Implementation of Cache in Express API

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To implement caching in an Express API, you can utilize various caching mechanisms such as in-memory caching or external caching services like Redis. Here’s a general guide on how you can implement caching in an Express API using in-memory caching:

Step 1: Install Required Packages

First, install the necessary packages for caching in your Express API. You can use a package like memory-cache for in-memory caching.


  npm install memory-cache

Step 2: Create a Middleware

create a middleware function that will handle the caching logic. This middleware will check if the requested data is available in the cache and return it if it exists. If not, it will proceed to execute the route handler and cache the response.


  const cache = require('memory-cache');

const cacheMiddleware = (duration) => {
  return (req, res, next) => {
    const key = '__express__' + req.originalUrl || req.url;
    const cachedData = cache.get(key);

    if (cachedData) {
      res.send(cachedData);
      return;
    }

    res.sendResponse = res.send;
    res.send = (body) => {
      cache.put(key, body, duration * 1000);
      res.sendResponse(body);
    };

    next();
  };
};

module.exports = cacheMiddleware;

Step 3: Apply the Middleware

In Express API, apply the cache middleware to the routes or route handlers that you want to cache. Specify the desired caching duration in seconds when applying the middleware.


  const express = require('express');
const cacheMiddleware = require('./cacheMiddleware');

const app = express();

app.get('/data', cacheMiddleware(60), (req, res) => {
  // Your route handler logic here
  // This code will only be executed if the data is not cached or has expired
  res.send('Data from the API');
});

app.listen(3000, () => {
  console.log('Server listening on port 3000');
});

In the example above, the /data route will be cached for 60 seconds. If a subsequent request is made within that duration, the cached data will be returned directly, skipping the execution of the route handler. Once the cache expires, the next request will trigger the route handler again, and the response will be cached once more.

Remember to adapt the caching mechanism based on your specific requirements and consider using more robust caching solutions like Redis for production environments or when you require distributed caching.

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