Bug 1915183 - Collect telemetry for usage of storage.sync r=rpl

Differential Revision: https://phabricator.services.mozilla.com/D222442

toolkit/components/extensions/ExtensionStorageSync.sys.mjs

@@ -82,6 +82,7 @@ export class ExtensionStorageSync {
     // migration failure, it will become false. In practice, this will only ever
     // happen on the first operation.
     this.migrationOk = true;
+    this.backend = "rust";
   }
 
   // The main entry-point to our bridge. It performs some important roles:

toolkit/components/extensions/ExtensionStorageSyncKinto.sys.mjs

@@ -735,6 +735,7 @@ export class ExtensionStorageSyncKinto {
     this._fxaService = fxaService;
     this.cryptoCollection = new CryptoCollection(fxaService);
     this.listeners = new WeakMap();
+    this.backend = "kinto";
   }
 
   /**

toolkit/components/extensions/metrics.yaml

@@ -366,6 +366,37 @@ extensions.data:
         type: string
     expires: 140
 
+  sync_usage_quotas:
+    type: event
+    description: |
+      These events record the basic stat about usage, and are collected the
+      first time an extension uses the sync storage API during a session.
+    bugs:
+      - https://bugzilla.mozilla.org/1915183
+    data_reviews:
+      - https://phabricator.services.mozilla.com/D222442
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - addons-dev-internal@mozilla.com
+    extra_keys:
+      addon_id:
+        description: Id of the addon.
+        type: string
+      total_size_bytes:
+        description: Size of the sync data.
+        type: quantity
+      items_count:
+        description: Number of items in sync storage.
+        type: quantity
+      items_over_quota:
+        description: Count of items larger than QUOTA_BYTES_PER_ITEM.
+        type: quantity
+      backend:
+        description: Backend engine used, currently either "kinto" or "rust"
+        type: string
+    expires: 140
+
 extensions.counters:
 
     browser_action_preload_result:

toolkit/components/extensions/parent/ext-storage.js

@@ -30,6 +30,13 @@ ChromeUtils.defineLazyGetter(this, "extensionStorageSync", () => {
   return extensionStorageSync;
 });
 
+XPCOMUtils.defineLazyPreferenceGetter(
+  this,
+  "prefStorageSyncEnabled",
+  "webextensions.storage.sync.enabled",
+  true
+);
+
 const enforceNoTemporaryAddon = extensionId => {
   const EXCEPTION_MESSAGE =
     "The storage API will not work with a temporary addon ID. " +
@@ -40,6 +47,35 @@ const enforceNoTemporaryAddon = extensionId => {
   }
 };
 
+// Set of extensions that already recorded the sync quota event.
+const syncQuotasRecorded = new WeakSet();
+const QUOTA_BYTES_PER_ITEM = 8_192;
+
+async function recordSyncQuotaTelemetry(extension, context) {
+  if (syncQuotasRecorded.has(extension) || !prefStorageSyncEnabled) {
+    return;
+  }
+  syncQuotasRecorded.add(extension);
+  let items = await extensionStorageSync.get(extension, null, context);
+  let items_over_quota = 0;
+  let total_size_bytes = 0;
+  let entries = Object.entries(items);
+  for (let [key, value] of entries) {
+    let bytes = JSON.stringify(value).length;
+    total_size_bytes += key.length + bytes;
+    if (bytes > QUOTA_BYTES_PER_ITEM) {
+      items_over_quota++;
+    }
+  }
+  Glean.extensionsData.syncUsageQuotas.record({
+    addon_id: extension.id,
+    total_size_bytes,
+    items_count: entries.length,
+    items_over_quota,
+    backend: extensionStorageSync.backend,
+  });
+}
+
 // WeakMap[extension -> Promise<SerializableMap?>]
 const managedStorage = new WeakMap();
 
@@ -324,22 +360,27 @@ this.storage = class extends ExtensionAPIPersistent {
         sync: {
           get(spec) {
             enforceNoTemporaryAddon(extension.id);
+            recordSyncQuotaTelemetry(extension, context);
             return extensionStorageSync.get(extension, spec, context);
           },
           set(items) {
             enforceNoTemporaryAddon(extension.id);
+            recordSyncQuotaTelemetry(extension, context);
             return extensionStorageSync.set(extension, items, context);
           },
           remove(keys) {
             enforceNoTemporaryAddon(extension.id);
+            recordSyncQuotaTelemetry(extension, context);
             return extensionStorageSync.remove(extension, keys, context);
           },
           clear() {
             enforceNoTemporaryAddon(extension.id);
+            recordSyncQuotaTelemetry(extension, context);
             return extensionStorageSync.clear(extension, context);
           },
           getBytesInUse(keys) {
             enforceNoTemporaryAddon(extension.id);
+            recordSyncQuotaTelemetry(extension, context);
             return extensionStorageSync.getBytesInUse(extension, keys, context);
           },
           onChanged: new EventManager({

toolkit/components/extensions/test/xpcshell/head_storage.js

@@ -1398,3 +1398,58 @@ async function test_storage_change_event_page(areaName) {
 
   return runWithPrefs([["extensions.eventPages.enabled", true]], testFn);
 }
+
+async function test_storage_sync_telemetry_quota(backend, enforced = false) {
+  Services.fog.testResetFOG();
+  let id = "my-extension-id@23";
+
+  // Repeat twice to get the glean events "before" and "after".
+  for (let i = 0; i < 2; i++) {
+    let ext = ExtensionTestUtils.loadExtension({
+      manifest: {
+        browser_specific_settings: { gecko: { id: id } },
+        permissions: ["storage"],
+      },
+      background() {
+        browser.test.onMessage.addListener(async enforced => {
+          await browser.storage.sync.set({
+            a: "1",
+            b: "x".repeat(enforced ? 1_000 : 10_000),
+          });
+          browser.test.notifyPass("done");
+        });
+      },
+    });
+
+    await ext.startup();
+    ext.sendMessage(enforced);
+    await ext.awaitFinish("done");
+    await ext.unload();
+  }
+
+  let events = Glean.extensionsData.syncUsageQuotas.testGetValue();
+  events = events.filter(e => e.extra?.addon_id === id);
+
+  Assert.deepEqual(
+    events[0].extra,
+    {
+      addon_id: id,
+      total_size_bytes: 0,
+      items_count: 0,
+      items_over_quota: 0,
+      backend: backend,
+    },
+    "Expected event values before setting sync storage"
+  );
+  Assert.deepEqual(
+    events[1].extra,
+    {
+      addon_id: id,
+      total_size_bytes: enforced ? 1_007 : 10_007,
+      items_count: 2,
+      items_over_quota: enforced ? 0 : 1,
+      backend: backend,
+    },
+    "Expected event values after setting sync storage"
+  );
+}

toolkit/components/extensions/test/xpcshell/test_ext_storage_sync.js

@@ -8,6 +8,11 @@ AddonTestUtils.init(this);
 
 add_task(async function setup() {
   await ExtensionTestUtils.startAddonManager();
+
+  // FOG needs a profile directory to put its data in.
+  do_get_profile();
+  // FOG needs to be initialized in order for data to flow.
+  Services.fog.initializeFOG();
 });
 
 add_task(test_config_flag_needed);
@@ -33,3 +38,9 @@ add_task(function test_storage_onChanged_event_page() {
     test_storage_change_event_page("sync")
   );
 });
+
+add_task(async function test_storage_sync_telemetry() {
+  return runWithPrefs([[STORAGE_SYNC_PREF, true]], () =>
+    test_storage_sync_telemetry_quota("rust", true)
+  );
+});

toolkit/components/extensions/test/xpcshell/test_ext_storage_sync_kinto.js

@@ -664,6 +664,11 @@ function uuid() {
 
 add_task(async function test_setup() {
   await promiseStartupManager();
+
+  // FOG needs a profile directory to put its data in.
+  do_get_profile();
+  // FOG needs to be initialized in order for data to flow.
+  Services.fog.initializeFOG();
 });
 
 add_task(async function test_single_initialization() {
@@ -2307,3 +2312,9 @@ add_task(function test_storage_onChanged_event_page() {
     test_storage_change_event_page("sync")
   );
 });
+
+add_task(async function test_storage_sync_telemetry() {
+  return runWithPrefs([[STORAGE_SYNC_PREF, true]], () =>
+    test_storage_sync_telemetry_quota("kinto", false)
+  );
+});