seneca-memcached-cache

memcached plugin for seneca

seneca-memcached

This module is a plugin for the Seneca framework. It provides a set of common caching actions (get, set, etc), backed by memcached. It also exposes all the memcached specific actions (append, prepend, etc).

By moving cache operations into Seneca, you can change your cache implementation or business rules at a later point. For example, you might decide to send certain kinds of keys to a different cache mechanism, such as redis.

If you're using this module, feel free to contact @rjrodger or @darsee on twitter if you have any questions! :)

This code snippet sets a value and then retrieves it. You'll need to have memcached running for this to work:

$ memcached -vv
var seneca = require('seneca')();
seneca.use('memcached-cache');
 
seneca.ready(function(err) {
  seneca.act({role: 'cache', cmd: 'set', key: 'k1', val: 'v1'}, function(err) {
    seneca.act({role: 'cache', cmd: 'get', key: 'k1'}, function(err, out) {
      console.log('value = ' + out)
    });
  });
});

The full action argument pattern can be a bit tedious, so use a Seneca pin to make things more convenient:

var cache = seneca.pin({role:'cache',cmd:'*'})
 
cache.set({key:'k1', val:'v1'}, function(err){
 
  cache.get({key:'k1'}, function(err,out){
    console.log('value = '+out)
  })
})
npm install seneca
npm install seneca-memcached-cache

You'll also need memcached

Seneca has a common caching API with the following actions:

  • role:cache, cmd:set store a value - key and val arguments required
  • role:cache, cmd:get retreive a value - key argument is required
  • role:cache, cmd:add store a value, only if the key does not exist - key and val arguments required
  • role:cache, cmd:delete delete a value - key argument is required, no error if key does not exist
  • role:cache, cmd:incr increment a value - key and val (integer) arguments required
  • role:cache, cmd:decr decrement a value - key and val (integer) arguments required

All caching plugins, including this one, implement this action API.

The full memcached API is also available. Use the action pattern plugin:memcached, cmd:... where cmd is one of set, get, add, delete, incr, decr, replace, append, prepend, cas, gets, stats, flush.

To access the underlying memcached instance, use the action plugin:memcached, cmd:native.

The plugin also registers with the action role:seneca, cmd:close. This closes the memcached connection when you call the seneca.close method.

You can use any of the options from the node-memcached module directly as options to this plugin:

seneca.use('memcached',{
  servers:[ '127.0.0.1:11211', '127.0.0.1:11212' ],
  expires: 60
})
cd test
mocha cache.test.js --seneca.log.print