class WEBrick::HTTPServer
  alias :__rewrite_old_initialize :initialize
  alias :__rewrite_old_service :service
  def initialize(config={}, default=WEBrick::Config::HTTP)
    __rewrite_old_initialize(config, default)
    @rewrite_rules = []
  end
  def rewrite(pattern, subst)
    @logger.info("rewrite rule %s -> %s." % 
                  [pattern.inspect, subst])
    @rewrite_rules << [pattern, subst]
  end
  def service(req, res)
    olduri = URI.parse(req.path)
    olduri.query = req.query_string
    old = olduri.to_s
    @rewrite_rules.each do |pattern, subst|
      if pattern =~ old
        uri = URI.parse(old.gsub(pattern, subst))
        req.instance_variable_set("@path", uri.path)
        req.instance_variable_set("@query_string", uri.query)
        req.instance_variable_set("@query", nil)  # so it gets reparsed
        @logger.info("Rewrote URL %s -> %s" % [olduri.to_s, uri.to_s])
        break
      end
    end
    __rewrite_old_service(req, res)
  end
end