Class: FTW::WebSocket

Inherits:
Object
  • Object
show all
Includes:
Cabin::Inspectable, CRLF
Defined in:
lib/ftw/namespace.rb,
lib/ftw/websocket.rb

Overview

WebSockets, RFC6455.

TODO(sissel): Find a comfortable way to make this websocket stuff both use HTTP::Connection for the HTTP handshake and also be usable from HTTP::Client TODO(sissel): Also consider SPDY and the kittens.

Defined Under Namespace

Modules: Constants Classes: Parser, Rack, Writer

Constant Summary collapse

TEXTFRAME =

The frame identifier for a ‘text’ frame

0x0001
WEBSOCKET_ACCEPT_UUID =

Search RFC6455 for this string and you will find its definitions. It is used in servers accepting websocket upgrades.

"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"

Constants included from CRLF

CRLF::CRLF

Instance Method Summary collapse

Constructor Details

#initialize(request) ⇒ WebSocket

Creates a new websocket and fills in the given http request with any necessary settings.



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# File 'lib/ftw/websocket.rb', line 36

def initialize(request)
  @key_nonce = generate_key_nonce
  @request = request
  prepare(@request)
  @parser = FTW::WebSocket::Parser.new
  @messages = []
end

Instance Method Details

#connection=(connection) ⇒ Object

Set the connection for this websocket. This is usually invoked by FTW::Agent after the websocket upgrade and handshake have been successful.

You probably don’t call this yourself.



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# File 'lib/ftw/websocket.rb', line 48

def connection=(connection)
  @connection = connection
end

#each(&block) ⇒ Object

Iterate over each WebSocket message. This method will run forever unless you break from it.

The text payload of each message will be yielded to the block.



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# File 'lib/ftw/websocket.rb', line 121

def each(&block)
  while true
    block.call(receive)
  end
end

#handshake_ok?(response) ⇒ Boolean

Is this Response acceptable for our WebSocket Upgrade request?

Returns:

  • (Boolean) 


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# File 'lib/ftw/websocket.rb', line 102

def handshake_ok?(response)
  # See RFC6455 section 4.2.2
  return false unless response.status == 101 # "Switching Protocols"
  return false unless response.headers.get("upgrade").downcase == "websocket"
  return false unless response.headers.get("connection").downcase == "upgrade"

  # Now verify Sec-WebSocket-Accept. It should be the SHA-1 of the
  # Sec-WebSocket-Key (in base64) + WEBSOCKET_ACCEPT_UUID
  expected = @key_nonce + WEBSOCKET_ACCEPT_UUID
  expected_hash = Digest::SHA1.base64digest(expected)
  return false unless response.headers.get("Sec-WebSocket-Accept") == expected_hash

  return true
end

#publish(message) ⇒ Object

Publish a message text.

This will send a websocket text frame over the connection.



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# File 'lib/ftw/websocket.rb', line 145

def publish(message)
  writer = FTW::WebSocket::Writer.singleton
  writer.write_text(@connection, message)
end

#receive ⇒ Object

Receive a single payload



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# File 'lib/ftw/websocket.rb', line 128

def receive
  @messages += network_consume if @messages.empty?
  @messages.shift
end