Creating cache keys with the JavaScript Cache API

23 Oct 2023

caching

Caching is a common technique used in web development to improve performance by storing frequently accessed data or resources. The JavaScript Cache API provides a convenient way to cache responses from HTTP requests, allowing them to be stored and retrieved quickly.

One important aspect of caching is the ability to generate unique cache keys for each resource. This ensures that the correct response is retrieved from the cache when needed. In this blog post, we will explore how to create cache keys using the JavaScript Cache API.

The Cache API

The Cache interface provided by the JavaScript Cache API allows developers to store and retrieve responses from a cache storage area. It provides methods like put, match, and delete to interact with the cache. To use the Cache API, you need to open a specific cache storage using the caches.open() method.

// Opening a cache storage
caches.open('myCache')
  .then(cache => {
    // Perform cache operations
  });

Creating Unique Cache Keys

To create unique cache keys, you can combine multiple factors that define a particular resource. These factors can include the URL of the resource, any request headers, or other relevant parameters.

Using the Request Object

The Request object contains information about an HTTP request, including the URL, request headers, and more. By using the properties of the Request object, we can generate a unique cache key.

const request = new Request('https://api.example.com/data', { headers: { 'Authorization': 'Bearer xxx' } });

// Generate cache key
const cacheKey = request.url + JSON.stringify(request.headers);

In the above example, we create a Request object with the URL and headers. We then generate a cache key by combining the URL and headers using string concatenation.

Adding Custom Logic

In some cases, you might need to add custom logic to generate cache keys based on specific requirements. For example, you may want to exclude certain query parameters or modify the cache key based on specific conditions.

const request = new Request('https://api.example.com/data?param1=value1&param2=value2');

// Generate cache key with custom logic
const queryParams = new URL(request.url).searchParams;
const cacheKey = request.url.split('?')[0] + queryParams.get('param1');

In this example, we extract the query parameters from the URL and modify the cache key based on the value of one of the query parameters.

Conclusion

Generating unique cache keys is crucial for an effective caching strategy. By leveraging the JavaScript Cache API and considering factors such as the resource URL, request headers, and custom logic, you can create cache keys that accurately represent the resources you want to cache.

By using the Cache API effectively and creating meaningful cache keys, you can significantly improve the performance and efficiency of your web applications.

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