/**
   * Parse and process trade history information stream.
   *
   * @param in XML document reader
   * @throws IOException if error reading document
   * @throws XmlPullParserException on document parse error
   */
  public void parse(Reader in) throws IOException, XmlPullParserException {

    // set document source for parse
    m_parser.reset();
    m_parser.setInput(in);

    // main pull parsing loop
    byte type;
    while ((type = m_parser.next()) != XmlPullParser.END_DOCUMENT) {

      // ignore everything other than a start tag
      if (type == XmlPullParser.START_TAG) {

        // process the start tags we're interested in
        m_parser.readStartTag(m_startTag);
        String lname = m_startTag.getLocalName();
        if (lname.equals(STOCK_ELEMENT_NAME)) {
          parseStockTrade();
        } else if (lname.equals(OPTION_ELEMENT_NAME)) {
          parseOptionTrade();
        }
      }
    }
  }