webkitRTCPeerConnection = (function() {
  15   function getReportsAsDicts(getStatsResult) {
  16     var result = [];
  17     getStatsResult.forEach(function(report) {
  18       var values = {};
  19       report.names().forEach(function(name) {
  20         values[name] = report.stat(name);
  21       });
  22       result.push(values);
  23     });
  24     return result;
  25   }
  26
  27   function gatherStatsFromOneConnection(peerConnection) {
  28     var connectionId = window.peerConnectionReports.length;
  29     window.peerConnectionReports.push([]);
  30     var pollIntervalMs = 1000;
  31
  32     setInterval(function() {
  33       peerConnection.getStats(function(response) {
  34         var reports = getReportsAsDicts(response.result());
  35         window.peerConnectionReports[connectionId].push(reports);
  36       });
  37     }, pollIntervalMs);
  38   }
  39
  40   var originalConstructor = webkitRTCPeerConnection;
  41   return function() {
  42     // Bind the incoming arguments to the original constructor.
  43     var args = [null].concat(Array.prototype.slice.call(arguments));
  44     var factoryFunction = originalConstructor.bind.apply(
  45       originalConstructor, args);
  46
  47     // Create the object and track it.
  48     var peerConnection = new factoryFunction();
  49     gatherStatsFromOneConnection(peerConnection);
  50     return peerConnection;
  51   }
  52 })();