1 files changed, 141 insertions, 0 deletions
diff --git a/toolkit/components/translations/actors/TranslationsEngineParent.sys.mjs b/toolkit/components/translations/actors/TranslationsEngineParent.sys.mjs
new file mode 100644
index 0000000000..77b16d7ae9
--- /dev/null
+++ b/toolkit/components/translations/actors/TranslationsEngineParent.sys.mjs
@@ -0,0 +1,141 @@
+/* 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, {
+  TranslationsParent: "resource://gre/actors/TranslationsParent.sys.mjs",
+});
+
+/**
+ * The translations engine is in its own content process. This actor handles the
+ * marshalling of the data such as the engine payload and port passing.
+ */
+export class TranslationsEngineParent extends JSWindowActorParent {
+  /**
+   * Keep track of the live actors by InnerWindowID.
+   *
+   * @type {Map<InnerWindowID, TranslationsParent | AboutTranslationsParent>}
+   */
+  #translationsParents = new Map();
+
+  async receiveMessage({ name, data }) {
+    switch (name) {
+      case "TranslationsEngine:Ready":
+        if (!lazy.TranslationsParent.resolveEngine) {
+          throw new Error(
+            "Unable to find the resolve function for when the translations engine is ready."
+          );
+        }
+        lazy.TranslationsParent.resolveEngine(this);
+        return undefined;
+      case "TranslationsEngine:RequestEnginePayload": {
+        const { fromLanguage, toLanguage } = data;
+        const payloadPromise =
+          lazy.TranslationsParent.getTranslationsEnginePayload(
+            fromLanguage,
+            toLanguage
+          );
+        payloadPromise.catch(error => {
+          lazy.TranslationsParent.telemetry().onError(String(error));
+        });
+        return payloadPromise;
+      }
+      case "TranslationsEngine:ReportEngineStatus": {
+        const { innerWindowId, status } = data;
+        const translationsParent = this.#translationsParents.get(innerWindowId);
+
+        // about:translations will not have a TranslationsParent associated with
+        // this call.
+        if (translationsParent) {
+          switch (status) {
+            case "ready":
+              translationsParent.languageState.isEngineReady = true;
+              break;
+            case "error":
+              translationsParent.languageState.error = "engine-load-failure";
+              break;
+            default:
+              throw new Error("Unknown engine status: " + status);
+          }
+        }
+        return undefined;
+      }
+      case "TranslationsEngine:DestroyEngineProcess":
+        ChromeUtils.addProfilerMarker(
+          "TranslationsEngine",
+          {},
+          "Loading bergamot wasm array buffer"
+        );
+        lazy.TranslationsParent.destroyEngineProcess().catch(error =>
+          console.error(error)
+        );
+        return undefined;
+      default:
+        return undefined;
+    }
+  }
+
+  /**
+   * @param {string} fromLanguage
+   * @param {string} toLanguage
+   * @param {number} innerWindowId
+   * @param {MessagePort} port
+   * @param {number} innerWindowId
+   * @param {TranslationsParent} [translationsParent]
+   */
+  startTranslation(
+    fromLanguage,
+    toLanguage,
+    port,
+    innerWindowId,
+    translationsParent
+  ) {
+    if (translationsParent) {
+      this.#translationsParents.set(
+        translationsParent.innerWindowId,
+        translationsParent
+      );
+    }
+    if (this.#isDestroyed) {
+      throw new Error("The translation engine process was already destroyed.");
+    }
+    const transferables = [port];
+    this.sendAsyncMessage(
+      "TranslationsEngine:StartTranslation",
+      {
+        fromLanguage,
+        toLanguage,
+        innerWindowId,
+        port,
+      },
+      transferables
+    );
+  }
+
+  /**
+   * Remove all the translations that are currently queued, and remove
+   * the communication port.
+   *
+   * @param {number} innerWindowId
+   */
+  discardTranslations(innerWindowId) {
+    this.#translationsParents.delete(innerWindowId);
+    this.sendAsyncMessage("TranslationsEngine:DiscardTranslations", {
+      innerWindowId,
+    });
+  }
+
+  /**
+   * Manually shut down the engines, typically for testing purposes.
+   */
+  forceShutdown() {
+    return this.sendQuery("TranslationsEngine:ForceShutdown");
+  }
+
+  #isDestroyed = false;
+
+  didDestroy() {
+    this.#isDestroyed = true;
+  }
+}