def _elements_to_dict(
data: Any, view: Any, position: int, obj_end: int, opts: CodecOptions, result: Any = None
) -> Any:
"""Decode a BSON document into result."""
if result is None:
result = opts.document_class()
end = obj_end - 1
while position < end:
key, value, position = _element_to_dict(data, view, position, obj_end, opts)
result[key] = value
if position != obj_end:
raise InvalidBSON("bad object or element length")
return result
def _bson_to_dict(data: Any, opts: CodecOptions) -> Any:
"""Decode a BSON string to document_class."""
data, view = get_data_and_view(data)
try:
if _raw_document_class(opts.document_class):
return opts.document_class(data, opts)
_, end = _get_object_size(data, 0, len(data))
return _elements_to_dict(data, view, 4, end, opts)
except InvalidBSON:
raise
except Exception:
# Change exception type to InvalidBSON but preserve traceback.
_, exc_value, exc_tb = sys.exc_info()
raise InvalidBSON(str(exc_value)).with_traceback(exc_tb)
def _get_object(
data: Any, view: Any, position: int, obj_end: int, opts: CodecOptions, dummy: Any
) -> Tuple[Any, int]:
"""Decode a BSON subdocument to opts.document_class or bson.dbref.DBRef."""
obj_size, end = _get_object_size(data, position, obj_end)
if _raw_document_class(opts.document_class):
return (opts.document_class(data[position : end + 1], opts), position + obj_size)
obj = _elements_to_dict(data, view, position + 4, end, opts)
position += obj_size
# If DBRef validation fails, return a normal doc.
if (
isinstance(obj.get("$ref"), str)
and "$id" in obj
and isinstance(obj.get("$db"), (str, type(None)))
):
return (DBRef(obj.pop("$ref"), obj.pop("$id", None), obj.pop("$db", None), obj), position)
return obj, position