Introduction

Caching is a crucial aspect of many applications, as it helps to improve performance and reduce redundant computation. When working with immutable data structures, such as those handled with Immer, caching can become even more challenging. Immer provides a convenient way to work with immutable data, but it also introduces some considerations while implementing caching strategies. In this blog post, we will explore some strategies for handling caching with Immer effectively.

1. Shallow Copying

One straightforward strategy is to use shallow copies of the data structure when caching. Since Immer uses structural sharing, shallow copying ensures that we are not duplicating unnecessary data. Additionally, it allows us to benefit from Immer’s efficient update and creating new states.

import produce from 'immer';

let cache = null;

function fetchData() {
  if (cache) {
    // Use the cached data
    return cache;
  }

  // Fetch the data from the API
  const data = fetchAPI();
  
  // Cache the data
  cache = produce(data, draft => draft);

  return cache;
}

2. Cache Invalidation

When using caching with Immer, it’s essential to handle cache invalidation properly. Immer provides an efficient way to create a new state while reusing the unchanged parts of the data structure. To invalidate the cache, we need to detect changes and update the cache accordingly.

import produce, { isDraft } from 'immer';

let cache = null;

// Helper function to check if two states are equal
function areStatesEqual(state1, state2) {
  return isDraft(state1) === isDraft(state2) && JSON.stringify(state1) === JSON.stringify(state2);
}

function fetchData() {
  if (cache && areStatesEqual(cache, currentState)) {
    // Use the cached data
    return cache;
  }

  // Fetch the data from the API
  const data = fetchAPI();
  
  // Create a new state with Immer
  const newState = produce(currentState, draft => {
    // Apply changes to the draft
    draft.data = data;
  });

  // Cache the new state
  cache = newState;

  return cache;
}

Conclusion

Caching can significantly improve the performance of applications, but it requires careful consideration when working with immutable data structures like those managed by Immer. By employing strategies such as shallow copying and proper cache invalidation, we can effectively handle caching with Immer and achieve optimal performance in our applications.

#hashtags #Immer #caching