1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/toolkit/components/telemetry/TelemetryStopwatch.jsm Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,133 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.6 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +const Cc = Components.classes;
1.9 +const Ci = Components.interfaces;
1.10 +const Cu = Components.utils;
1.11 +
1.12 +this.EXPORTED_SYMBOLS = ["TelemetryStopwatch"];
1.13 +
1.14 +let Telemetry = Cc["@mozilla.org/base/telemetry;1"]
1.15 + .getService(Ci.nsITelemetry);
1.16 +
1.17 +// simpleTimers are directly associated with a histogram
1.18 +// name. objectTimers are associated with an object _and_
1.19 +// a histogram name.
1.20 +let simpleTimers = {};
1.21 +let objectTimers = new WeakMap();
1.22 +
1.23 +this.TelemetryStopwatch = {
1.24 + /**
1.25 + * Starts a timer associated with a telemetry histogram. The timer can be
1.26 + * directly associated with a histogram, or with a pair of a histogram and
1.27 + * an object.
1.28 + *
1.29 + * @param aHistogram a string which must be a valid histogram name
1.30 + * from TelemetryHistograms.h
1.31 + *
1.32 + * @param aObj Optional parameter. If specified, the timer is associated
1.33 + * with this object, meaning that multiple timers for a same
1.34 + * histogram may be run concurrently, as long as they are
1.35 + * associated with different objects.
1.36 + *
1.37 + * @return true if the timer was successfully started, false otherwise. If a
1.38 + * timer already exists, it can't be started again, and the existing
1.39 + * one will be cleared in order to avoid measurements errors.
1.40 + */
1.41 + start: function(aHistogram, aObj) {
1.42 + if (!validTypes(aHistogram, aObj))
1.43 + return false;
1.44 +
1.45 + let timers;
1.46 + if (aObj) {
1.47 + timers = objectTimers.get(aObj, {});
1.48 + objectTimers.set(aObj, timers);
1.49 + } else {
1.50 + timers = simpleTimers;
1.51 + }
1.52 +
1.53 + if (timers.hasOwnProperty(aHistogram)) {
1.54 + delete timers[aHistogram];
1.55 + Cu.reportError("TelemetryStopwatch: key \"" +
1.56 + aHistogram + "\" was already initialized");
1.57 + return false;
1.58 + }
1.59 +
1.60 + timers[aHistogram] = Date.now();
1.61 + return true;
1.62 + },
1.63 +
1.64 + /**
1.65 + * Deletes the timer associated with a telemetry histogram. The timer can be
1.66 + * directly associated with a histogram, or with a pair of a histogram and
1.67 + * an object. Important: Only use this method when a legitimate cancellation
1.68 + * should be done.
1.69 + *
1.70 + * @param aHistogram a string which must be a valid histogram name
1.71 + * from TelemetryHistograms.json
1.72 + *
1.73 + * @param aObj Optional parameter. If specified, the timer is associated
1.74 + * with this object, meaning that multiple timers for a same
1.75 + * histogram may be run concurrently, as long as they are
1.76 + * associated with different objects.
1.77 + *
1.78 + * @return true if the timer exist and it was cleared, false otherwise.
1.79 + */
1.80 + cancel: function ts_cancel(aHistogram, aObj) {
1.81 + if (!validTypes(aHistogram, aObj))
1.82 + return false;
1.83 +
1.84 + let timers = aObj
1.85 + ? objectTimers.get(aObj, {})
1.86 + : simpleTimers;
1.87 +
1.88 + if (timers.hasOwnProperty(aHistogram)) {
1.89 + delete timers[aHistogram];
1.90 + return true;
1.91 + }
1.92 +
1.93 + return false;
1.94 + },
1.95 +
1.96 + /**
1.97 + * Stops the timer associated with the given histogram (and object),
1.98 + * calculates the time delta between start and finish, and adds the value
1.99 + * to the histogram.
1.100 + *
1.101 + * @param aHistogram a string which must be a valid histogram name
1.102 + * from TelemetryHistograms.h. If an invalid name
1.103 + * is given, the function will throw.
1.104 + *
1.105 + * @param aObj Optional parameter which associates the histogram timer with
1.106 + * the given object.
1.107 + *
1.108 + * @return true if the timer was succesfully stopped and the data was
1.109 + * added to the histogram, false otherwise.
1.110 + */
1.111 + finish: function(aHistogram, aObj) {
1.112 + if (!validTypes(aHistogram, aObj))
1.113 + return false;
1.114 +
1.115 + let timers = aObj
1.116 + ? objectTimers.get(aObj, {})
1.117 + : simpleTimers;
1.118 +
1.119 + let start = timers[aHistogram];
1.120 + delete timers[aHistogram];
1.121 +
1.122 + if (start) {
1.123 + let delta = Date.now() - start;
1.124 + let histogram = Telemetry.getHistogramById(aHistogram);
1.125 + histogram.add(delta);
1.126 + return true;
1.127 + }
1.128 +
1.129 + return false;
1.130 + }
1.131 +}
1.132 +
1.133 +function validTypes(aKey, aObj) {
1.134 + return (typeof aKey == "string") &&
1.135 + (aObj === undefined || typeof aObj == "object");
1.136 +}
