1. class RequestThrottler {
  2. constructor(maxRequestsPerSecond) {
  3. this.maxRequestsPerSecond = maxRequestsPerSecond;
  4. this.requestQueue = [];
  5. this.lastRequestTime = 0;
  6. }
  8. /**
  9. * Throttles a request to prevent overwhelming the system.
  10. * @param {function} requestFunction The function to execute (the actual request).
  11. * @param {object} data The data to send with the request.
  12. * @returns {Promise} A promise that resolves when the request is complete.
  13. * @throws {Error} If the data is invalid.
  14. */
  15. throttle(requestFunction, data) {
  16. // Input validation
  17. if (!data || typeof data !== 'object') {
  18. throw new Error("Invalid data: Data must be an object.");
  19. }
  20. if (typeof requestFunction !== 'function') {
  21. throw new Error("Invalid requestFunction: requestFunction must be a function.");
  22. }
  25. return new Promise((resolve, reject) => {
  26. const now = Date.now();
  27. const timeSinceLastRequest = now - this.lastRequestTime;
  29. if (timeSinceLastRequest < 1000 / this.maxRequestsPerSecond) {
  30. // Queue the request if it's too frequent.
  31. this.requestQueue.push({ function: requestFunction, data: data });
  32. } else {
  33. // Execute the request immediately.
  34. this.lastRequestTime = now;
  35. requestFunction(data, resolve, reject); // Pass resolve and reject to the function.
  36. }
  37. });
  38. }
  40. /**
  41. * Processes the request queue.
  42. */
  43. processQueue() {
  44. while (this.requestQueue.length > 0) {
  45. const { function: requestFunction, data: data } = this.requestQueue.shift();
  46. this.throttle(requestFunction, data)
  47. .then(() => {
  48. // Request completed successfully.
  49. })
  50. .catch(error => {
  51. // Request failed.
  52. console.error("Request failed:", error);
  53. // Optionally, handle the error (e.g., retry, log).
  54. });
  55. }
  56. }
  57. }
  59. // Example usage:
  60. // const throttler = new RequestThrottler(5); // Allow 5 requests per second
  62. // async function fetchData(data, resolve, reject) {
  63. // console.log("Fetching data:", data);
  64. // await new Promise(resolve => setTimeout(resolve, 200)); // Simulate network request
  65. // resolve({ message: "Data fetched successfully" });
  66. // }
  68. // try {
  69. // await throttler.throttle(fetchData, { userId: 123 });
  70. // console.log("Request completed.");
  71. // } catch (error) {
  72. // console.error("Error:", error);
  73. // }

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