LRU cache for the npm registry.

regcache.js

var lru = require('lru-cache')
  , couchwatch = require('couchwatch')
  , request = require('request')
  ;

function RegistryCache () {
  this.cache = lru()
  this.watch = couchwatch('http://isaacs.iriscouch.com/registry', -1)
  this.watch.on('row', function (change) {
    this.cache.del(change.id)
  })
}
RegistryCache.prototype.get = function (key, cb) {
  if (this.cache.has(key)) return cb(null, this.cache.get(key))
  var self = this
  request.get('http://isaacs.iriscouch.com/registry/'+key, {json:true}, function (e, resp, doc) {
    if (e) return cb(e)
    if (resp.statusCode !== 200) return cb(new Error('not found'))
    self.cache.set(doc._id, doc)
    cb(null, doc)
  })
}

module.exports = function () {return new RegistryCache()}

// ;(new RegistryCache()).get('request', function (e, doc) {
//   console.log(e, doc)
// })