2 files changed, 130 insertions, 0 deletions
diff --git a/remote/shared/webdriver/process-actors/WebDriverProcessDataChild.sys.mjs b/remote/shared/webdriver/process-actors/WebDriverProcessDataChild.sys.mjs
new file mode 100644
index 0000000000..39db9d939e
--- /dev/null
+++ b/remote/shared/webdriver/process-actors/WebDriverProcessDataChild.sys.mjs
@@ -0,0 +1,93 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+  NodeCache: "chrome://remote/content/shared/webdriver/NodeCache.sys.mjs",
+});
+
+ChromeUtils.defineLazyGetter(lazy, "logger", () => lazy.Log.get());
+
+// Observer to clean-up element references for closed browsing contexts.
+class BrowsingContextObserver {
+  constructor(actor) {
+    this.actor = actor;
+  }
+
+  async observe(subject, topic, data) {
+    if (topic === "browsing-context-discarded") {
+      this.actor.cleanUp({ browsingContext: subject });
+    }
+  }
+}
+
+export class WebDriverProcessDataChild extends JSProcessActorChild {
+  #browsingContextObserver;
+  #nodeCache;
+
+  constructor() {
+    super();
+
+    // For now have a single reference store only. Once multiple WebDriver
+    // sessions are supported, it needs to be hashed by the session id.
+    this.#nodeCache = new lazy.NodeCache();
+
+    // Register observer to cleanup element references when a browsing context
+    // gets destroyed.
+    this.#browsingContextObserver = new BrowsingContextObserver(this);
+    Services.obs.addObserver(
+      this.#browsingContextObserver,
+      "browsing-context-discarded"
+    );
+  }
+
+  actorCreated() {
+    lazy.logger.trace(
+      `WebDriverProcessData actor created for PID ${Services.appinfo.processID}`
+    );
+  }
+
+  didDestroy() {
+    Services.obs.removeObserver(
+      this.#browsingContextObserver,
+      "browsing-context-discarded"
+    );
+  }
+
+  /**
+   * Clean up all the process specific data.
+   *
+   * @param {object=} options
+   * @param {BrowsingContext=} options.browsingContext
+   *     If specified only clear data living in that browsing context.
+   */
+  cleanUp(options = {}) {
+    const { browsingContext = null } = options;
+
+    this.#nodeCache.clear({ browsingContext });
+  }
+
+  /**
+   * Get the node cache.
+   *
+   * @returns {NodeCache}
+   *     The cache containing DOM node references.
+   */
+  getNodeCache() {
+    return this.#nodeCache;
+  }
+
+  async receiveMessage(msg) {
+    switch (msg.name) {
+      case "WebDriverProcessDataParent:CleanUp":
+        return this.cleanUp(msg.data);
+      default:
+        return Promise.reject(
+          new Error(`Unexpected message received: ${msg.name}`)
+        );
+    }
+  }
+}
diff --git a/remote/shared/webdriver/process-actors/WebDriverProcessDataParent.sys.mjs b/remote/shared/webdriver/process-actors/WebDriverProcessDataParent.sys.mjs
new file mode 100644
index 0000000000..a895106c4b
--- /dev/null
+++ b/remote/shared/webdriver/process-actors/WebDriverProcessDataParent.sys.mjs
@@ -0,0 +1,37 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Log: "chrome://remote/content/shared/Log.sys.mjs",
+});
+
+ChromeUtils.defineLazyGetter(lazy, "logger", () => lazy.Log.get());
+
+/**
+ * Register the WebDriverProcessData actor that holds session data.
+ */
+export function registerProcessDataActor() {
+  try {
+    ChromeUtils.registerProcessActor("WebDriverProcessData", {
+      kind: "JSProcessActor",
+      child: {
+        esModuleURI:
+          "chrome://remote/content/shared/webdriver/process-actors/WebDriverProcessDataChild.sys.mjs",
+      },
+      includeParent: true,
+    });
+  } catch (e) {
+    if (e.name === "NotSupportedError") {
+      lazy.logger.warn(`WebDriverProcessData actor is already registered!`);
+    } else {
+      throw e;
+    }
+  }
+}
+
+export function unregisterProcessDataActor() {
+  ChromeUtils.unregisterProcessActor("WebDriverProcessData");
+}