Async::WebSocket

A simple asynchronous websocket client/server implementation for HTTP/1 and HTTP/2.

Installation

Add this line to your application's Gemfile:

gem 'async-websocket'

And then execute:

$ bundle

Or install it yourself as:

$ gem install async-websocket

Usage

There are examples which include:

• A command line chat client/server which can read input from stdin and send messages to the server.
• A small MUD client/server which uses JSON for communation between client/server.
• A utopia-based web application which uses a JavaScript client to connect to a web application server.

Client Side with Async

#!/usr/bin/env ruby

require 'async'
require 'async/io/stream'
require 'async/http/endpoint'
require 'async/websocket/client'

USER = ARGV.pop || "anonymous"
URL = ARGV.pop || "http://localhost:7070"

Async do |task|
    stdin = Async::IO::Stream.new(
        Async::IO::Generic.new($stdin)
    )

    endpoint = Async::HTTP::Endpoint.parse(URL)

    Async::WebSocket::Client.open(endpoint) do |connection|
        input_task = task.async do
            while line = stdin.read_until("\n")
                connection.write({user: USER, text: line})
                connection.flush
            end
        end

        connection.write({
            user: USER,
            status: "connected",
        })

        while message = connection.read
            puts message.inspect
        end
    ensure
        input_task&.stop
    end
end

Server Side with Rack & Falcon

#!/usr/bin/env -S falcon serve --bind http://localhost:7070 --count 1 -c

require 'async/websocket/adapters/rack'
require 'set'

$connections = Set.new

run lambda {|env|
    Async::WebSocket::Adapters::Rack.open(env, protocols: ['ws']) do |connection|
        $connections << connection

        while message = connection.read
            $connections.each do |connection|
                connection.write(message)
                connection.flush
            end
        end
    ensure
        $connections.delete(connection)
    end or [200, {}, ["Hello World"]]
}

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

Released under the MIT license.

Copyright, 2015, by Samuel G. D. Williams.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.