Overhauled the schema system to make more sense. Implemented a dump_structure utility.

[~jspiros/python-ebml.git] / ebml / utils / dump_structure.py

diff --git a/ebml/utils/dump_structure.py b/ebml/utils/dump_structure.py
new file mode 100644 (file)
index 0000000..8e36663
--- /dev/null
+++ b/ebml/utils/dump_structure.py
@@ -0,0 +1,60 @@
+from ..schema import EBMLDocument, UnknownElement, CONTAINER, BINARY
+
+
+def dump_element(element, indent=0):
+       if isinstance(element, UnknownElement):
+               print(('\t' * indent) + ('<Unknown id=\'%s\' bytes=\'%i\' />' % (hex(element.id), element.encoding[0])))
+       else:
+               sargs = {
+                       'name': element.name,
+                       'bytes': element.body_size,
+                       'value': element.value
+               }
+               def print_indented(foo):
+                       print(('\t' * indent) + foo)
+               if element.type == CONTAINER:
+                       print_indented('<%(name)s>' % sargs)
+                       for sub_el in element.value:
+                               dump_element(sub_el, indent + 1)
+                       print_indented('</%(name)s>' % sargs)
+               elif element.type == BINARY:
+                       print_indented('<%(name)s bytes=\'%(bytes)i\' />' % sargs)
+               else:
+                       print_indented('<%(name)s>%(value)s</%(name)s>' % sargs)
+
+
+def dump_document(document):
+       for el in document.roots:
+               dump_element(el)
+
+
+if __name__ == '__main__':
+       import sys
+       from optparse import OptionParser
+       
+       parser = OptionParser(usage='Usage: %prog [OPTION] FILE')
+       parser.add_option('--document-class', dest='document_class', help='the document class to use', metavar='CLASS')
+       options, args = parser.parse_args()
+       
+       if options.document_class is None:
+               class doc_cls(EBMLDocument):
+                       type = None
+                       version = None
+       else:
+               mod_name, _, cls_name = options.document_class.rpartition('.')
+               try:
+                       doc_mod = __import__(mod_name, fromlist=[cls_name])
+                       doc_cls = getattr(doc_mod, cls_name)
+               except ImportError:
+                       parser.error('unable to import module %s' % mod_name)
+               except AttributeError:
+                       parser.error('unable to import class %s from %s' % (cls_name, mod_name))
+       
+       if not args:
+               parser.error('no file provided')
+       elif len(args) > 1:
+               parser.error('more than one file provided')
+       
+       with open(args[0], 'rb') as stream:
+               doc = doc_cls(stream)
+               dump_document(doc)
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