code: def _compute_document_meta(self):
          
          meta = OrderedDict()
  
          bounds_iter = xml_utils.bounds(self.filename,
                              start_re=r'<text id="(\d+)"[^>]*name="([^"]*)"',
                              end_re=r'</text>')
  
          for match, bounds in bounds_iter:
              doc_id, title = str(match.group(1)), match.group(2)
              title = xml_utils.unescape_attribute(title)
  
              # cache categories
              xml_data = xml_utils.load_chunk(self.filename, bounds)
              doc = Document(compat.ElementTree.XML(xml_data.encode('utf8')))
  
              meta[doc_id] = _DocumentMeta(title, bounds, doc.categories())
          return meta
docs: Return documents meta information that can
          be used for fast document lookups. Meta information
          consists of documents titles, categories and positions
          in file.