TAG_UINT16 = 0x04
TAG_UINT32 = 0x05
TAG_UINT64 = 0x06
+TAG_INT8 = 0x10
+TAG_INT16 = 0x11
+TAG_INT32 = 0x12
+TAG_INT64 = 0x13
+TAG_BINARY = 0x20
+TAG_UTF8 = 0x21
+TAG_UTF16 = 0x22
+TAG_UTF32 = 0x23
+TAG_TUPLE = 0x30
TaggedObject = collections.namedtuple(
'TaggedObject',
return serializer
+def _make_string_serializer(encoder):
+ packer = functools.partial(struct.pack, '!BI')
+
+ def serializer(to):
+ encoded = encoder(to.instance)
+ return packer(to.tag, len(encoded)) + encoded
+
+ return serializer
+
+def _serialize_tuple(to):
+ assert isinstance(to.instance, tuple)
+
+ payload = b''.join(serialize(item) for item in to.instance)
+
+ fmt = '!BI'
+
+ return struct.pack('!BI', TAG_TUPLE, len(payload)) + payload
+
+
_TAGS_TO_SERIALIZERS = {
TAG_NULL: _make_tag_only_serializer(TAG_NULL, None),
TAG_TRUE: _make_tag_only_serializer(TAG_TRUE, True),
TAG_UINT16: _make_struct_serializer('H'),
TAG_UINT32: _make_struct_serializer('I'),
TAG_UINT64: _make_struct_serializer('Q'),
+ TAG_INT8: _make_struct_serializer('b'),
+ TAG_INT16: _make_struct_serializer('h'),
+ TAG_INT32: _make_struct_serializer('i'),
+ TAG_INT64: _make_struct_serializer('q'),
+ TAG_BINARY: _make_string_serializer(lambda s: s),
+ TAG_UTF8: _make_string_serializer(lambda s: s.encode('utf-8')),
+ TAG_UTF16: _make_string_serializer(lambda s: s.encode('utf-16')),
+ TAG_UTF32: _make_string_serializer(lambda s: s.encode('utf-32')),
+ TAG_TUPLE: _serialize_tuple,
}
def serialize(to):
def _make_tag_only_parser(tag, value):
def parser(b):
- return TaggedObject(tag = tag, instance = value)
+ return 0, TaggedObject(tag = tag, instance = value)
return parser
def parser(b):
b = b.read(size)
assert len(b) == size
- return TaggedObject(tag = tag, instance = unpacker(b)[0])
+ return size, TaggedObject(tag = tag, instance = unpacker(b)[0])
return parser
+_LENGTH_FMT = '!I'
+_LENGTH_FMT_SIZE = struct.calcsize(_LENGTH_FMT)
+
+def _read_length_then_payload(b):
+ length_b = b.read(_LENGTH_FMT_SIZE)
+ assert len(length_b) == _LENGTH_FMT_SIZE
+ length = struct.unpack(_LENGTH_FMT, length_b)[0]
+
+ payload = b.read(length)
+ assert len(payload) == length
+ return _LENGTH_FMT_SIZE + length, payload
+
+def _make_string_deserializer(tag, decoder):
+ fmt = '!I'
+ size = struct.calcsize(fmt)
+ unpacker = functools.partial(struct.unpack, fmt)
+
+ def parser(b):
+ bytes_read, payload = _read_length_then_payload(b)
+ return bytes_read, TaggedObject(tag = tag, instance = decoder(payload))
+
+ return parser
+
+def _deserialize_tuple(b):
+ bytes_read, payload = _read_length_then_payload(b)
+
+ payload_stream = io.BytesIO(payload)
+
+ total_bytes_read = 0
+ instance = []
+
+ while total_bytes_read < len(payload):
+ partial_bytes_read, item = _deserialize_partial(payload_stream)
+ total_bytes_read += partial_bytes_read
+ instance.append(item)
+
+ return bytes_read, TaggedObject(tag = TAG_TUPLE, instance = tuple(instance))
+
_TAGS_TO_PARSERS = {
TAG_NULL: _make_tag_only_parser(TAG_NULL, None),
TAG_TRUE: _make_tag_only_parser(TAG_TRUE, True),
TAG_UINT16: _make_struct_deserializer(TAG_UINT16, 'H'),
TAG_UINT32: _make_struct_deserializer(TAG_UINT32, 'I'),
TAG_UINT64: _make_struct_deserializer(TAG_UINT64, 'Q'),
+ TAG_INT8: _make_struct_deserializer(TAG_INT8, 'b'),
+ TAG_INT16: _make_struct_deserializer(TAG_INT16, 'h'),
+ TAG_INT32: _make_struct_deserializer(TAG_INT32, 'i'),
+ TAG_INT64: _make_struct_deserializer(TAG_INT64, 'q'),
+ TAG_BINARY: _make_string_deserializer(TAG_BINARY, lambda b: b),
+ TAG_UTF8: _make_string_deserializer(TAG_UTF8, lambda b: b.decode('utf-8')),
+ TAG_UTF16: _make_string_deserializer(TAG_UTF16, lambda b: b.decode('utf-16')),
+ TAG_UTF32: _make_string_deserializer(TAG_UTF32, lambda b: b.decode('utf-32')),
+ TAG_TUPLE: _deserialize_tuple,
}
+def _deserialize_partial(b):
+ tag = b.read(1)
+ assert len(tag) == 1
+ bytes_read, to = _TAGS_TO_PARSERS[tag[0]](b)
+ return bytes_read + 1, to
+
def deserialize(b):
if isinstance(b, bytes):
b = io.BytesIO(b)
- tag = b.read(1)[0]
-
- result = _TAGS_TO_PARSERS[tag](b)
+ bytes_read, result = _deserialize_partial(b)
remainder = b.read()