express-redis-cache

A module to make Express interact with Redis (create, get, delete). You can automatically cache all your most popular routes in Redis.

Install

npm install -g express-redis-cache

Automatically cache a route

Just use it as a middleware in your route.

var cache = require('express-redis-cache')();

// replace
app.get('/',
    function (req, res)  { ... });

// by
app.get('/',
    cache.route(),
    function (req, res)  { ... });

This will check if there is a cache entry for this route. If not. it will cache it and serve the cache next time route is called.

Redis connexion info

By default, redis-express-cache connects to Redis using localhost as host and nothing as port (using Redis default port). To use different port or host, declare them when you require express-redis-cache.

var cache = require('express-redis-cache')({
    host: String, port: Number
    });

You can pass a Redis client as well:

require('express-redis-cache')({ client: require('redis').createClient() })

Errors

You can catch errors by adding a listener:

cache.on('error', function (error) {
    // ...
});

Messages

express-redis-cache logs some information at runtime. You can access them like this:

cache.on('message', function (message) {
    // ...
});

Objects

The Entry object

Object Entry {
    body:    String // the content of the cache
    touched: Number // last time cache was set (created or updated) as a Unix timestamp
    expire:  Number // the seconds cache entry lives (-1 if does not expire)
}

The ConstructorOptions Object

Object ConstructorOptions {
    host:   String?       // Redis Host
    port:   Number?       // Redis port
    prefix: String?       // Cache entry name prefix,
    expire: Number?       // Default expiration time in seconds
    client: RedisClient   // A Redis client of npm/redis
    errors: bool?         // If true, errors are emitted. Otherwise, suppressed.
}

Commands

Constructor

cache( Object ConstructorOPtions? )

Route

cache.route( String name?, Number expire? )

If name is a string, it is a cache entry name. If it is null, the route's URI (req.originalUrl) will be used as the entry name.

app.get('/', cache.route('home'), require('./routes/'))
// will get/set a cache entry named 'home'

app.get('/about', cache.route(), require('./routes/'))
// will get/set a cache entry named '/about'

Optionally, you can get more naming control on defining res.expressRedisCacheName:

app.get('/user/:userid',
    function (req, res, next) {
        res.expressRedisCacheName = '/user/' + req.params.userid;
        next();
    },
    cache.route(),
    require('./routes/user')
);

app.post('/search',
    function (req, res, next) {
        res.expressRedisCacheName = '/search/' + req.body.tag;
        next();
    },
    cache.route(),
    require('./routes/user')
);

Set an expiration date for the cache entry

The number of seconds the cache entry will live

cache.route('home', ( 60 * 5 ));
// cache will expire in 5 minutes

If you don't define an expiration date in your route but have set a default one in your constructor, the latter will be used. If you want your cache entry not to expire even though you have set a default expiration date in your constructor, do like this:

cache.route('my-page', cache.FOREVER);

Get the list of all cache entries

cache.ls( Function ( Error, [Entry] ) )

Feed a callback with an array of the cache entry names.

Get a single cache entry by name

cache.get( String name, Function( Error, Entry ) )

Add a new cache entry

cache.add( String name, String body, Number expire?, Function( Error, Entry ) )

Example:

cache.add('user:info', JSON.stringify({ id: 1, email: '[email protected]' }), 60, console.log);

Delete a cache entry

cache.del( String name, Function ( Error, Number deletedEntries ) )

Get cache size for all entries

cache.size( Function ( Error, Number bytes ) )

Command line

We ship with a CLI. You can invoke it like this: express-redis-cache

Test

node test/test --host <redis-host> --port <redis-port>

# or

npm test --host=<redis-host> --port=<redis-port>

medseek-engineering / express-redis-cache Goto Github PK