http_cluster.cr

require "http/server"

module HTTPCluster
  struct Worker
    def initialize(@pid : Int32, @master : Int32)
    end

    def call(port)
      yield(port)
    end

    def kill
      Process.kill(Signal::KILL, @pid)
    end
  end

  class Cluster
    def initialize(@n : Int32, @handler : HTTP::Handler)
      @master = Process.pid
      @workers = [] of Worker
    end

    def start
      @n.times do |i|
        fork do
          worker = Worker.new(Process.pid, @master)
          @workers << worker 
          worker.call(9292 + i) do |port|
            puts "Listening on http://127.0.0.1:#{port}"
            HTTP::Server.new(port, @handler).listen
          end
        end
      end 
      loop {}
    ensure
      stop
    end

    private def stop
      @workers.each(&.kill)
    end
  end
end

n = ARGV[0]? || 7

require "big"


class HelloWorld < HTTP::Handler
  def fib(n)
    if n <= 1
      BigInt.new(1)
    else
      fib(n - 1) + fib(n - 2)
    end
  end
  
  def call(context)
    fib(BigInt.new(20))
    context.response.content_type = "text/plain"
    context.response.print "Hello World"
  end
end

cluster = HTTPCluster::Cluster.new(n.to_i, HelloWorld.new)
cluster.start