jobs.rb

require 'rubygems'
require 'activerecord'

ActiveRecord::Base.configurations = {'sqlite3' => {:adapter => 'sqlite3', :database => ':memory:'}}
ActiveRecord::Base.establish_connection('sqlite3')
 
ActiveRecord::Base.logger = Logger.new(STDERR)
ActiveRecord::Base.logger.level = Logger::DEBUG
 
ActiveRecord::Schema.define(:version => 0) do
  create_table :jobs do |t|
    t.string :klazz, :method
    t.string :obj_id
  end
  
  create_table :users do |t|
  end
end

class User < ActiveRecord::Base
  def notify_signup
    puts "notified!"
  end
end

class Job < ActiveRecord::Base
  def self.schedule(obj, method)
    create(:klazz => obj.class.name,
           :obj_id => obj.id,
           :method => method.to_s)
  end
  
  def run
    puts klazz
    obj = klazz.constantize.find(obj_id)
    obj.send(self[:method])
  end
end

Job.schedule(User.create, :notify_signup)

class JobPoller
  def run
    loop do
      job = Job.find(:first, :lock => true)
      next unless job
      job.run
      job.delete
      break
    end
  end
end

JobPoller.new.run