koa-response-cache

koa-response-cache

a middleware for koa to cache response with redis.

extend from koa-redis-cache

https://github.com/coderhaoxin/koa-redis-cache

Extra Features:

• support extra match condition. (eg. when mobile visit not get from cache)
• support cache backup, cache backup for high availability.

Installation

$ npm install koa-response-cache

Example

const cache = require('koa-response-cache');
const koa = require('koa');
const app = koa();
 
let options = {
  expire: 60,
  routes: ['/index']
}
 
app.use(cache(options));

options

• prefix
  • type: String or Function
  • redis key prefix, default is koa-response-cache:
  • if a function is supplied, its signature should be function(ctx) {} and it should return a string to use as the redis key prefix
• expire
  • type: Number
  • redis expire time (second), default is 30 * 60 (30 min)
• passParam
  • type: String
  • if the passParam is existed in query string, not get from cache
• maxLength
  • type: Number
  • max length of the body to cache
• routes
  • type: Array
  • the routes to cache, default is ['(.*)']
  • it could be ['/api/(.*)', '/view/:id'], see path-to-regexp
• exclude
  • type: Array
  • the routes to exclude, default is []
  • it could be ['/api/(.*)', '/view/:id'], see path-to-regexp
• onError
  • type: Function
  • callback function for error, default is function() {}
• condition
  • type: Function
  • should be function(ctx) {} and it should return true or false to match redis cache condition
• isBackup
  • type: Boolean
  • if set to true, then cache will backup, default is false
• expireDump
  • type: Number
  • backup redis expire time (second), default is 120 * 60 (2 hours)
• checkDump
  • type: Function
  • should be function(ctx) {} and it should return true or false, if return true then will return backup cache
• redis
  • type: Object
  • redis options
• redis.port
  • type: Number
• redis.host
  • type: String
• redis.options
  • type: Object
  • see node_redis

set different expire for each route

const cache = require('koa-response-cache');
const koa = require('koa');
const app = koa();
 
let options = {
  routes: [{
    path: '/index',
    expire: 60
  }, {
    path: '/user',
    expire: 5
  }]
}
 
app.use(cache(options));

notes

• koa-response-cache will set a custom http header X-Koa-Response-Cache: true when the response is from cache, and will set X-Koa-Response-Cache: false when the response is from backup cache.

License

MIT