Aircraft position streaming

ac_stream.rb

require 'socket'
require 'json'

class AircraftPositionStream

  def initialize host, port
    @host = host
    @port = port
  end

  # Stream acList JSON chunks
  def stream_json &block

    depth  = 0
    struct = true
    buffer = ''
    socket = TCPSocket.new(@host, @port)

    while byte = socket.getc
      buffer << byte
      if byte == '{' && struct
        depth += 1
      elsif byte == '}' && struct
        depth -= 1
        # Call the block if we have a record
        if depth == 0
          block.call(JSON.parse(buffer))
          buffer = ''
        end
      elsif byte == '"' && buffer[-2] != '\\'
        struct = !struct
      end
    end

  ensure
    socket.close
  end

  # Stream aircraft postition objects
  def stream_updates &block
    stream_json { |records|
      records['acList'].each { |record|
        block.call(record)
      }
    }
  end

end

stream = AircraftPositionStream.new('pub-vrs.adsbexchange.com', 32005)
stream.stream_updates { |record|
  puts "#{Time.now} - #{record['Icao']}"
}