Merging upstream version 126.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

9 files changed, 618 insertions, 11 deletions

diff --git a/browser/components/backup/resources/AddonsBackupResource.sys.mjs b/browser/components/backup/resources/AddonsBackupResource.sys.mjs
new file mode 100644
index 0000000000..83b97ed2f2
--- /dev/null
+++ b/browser/components/backup/resources/AddonsBackupResource.sys.mjs
@@ -0,0 +1,100 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+
+/**
+ * Backup for addons and extensions files and data.
+ */
+export class AddonsBackupResource extends BackupResource {
+  static get key() {
+    return "addons";
+  }
+
+  static get requiresEncryption() {
+    return false;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    // Report the total size of the extension json files.
+    const jsonFiles = [
+      "extensions.json",
+      "extension-settings.json",
+      "extension-preferences.json",
+      "addonStartup.json.lz4",
+    ];
+    let extensionsJsonSize = 0;
+    for (const filePath of jsonFiles) {
+      let resourcePath = PathUtils.join(profilePath, filePath);
+      let resourceSize = await BackupResource.getFileSize(resourcePath);
+      if (Number.isInteger(resourceSize)) {
+        extensionsJsonSize += resourceSize;
+      }
+    }
+    Glean.browserBackup.extensionsJsonSize.set(extensionsJsonSize);
+
+    // Report the size of permissions store data, if present.
+    let extensionStorePermissionsDataPath = PathUtils.join(
+      profilePath,
+      "extension-store-permissions",
+      "data.safe.bin"
+    );
+    let extensionStorePermissionsDataSize = await BackupResource.getFileSize(
+      extensionStorePermissionsDataPath
+    );
+    if (Number.isInteger(extensionStorePermissionsDataSize)) {
+      Glean.browserBackup.extensionStorePermissionsDataSize.set(
+        extensionStorePermissionsDataSize
+      );
+    }
+
+    // Report the size of extensions storage sync database.
+    let storageSyncPath = PathUtils.join(profilePath, "storage-sync-v2.sqlite");
+    let storageSyncSize = await BackupResource.getFileSize(storageSyncPath);
+    Glean.browserBackup.storageSyncSize.set(storageSyncSize);
+
+    // Report the total size of XPI files in the extensions directory.
+    let extensionsXpiDirectoryPath = PathUtils.join(profilePath, "extensions");
+    let extensionsXpiDirectorySize = await BackupResource.getDirectorySize(
+      extensionsXpiDirectoryPath,
+      {
+        shouldExclude: (filePath, fileType) =>
+          fileType !== "regular" || !filePath.endsWith(".xpi"),
+      }
+    );
+    Glean.browserBackup.extensionsXpiDirectorySize.set(
+      extensionsXpiDirectorySize
+    );
+
+    // Report the total size of the browser extension data.
+    let browserExtensionDataPath = PathUtils.join(
+      profilePath,
+      "browser-extension-data"
+    );
+    let browserExtensionDataSize = await BackupResource.getDirectorySize(
+      browserExtensionDataPath
+    );
+    Glean.browserBackup.browserExtensionDataSize.set(browserExtensionDataSize);
+
+    // Report the size of all moz-extension IndexedDB databases.
+    let defaultStoragePath = PathUtils.join(profilePath, "storage", "default");
+    let extensionsStorageSize = await BackupResource.getDirectorySize(
+      defaultStoragePath,
+      {
+        shouldExclude: (filePath, _fileType, parentPath) => {
+          if (
+            parentPath == defaultStoragePath &&
+            !PathUtils.filename(filePath).startsWith("moz-extension")
+          ) {
+            return true;
+          }
+          return false;
+        },
+      }
+    );
+    if (Number.isInteger(extensionsStorageSize)) {
+      Glean.browserBackup.extensionsStorageSize.set(extensionsStorageSize);
+    }
+  }
+}
diff --git a/browser/components/backup/resources/BackupResource.sys.mjs b/browser/components/backup/resources/BackupResource.sys.mjs
index bde3f0669c..d851eb5199 100644
--- a/browser/components/backup/resources/BackupResource.sys.mjs
+++ b/browser/components/backup/resources/BackupResource.sys.mjs
@@ -3,7 +3,19 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 // Convert from bytes to kilobytes (not kibibytes).
-const BYTES_IN_KB = 1000;
+export const BYTES_IN_KB = 1000;
+
+/**
+ * Convert bytes to the nearest 10th kilobyte to make the measurements fuzzier.
+ *
+ * @param {number} bytes - size in bytes.
+ * @returns {number} - size in kilobytes rounded to the nearest 10th kilobyte.
+ */
+export function bytesToFuzzyKilobytes(bytes) {
+  let sizeInKb = Math.ceil(bytes / BYTES_IN_KB);
+  let nearestTenthKb = Math.round(sizeInKb / 10) * 10;
+  return Math.max(nearestTenthKb, 1);
+}
 
 /**
  * An abstract class representing a set of data within a user profile
@@ -23,6 +35,21 @@ export class BackupResource {
   }
 
   /**
+   * This must be overridden to return a boolean indicating whether the
+   * resource requires encryption when being backed up. Encryption should be
+   * required for particularly sensitive data, such as passwords / credentials,
+   * cookies, or payment methods. If you're not sure, talk to someone from the
+   * Privacy team.
+   *
+   * @type {boolean}
+   */
+  static get requiresEncryption() {
+    throw new Error(
+      "BackupResource::requiresEncryption needs to be overridden."
+    );
+  }
+
+  /**
    * Get the size of a file.
    *
    * @param {string} filePath - path to a file.
@@ -40,21 +67,25 @@ export class BackupResource {
       return null;
     }
 
-    let sizeInKb = Math.ceil(size / BYTES_IN_KB);
-    // Make the measurement fuzzier by rounding to the nearest 10kb.
-    let nearestTenthKb = Math.round(sizeInKb / 10) * 10;
+    let nearestTenthKb = bytesToFuzzyKilobytes(size);
 
-    return Math.max(nearestTenthKb, 1);
+    return nearestTenthKb;
   }
 
   /**
    * Get the total size of a directory.
    *
    * @param {string} directoryPath - path to a directory.
+   * @param {object}   options - A set of additional optional parameters.
+   * @param {Function} [options.shouldExclude] - an optional callback which based on file path and file type should return true
+   * if the file should be excluded from the computed directory size.
    * @returns {Promise<number|null>} - the size of all descendants of the directory in kilobytes, or null if the
    * directory does not exist, the path is not a directory or the size is unknown.
    */
-  static async getDirectorySize(directoryPath) {
+  static async getDirectorySize(
+    directoryPath,
+    { shouldExclude = () => false } = {}
+  ) {
     if (!(await IOUtils.exists(directoryPath))) {
       return null;
     }
@@ -75,15 +106,20 @@ export class BackupResource {
         childFilePath
       );
 
+      if (shouldExclude(childFilePath, childType, directoryPath)) {
+        continue;
+      }
+
       if (childSize >= 0) {
-        let sizeInKb = Math.ceil(childSize / BYTES_IN_KB);
-        // Make the measurement fuzzier by rounding to the nearest 10kb.
-        let nearestTenthKb = Math.round(sizeInKb / 10) * 10;
-        size += Math.max(nearestTenthKb, 1);
+        let nearestTenthKb = bytesToFuzzyKilobytes(childSize);
+
+        size += nearestTenthKb;
       }
 
       if (childType == "directory") {
-        let childDirectorySize = await this.getDirectorySize(childFilePath);
+        let childDirectorySize = await this.getDirectorySize(childFilePath, {
+          shouldExclude,
+        });
         if (Number.isInteger(childDirectorySize)) {
           size += childDirectorySize;
         }
@@ -106,4 +142,29 @@ export class BackupResource {
   async measure(profilePath) {
     throw new Error("BackupResource::measure needs to be overridden.");
   }
+
+  /**
+   * Perform a safe copy of the resource(s) and write them into the backup
+   * database. The Promise should resolve with an object that can be serialized
+   * to JSON, as it will be written to the manifest file. This same object will
+   * be deserialized and passed to restore() when restoring the backup. This
+   * object can be null if no additional information is needed to restore the
+   * backup.
+   *
+   * @param {string} stagingPath
+   *   The path to the staging folder where copies of the datastores for this
+   *   BackupResource should be written to.
+   * @param {string} [profilePath=null]
+   *   This is null if the backup is being run on the currently running user
+   *   profile. If, however, the backup is being run on a different user profile
+   *   (for example, it's being run from a BackgroundTask on a user profile that
+   *   just shut down, or during test), then this is a string set to that user
+   *   profile path.
+   *
+   * @returns {Promise<object|null>}
+   */
+  // eslint-disable-next-line no-unused-vars
+  async backup(stagingPath, profilePath = null) {
+    throw new Error("BackupResource::backup must be overridden");
+  }
 }
diff --git a/browser/components/backup/resources/CookiesBackupResource.sys.mjs b/browser/components/backup/resources/CookiesBackupResource.sys.mjs
new file mode 100644
index 0000000000..8b988fd532
--- /dev/null
+++ b/browser/components/backup/resources/CookiesBackupResource.sys.mjs
@@ -0,0 +1,25 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+
+/**
+ * Class representing Cookies database within a user profile.
+ */
+export class CookiesBackupResource extends BackupResource {
+  static get key() {
+    return "cookies";
+  }
+
+  static get requiresEncryption() {
+    return true;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    let cookiesDBPath = PathUtils.join(profilePath, "cookies.sqlite");
+    let cookiesSize = await BackupResource.getFileSize(cookiesDBPath);
+
+    Glean.browserBackup.cookiesSize.set(cookiesSize);
+  }
+}
diff --git a/browser/components/backup/resources/CredentialsAndSecurityBackupResource.sys.mjs b/browser/components/backup/resources/CredentialsAndSecurityBackupResource.sys.mjs
new file mode 100644
index 0000000000..89069de826
--- /dev/null
+++ b/browser/components/backup/resources/CredentialsAndSecurityBackupResource.sys.mjs
@@ -0,0 +1,53 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+
+/**
+ * Class representing files needed for logins, payment methods and form autofill within a user profile.
+ */
+export class CredentialsAndSecurityBackupResource extends BackupResource {
+  static get key() {
+    return "credentials_and_security";
+  }
+
+  static get requiresEncryption() {
+    return true;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    const securityFiles = ["cert9.db", "pkcs11.txt"];
+    let securitySize = 0;
+
+    for (let filePath of securityFiles) {
+      let resourcePath = PathUtils.join(profilePath, filePath);
+      let resourceSize = await BackupResource.getFileSize(resourcePath);
+      if (Number.isInteger(resourceSize)) {
+        securitySize += resourceSize;
+      }
+    }
+
+    Glean.browserBackup.securityDataSize.set(securitySize);
+
+    const credentialsFiles = [
+      "key4.db",
+      "logins.json",
+      "logins-backup.json",
+      "autofill-profiles.json",
+      "credentialstate.sqlite",
+      "signedInUser.json",
+    ];
+    let credentialsSize = 0;
+
+    for (let filePath of credentialsFiles) {
+      let resourcePath = PathUtils.join(profilePath, filePath);
+      let resourceSize = await BackupResource.getFileSize(resourcePath);
+      if (Number.isInteger(resourceSize)) {
+        credentialsSize += resourceSize;
+      }
+    }
+
+    Glean.browserBackup.credentialsDataSize.set(credentialsSize);
+  }
+}
diff --git a/browser/components/backup/resources/FormHistoryBackupResource.sys.mjs b/browser/components/backup/resources/FormHistoryBackupResource.sys.mjs
new file mode 100644
index 0000000000..cb314eb34d
--- /dev/null
+++ b/browser/components/backup/resources/FormHistoryBackupResource.sys.mjs
@@ -0,0 +1,25 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+
+/**
+ * Class representing Form history database within a user profile.
+ */
+export class FormHistoryBackupResource extends BackupResource {
+  static get key() {
+    return "formhistory";
+  }
+
+  static get requiresEncryption() {
+    return false;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    let formHistoryDBPath = PathUtils.join(profilePath, "formhistory.sqlite");
+    let formHistorySize = await BackupResource.getFileSize(formHistoryDBPath);
+
+    Glean.browserBackup.formHistorySize.set(formHistorySize);
+  }
+}
diff --git a/browser/components/backup/resources/MiscDataBackupResource.sys.mjs b/browser/components/backup/resources/MiscDataBackupResource.sys.mjs
new file mode 100644
index 0000000000..97224f0e31
--- /dev/null
+++ b/browser/components/backup/resources/MiscDataBackupResource.sys.mjs
@@ -0,0 +1,101 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Sqlite: "resource://gre/modules/Sqlite.sys.mjs",
+});
+
+/**
+ * Class representing miscellaneous files for telemetry, site storage,
+ * media device origin mapping, chrome privileged IndexedDB databases,
+ * and Mozilla Accounts within a user profile.
+ */
+export class MiscDataBackupResource extends BackupResource {
+  static get key() {
+    return "miscellaneous";
+  }
+
+  static get requiresEncryption() {
+    return false;
+  }
+
+  async backup(stagingPath, profilePath = PathUtils.profileDir) {
+    const files = [
+      "times.json",
+      "enumerate_devices.txt",
+      "SiteSecurityServiceState.bin",
+    ];
+
+    for (let fileName of files) {
+      let sourcePath = PathUtils.join(profilePath, fileName);
+      let destPath = PathUtils.join(stagingPath, fileName);
+      if (await IOUtils.exists(sourcePath)) {
+        await IOUtils.copy(sourcePath, destPath, { recursive: true });
+      }
+    }
+
+    const sqliteDatabases = ["protections.sqlite"];
+
+    for (let fileName of sqliteDatabases) {
+      let sourcePath = PathUtils.join(profilePath, fileName);
+      let destPath = PathUtils.join(stagingPath, fileName);
+      let connection;
+
+      try {
+        connection = await lazy.Sqlite.openConnection({
+          path: sourcePath,
+          readOnly: true,
+        });
+
+        await connection.backup(destPath);
+      } finally {
+        await connection.close();
+      }
+    }
+
+    // Bug 1890585 - we don't currently have the ability to copy the
+    // chrome-privileged IndexedDB databases under storage/permanent/chrome, so
+    // we'll just skip that for now.
+
+    return null;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    const files = [
+      "times.json",
+      "enumerate_devices.txt",
+      "protections.sqlite",
+      "SiteSecurityServiceState.bin",
+    ];
+
+    let fullSize = 0;
+
+    for (let filePath of files) {
+      let resourcePath = PathUtils.join(profilePath, filePath);
+      let resourceSize = await BackupResource.getFileSize(resourcePath);
+      if (Number.isInteger(resourceSize)) {
+        fullSize += resourceSize;
+      }
+    }
+
+    let chromeIndexedDBDirPath = PathUtils.join(
+      profilePath,
+      "storage",
+      "permanent",
+      "chrome"
+    );
+    let chromeIndexedDBDirSize = await BackupResource.getDirectorySize(
+      chromeIndexedDBDirPath
+    );
+    if (Number.isInteger(chromeIndexedDBDirSize)) {
+      fullSize += chromeIndexedDBDirSize;
+    }
+
+    Glean.browserBackup.miscDataSize.set(fullSize);
+  }
+}
diff --git a/browser/components/backup/resources/PlacesBackupResource.sys.mjs b/browser/components/backup/resources/PlacesBackupResource.sys.mjs
new file mode 100644
index 0000000000..1955406f51
--- /dev/null
+++ b/browser/components/backup/resources/PlacesBackupResource.sys.mjs
@@ -0,0 +1,91 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  BookmarkJSONUtils: "resource://gre/modules/BookmarkJSONUtils.sys.mjs",
+  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
+  Sqlite: "resource://gre/modules/Sqlite.sys.mjs",
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "isBrowsingHistoryEnabled",
+  "places.history.enabled",
+  true
+);
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "isSanitizeOnShutdownEnabled",
+  "privacy.sanitize.sanitizeOnShutdown",
+  false
+);
+
+/**
+ * Class representing Places database related files within a user profile.
+ */
+export class PlacesBackupResource extends BackupResource {
+  static get key() {
+    return "places";
+  }
+
+  static get requiresEncryption() {
+    return false;
+  }
+
+  async backup(stagingPath, profilePath = PathUtils.profileDir) {
+    const sqliteDatabases = ["places.sqlite", "favicons.sqlite"];
+    let canBackupHistory =
+      !lazy.PrivateBrowsingUtils.permanentPrivateBrowsing &&
+      !lazy.isSanitizeOnShutdownEnabled &&
+      lazy.isBrowsingHistoryEnabled;
+
+    /**
+     * Do not backup places.sqlite and favicons.sqlite if users have history disabled, want history cleared on shutdown or are using permanent private browsing mode.
+     * Instead, export all existing bookmarks to a compressed JSON file that we can read when restoring the backup.
+     */
+    if (!canBackupHistory) {
+      let bookmarksBackupFile = PathUtils.join(
+        stagingPath,
+        "bookmarks.jsonlz4"
+      );
+      await lazy.BookmarkJSONUtils.exportToFile(bookmarksBackupFile, {
+        compress: true,
+      });
+      return { bookmarksOnly: true };
+    }
+
+    for (let fileName of sqliteDatabases) {
+      let sourcePath = PathUtils.join(profilePath, fileName);
+      let destPath = PathUtils.join(stagingPath, fileName);
+      let connection;
+
+      try {
+        connection = await lazy.Sqlite.openConnection({
+          path: sourcePath,
+          readOnly: true,
+        });
+
+        await connection.backup(destPath);
+      } finally {
+        await connection.close();
+      }
+    }
+    return null;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    let placesDBPath = PathUtils.join(profilePath, "places.sqlite");
+    let faviconsDBPath = PathUtils.join(profilePath, "favicons.sqlite");
+    let placesDBSize = await BackupResource.getFileSize(placesDBPath);
+    let faviconsDBSize = await BackupResource.getFileSize(faviconsDBPath);
+
+    Glean.browserBackup.placesSize.set(placesDBSize);
+    Glean.browserBackup.faviconsSize.set(faviconsDBSize);
+  }
+}
diff --git a/browser/components/backup/resources/PreferencesBackupResource.sys.mjs b/browser/components/backup/resources/PreferencesBackupResource.sys.mjs
new file mode 100644
index 0000000000..012c0bf91e
--- /dev/null
+++ b/browser/components/backup/resources/PreferencesBackupResource.sys.mjs
@@ -0,0 +1,98 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import { BackupResource } from "resource:///modules/backup/BackupResource.sys.mjs";
+import { Sqlite } from "resource://gre/modules/Sqlite.sys.mjs";
+
+/**
+ * Class representing files that modify preferences and permissions within a user profile.
+ */
+export class PreferencesBackupResource extends BackupResource {
+  static get key() {
+    return "preferences";
+  }
+
+  static get requiresEncryption() {
+    return false;
+  }
+
+  async backup(stagingPath, profilePath = PathUtils.profileDir) {
+    // These are files that can be simply copied into the staging folder using
+    // IOUtils.copy.
+    const simpleCopyFiles = [
+      "xulstore.json",
+      "containers.json",
+      "handlers.json",
+      "search.json.mozlz4",
+      "user.js",
+      "chrome",
+    ];
+
+    for (let fileName of simpleCopyFiles) {
+      let sourcePath = PathUtils.join(profilePath, fileName);
+      let destPath = PathUtils.join(stagingPath, fileName);
+      if (await IOUtils.exists(sourcePath)) {
+        await IOUtils.copy(sourcePath, destPath, { recursive: true });
+      }
+    }
+
+    const sqliteDatabases = ["permissions.sqlite", "content-prefs.sqlite"];
+
+    for (let fileName of sqliteDatabases) {
+      let sourcePath = PathUtils.join(profilePath, fileName);
+      let destPath = PathUtils.join(stagingPath, fileName);
+      let connection;
+
+      try {
+        connection = await Sqlite.openConnection({
+          path: sourcePath,
+        });
+
+        await connection.backup(destPath);
+      } finally {
+        await connection.close();
+      }
+    }
+
+    // prefs.js is a special case - we have a helper function to flush the
+    // current prefs state to disk off of the main thread.
+    let prefsDestPath = PathUtils.join(stagingPath, "prefs.js");
+    let prefsDestFile = await IOUtils.getFile(prefsDestPath);
+    await Services.prefs.backupPrefFile(prefsDestFile);
+
+    return null;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    const files = [
+      "prefs.js",
+      "xulstore.json",
+      "permissions.sqlite",
+      "content-prefs.sqlite",
+      "containers.json",
+      "handlers.json",
+      "search.json.mozlz4",
+      "user.js",
+    ];
+    let fullSize = 0;
+
+    for (let filePath of files) {
+      let resourcePath = PathUtils.join(profilePath, filePath);
+      let resourceSize = await BackupResource.getFileSize(resourcePath);
+      if (Number.isInteger(resourceSize)) {
+        fullSize += resourceSize;
+      }
+    }
+
+    const chromeDirectoryPath = PathUtils.join(profilePath, "chrome");
+    let chromeDirectorySize = await BackupResource.getDirectorySize(
+      chromeDirectoryPath
+    );
+    if (Number.isInteger(chromeDirectorySize)) {
+      fullSize += chromeDirectorySize;
+    }
+
+    Glean.browserBackup.preferencesSize.set(fullSize);
+  }
+}
diff --git a/browser/components/backup/resources/SessionStoreBackupResource.sys.mjs b/browser/components/backup/resources/SessionStoreBackupResource.sys.mjs
new file mode 100644
index 0000000000..fa5dcca848
--- /dev/null
+++ b/browser/components/backup/resources/SessionStoreBackupResource.sys.mjs
@@ -0,0 +1,53 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+import {
+  BackupResource,
+  bytesToFuzzyKilobytes,
+} from "resource:///modules/backup/BackupResource.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+});
+
+/**
+ * Class representing Session store related files within a user profile.
+ */
+export class SessionStoreBackupResource extends BackupResource {
+  static get key() {
+    return "sessionstore";
+  }
+
+  static get requiresEncryption() {
+    // Session store data does not require encryption, but if encryption is
+    // disabled, then session cookies will be cleared from the backup before
+    // writing it to the disk.
+    return false;
+  }
+
+  async measure(profilePath = PathUtils.profileDir) {
+    // Get the current state of the session store JSON and
+    // measure it's uncompressed size.
+    let sessionStoreJson = lazy.SessionStore.getCurrentState(true);
+    let sessionStoreSize = new TextEncoder().encode(
+      JSON.stringify(sessionStoreJson)
+    ).byteLength;
+    let sessionStoreNearestTenthKb = bytesToFuzzyKilobytes(sessionStoreSize);
+
+    Glean.browserBackup.sessionStoreSize.set(sessionStoreNearestTenthKb);
+
+    let sessionStoreBackupsDirectoryPath = PathUtils.join(
+      profilePath,
+      "sessionstore-backups"
+    );
+    let sessionStoreBackupsDirectorySize =
+      await BackupResource.getDirectorySize(sessionStoreBackupsDirectoryPath);
+
+    Glean.browserBackup.sessionStoreBackupsDirectorySize.set(
+      sessionStoreBackupsDirectorySize
+    );
+  }
+}