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;
};