Class: EventMachine::WebSocketCodec::Encoder

Inherits:
Object
  • Object
show all
Includes:
Protocol
Defined in:
lib/em-ws-client/encoder.rb

Overview

Internal: Encodes messages into WebSocket frames based on RFC 6455

Constant Summary

Constants included from Protocol

Protocol::BINARY_FRAME, Protocol::CLOSE, Protocol::CONTINUATION, Protocol::PING, Protocol::PONG, Protocol::TEXT_FRAME

Instance Method Summary collapse

Instance Method Details

#close(code, message) ⇒ Object

create a close payload with code



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# File 'lib/em-ws-client/encoder.rb', line 58

def close code, message
  encode [code ? code : 1000, message].pack("nA*"), CLOSE
end

#encode(data, opcode = TEXT_FRAME) ⇒ Object

Encode a standard payload to a hybi10 WebSocket frame



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# File 'lib/em-ws-client/encoder.rb', line 13

def encode data, opcode=TEXT_FRAME
  frame = []
  frame << (opcode | 0x80)

  packr = "CC"

  if opcode == TEXT_FRAME
    data.force_encoding("UTF-8")

    if !data.valid_encoding?
      raise "Invalid UTF!"
    end
  end

  # append frame length and mask bit 0x80
  len = data ? data.bytesize : 0
  if len <= 125
    frame << (len | 0x80)
  elsif len < 65536
    frame << (126 | 0x80)
    frame << len
    packr << "n"
  else
    frame << (127 | 0x80)
    frame << len
    packr << "L!>"
  end

  # generate a masking key
  key = rand(2 ** 31)

  # mask each byte with the key
  frame << key
  packr << "N"

  #puts "op #{opcode} len #{len} bytes #{data}"
  # Apply the masking key to every byte
  len.times do |i|
    frame << ((data.getbyte(i) ^ (key >> ((3 - (i % 4)) * 8))) & 0xFF)
  end

  frame.pack("#{packr}C*")
end

#ping(data = nil) ⇒ Object

create a ping payload



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# File 'lib/em-ws-client/encoder.rb', line 63

def ping data=nil
  encode data, PING
end

#pong(data = nil) ⇒ Object

create a pong payload



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# File 'lib/em-ws-client/encoder.rb', line 68

def pong data=nil
  encode data, PONG
end