Ejemplo n.º 1
0
   def compile(self, position, fields, bisturi_conf):
      slots = Field._compile(self, position, fields, bisturi_conf)
      if self.aligned_to is None:
          self.aligned_to = bisturi_conf.get('align', 1)

      # XXX we are propagating the 'align' attribute (in bisturi_conf) to
      # the prototype packet. This is valid ...but inelegant
      # This happen in others fields like Optional and Ref
      self.seq_elem_field_name = "_seq_elem__"+self.field_name
      self.prototype_field.field_name = self.seq_elem_field_name
      self.prototype_field.compile(position=-1, fields=[], bisturi_conf=bisturi_conf)

      count, until, when = self.tmp

      if isinstance(count, (UnaryExpr, BinaryExpr)):
         count = compile_expr_into_callable(count)

      #if isinstance(until, (UnaryExpr, BinaryExpr)):
      #   until = compile_expr_into_callable(until)
      
      if isinstance(when, (UnaryExpr, BinaryExpr)):
         when = compile_expr_into_callable(when)

      self.resolved_count = None if count is None else _get_count(count)
      self.when = _get_when(self.resolved_count, when)
      self.until_condition = _get_until(self.resolved_count, until)

      return slots + [self.seq_elem_field_name]
Ejemplo n.º 2
0
   def compile(self, position, fields, bisturi_conf):
      slots = Field._compile(self, position, fields, bisturi_conf)
      self.opt_elem_field_name = "_opt_elem__"+self.field_name
      self.prototype_field.field_name = self.opt_elem_field_name
      self.prototype_field.compile(position=-1, fields=[], bisturi_conf=bisturi_conf)

      when = self.tmp
      del self.tmp
      
      if isinstance(when, (UnaryExpr, BinaryExpr)):
         when = compile_expr_into_callable(when)

      self.when = _get_when(None, when)
      return slots + [self.opt_elem_field_name]
Ejemplo n.º 3
0
   def compile(self, position, fields, bisturi_conf):
      slots = Field._compile(self, position, fields, bisturi_conf)

      if self.byte_count is not None:
         if isinstance(self.byte_count, (int, long)):
            self.struct_code = "%is" % self.byte_count
            self.unpack = self._unpack_fixed_size
         
         elif isinstance(self.byte_count, Field):
            self.unpack = self._unpack_variable_size_field

         elif callable(self.byte_count):
            self.unpack = self._unpack_variable_size_callable

         elif isinstance(self.byte_count, (UnaryExpr, BinaryExpr)):
            self.byte_count = compile_expr_into_callable(self.byte_count)
            self.unpack = self._unpack_variable_size_callable

         else:
            assert False

      else:
         self._search_buffer_length = bisturi_conf.get('search_buffer_length')
         if self._search_buffer_length is not None:
             assert self._search_buffer_length >= 0 # the length can be 0 or None (means infinite) or a positive number

         if isinstance(self.until_marker, basestring):
            self.unpack = self._unpack_with_string_marker

         elif hasattr(self.until_marker, 'search'):
            self.unpack = self._unpack_with_regexp_marker
         
         else:
            assert False

      return slots