proxymanager.rb by jake232 - refactoring

proxymanager.rb

class ProxyManager
  class Proxy
    attr_reader   :address
    attr_accessor :last_used

    def initialize(address, last_used=nil)
      @address    = address
      @last_used  = last_used
    end

    def used_since?(time)
      @last_used && @last_used > time
    end
  end

  def self.from_proxy_file(path="proxies.txt", delay=10)
    proxies = IO.readlines(path).map { |line| line.strip }

    new(proxies, delay)
  end

  def initialize(proxies, delay=10)
    raise ArgumentError, "proxies must contain at least 1 proxy" if proxies.empty?

    @proxies  = proxies
    @delay    = delay
    @records  = proxies.map { |address| Proxy.new(address) }
  end

  # @return [Proxy]
  #   A proxy that hasn't been used for at least #delay seconds.
  #   If none is available, the method will block until one becomes available
  def get
    # find all electable proxies
    choices = @records.select { |proxy| proxy.used_since?(last_time) }

    # if no proxy was electable, find the one that's ready the soonest, then wait until
    # it is ready
    if choices.empty?
      proxy     = @records.min_by { |proxy| proxy.last_used }
      nap_time  = @delay - (Time.now - proxy.last_used)
      sleep(nap_time) if nap_time > 0
    # use randomly one of the ready proxies
    else
      proxy = choices.sample
    end
    proxy.last_used = Time.now

    proxy
  end