Bug 1933053 - QM: Introduce nsIQuotaUtilsService for accessing information available only in JS; r=dom-storage-reviewers,asuth

This patch introduces a new scriptable interface, nsIQuotaUtilsService,
designed to enable C++ code to access information that is exclusively available
through JavaScript system modules.

Differential Revision: https://phabricator.services.mozilla.com/D231264

dom/quota/QuotaUtilsService.sys.mjs

@@ -0,0 +1,21 @@
+/* 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 { ContextualIdentityService } from "resource://gre/modules/ContextualIdentityService.sys.mjs";
+
+export function QuotaUtilsService() {}
+
+QuotaUtilsService.prototype = {
+  getPrivateIdentityId(aName) {
+    const privateIdentity = ContextualIdentityService.getPrivateIdentity(aName);
+    if (!privateIdentity) {
+      return 0;
+    }
+    return privateIdentity.userContextId;
+  },
+  QueryInterface: ChromeUtils.generateQI(["nsIQuotaUtilsService"]),
+  classDescription: "Quota Utils Service",
+  contractID: "@mozilla.org/dom/quota-utils-service;1",
+  classID: Components.ID("3e65d9b5-5b41-4c18-ac7b-681b9df9df97"),
+};

dom/quota/components.conf

@@ -5,6 +5,12 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 Classes = [
+    {
+        'cid': '{3e65d9b5-5b41-4c18-ac7B-681b9df9df97}',
+        'contract_ids': ['@mozilla.org/dom/quota-utils-service;1'],
+        'esModule': 'resource://gre/modules/QuotaUtilsService.sys.mjs',
+        'constructor': 'QuotaUtilsService',
+    },
     {
         'cid': '{b6f2f870-b0bc-4a1a-9c40-02cc171adb5b}',
         'contract_ids': ['@mozilla.org/network/protocol;1?name=indexeddb'],

dom/quota/moz.build

@@ -15,6 +15,7 @@ XPIDL_SOURCES += [
     "nsIQuotaManagerService.idl",
     "nsIQuotaRequests.idl",
     "nsIQuotaResults.idl",
+    "nsIQuotaUtilsService.idl",
 ]
 
 XPIDL_MODULE = "dom_quota"
@@ -170,6 +171,10 @@ IPDL_SOURCES += [
     "PRemoteQuotaObject.ipdl",
 ]
 
+EXTRA_JS_MODULES += [
+    "QuotaUtilsService.sys.mjs",
+]
+
 include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"

dom/quota/nsIQuotaUtilsService.idl

@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "nsISupports.idl"
+
+/**
+ * This interface provides utility methods for storage and quota management
+ * that require information only available in JavaScript system modules. It
+ * serves as a bridge for accessing such information from C++ code where direct
+ * access is not feasible.
+ */
+[scriptable, uuid(cdeca40d-74f4-44a2-beb3-84cd0bbc7785)]
+interface nsIQuotaUtilsService : nsISupports
+{
+  /**
+   * Retrieves the private identity id corresponding to the specified name.
+   *
+   * @param aName The name for which the private identity id is requested.
+   * @return The private identity id as an unsigned long.
+   */
+  unsigned long getPrivateIdentityId(in AString aName);
+};

dom/quota/test/xpcshell/test_quotaUtilsService.js

@@ -0,0 +1,23 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+/* exported testSteps */
+async function testSteps() {
+  const quotaUtilsService = Cc[
+    "@mozilla.org/dom/quota-utils-service;1"
+  ].getService(Ci.nsIQuotaUtilsService);
+
+  {
+    const id = quotaUtilsService.getPrivateIdentityId("");
+    Assert.equal(id, 0, "Correct id");
+  }
+
+  {
+    const id = quotaUtilsService.getPrivateIdentityId(
+      "userContextIdInternal.thumbnail"
+    );
+    Assert.greater(id, 4, "Correct id");
+  }
+}

dom/quota/test/xpcshell/xpcshell.toml

@@ -113,6 +113,8 @@ skip-if = ["condprof"] # frequent perma fail, then goes away.
 
 ["test_quotaClientInteractions.js"]
 
+["test_quotaUtilsService.js"]
+
 ["test_removeLocalStorage.js"]
 
 ["test_simpledb.js"]