Support modules in web workers.

common/changes/c2pa/duggaraju-worker_module_2024-03-15-19-00.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "c2pa",
+      "comment": "Add support for worker thread to use modules",
+      "type": "patch"
+    }
+  ],
+  "packageName": "c2pa"
+}

packages/c2pa/src/c2pa.ts

@@ -200,7 +200,9 @@ export async function createC2pa(config: C2paConfig): Promise<C2pa> {
 
   const pool = await createPoolWrapper({
     scriptSrc: config.workerSrc,
-    maxWorkers: navigator.hardwareConcurrency || 4,
+    maxWorkers:
+      config.poolOptions?.maxWorkers || navigator.hardwareConcurrency || 4,
+    type: config.poolOptions?.type,
   });
 
   const downloader = new Downloader(pool, config.downloaderOptions);

packages/c2pa/src/lib/pool/workerManager.ts

@@ -22,8 +22,11 @@ export interface WorkerManager {
  * @param scriptUrl URL to worker script
  * @returns {WorkerManager}
  */
-export function createWorkerManager(scriptUrl: string): WorkerManager {
-  const worker = new Worker(scriptUrl);
+export function createWorkerManager(
+  scriptUrl: string,
+  options?: WorkerOptions,
+): WorkerManager {
+  const worker = new Worker(scriptUrl, options);
   let working = false;
 
   const execute: WorkerManager['execute'] = async (request) => {

packages/c2pa/src/lib/pool/workerPool.ts

@@ -13,6 +13,7 @@ import { createWorkerManager, WorkerManager } from './workerManager';
 export interface WorkerPoolConfig {
   scriptSrc: string;
   maxWorkers: number;
+  type?: WorkerType;
 }
 
 interface WorkerPool {
@@ -40,7 +41,10 @@ export function createWorkerPool(config: WorkerPoolConfig): WorkerPool {
       if (!worker.isWorking()) return worker;
     }
     if (workers.length < config.maxWorkers) {
-      const newWorker = createWorkerManager(config.scriptSrc);
+      const options: WorkerOptions = {
+        type: config.type,
+      };
+      const newWorker = createWorkerManager(config.scriptSrc, options);
       workers.push(newWorker);
       return newWorker;
     }

packages/c2pa/src/lib/poolWrapper.ts

@@ -21,21 +21,20 @@ export interface SdkWorkerPool extends Worker {
 export async function createPoolWrapper(
   config: WorkerPoolConfig,
 ): Promise<SdkWorkerPool> {
-  const res = await fetch(config.scriptSrc);
+  const res = await fetch(config.scriptSrc, {
+    method: 'HEAD',
+  });
 
   if (!res.ok) throw new InvalidWorkerSourceError(config.scriptSrc, res);
 
-  const src = await res.text();
   // @TODO: check subresource integrity
-  dbg('Fetched worker from %s (%d bytes)', config.scriptSrc, src.length);
-
-  const workerBlob = new Blob([src], { type: 'application/javascript' });
-  const workerUrl = URL.createObjectURL(workerBlob);
+  dbg(
+    'Fetched worker from %s (%d bytes)',
+    config.scriptSrc,
+    res.headers.get('Content-Length'),
+  );
 
-  const workerPool = createWorkerPool({
-    ...config,
-    scriptSrc: workerUrl,
-  });
+  const workerPool = createWorkerPool(config);
 
   const pool: Worker = {
     compileWasm: async (...args) => workerPool.execute('compileWasm', args),
@@ -48,7 +47,6 @@ export async function createPoolWrapper(
   return {
     ...pool,
     dispose: () => {
-      URL.revokeObjectURL(workerUrl);
       return workerPool.terminate();
     },
   };