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Diffstat (limited to '')
| -rw-r--r-- | browser/components/urlbar/private/ImpressionCaps.sys.mjs | 566 |
1 files changed, 566 insertions, 0 deletions
diff --git a/browser/components/urlbar/private/ImpressionCaps.sys.mjs b/browser/components/urlbar/private/ImpressionCaps.sys.mjs new file mode 100644 index 0000000000..b50d87bf9e --- /dev/null +++ b/browser/components/urlbar/private/ImpressionCaps.sys.mjs @@ -0,0 +1,566 @@ +/* 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 { BaseFeature } from "resource:///modules/urlbar/private/BaseFeature.sys.mjs"; + +const lazy = {}; + +ChromeUtils.defineESModuleGetters(lazy, { + AsyncShutdown: "resource://gre/modules/AsyncShutdown.sys.mjs", + QuickSuggest: "resource:///modules/QuickSuggest.sys.mjs", + QuickSuggestRemoteSettings: + "resource:///modules/urlbar/private/QuickSuggestRemoteSettings.sys.mjs", + UrlbarPrefs: "resource:///modules/UrlbarPrefs.sys.mjs", + clearInterval: "resource://gre/modules/Timer.sys.mjs", + setInterval: "resource://gre/modules/Timer.sys.mjs", +}); + +const IMPRESSION_COUNTERS_RESET_INTERVAL_MS = 60 * 60 * 1000; // 1 hour + +// This object maps impression stats object keys to their corresponding keys in +// the `extra` object of impression cap telemetry events. The main reason this +// is necessary is because the keys of the `extra` object are limited to 15 +// characters in length, which some stats object keys exceed. It also forces us +// to be deliberate about keys we add to the `extra` object, since the `extra` +// object is limited to 10 keys. +const TELEMETRY_IMPRESSION_CAP_EXTRA_KEYS = { + // stats object key -> `extra` telemetry event object key + intervalSeconds: "intervalSeconds", + startDateMs: "startDate", + count: "count", + maxCount: "maxCount", + impressionDateMs: "impressionDate", +}; + +/** + * Impression caps and stats for quick suggest suggestions. + */ +export class ImpressionCaps extends BaseFeature { + constructor() { + super(); + lazy.UrlbarPrefs.addObserver(this); + } + + get shouldEnable() { + return ( + lazy.UrlbarPrefs.get("quickSuggestImpressionCapsSponsoredEnabled") || + lazy.UrlbarPrefs.get("quickSuggestImpressionCapsNonSponsoredEnabled") + ); + } + + enable(enabled) { + if (enabled) { + this.#init(); + } else { + this.#uninit(); + } + } + + /** + * Increments the user's impression stats counters for the given type of + * suggestion. This should be called only when a suggestion impression is + * recorded. + * + * @param {string} type + * The suggestion type, one of: "sponsored", "nonsponsored" + */ + updateStats(type) { + this.logger.info("Starting impression stats update"); + this.logger.debug( + JSON.stringify({ + type, + currentStats: this.#stats, + impression_caps: lazy.QuickSuggestRemoteSettings.config.impression_caps, + }) + ); + + // Don't bother recording anything if caps are disabled. + let isSponsored = type == "sponsored"; + if ( + (isSponsored && + !lazy.UrlbarPrefs.get("quickSuggestImpressionCapsSponsoredEnabled")) || + (!isSponsored && + !lazy.UrlbarPrefs.get("quickSuggestImpressionCapsNonSponsoredEnabled")) + ) { + this.logger.info("Impression caps disabled, skipping update"); + return; + } + + // Get the user's impression stats. Since stats are synced from caps, if the + // stats don't exist then the caps don't exist, and don't bother recording + // anything in that case. + let stats = this.#stats[type]; + if (!stats) { + this.logger.info("Impression caps undefined, skipping update"); + return; + } + + // Increment counters. + for (let stat of stats) { + stat.count++; + stat.impressionDateMs = Date.now(); + + // Record a telemetry event for each newly hit cap. + if (stat.count == stat.maxCount) { + this.logger.info(`'${type}' impression cap hit`); + this.logger.debug(JSON.stringify({ type, hitStat: stat })); + this.#recordCapEvent({ + stat, + eventType: "hit", + suggestionType: type, + }); + } + } + + // Save the stats. + this.#updatingStats = true; + try { + lazy.UrlbarPrefs.set( + "quicksuggest.impressionCaps.stats", + JSON.stringify(this.#stats) + ); + } finally { + this.#updatingStats = false; + } + + this.logger.info("Finished impression stats update"); + this.logger.debug(JSON.stringify({ newStats: this.#stats })); + } + + /** + * Returns a non-null value if an impression cap has been reached for the + * given suggestion type and null otherwise. This method can therefore be used + * to tell whether a cap has been reached for a given type. The actual return + * value an object describing the impression stats that caused the cap to be + * reached. + * + * @param {string} type + * The suggestion type, one of: "sponsored", "nonsponsored" + * @returns {object} + * An impression stats object or null. + */ + getHitStats(type) { + this.#resetElapsedCounters(); + let stats = this.#stats[type]; + if (stats) { + let hitStats = stats.filter(s => s.maxCount <= s.count); + if (hitStats.length) { + return hitStats; + } + } + return null; + } + + /** + * Called when a urlbar pref changes. + * + * @param {string} pref + * The name of the pref relative to `browser.urlbar`. + */ + onPrefChanged(pref) { + switch (pref) { + case "quicksuggest.impressionCaps.stats": + if (!this.#updatingStats) { + this.logger.info( + "browser.urlbar.quicksuggest.impressionCaps.stats changed" + ); + this.#loadStats(); + } + break; + } + } + + #init() { + this.#loadStats(); + + // Validate stats against any changes to the impression caps in the config. + this._onConfigSet = () => this.#validateStats(); + lazy.QuickSuggestRemoteSettings.emitter.on("config-set", this._onConfigSet); + + // Periodically record impression counters reset telemetry. + this.#setCountersResetInterval(); + + // On shutdown, record any final impression counters reset telemetry. + this._shutdownBlocker = () => this.#resetElapsedCounters(); + lazy.AsyncShutdown.profileChangeTeardown.addBlocker( + "QuickSuggest: Record impression counters reset telemetry", + this._shutdownBlocker + ); + } + + #uninit() { + lazy.QuickSuggestRemoteSettings.emitter.off( + "config-set", + this._onConfigSet + ); + this._onConfigSet = null; + + lazy.clearInterval(this._impressionCountersResetInterval); + this._impressionCountersResetInterval = 0; + + lazy.AsyncShutdown.profileChangeTeardown.removeBlocker( + this._shutdownBlocker + ); + this._shutdownBlocker = null; + } + + /** + * Loads and validates impression stats. + */ + #loadStats() { + let json = lazy.UrlbarPrefs.get("quicksuggest.impressionCaps.stats"); + if (!json) { + this.#stats = {}; + } else { + try { + this.#stats = JSON.parse( + json, + // Infinity, which is the `intervalSeconds` for the lifetime cap, is + // stringified as `null` in the JSON, so convert it back to Infinity. + (key, value) => + key == "intervalSeconds" && value === null ? Infinity : value + ); + } catch (error) {} + } + this.#validateStats(); + } + + /** + * Validates impression stats, which includes two things: + * + * - Type checks stats and discards any that are invalid. We do this because + * stats are stored in prefs where anyone can modify them. + * - Syncs stats with impression caps so that there is one stats object + * corresponding to each impression cap. See the `#stats` comment for info. + */ + #validateStats() { + let { impression_caps } = lazy.QuickSuggestRemoteSettings.config; + + this.logger.info("Validating impression stats"); + this.logger.debug( + JSON.stringify({ + impression_caps, + currentStats: this.#stats, + }) + ); + + if (!this.#stats || typeof this.#stats != "object") { + this.#stats = {}; + } + + for (let [type, cap] of Object.entries(impression_caps || {})) { + // Build a map from interval seconds to max counts in the caps. + let maxCapCounts = (cap.custom || []).reduce( + (map, { interval_s, max_count }) => { + map.set(interval_s, max_count); + return map; + }, + new Map() + ); + if (typeof cap.lifetime == "number") { + maxCapCounts.set(Infinity, cap.lifetime); + } + + let stats = this.#stats[type]; + if (!Array.isArray(stats)) { + stats = []; + this.#stats[type] = stats; + } + + // Validate existing stats: + // + // * Discard stats with invalid properties. + // * Collect and remove stats with intervals that aren't in the caps. This + // should only happen when caps are changed or removed. + // * For stats with intervals that are in the caps: + // * Keep track of the max `stat.count` across all stats so we can + // update the lifetime stat below. + // * Set `stat.maxCount` to the max count in the corresponding cap. + let orphanStats = []; + let maxCountInStats = 0; + for (let i = 0; i < stats.length; ) { + let stat = stats[i]; + if ( + typeof stat.intervalSeconds != "number" || + typeof stat.startDateMs != "number" || + typeof stat.count != "number" || + typeof stat.maxCount != "number" || + typeof stat.impressionDateMs != "number" + ) { + stats.splice(i, 1); + } else { + maxCountInStats = Math.max(maxCountInStats, stat.count); + let maxCount = maxCapCounts.get(stat.intervalSeconds); + if (maxCount === undefined) { + stats.splice(i, 1); + orphanStats.push(stat); + } else { + stat.maxCount = maxCount; + i++; + } + } + } + + // Create stats for caps that don't already have corresponding stats. + for (let [intervalSeconds, maxCount] of maxCapCounts.entries()) { + if (!stats.some(s => s.intervalSeconds == intervalSeconds)) { + stats.push({ + maxCount, + intervalSeconds, + startDateMs: Date.now(), + count: 0, + impressionDateMs: 0, + }); + } + } + + // Merge orphaned stats into other ones if possible. For each orphan, if + // its interval is no bigger than an existing stat's interval, then the + // orphan's count can contribute to the existing stat's count, so merge + // the two. + for (let orphan of orphanStats) { + for (let stat of stats) { + if (orphan.intervalSeconds <= stat.intervalSeconds) { + stat.count = Math.max(stat.count, orphan.count); + stat.startDateMs = Math.min(stat.startDateMs, orphan.startDateMs); + stat.impressionDateMs = Math.max( + stat.impressionDateMs, + orphan.impressionDateMs + ); + } + } + } + + // If the lifetime stat exists, make its count the max count found above. + // This is only necessary when the lifetime cap wasn't present before, but + // it doesn't hurt to always do it. + let lifetimeStat = stats.find(s => s.intervalSeconds == Infinity); + if (lifetimeStat) { + lifetimeStat.count = maxCountInStats; + } + + // Sort the stats by interval ascending. This isn't necessary except that + // it guarantees an ordering for tests. + stats.sort((a, b) => a.intervalSeconds - b.intervalSeconds); + } + + this.logger.debug(JSON.stringify({ newStats: this.#stats })); + } + + /** + * Resets the counters of impression stats whose intervals have elapased. + */ + #resetElapsedCounters() { + this.logger.info("Checking for elapsed impression cap intervals"); + this.logger.debug( + JSON.stringify({ + currentStats: this.#stats, + impression_caps: lazy.QuickSuggestRemoteSettings.config.impression_caps, + }) + ); + + let now = Date.now(); + for (let [type, stats] of Object.entries(this.#stats)) { + for (let stat of stats) { + let elapsedMs = now - stat.startDateMs; + let intervalMs = 1000 * stat.intervalSeconds; + let elapsedIntervalCount = Math.floor(elapsedMs / intervalMs); + if (elapsedIntervalCount) { + // At least one interval period elapsed for the stat, so reset it. We + // may also need to record a telemetry event for the reset. + this.logger.info( + `Resetting impression counter for interval ${stat.intervalSeconds}s` + ); + this.logger.debug( + JSON.stringify({ type, stat, elapsedMs, elapsedIntervalCount }) + ); + + let newStartDateMs = + stat.startDateMs + elapsedIntervalCount * intervalMs; + + // Compute the portion of `elapsedIntervalCount` that happened after + // startup. This will be the interval count we report in the telemetry + // event. By design we don't report intervals that elapsed while the + // app wasn't running. For example, if the user stopped using Firefox + // for a year, we don't want to report a year's worth of intervals. + // + // First, compute the count of intervals that elapsed before startup. + // This is the same arithmetic used above except here it's based on + // the startup date instead of `now`. Keep in mind that startup may be + // before the stat's start date. Then subtract that count from + // `elapsedIntervalCount` to get the portion after startup. + let startupDateMs = this._getStartupDateMs(); + let elapsedIntervalCountBeforeStartup = Math.floor( + Math.max(0, startupDateMs - stat.startDateMs) / intervalMs + ); + let elapsedIntervalCountAfterStartup = + elapsedIntervalCount - elapsedIntervalCountBeforeStartup; + + if (elapsedIntervalCountAfterStartup) { + this.#recordCapEvent({ + eventType: "reset", + suggestionType: type, + eventDateMs: newStartDateMs, + eventCount: elapsedIntervalCountAfterStartup, + stat: { + ...stat, + startDateMs: + stat.startDateMs + + elapsedIntervalCountBeforeStartup * intervalMs, + }, + }); + } + + // Reset the stat. + stat.startDateMs = newStartDateMs; + stat.count = 0; + } + } + } + + this.logger.debug(JSON.stringify({ newStats: this.#stats })); + } + + /** + * Records an impression cap telemetry event. + * + * @param {object} options + * Options object + * @param {"hit" | "reset"} options.eventType + * One of: "hit", "reset" + * @param {string} options.suggestionType + * One of: "sponsored", "nonsponsored" + * @param {object} options.stat + * The stats object whose max count was hit or whose counter was reset. + * @param {number} options.eventCount + * The number of intervals that elapsed since the last event. + * @param {number} options.eventDateMs + * The `eventDate` that should be recorded in the event's `extra` object. + * We include this in `extra` even though events are timestamped because + * "reset" events are batched during periods where the user doesn't perform + * any searches and therefore impression counters are not reset. + */ + #recordCapEvent({ + eventType, + suggestionType, + stat, + eventCount = 1, + eventDateMs = Date.now(), + }) { + // All `extra` object values must be strings. + let extra = { + type: suggestionType, + eventDate: String(eventDateMs), + eventCount: String(eventCount), + }; + for (let [statKey, value] of Object.entries(stat)) { + let extraKey = TELEMETRY_IMPRESSION_CAP_EXTRA_KEYS[statKey]; + if (!extraKey) { + throw new Error("Unrecognized stats object key: " + statKey); + } + extra[extraKey] = String(value); + } + Services.telemetry.recordEvent( + lazy.QuickSuggest.TELEMETRY_EVENT_CATEGORY, + "impression_cap", + eventType, + "", + extra + ); + } + + /** + * Creates a repeating timer that resets impression counters and records + * related telemetry. Since counters are also reset when suggestions are + * triggered, the only point of this is to make sure we record reset telemetry + * events in a timely manner during periods when suggestions aren't triggered. + * + * @param {number} ms + * The number of milliseconds in the interval. + */ + #setCountersResetInterval(ms = IMPRESSION_COUNTERS_RESET_INTERVAL_MS) { + if (this._impressionCountersResetInterval) { + lazy.clearInterval(this._impressionCountersResetInterval); + } + this._impressionCountersResetInterval = lazy.setInterval( + () => this.#resetElapsedCounters(), + ms + ); + } + + /** + * Gets the timestamp of app startup in ms since Unix epoch. This is only + * defined as its own method so tests can override it to simulate arbitrary + * startups. + * + * @returns {number} + * Startup timestamp in ms since Unix epoch. + */ + _getStartupDateMs() { + return Services.startup.getStartupInfo().process.getTime(); + } + + get _test_stats() { + return this.#stats; + } + + _test_reloadStats() { + this.#stats = null; + this.#loadStats(); + } + + _test_resetElapsedCounters() { + this.#resetElapsedCounters(); + } + + _test_setCountersResetInterval(ms) { + this.#setCountersResetInterval(ms); + } + + // An object that keeps track of impression stats per sponsored and + // non-sponsored suggestion types. It looks like this: + // + // { sponsored: statsArray, nonsponsored: statsArray } + // + // The `statsArray` values are arrays of stats objects, one per impression + // cap, which look like this: + // + // { intervalSeconds, startDateMs, count, maxCount, impressionDateMs } + // + // {number} intervalSeconds + // The number of seconds in the corresponding cap's time interval. + // {number} startDateMs + // The timestamp at which the current interval period started and the + // object's `count` was reset to zero. This is a value returned from + // `Date.now()`. When the current date/time advances past `startDateMs + + // 1000 * intervalSeconds`, a new interval period will start and `count` + // will be reset to zero. + // {number} count + // The number of impressions during the current interval period. + // {number} maxCount + // The maximum number of impressions allowed during an interval period. + // This value is the same as the `max_count` value in the corresponding + // cap. It's stored in the stats object for convenience. + // {number} impressionDateMs + // The timestamp of the most recent impression, i.e., when `count` was + // last incremented. + // + // There are two types of impression caps: interval and lifetime. Interval + // caps are periodically reset, and lifetime caps are never reset. For stats + // objects corresponding to interval caps, `intervalSeconds` will be the + // `interval_s` value of the cap. For stats objects corresponding to lifetime + // caps, `intervalSeconds` will be `Infinity`. + // + // `#stats` is kept in sync with impression caps, and there is a one-to-one + // relationship between stats objects and caps. A stats object's corresponding + // cap is the one with the same suggestion type (sponsored or non-sponsored) + // and interval. See `#validateStats()` for more. + // + // Impression caps are stored in the remote settings config. See + // `QuickSuggestRemoteSettingsClient.confg.impression_caps`. + #stats = {}; + + // Whether impression stats are currently being updated. + #updatingStats = false; +} |