"A dizzying lifetime... reeling by on celluloid" -- Rush / Between The Wheels

Reel is a fast, non-blocking "evented" web server built on http_parser.rb, websocket-driver, Celluloid::IO, and nio4r. Thanks to Celluloid, Reel also works great for multithreaded applications and provides traditional multithreaded blocking I/O support too.

Connections to Reel can be either non-blocking and handled entirely within the Reel::Server thread (handling HTTP, HTTPS, or UNIX sockets), or the same connections can be dispatched to worker threads where they will perform ordinary blocking IO. Reel provides no built-in thread pool, however you can build one yourself using Celluloid.pool, or because Celluloid already pools threads to begin with, you can simply use an actor per connection.

This gives you the best of both worlds: non-blocking I/O for when you're primarily I/O bound, and threads for where you're compute bound.

Yes

Please see the Reel Wiki for detailed documentation and usage notes.

YARD documentation is also available.

A Rack adapter for Reel is available at:

https://github.com/celluloid/reel-rack

The most notable library with native Reel support is webmachine-ruby, an advanced HTTP framework for Ruby with a complete state machine for proper processing of HTTP/1.1 requests. Together with Reel, Webmachine provides full streaming support for both requests and responses.

To use Reel with Webmachine, add the following to your Gemfile:

gem 'webmachine', git: 'git://github.com/seancribbs/webmachine-ruby.git'

Then use config.adapter = :Reel when configuring a Webmachine app, e.g:

MyApp = Webmachine::Application.new do |app|
  app.routes do
    add ['*'], MyHome
  end

  app.configure do |config|
    config.ip      = MYAPP_IP
    config.port    = MYAPP_PORT
    config.adapter = :Reel

    # Optional: handler for incoming websockets
    config.adapter_options[:websocket_handler] = proc do |websocket|
      # websocket is a Reel::WebSocket
      websocket << "hello, world"
    end
  end
end

MyApp.run

See the Webmachine documentation for further information

Reel aims to provide a "bare metal" API that other frameworks (such as Rack and Webmachine) can leverage. This API can also be nice in performance critical applications.

Reel lets you pass a block to initialize which receives connections:

require 'celluloid/autostart'
require 'reel'

Reel::Server::HTTP.supervise("0.0.0.0", 3000) do |connection|
  # Support multiple keep-alive requests per connection
  connection.each_request do |request|
    # WebSocket support
    if request.websocket?
      puts "Client made a WebSocket request to: #{request.url}"
      websocket = request.websocket

      websocket << "Hello everyone out there in WebSocket land"
      websocket.close
    else
      puts "Client requested: #{request.method} #{request.url}"
      request.respond :ok, "Hello, world!"
    end
  end
end

sleep

When we read a request from the incoming connection, we'll either get back a Reel::Request object, indicating a normal HTTP connection, or a Reel::WebSocket object for WebSockets connections.

You can also subclass Reel, which allows additional customizations:

require 'celluloid/autostart'
require 'reel'

class MyServer < Reel::Server::HTTP
  def initialize(host = "127.0.0.1", port = 3000)
    super(host, port, &method(:on_connection))
  end

  def on_connection(connection)
    connection.each_request do |request|
      if request.websocket?
        handle_websocket(request.websocket)
      else
        handle_request(request)
      end
    end
  end

  def handle_request(request)
    request.respond :ok, "Hello, world!"
  end

  def handle_websocket(sock)
    sock << "Hello everyone out there in WebSocket land!"
    sock.close
  end
end

MyServer.run

This library supports and is tested against the following Ruby versions:

• Ruby (MRI) 2.0, 2.1, 2.2, 2.3
• JRuby 9000

• Fork this repository on GitHub
• Make your changes and send us a pull request
• If we like them we'll merge them
• If we've accepted a patch, feel free to ask for commit access

Copyright (c) 2012-2016 Tony Arcieri. Distributed under the MIT License. See LICENSE.txt for further details.