Expiring Brain Repository

expires.coffee

#
# data structure
# {
#   key: ...,
#   expires_at: ...,
#   ...
# }
#

class CacheBrain
  KEY = 'cache-it'
  LIFETIME = 5

  constructor: (@brain, key, lifetime) ->
    KEY = key if key
    LIFETIME = lifetime || @minutes LIFETIME

  find: (key) ->
    @all().filter((o) -> o.key is key.toLowerCase())?[0]

  save: (data, lifetime) ->
    data.expires_at = Date.now() + (lifetime || LIFETIME)
    datas = @all data.key
    datas.push data
    @set datas
    data

  findOrNew: (key) ->
    @find(key) || @new(key)

  new: (key) ->
    key: key.toLowerCase(), created_at: Date.now()

  remove: (key) ->
    @set @all key

  all: (without) ->
    data = @brain.get(KEY) || []
    data.filter (o) ->
      (o.expires_at > Date.now()) && (without? && (o.key isnt without.toLowerCase()) || true)

  set: (data) ->
    @brain.set KEY, data

  clear: ->
    @brain.remove KEY

# time helpers
  days: (days) -> (days || 1) * @hours 24
  hours: (hours) -> (hours || 1) * @minutes 60
  minutes: (minutes) -> (minutes || 1) * @seconds 60
  seconds: (seconds) -> (seconds || 1) * 1000

module.exports = CacheBrain