ebml/utils/dump_structure.py

   1 from ..schema import EBMLDocument, UnknownElement, CONTAINER, BINARY
   2
   3
   4 def dump_element(element, indent=0):
   5         if isinstance(element, UnknownElement):
   6                 print(('\t' * indent) + ('<Unknown id=\'%s\' bytes=\'%i\' />' % (hex(element.id), element.encoding[0])))
   7         else:
   8                 sargs = {
   9                         'name': element.name,
  10                         'bytes': element.body_size,
  11                         'value': element.value
  12                 }
  13                 def print_indented(foo):
  14                         print(('\t' * indent) + foo)
  15                 if element.type == CONTAINER:
  16                         print_indented('<%(name)s>' % sargs)
  17                         for sub_el in element.value:
  18                                 dump_element(sub_el, indent + 1)
  19                         print_indented('</%(name)s>' % sargs)
  20                 elif element.type == BINARY:
  21                         print_indented('<%(name)s bytes=\'%(bytes)i\' />' % sargs)
  22                 else:
  23                         print_indented('<%(name)s>%(value)s</%(name)s>' % sargs)
  24
  25
  26 def dump_document(document):
  27         for el in document.roots:
  28                 dump_element(el)
  29
  30
  31 if __name__ == '__main__':
  32         import sys
  33         from optparse import OptionParser
  34
  35         parser = OptionParser(usage='Usage: %prog [OPTION] FILE')
  36         parser.add_option('--document-class', dest='document_class', help='the document class to use', metavar='CLASS')
  37         options, args = parser.parse_args()
  38
  39         if options.document_class is None:
  40                 class doc_cls(EBMLDocument):
  41                         type = None
  42                         version = None
  43         else:
  44                 mod_name, _, cls_name = options.document_class.rpartition('.')
  45                 try:
  46                         doc_mod = __import__(mod_name, fromlist=[cls_name])
  47                         doc_cls = getattr(doc_mod, cls_name)
  48                 except ImportError:
  49                         parser.error('unable to import module %s' % mod_name)
  50                 except AttributeError:
  51                         parser.error('unable to import class %s from %s' % (cls_name, mod_name))
  52
  53         if not args:
  54                 parser.error('no file provided')
  55         elif len(args) > 1:
  56                 parser.error('more than one file provided')
  57
  58         with open(args[0], 'rb') as stream:
  59                 doc = doc_cls(stream)
  60                 dump_document(doc)