metatrader 4 hst reader

hst.rb

class Hst
  attr_reader :version
  attr_reader :copyright
  attr_reader :symbol
  attr_reader :period
  attr_reader :digits
  attr_reader :timesign
  attr_reader :lastsync

  def initialize(file)
    open(file)
  end

  def open(file)
    @f = File.open(file)
    e = @f.read(96).unpack('IC64C12I4')
    raise "File size too small (must be >= 96 bytes)" if e[-1].nil?
    @version = e[0]
    @packet_size, @packet_unpack =
      case @version
      when 400 then [44, 'ID5']
      when 401 then [60, 'QD4QIQ']
      else raise "Unsupported version #{@version}. [400, 401] required."
      end
    @copyright = e[1..64].pack('C64').strip
    @symbol = e[65..76].pack('C12').strip
    @period = e[77]
    @digits = e[78]
    @timesign = Time.at(e[79])
    @lastsync = e[80]
    @f.read(52)
  end

  def read
    while not @f.eof do
      t, o, h, l, c, v, s, rv = @f.read(@packet_size).unpack(@packet_unpack)
      yield Time.at(t), o, h, l, c, v, s, rv
    end
    @f.close
  end
end