refactor: migrate @krlwlfrt/async-pool to @openstapps/collection-utils

packages/collection-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@openstapps/collection-utils",
-  "version": "3.0.0",
+  "version": "2.0.0",
   "type": "module",
   "license": "GPL-3.0-only",
   "main": "lib/index.js",

packages/collection-utils/src/index.ts

@@ -14,3 +14,4 @@ export * from './sum.js';
 export * from './tree-group.js';
 export * from './uniq.js';
 export * from './zip.js';
+export * from './map-async-limit.js';

packages/collection-utils/src/map-async-limit.ts

@@ -0,0 +1,42 @@
+/**
+ * Copyright (C) 2023 StApps
+ *  This program is free software: you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the Free
+ *  Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ *  more details.
+ *
+ *  You should have received a copy of the GNU General Public License along with
+ *  this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Runs async tasks in parallel, with a limit
+ *
+ * Note: JavaScript is not multithreaded.
+ * This will not let you run tasks in parallel, use it only to limit how many network requests should be
+ * running at once.
+ * @param items the items to iterate through
+ * @param task the task to be run
+ * @param limit the maximum number of tasks that should be run asynchronously
+ */
+export async function mapAsyncLimit<T, U = void>(
+  items: T[],
+  task: (item: T, index: number) => Promise<U>,
+  limit = 5,
+): Promise<U[]> {
+  return Promise.all(
+    Array.from({length: limit}).map(async () => {
+      let i = 0;
+      const results: U[] = [];
+      for (let item = items.shift(); item !== undefined; item = items.shift()) {
+        results.push(await task(item, i));
+        i++;
+      }
+      return results;
+    }),
+  ).then(it => it.flat());
+}