chore: import upstream snapshot with attribution

api/server/utils/queue.js

@@ -0,0 +1,58 @@
+/**
+ * A leaky bucket queue structure to manage API requests.
+ * @type {{queue: Array, interval: NodeJS.Timer | null}}
+ */
+const _LB = {
+  queue: [],
+  interval: null,
+};
+
+/**
+ * Interval in milliseconds to control the rate of API requests.
+ * Adjust the interval according to your rate limit needs.
+ */
+const _LB_INTERVAL_MS = Math.ceil(1000 / 60); // 60 req/s
+
+/**
+ * Executes the next function in the leaky bucket queue.
+ * This function is called at regular intervals defined by _LB_INTERVAL_MS.
+ */
+const _LB_EXEC_NEXT = async () => {
+  if (_LB.queue.length === 0) {
+    clearInterval(_LB.interval);
+    _LB.interval = null;
+    return;
+  }
+
+  const next = _LB.queue.shift();
+  if (!next) {
+    return;
+  }
+
+  const { asyncFunc, args, callback } = next;
+
+  try {
+    const data = await asyncFunc(...args);
+    callback(null, data);
+  } catch (e) {
+    callback(e);
+  }
+};
+
+/**
+ * Adds an async function call to the leaky bucket queue.
+ * @param {Function} asyncFunc - The async function to be executed.
+ * @param {Array} args - Arguments to pass to the async function.
+ * @param {Function} callback - Callback function for handling the result or error.
+ */
+function LB_QueueAsyncCall(asyncFunc, args, callback) {
+  _LB.queue.push({ asyncFunc, args, callback });
+
+  if (_LB.interval === null) {
+    _LB.interval = setInterval(_LB_EXEC_NEXT, _LB_INTERVAL_MS);
+  }
+}
+
+module.exports = {
+  LB_QueueAsyncCall,
+};