Module: RBus::MarshalMixin

Defined in:
lib/rbus/message/marshal.rb

Overview

Mix in an array of values to gain the dbus_marshal method Generally, this is used on the arguments of a message, and an array of header values. See Message::Writer#send_message.

Instance Method Summary collapse

Instance Method Details

#dbus_marshal(signature) ⇒ Object 



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# File 'lib/rbus/message/marshal.rb', line 31

def dbus_marshal(signature)

  tokens = StringIO.new(signature)        
  ms = StringIO.new('')
  
  skip = lambda {|alignment| ms.write("\0" * (-ms.pos & alignment - 1))}
  
  parser = lambda {|element,sig|
    case sig
      when 'b'
        skip.call(4)
        if element && element != 0 && element != false
          ms.write([1].pack('I'))
        else
          ms.write([0].pack('I'))
        end
      when 'y'
        ms.write([element.to_i].pack('C'))
      when 'n'
        skip.call(2)
        ms.write([element.to_i].pack('s'))
      when 'q'
        skip.call(2)
        ms.write([element.to_i].pack('S'))
      when 'u'
        skip.call(4)
        ms.write([element.to_i].pack('I'))
      when 'i'
        skip.call(4)
        ms.write([element.to_i].pack('i'))
      when 'd'
        skip.call(8)
        ms.write([element.to_f].pack('D'))
      when 's','o'
        skip.call(4)
        str = element.to_s
        ms.write([str.length,str].pack('Ia*x'))
      when 'g'
        str = element.to_s
        ms.write([str.length,str].pack('Ca*x'))
      when 'v'
        parser.call(element.object_signature, 'g')
        parser.call(element.object, element.object_signature)
      when 'a'
        skip.call(4)
        next_token = tokens.read(1)
        t_pos = tokens.pos
        
        # Postion of array length int
        a_len_pos = ms.pos
        # ...which is here
        ms.write("\0\0\0\0")
        
        # Pad already here, to find correct end of padding...
        case next_token
          when 's','o','b','i','u'
            skip.call(4)
          when '{','(','a','d'
            skip.call(8)
          when 'q','n'
            skip.call(2)
        end
        pad_pos = ms.pos
                      
        if next_token == '{'
          skip.call(8)
          element.each do |key,value|
            tokens.pos = t_pos
            parser.call(key,tokens.read(1))
            parser.call(value,tokens.read(1))
          end
          while next_token != '}'
            next_token = tokens.read(1)
          end
        else
              
          element.each do |value|
            tokens.pos = t_pos
            parser.call(value,next_token)
          end
        end
                                  
        # Fill in array length              
        m_new_pos = ms.pos
        a_length = ms.pos - pad_pos
        ms.pos = a_len_pos
        parser.call(a_length, 'u')
        ms.pos = m_new_pos
        
      when '('
        skip.call(8)
        ret_val = ''
        element.each {|value|
          next_token = tokens.read(1)
          break if next_token == ')'
          parser.call(value, next_token)
        }
      else
        raise NotImplementedError, "can't marshal #{sig}"
    end
  }
  each do |el|
    parser.call(el,tokens.read(1))
  end

  ms.string
end