summaryrefslogtreecommitdiffstats
path: root/toolkit/components/extensions/ExtensionTelemetry.sys.mjs
blob: 57f052372c494dba537fd7018c8918396f833ce8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set sts=2 sw=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import { ExtensionUtils } from "resource://gre/modules/ExtensionUtils.sys.mjs";

const { DefaultWeakMap } = ExtensionUtils;

// Map of the base histogram ids for the metrics recorded for the extensions.
const HISTOGRAMS_IDS = {
  backgroundPageLoad: "WEBEXT_BACKGROUND_PAGE_LOAD_MS",
  browserActionPopupOpen: "WEBEXT_BROWSERACTION_POPUP_OPEN_MS",
  browserActionPreloadResult: "WEBEXT_BROWSERACTION_POPUP_PRELOAD_RESULT_COUNT",
  contentScriptInjection: "WEBEXT_CONTENT_SCRIPT_INJECTION_MS",
  eventPageRunningTime: "WEBEXT_EVENTPAGE_RUNNING_TIME_MS",
  eventPageIdleResult: "WEBEXT_EVENTPAGE_IDLE_RESULT_COUNT",
  extensionStartup: "WEBEXT_EXTENSION_STARTUP_MS",
  pageActionPopupOpen: "WEBEXT_PAGEACTION_POPUP_OPEN_MS",
  storageLocalGetJson: "WEBEXT_STORAGE_LOCAL_GET_MS",
  storageLocalSetJson: "WEBEXT_STORAGE_LOCAL_SET_MS",
  storageLocalGetIdb: "WEBEXT_STORAGE_LOCAL_IDB_GET_MS",
  storageLocalSetIdb: "WEBEXT_STORAGE_LOCAL_IDB_SET_MS",
};

const GLEAN_METRICS_TYPES = {
  backgroundPageLoad: "timing_distribution",
  browserActionPopupOpen: "timing_distribution",
  browserActionPreloadResult: "labeled_counter",
  contentScriptInjection: "timing_distribution",
  eventPageRunningTime: "custom_distribution",
  eventPageIdleResult: "labeled_counter",
  extensionStartup: "timing_distribution",
  pageActionPopupOpen: "timing_distribution",
  storageLocalGetJson: "timing_distribution",
  storageLocalSetJson: "timing_distribution",
  storageLocalGetIdb: "timing_distribution",
  storageLocalSetIdb: "timing_distribution",
};

/**
 * Get a trimmed version of the given string if it is longer than 80 chars (used in telemetry
 * when a string may be longer than allowed).
 *
 * @param {string} str
 *        The original string content.
 *
 * @returns {string}
 *          The trimmed version of the string when longer than 80 chars, or the given string
 *          unmodified otherwise.
 */
export function getTrimmedString(str) {
  if (str.length <= 80) {
    return str;
  }

  const length = str.length;

  // Trim the string to prevent a flood of warnings messages logged internally by recordEvent,
  // the trimmed version is going to be composed by the first 40 chars and the last 37 and 3 dots
  // that joins the two parts, to visually indicate that the string has been trimmed.
  return `${str.slice(0, 40)}...${str.slice(length - 37, length)}`;
}

/**
 * Get a string representing the error which can be included in telemetry data.
 * If the resulting string is longer than 80 characters it is going to be
 * trimmed using the `getTrimmedString` helper function.
 *
 * @param {Error | DOMException | Components.Exception} error
 *        The error object to convert into a string representation.
 *
 * @returns {string}
 *          - The `error.name` string on DOMException or Components.Exception
 *            (trimmed to 80 chars).
 *          - "NoError" if error is falsey.
 *          - "UnkownError" as a fallback.
 */
export function getErrorNameForTelemetry(error) {
  let text = "UnknownError";
  if (!error) {
    text = "NoError";
  } else if (
    DOMException.isInstance(error) ||
    error instanceof Components.Exception
  ) {
    text = error.name;
    if (text.length > 80) {
      text = getTrimmedString(text);
    }
  }
  return text;
}

/**
 * This is a internal helper object which contains a collection of helpers used to make it easier
 * to collect extension telemetry (in both the general histogram and in the one keyed by addon id).
 *
 * This helper object is not exported from ExtensionUtils, it is used by the ExtensionTelemetry
 * Proxy which is exported and used by the callers to record telemetry data for one of the
 * supported metrics.
 */
class ExtensionTelemetryMetric {
  constructor(metric) {
    this.metric = metric;
    this.gleanTimerIdsMap = new DefaultWeakMap(() => new WeakMap());
  }

  // Stopwatch methods.
  stopwatchStart(extension, obj = extension) {
    this._wrappedStopwatchMethod("start", this.metric, extension, obj);
    this._wrappedTimingDistributionMethod("start", this.metric, extension, obj);
  }

  stopwatchFinish(extension, obj = extension) {
    this._wrappedStopwatchMethod("finish", this.metric, extension, obj);
    this._wrappedTimingDistributionMethod(
      "stopAndAccumulate",
      this.metric,
      extension,
      obj
    );
  }

  stopwatchCancel(extension, obj = extension) {
    this._wrappedStopwatchMethod("cancel", this.metric, extension, obj);
    this._wrappedTimingDistributionMethod(
      "cancel",
      this.metric,
      extension,
      obj
    );
  }

  // Histogram counters methods.
  histogramAdd(opts) {
    this._histogramAdd(this.metric, opts);
  }

  /**
   * Wraps a call to Glean timing_distribution methods for a given metric and extension.
   *
   * @param {string} method
   *        The Glean timing_distribution method to call ("start", "stopAndAccumulate" or "cancel").
   * @param {string} metric
   *        The Glean timing_distribution metric to record (used to retrieve the Glean metric type from the
   *        GLEAN_METRICS_TYPES map).
   * @param {Extension | BrowserExtensionContent} extension
   *        The extension to record the telemetry for.
   * @param {any | undefined} [obj = extension]
   *        An optional object the timing_distribution method call should be related to
   *        (defaults to the extension parameter when missing).
   */
  _wrappedTimingDistributionMethod(method, metric, extension, obj = extension) {
    if (!extension) {
      Cu.reportError(`Mandatory extension parameter is undefined`);
      return;
    }

    const gleanMetricType = GLEAN_METRICS_TYPES[metric];
    if (!gleanMetricType) {
      Cu.reportError(`Unknown metric ${metric}`);
      return;
    }

    if (gleanMetricType !== "timing_distribution") {
      Cu.reportError(
        `Glean metric ${metric} is of type ${gleanMetricType}, expected timing_distribution`
      );
      return;
    }

    switch (method) {
      case "start": {
        const timerId = Glean.extensionsTiming[metric].start();
        this.gleanTimerIdsMap.get(extension).set(obj, timerId);
        break;
      }
      case "stopAndAccumulate": // Intentional fall-through.
      case "cancel": {
        if (
          !this.gleanTimerIdsMap.has(extension) ||
          !this.gleanTimerIdsMap.get(extension).has(obj)
        ) {
          Cu.reportError(
            `timerId not found for Glean timing_distribution ${metric}`
          );
          return;
        }
        const timerId = this.gleanTimerIdsMap.get(extension).get(obj);
        this.gleanTimerIdsMap.get(extension).delete(obj);
        Glean.extensionsTiming[metric][method](timerId);
        break;
      }
      default:
        Cu.reportError(
          `Unknown method ${method} call for Glean metric ${metric}`
        );
    }
  }

  /**
   * Wraps a call to a TelemetryStopwatch method for a given metric and extension.
   *
   * @param {string} method
   *        The stopwatch method to call ("start", "finish" or "cancel").
   * @param {string} metric
   *        The stopwatch metric to record (used to retrieve the base histogram id from the HISTOGRAMS_IDS object).
   * @param {Extension | BrowserExtensionContent} extension
   *        The extension to record the telemetry for.
   * @param {any | undefined} [obj = extension]
   *        An optional telemetry stopwatch object (which defaults to the extension parameter when missing).
   */
  _wrappedStopwatchMethod(method, metric, extension, obj = extension) {
    if (!extension) {
      Cu.reportError(`Mandatory extension parameter is undefined`);
      return;
    }

    const baseId = HISTOGRAMS_IDS[metric];
    if (!baseId) {
      Cu.reportError(`Unknown metric ${metric}`);
      return;
    }

    // Record metric in the general histogram.
    TelemetryStopwatch[method](baseId, obj);

    // Record metric in the histogram keyed by addon id.
    let extensionId = getTrimmedString(extension.id);
    TelemetryStopwatch[`${method}Keyed`](
      `${baseId}_BY_ADDONID`,
      extensionId,
      obj
    );
  }

  /**
   * Record a telemetry category and/or value for a given metric.
   *
   * @param {string} metric
   *        The metric to record (used to retrieve the base histogram id from the _histogram object).
   * @param {object}                              options
   * @param {Extension | BrowserExtensionContent} options.extension
   *        The extension to record the telemetry for.
   * @param {string | undefined}                  [options.category]
   *        An optional histogram category.
   * @param {number | undefined}                  [options.value]
   *        An optional value to record.
   */
  _histogramAdd(metric, { category, extension, value }) {
    if (!extension) {
      Cu.reportError(`Mandatory extension parameter is undefined`);
      return;
    }

    const baseId = HISTOGRAMS_IDS[metric];
    if (!baseId) {
      Cu.reportError(`Unknown metric ${metric}`);
      return;
    }

    const histogram = Services.telemetry.getHistogramById(baseId);
    if (typeof category === "string") {
      histogram.add(category, value);
    } else {
      histogram.add(value);
    }

    const keyedHistogram = Services.telemetry.getKeyedHistogramById(
      `${baseId}_BY_ADDONID`
    );
    const extensionId = getTrimmedString(extension.id);

    if (typeof category === "string") {
      keyedHistogram.add(extensionId, category, value);
    } else {
      keyedHistogram.add(extensionId, value);
    }

    switch (GLEAN_METRICS_TYPES[metric]) {
      case "custom_distribution": {
        if (typeof category === "string") {
          Cu.reportError(
            `Unexpected unsupported category parameter set on Glean metric ${metric}`
          );
          return;
        }
        // NOTE: extensionsTiming may become a property of the GLEAN_METRICS_TYPES
        // map once we may introduce new histograms that are not part of the
        // extensionsTiming Glean metrics category.
        Glean.extensionsTiming[metric].accumulateSamples([value]);
        break;
      }
      case "labeled_counter": {
        if (typeof category !== "string") {
          Cu.reportError(
            `Missing mandatory category on adding data to labeled Glean metric ${metric}`
          );
          return;
        }
        Glean.extensionsCounters[metric][category].add(value ?? 1);
        break;
      }
      default:
        Cu.reportError(
          `Unexpected unsupported Glean metric type "${GLEAN_METRICS_TYPES[metric]}" for metric ${metric}`
        );
    }
  }
}

// Cache of the ExtensionTelemetryMetric instances that has been lazily created by the
// Extension Telemetry Proxy.
/** @type {Map<string|symbol, ExtensionTelemetryMetric>} */
const metricsCache = new Map();

/**
 * This proxy object provides the telemetry helpers for the currently supported metrics (the ones listed in
 * HISTOGRAMS_IDS), the telemetry helpers for a particular metric are lazily created
 * when the related property is being accessed on this object for the first time, e.g.:
 *
 *      ExtensionTelemetry.extensionStartup.stopwatchStart(extension);
 *      ExtensionTelemetry.browserActionPreloadResult.histogramAdd({category: "Shown", extension});
 */
export var ExtensionTelemetry = new Proxy(metricsCache, {
  get(target, prop) {
    // NOTE: if we would be start adding glean probes that do not have a unified
    // telemetry histogram counterpart, we would need to change this check
    // accordingly.
    if (!(prop in HISTOGRAMS_IDS)) {
      throw new Error(`Unknown metric ${String(prop)}`);
    }

    // Lazily create and cache the metric result object.
    if (!target.has(prop)) {
      target.set(prop, new ExtensionTelemetryMetric(prop));
    }

    return target.get(prop);
  },
});