feat: 🎸 Add a shared service between web workers (#2932)

* feat: 🎸 Add a shared service between web workers

✅ Closes: https://hashicorp.atlassian.net/browse/ICU-17409

addons/api/addon/workers/sqlite-worker.js

@@ -0,0 +1,45 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: BUSL-1.1
+ */
+
+import { PWBWorker } from 'promise-worker-bi';
+import sqlite3InitModule from '@sqlite.org/sqlite-wasm';
+import sharedServiceInit from './utils/shared-service';
+
+const methods = {
+  initializeSQLite: async () => {
+    try {
+      const sqlite3 = await sqlite3InitModule({
+        print: console.log,
+        printErr: console.error,
+      });
+      console.log(`SQLite Version: ${sqlite3?.version.libVersion}`);
+      const poolUtil = await sqlite3.installOpfsSAHPoolVfs();
+      new poolUtil.OpfsSAHPoolDb('/boundary');
+    } catch (err) {
+      console.error('Initialization error:', err.name, err.message);
+    }
+  },
+};
+
+const promiseWorker = new PWBWorker();
+promiseWorker.register(async ({ method, payload }) => {
+  await sharedService.status.ready;
+
+  return sharedService.proxy[method](payload);
+});
+
+const initializeOnProviderChange = async (isProvider) => {
+  if (!isProvider) {
+    return;
+  }
+  // Initialize the SQLite database when we become a provider
+  await sharedService.proxy.initializeSQLite();
+};
+
+const sharedService = sharedServiceInit(
+  'sqlite',
+  methods,
+  initializeOnProviderChange,
+);