Ruby in-memory cache.

cache.rb

require 'date'

class Cache

  Entry = Struct.new(:expiry, :value)

  def initialize(opts={})
    @data = Hash.new
    @opts = opts
  end

  def keys
    @data.keys
  end

  def get(key)
    @data[key][:value] if has(key)
  end

  def has(key)
    @data.has_key? key
  end

  def put(key, value, ttl=nil)
    ttl ||= @opts[:ttl]
    @data[key] = Entry.new(DateTime.new + Rational(ttl, 1440), value)
  end

  def delete(key)
    @data.delete key
  end

  def clear
    @data = Hash.new
  end

  def invalidate
    now = DateTime.new
    @data.delete_if {|k, v| v[:expiry] < now}
  end

end

ttl is in seconds/minutes or days ?

minutes