Libevent

Libevent

C extension to libevent library.

Description

The nice feature of libevent is it already contains build in HTTP server (evhttp).

Currently libevent extension implements mostly http server.

Dependencies

• libevent v2

Documentation

Please read libevent rubydoc

Installation

gem install libevent

Using Libevent HTTP server

Check samples directory

From scratch

Simple server

require "libevent" 

# create event base
base = Libevent::Base.new

# create http server instance
http = Libevent::Http.new(base)

# bind socket
http.bind_socket("0.0.0.0", 15015)

# set handler
http.handler do |request|
  request.send_reply(200, {}, ["Hello World\n"])
end

# catch SIGINT
base.trap_signal("INT") { base.exit_loop }

# start libevent loop
base.dispatch

Check with curl

$ curl -v http://localhost:15015
> GET / HTTP/1.1
> User-Agent: curl/7.22.0 (x86_64-unknown-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.0e zlib/1.2.5 libssh2/1.3.0
> Host: localhost:15015
> Accept: */*
> 
< HTTP/1.1 200 OK
< Transfer-Encoding: chunked
< Date: Fri, 18 Nov 2011 19:09:04 GMT
< Content-Type: text/html; charset=ISO-8859-1
< 
Hello World

Server with virtual hosts

require "libevent"

Libevent::Builder.new do

  server "0.0.0.0", 3000 do |http|

http.handler do |request|
  case request.get_uri_path
  when '/hello'
    request.send_reply 200, { 'Content->Type' => 'text/plain'},  [ "Hello World" ]
  when '/api'
    request.send_reply 200, { 'Content->Type' => 'application/json'},  [ "{\"version\":\"1.0\"}" ]
  else
    request.send_error 404, "Nothing Found"
  end
end

http.vhost "blog.local" do |host|
  host.handler do |request|
    request.send_reply 200, {}, ["It's blog"]
  end
end

http.vhost "wiki.local" do |host|
  host.handler do |request|
    request.send_reply 200, {}, ["It's wiki"]
  end
end

http.vhost "*.local" do |host|
  host.handler do |request|
    request.send_error 404, "Please use blog.local or wiki.local"
  end
end

  end

  server "0.0.0.0", 3001 do |http|
http.handler do |request|
  request.send_reply 200, { 'Content->Type' => 'text/plain'},  [ "Hello World 3001" ]
end
  end

  signal("INT") do
base.exit_loop
  end

  signal("HUP") do
Kernel.puts "HUP received ..."
  end

  dispatch

end

Serve Rails application

Add to Gemfile

gem "libevent", :require => false

Update gems

$ bundle install

Run application

$ script/rails s Libevent

Or via rackup

$ bundle exec rackup -s Libevent -p 3000

Serve Rack application

Check rack handler rack/handler/libevent.rb

References

• libevent2 documentation
• libevent ruby binding documentation