global: private xpub support part 1

website_next/wallets/concurrent.js

@@ -0,0 +1,24 @@
+/**
+ * @template Item, Result
+ * @param {readonly Item[]} items
+ * @param {number} limit
+ * @param {(item: Item) => Promise<Result>} fn
+ * @returns {Promise<Result[]>}
+ */
+export async function mapConcurrent(items, limit, fn) {
+  const results = /** @type {Result[]} */ ([]);
+  let next = 0;
+  const workerCount = Math.min(limit, items.length);
+  const workers = Array.from({ length: workerCount }, async () => {
+    while (next < items.length) {
+      const index = next;
+
+      next += 1;
+      results[index] = await fn(items[index]);
+    }
+  });
+
+  await Promise.all(workers);
+
+  return results;
+}