Request Deduplication in Speedcast API

Overview

Request deduplication is a powerful optimization technique that prevents duplicate API calls when multiple parts of your application request the same data simultaneously. Speedcast API intelligently manages concurrent identical requests to improve performance and reduce server load.

How Request Deduplication Works

When multiple identical requests occur concurrently, Speedcast API:

1. Detects when the same request is made while a previous one is still pending
2. Returns the same promise for all duplicate requests
3. Makes only a single network request to the API
4. Resolves all waiting promises with the same response when it completes
5. Automatically handles errors and propagates them to all waiting promises

Automatic Deduplication

Request deduplication is built into Speedcast API and works automatically without any additional configuration. It's active for all request methods including GET, POST, PUT, DELETE, etc.

import { SpeedcastApi } from 'speedcast-api';

const api = new SpeedcastApi({
  baseURL: 'https://api.example.com'
});

// If this function is called multiple times in quick succession,
// only one actual HTTP request will be made
async function getUserData(userId: string) {
  const response = await api.get(`/users/${userId}`);
  return response.data;
}

Real-World Benefits

Improved Frontend Performance

// Common scenario: Component mounting triggers multiple identical API calls
function UserProfile({ userId }) {
  // These components might all fetch the same user data on mount
  return (
    <div>
      <UserHeader userId={userId} />
      <UserDetails userId={userId} />
      <UserActivity userId={userId} />
    </div>
  );
}

// With Speedcast API, all these components can call the same function without worry
// Only ONE network request will actually be made
function UserHeader({ userId }) {
  const [user, setUser] = useState(null);
  
  useEffect(() => {
    // This same call might happen in multiple components
    api.get(`/users/${userId}`).then(response => {
      setUser(response.data);
    });
  }, [userId]);
  
  // Component rendering...
}

API Call Optimization

Deduplication is particularly valuable in these scenarios:

1. React/Vue Component Trees - When multiple components need the same data
2. Parallel Data Fetching - When using Promise.all with potentially duplicate requests
3. User Interactions - When users rapidly click buttons that trigger the same API call
4. Server-Side Rendering - When rendering requires the same data in multiple places

Deduplication vs. Caching

It's important to understand the distinction between request deduplication and caching:

Advanced Example: Data Fetching Library

// Example of a custom data fetching library built on Speedcast API
import { SpeedcastApi } from 'speedcast-api';

const api = new SpeedcastApi({
  baseURL: 'https://api.example.com',
  cache: true, // Enable caching for even more optimization
  cacheTTL: 60000 // 1 minute cache
});

// Create a simple data fetching library
export function createDataFetcher() {
  return {
    // Get data with both deduplication and caching
    async fetch<T>(endpoint: string): Promise<T> {
      const response = await api.get<T>(endpoint);
      return response.data;
    },
    
    // Post data with deduplication (but no caching)
    async save<T>(endpoint: string, data: any): Promise<T> {
      const response = await api.post<T>(endpoint, data);
      return response.data;
    }
  };
}

// Usage of the data fetcher
const dataFetcher = createDataFetcher();

// These will be automatically deduplicated if called at the same time
const users1 = dataFetcher.fetch('/users');
const users2 = dataFetcher.fetch('/users');
// Only ONE actual API call will be made

Best Practices

1. Take Advantage of Automatic Deduplication

   • Don't worry about duplicate requests in your application
   • Design your code for clarity rather than avoiding duplicate calls

2. Combine with Caching

   • Use both deduplication and caching for maximum efficiency
   • Deduplication handles concurrent requests, caching handles sequential ones

3. Request Identification

   • Remember that requests are deduplicated based on URL, method, and body
   • Requests with different headers are considered different requests

By leveraging Speedcast API's automatic request deduplication, your application will be more efficient and performant without any additional effort.