class AWS::Core::Http::CurbHandler

def fill_multi(items)
  items.each do |item|
    c = make_easy_handle(*item)
    @multi.add(c)
  end
end

def handle request, response
  raise "unsupport http reqest method: #{request.http_method}" unless
    ['GET', 'HEAD', 'PUT', 'POST', 'DELETE'].include? request.http_method
  @sem.synchronize do
    @q << [request, response, Thread.current]
    @processor.wakeup
  end
  Thread.stop
  nil
end

def initialize
  @q = []
  @sem = Mutex.new
  @multi = Curl::Multi.new
  start_processor
end

def make_easy_handle request, response, thread = nil
  url = request.use_ssl? ? 
    "https://#{request.host}:443#{request.uri}" :
    "http://#{request.host}#{request.uri}"
  curl = Curl::Easy.new(url)
  curl.headers = request.headers
  if proxy = request.proxy_uri
    curl.proxy_url = proxy.to_s
    curl.proxy_port = proxy.port
  end
  curl.on_header {|header_data|
    name, value = header_data.strip.split(/:\s+/, 2)
    response.headers[name] = value
    header_data.length
  }
  case request.http_method
  when 'GET'
    # ....
  when 'HEAD'
    curl.head = true
  when 'PUT'
    curl.put_data = request.body
  when 'POST'
    curl.post_body = request.body
  when 'DELETE'
    curl.delete = true
  end
  curl.on_complete do
    response.body = curl.body_str
    response.status = curl.response_code
    thread.run if thread
  end
  curl
end

def start_processor
  @processor = Thread.new do
    loop do
      items = nil
      @sem.synchronize do
        items = @q.slice!(0..-1)
      end
      unless items.empty?
        fill_multi(items)
        @multi.perform do
          # curl is idle, so process more items if we can get them
          # without blocking
          if !@q.empty? && @sem.try_lock
            begin
              fill_multi(@q.slice!(0..-1))
            ensure
              @sem.unlock
            end
          end
        end
      end
      # wait for a new item to show up before continuing
      Thread.stop if @q.empty?
    end
  end
end