PYTHON-472 - Add a RawBSONDocument class that decodes its comprising bytes only on-demand.

This provides an API for inserting and returning raw BSON.

Author: Luke Lovett

bson/__init__.py

@@ -31,7 +31,8 @@
  JAVA_LEGACY, CSHARP_LEGACY,
  UUIDLegacy)
 from bson.code import Code
-from bson.codec_options import CodecOptions, DEFAULT_CODEC_OPTIONS
+from bson.codec_options import (
+ CodecOptions, DEFAULT_CODEC_OPTIONS, _raw_document_class)
 from bson.dbref import DBRef
 from bson.errors import (InvalidBSON,
  InvalidDocument,
@@ -132,6 +133,10 @@ def _get_object(data, position, obj_end, opts):
  raise InvalidBSON("bad eoo")
  if end >= obj_end:
  raise InvalidBSON("invalid object length")
+ if _raw_document_class(opts.document_class):
+ return (opts.document_class(data[position:end + 1], opts),
+ position + obj_size)
+
  obj = _elements_to_dict(data, position + 4, end, opts)
 
  position += obj_size
@@ -147,6 +152,7 @@ def _get_array(data, position, obj_end, opts):
  end = position + size - 1
  if data[end:end + 1] != b"\x00":
  raise InvalidBSON("bad eoo")
+
  position += 4
  end -= 1
  result = []
@@ -304,14 +310,21 @@ def _element_to_dict(data, position, obj_end, opts):
  value, position = _ELEMENT_GETTER[element_type](data,
  position, obj_end, opts)
  return element_name, value, position
+if _USE_C:
+ _element_to_dict = _cbson._element_to_dict
 
 
-def _elements_to_dict(data, position, obj_end, opts):
- """Decode a BSON document."""
- result = opts.document_class()
+def _iterate_elements(data, position, obj_end, opts):
  end = obj_end - 1
  while position < end:
  (key, value, position) = _element_to_dict(data, position, obj_end, opts)
+ yield key, value
+
+
+def _elements_to_dict(data, position, obj_end, opts):
+ """Decode a BSON document."""
+ result = opts.document_class()
+ for key, value in _iterate_elements(data, position, obj_end, opts):
  result[key] = value
  return result
 
@@ -327,6 +340,8 @@ def _bson_to_dict(data, opts):
  if data[obj_size - 1:obj_size] != b"\x00":
  raise InvalidBSON("bad eoo")
  try:
+ if _raw_document_class(opts.document_class):
+ return opts.document_class(data, opts)
  return _elements_to_dict(data, 4, obj_size - 1, opts)
  except InvalidBSON:
  raise
@@ -429,6 +444,8 @@ def _encode_bytes(name, value, dummy0, dummy1):
 
 def _encode_mapping(name, value, check_keys, opts):
  """Encode a mapping type."""
+ if _raw_document_class(value):
+ return b'\x03' + name + value.raw
  data = b"".join([_element_to_bson(key, val, check_keys, opts)
  for key, val in iteritems(value)])
  return b"\x03" + name + _PACK_INT(len(data) + 5) + data + b"\x00"
@@ -694,6 +711,8 @@ def _element_to_bson(key, value, check_keys, opts):
 
 def _dict_to_bson(doc, check_keys, opts, top_level=True):
  """Encode a document to BSON."""
+ if _raw_document_class(doc):
+ return doc.raw
  try:
  elements = []
  if top_level and "_id" in doc:
@@ -751,6 +770,7 @@ def decode_all(data, codec_options=DEFAULT_CODEC_OPTIONS):
  docs = []
  position = 0
  end = len(data) - 1
+ use_raw = _raw_document_class(codec_options.document_class)
  try:
  while position < end:
  obj_size = _UNPACK_INT(data[position:position + 4])[0]
@@ -759,10 +779,15 @@ def decode_all(data, codec_options=DEFAULT_CODEC_OPTIONS):
  obj_end = position + obj_size - 1
  if data[obj_end:position + obj_size] != b"\x00":
  raise InvalidBSON("bad eoo")
- docs.append(_elements_to_dict(data,
- position + 4,
- obj_end,
- codec_options))
+ if use_raw:
+ docs.append(
+ codec_options.document_class(
+ data[position:obj_end + 1], codec_options))
+ else:
+ docs.append(_elements_to_dict(data,
+ position + 4,
+ obj_end,
+ codec_options))
  position += obj_size
  return docs
  except InvalidBSON: