koa-router-cache

koa-router-cache

Router cache middleware for koa@1.

$3

``
npm i koa-router-cache --save
`

$3

`
cache(app, options)
`

Options:

- key: {String|GeneratorFunction} cache key. (Required)
- expire: {Number} expire time, in ms. (Required)
- get: {GeneratorFunction} custom getter function for getting data from cache. (Required)
- set: {GeneratorFunction} custom setter function for setting data to cache. (Required)
- passthrough: {GeneratorFunction} whether pass request through, return an object. (Required)
- shouldCache: {Boolean} whether cache this result
- shouldPass: {Boolean} whether pass this request through
- evtName: {String} event name for destroy cache. (Optional)
- destroy: {function} destroy cache. (Optional)
- pathToRegexp {Object} pathToRegexp options, see https://github.com/pillarjs/path-to-regexp#usage. (Optional)

$3

koa-router-cache build-in simple MemoryCache and RedisCache, also you can write by yourself.

MemoryCache

`
'use strict';

var app = require('koa')();
var cache = require('koa-router-cache');
var MemoryCache = cache.MemoryCache;

var count = 0;

app.use(cache(app, {
'GET /': {
key: 'cache:index',
expire: 2 * 1000,
get: MemoryCache.get,
set: MemoryCache.set,
passthrough: MemoryCache.passthrough,
evtName: 'clearIndexCache',
destroy: MemoryCache.destroy
}
}));

app.use(function* () {
if (this.path === '/') {
this.body = count++;
if (count === 3) {
count = 0;
this.app.emit('clearIndexCache');
}
}
});

app.listen(3000, function () {
console.log('listening on 3000.');
});
`

RedisCache

`
'use strict';

var app = require('koa')();
var cache = require('koa-router-cache');
var RedisCache = cache.RedisCache();// or RedisCache(client)

var count = 0;

app.use(cache(app, {
'GET /': {
key: 'cache:index',
expire: 2 * 1000,
get: RedisCache.get,
set: RedisCache.set,
passthrough: RedisCache.passthrough,
evtName: 'clearIndexCache',
destroy: RedisCache.destroy
}
}));

app.use(function* () {
if (this.path === '/') {
this.body = {
count: count++
};
if (count === 3) {
count = 0;
this.app.emit('clearIndexCache');
}
}
});

app.listen(3000, function () {
console.log('listening on 3000.');
});
`

another usage:

`
// Guests share one index page cache
GET /': {
key: 'cache:index',
expire: 10 * 1000,
get: MemoryCache.get,
set: MemoryCache.set,
destroy: MemoryCache.destroy,
passthrough: function* passthrough(_cache) {
// Guests
if (!this.session || !this.session.user) {
if (_cache == null) {
return {
shouldCache: true,
shouldPass: true
};
}
this.type = 'text/html; charset=utf-8';
this.set('content-encoding', 'gzip');
this.body = _cache;
return {
shouldCache: true,
shouldPass: false
};
}
// Logged-in users
return {
shouldCache: false,
shouldPass: true
};
}
}
`

$3

`
npm test
``

$3

MIT