Streaming zip file contents in Rails 4

stream_zip_controller.rb

class StreamZipController < ApplicationController
  include ActionController::Live

  # list of interesting file paths to include in the zip.
  def paths
    []
  end
  
  def send_message
    response.headers['Content-Type'] = 'text/event-stream'
    Zip::OutputStream.write_buffer(response.stream) do |out|
      paths.each do |path|
        out.put_next_entry(path)
        File.open(path, 'rb') do |f|
          while (chunk = f.read(64.kilobytes))
            out.write(chunk)
          end
        end
      end
    end
    response.stream.close
  end
end