REFACTOR: Use Async and family

Rakefile

@@ -2,6 +2,7 @@
 
 require "fileutils"
 require "rubygems"
+require 'rspec/core/rake_task'
 
 require "mail_catcher/version"
 

lib/mail_catcher.rb

@@ -1,26 +1,22 @@
 # frozen_string_literal: true
 
+require 'async/io/address_endpoint'
+require 'async/http/endpoint'
+require 'async/websocket/adapters/rack'
+require 'async/io/shared_endpoint'
+require 'falcon'
 require "open3"
 require "optparse"
 require "rbconfig"
-
-require "eventmachine"
-require "thin"
-
-module EventMachine
- # Monkey patch fix for 10deb4
- # See https://github.com/eventmachine/eventmachine/issues/569
- def self.reactor_running?
- (@reactor_running || false)
- end
-end
+require 'socket'
+require 'mail'
 
 require "mail_catcher/version"
 
 module MailCatcher extend self
  autoload :Bus, "mail_catcher/bus"
  autoload :Mail, "mail_catcher/mail"
- autoload :Smtp, "mail_catcher/smtp"
+ autoload :SMTP, "mail_catcher/smtp"
  autoload :Web, "mail_catcher/web"
 
  def env
@@ -173,75 +169,90 @@ def run! options=nil
 
  puts "Starting MailCatcher v#{VERSION}"
 
- Thin::Logging.debug = development?
- Thin::Logging.silent = !development?
+ Async.run do
+ @smtp_address = Async::IO::Address.tcp(options[:smtp_ip], options[:smtp_port])
+ @smtp_endpoint = Async::IO::AddressEndpoint.new(@smtp_address)
+ @smtp_socket = rescue_port(options[:smtp_port]) { @smtp_endpoint.bind }
+ puts "==> #{smtp_url}"
+
+ @http_address = Async::IO::Address.tcp(options[:http_ip], options[:http_port])
+ @http_endpoint = Async::IO::AddressEndpoint.new(@http_address)
+ @http_socket = rescue_port(options[:http_port]) { @http_endpoint.bind }
+ puts "==> #{http_url}"
+ end
 
- # One EventMachine loop...
- EventMachine.run do
- # Set up an SMTP server to run within EventMachine
- rescue_port options[:smtp_port] do
- EventMachine.start_server options[:smtp_ip], options[:smtp_port], Smtp
- puts "==> #{smtp_url}"
+ Async.logger.level = :debug if options[:verbose]
+
+ if options[:daemon]
+ if quittable?
+ puts "*** MailCatcher runs as a daemon by default. Go to the web interface to quit."
+ else
+ puts "*** MailCatcher is now running as a daemon that cannot be quit."
  end
+ Process.daemon
+ end
 
-  # Let Thin set itself up inside our EventMachine loop
- # (Skinny/WebSockets just works on the inside)
- rescue_port options[:http_port] do
- Thin::Server.start(options[:http_ip], options[:http_port], Web)
- puts "==> #{http_url}"
+ Async::Reactor.run do |task|
+ smtp_endpoint = MailCatcher::SMTP::URLEndpoint.new(URI.parse(smtp_url), @smtp_endpoint)
+ smtp_server = MailCatcher::SMTP::Server.new(smtp_endpoint) do |envelope|
+ MailCatcher::Mail.add_message(sender: envelope.sender, recipients: envelope.recipients,
+  source: envelope.content)
  end
 
- # Open the web browser before detatching console
- if options[:browse]
- EventMachine.next_tick do
- browse http_url
+ smtp_task = task.async do |task|
+ task.annotate "binding to #{@smtp_socket.local_address.inspect}"
+
+ begin
+ @smtp_socket.listen(Socket::SOMAXCONN)
+ @smtp_socket.accept_each(task: task, &smtp_server.method(:accept))
+ ensure
+ @smtp_socket.close
  end
  end
 
- # Daemonize, if we should, but only after the servers have started.
- if options[:daemon]
- EventMachine.next_tick do
- if quittable?
- puts "*** MailCatcher runs as a daemon by default. Go to the web interface to quit."
- else
- puts "*** MailCatcher is now running as a daemon that cannot be quit."
- end
- Process.daemon
+ http_endpoint = Async::HTTP::Endpoint.new(URI.parse(http_url), @http_endpoint)
+ http_app = Falcon::Adapters::Rack.new(Web.app)
+ http_server = Falcon::Server.new(http_app, http_endpoint)
+
+ task.async do |task|
+ task.annotate "binding to #{@http_socket.local_address.inspect}"
+
+ begin
+ @http_socket.listen(Socket::SOMAXCONN)
+ @http_socket.accept_each(task: task, &http_server.method(:accept))
+ ensure
+ @http_socket.close
  end
  end
+
+ browse(http_url) if options[:browse]
  end
+ rescue Interrupt
+ # Cool story
  end
 
  def quit!
- MailCatcher::Bus.push(type: "quit")
+ Async::Task.current.reactor.stop
+ end
 
- EventMachine.next_tick { EventMachine.stop_event_loop }
+ def http_url
+ "http://#{@@options[:http_ip]}:#{@@options[:http_port]}#{@@options[:http_path]}"
  end
 
-protected
+ protected
 
  def smtp_url
  "smtp://#{@@options[:smtp_ip]}:#{@@options[:smtp_port]}"
  end
 
- def http_url
- "http://#{@@options[:http_ip]}:#{@@options[:http_port]}#{@@options[:http_path]}".chomp("/")
- end
-
  def rescue_port port
  begin
  yield
-
- # XXX: EventMachine only spits out RuntimeError with a string description
- rescue RuntimeError
- if $!.to_s =~ /\bno acceptor\b/
- puts "~~> ERROR: Something's using port #{port}. Are you already running MailCatcher?"
- puts "==> #{smtp_url}"
- puts "==> #{http_url}"
- exit -1
- else
- raise
- end
+ rescue Errno::EADDRINUSE
+ puts "~~> ERROR: Something's using port #{port}. Are you already running MailCatcher?"
+ puts "==> #{smtp_url}"
+ puts "==> #{http_url}"
+ exit(-1)
  end
  end
 end

lib/mail_catcher/bus.rb

@@ -1,7 +1,48 @@
 # frozen_string_literal: true
 
-require "eventmachine"
-
 module MailCatcher
- Bus = EventMachine::Channel.new
+ # Async-friendly broadcast channel
+ class Channel
+ def initialize
+ @subscription_id = 0
+ @subscriptions = {}
+ end
+
+ def subscriber_count
+ @subscriptions.size
+ end
+
+ def push(*values)
+ Async.run do
+ values.each do |value|
+ @subscriptions.each_value do |subscription|
+ Async do
+ subscription.call(value)
+ end
+ end
+ end
+ end
+ end
+
+ def subscribe(&block)
+ subscription_id = next_subscription_id
+
+ @subscriptions[subscription_id] = block
+
+ subscription_id
+ end
+
+ def unsubscribe(subscription_id)
+ @subscriptions.delete(subscription_id)
+ end
+
+ private
+
+ def next_subscription_id
+ @subscription_id += 1
+ end
+ end
+
+ # Then we instantiate a global one
+ Bus = Channel.new
 end

lib/mail_catcher/mail.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "eventmachine"
 require "json"
 require "mail"
 require "sqlite3"
@@ -56,10 +55,7 @@ def add_message(message)
  add_message_part(message_id, cid, part.mime_type || "text/plain", part.attachment? ? 1 : 0, part.filename, part.charset, body, body.length)
  end
 
- EventMachine.next_tick do
- message = MailCatcher::Mail.message message_id
- MailCatcher::Bus.push(type: "add", message: message)
- end
+ MailCatcher::Bus.push(type: "add", message: message(message_id))
  end
 
  def add_message_part(*args)
@@ -157,18 +153,14 @@ def delete!
  @delete_all_messages_query ||= db.prepare "DELETE FROM message"
  @delete_all_messages_query.execute
 
- EventMachine.next_tick do
- MailCatcher::Bus.push(type: "clear")
- end
+ MailCatcher::Bus.push(type: "clear")
  end
 
  def delete_message!(message_id)
  @delete_messages_query ||= db.prepare "DELETE FROM message WHERE id = ?"
  @delete_messages_query.execute(message_id)
 
- EventMachine.next_tick do
- MailCatcher::Bus.push(type: "remove", id: message_id)
- end
+ MailCatcher::Bus.push(type: "remove", id: message_id)
  end
 
  def delete_older_messages!(count = MailCatcher.options[:messages_limit])