Cachios

A simple axios cache wrapper using node-cache.

Cachios is meant to be a replacement for the following pattern:

const axios = require('axios');

const resources = {};

function getResource(id) {
  if (!resources[id]) {
    // actually retrieve the resource
    return axios.get(`/api/thing/${id}`).then((resp) => {
      // store the resource
      resources[id] = resp.data;
      return resp.data;
    });
  } else {
    // return the resource we already have
    return Promise.resolve(resources[id]);
  }
}

With Cachios, this is replaced with:

const cachios = require('cachios');

function getResource(id) {
  return cachios.get(`/api/thing/${id}`).then((resp) => {
    return resp.data;
  });
}

The following axios methods are supported:

request
get
delete
head
options
post
put
patch

The entire response is not cached, and is instead trimmed down (by default) to status and data. To configure this, see "Custom Response Copier".

Installation

npm install --save cachios

Examples

Basic:

const cachios = require('cachios');

cachios.get('https://jsonplaceholder.typicode.com/posts/1', {
  ttl: 300 /* seconds */,
}).then(console.log);

Custom axios client:

// your normal, non-cached axios instance that is already setup.
import axios from './configured-axios';

const cachios = require('cachios');
const cachiosInstance = cachios.create(axios);

const postData = {/* your postdata here */};

cachiosInstance.post('/posts/1', postData, {
  ttl: 30, // persist 30 seconds
}).then((resp) => {
  console.log(resp.status);

  const data = resp.data;
  console.log(data.title);
  console.log(data.body);
});

Multiple cached GET requests: Runkit

Multiple cached GET requests with different query parameters: Runkit

Configuration

TTL

To set the cache TTL, pass it in with your request config:

const cachios = require('cachios');

cachios.get('url', {
  ttl: /* time to live in seconds */,
});

const postData = {};
cachios.post('url', postData, {
  headers: /* your custom headers */
  ...
  ttl: 60, // persist this result for 60 seconds
});

Force Ignore Cache

To ignore existing cache items and force a fresh request to go through, use force: true:

const cachios = require('cachios');

cachios.get('url'); // cache 'url'

// ignore and update cache for 'url' by using `force: true`
cachios.get('url', {
  force: true,
});

Custom Axios Instance

Cachios also supports using a pre-configured axios instance:

const cachios = require('cachios');
const axios = require('axios');

const axiosInstance = axios.create({
  baseURL: 'https://jsonplaceholder.typicode.com',
});

// all requests will now use this axios instance
const cachiosInstance = cachios.create(axiosInstance);

Custom Cache Configuration

Internally, Cachios uses node-cache with sane defaults. To configure it yourself, pass it during cachios.create:

const cachios = require('cachios');
const axios = require('axios');

// configure `node-cache` to keep cache forever!
const cachiosInstance = cachios.create(axios, {
  stdTTL: 0,
  checkperiod: 0,
});

Alternative Cache Implementation

Don't want to use node-cache? The .cache property can be overridden.

cachios expects the cache implementation to work as follows:

cachios.cache = {
  /**
  cacheKey: string

  if a value has been set for this `cacheKey`, return it.
  otherwise, return a falsey value (undefined, false, null).

  synchronous, asynchronous, and promise-returning functions are supported.
  */
  get(cacheKey),

  /**
  cacheKey: string
  cacheValue: mixed
  ttl: number|undefined

  store the value `cacheValue` under `cacheKey` for `ttl` seconds.
  if `ttl` is not set, it is assumed the value is stored forever.

  synchronous, asynchronous, and promise-returning functions are supported.
  */
  set(cacheKey, cacheValue, ttl),
}

Example using lru-cache:

const cachios = require('cachios');
const LRU  = require('lru-cache');

cachios.cache = LRU(500);

cachios.get('http://example.com/') // not cached
.then(() => cachios.get('http://example.com/')); // cached
.then(() => {
  console.log(cachios.cache.itemCount); // 1 item in cache - the first request
});

Example of persistent cache with keyv and @keyv/sqlite:

const cachios = require('cachios');
const Keyv = require('keyv');

cachios.cache = new Keyv('sqlite://cache.sqlite');

cachios.get('http://example.com/') // not cached
.then(() => cachios.get('http://example.com/')); // cached
.then(() => cachios.cache.opts.store.query('SELECT COUNT(*) as count FROM keyv'))
.then((cacheSize) => {
  console.log(cacheSize[0].count); // 1 item in cache - the first request
});

Custom Response Copier

By default, Cachios uses the following function to trim responses:

function defaultResponseCopier(response) {
  return {
    status: response.status,
    data: response.data,
  };
}

This was originally implemented because of errors during response storage.

To change what is saved, set the getResponseCopy property of your Cachios instance:

const cachios = require('cachios');

cachios.getResponseCopy = function (response) {
  return {
    status: response.status,
    statusText: response.statusText,
    data: response.data,
  };
};

Custom Cache Identifier

By default, Cachios uses the following function to create a unique cache identifier:

function defaultCacheIdentifer(config) {
  return {
    method: config.method,
    url: config.url,
    params: config.params,
    data: config.data,
  };
}

To override this, set the getCacheIdentifier property of your Cachios instance:

const cachios = require('cachios');

cachios.getCacheIdentifier = function (config) {
  return {
    method: config.method,
    url: config.url,
    params: config.params,
    data: config.data,
    headers: config.headers,
  };
};

Custom object-hash Replacer

By default, Cachios uses an internal defaultReplacer function to add FormData support to object-hash.

To override this, set the getReplaced property of your Cachios instance:

const cachios = require('cachios');

cachios.getReplaced = function (thing) {
  if (thing === 'foo') {
    return 'bar';
  }

  return thing;
};

License

MIT

AlbinoDrought/cachios