cashcow

A smart cached value fetcher that...

• pools consumers while fetching to avoid doing multiple trips
• guarantees only one instance of resource is ever held in memory
• satisfies consumers early if already fetching

cashcow is not prescriptive about what cache your using, simply provide it with two functions:

• get(key) a function that gets value from cache and returns a promise for that value
• populate(key) a function that populates the cache, returning a promise that resolves when complete

installation

npm install cashcow

usage

var cashcow = require('cashcow')
var cowFetch = cashcow(get, populate)

cowFetch('mything') // populates cache then returns value from cache
cowFetch('mything') // combined with previous fetch
cowFetch('mything').then(function (thing) {
  // cache has been populated
  cowFetch('mything') // gets from cache
  cowFetch('mything') // combined with previous fetch
  cowFetch('mything').then(function (thing) {
    cowFetch('mything') // requests again from cache
  })
})

function get (key) {
  return myCustomCache.get(key)
}

function populate (key) {
  return fetchFromSource(key).then(function (val) {
    return myCustomCache.set(key, val)
  })
}

run tests

npm test