class Bootsnap::CLI::WorkerPool::Worker

def close
  to_io.close
end

def initialize(jobs)
  @jobs = jobs
  @pipe_out, @to_io = IO.pipe(binmode: true)
  # Set the writer encoding to binary since IO.pipe only sets it for the reader.
  # https://github.com/rails/rails/issues/16514#issuecomment-52313290
  @to_io.set_encoding(Encoding::BINARY)
  @pid = nil
end

def spawn
  @pid = Process.fork do
    to_io.close
    work_loop
    exit!(0)
  end
  @pipe_out.close
  true
end

def work_loop
  loop do
    job, *args = Marshal.load(@pipe_out)
    return if job == :exit
    @jobs.fetch(job).call(*args)
  end
rescue IOError
  nil
end

def write(message, block: true)
  payload = Marshal.dump(message)
  if block
    to_io.write(payload)
    true
  else
    to_io.write_nonblock(payload, exception: false) != :wait_writable
  end
end