7 def _make_tag_only_serializer(tag, expected_value):
11 assert to.instance == expected_value
16 def _make_struct_serializer(fmt):
18 packer = functools.partial(struct.pack, fmt)
21 return packer(to.tag, to.instance)
25 def _make_string_serializer(encoder):
26 packer = functools.partial(struct.pack, '!BI')
29 encoded = encoder(to.instance)
30 return packer(to.tag, len(encoded)) + encoded
34 def _serialize_tuple(to):
35 assert isinstance(to.instance, tuple)
37 payload = b''.join(serialize(item) for item in to.instance)
41 return struct.pack('!BI', tags.TUPLE, len(payload)) + payload
43 def _serialize_list(to):
44 assert isinstance(to.instance, list)
46 # TODO Actually handle this case somehow
47 assert len(to.instance) > 0
49 # TODO Do this a better way
50 serialized_items = [serialize(i) for i in to.instance]
51 list_tag = serialized_items[0][0]
53 def check_and_strip_prefix(b):
55 assert list_tag == item_tag
58 payload = b''.join(check_and_strip_prefix(si) for si in serialized_items)
62 return struct.pack(fmt, tags.LIST, list_tag, len(payload)) + payload
64 _TAGS_TO_SERIALIZERS = {
65 tags.NULL: _make_tag_only_serializer(tags.NULL, None),
66 tags.TRUE: _make_tag_only_serializer(tags.TRUE, True),
67 tags.FALSE: _make_tag_only_serializer(tags.FALSE, False),
68 tags.UINT8: _make_struct_serializer('B'),
69 tags.UINT16: _make_struct_serializer('H'),
70 tags.UINT32: _make_struct_serializer('I'),
71 tags.UINT64: _make_struct_serializer('Q'),
72 tags.INT8: _make_struct_serializer('b'),
73 tags.INT16: _make_struct_serializer('h'),
74 tags.INT32: _make_struct_serializer('i'),
75 tags.INT64: _make_struct_serializer('q'),
76 tags.BINARY: _make_string_serializer(lambda s: s),
77 tags.UTF8: _make_string_serializer(lambda s: s.encode('utf-8')),
78 tags.UTF16: _make_string_serializer(lambda s: s.encode('utf-16')),
79 tags.UTF32: _make_string_serializer(lambda s: s.encode('utf-32')),
80 tags.TUPLE: _serialize_tuple,
81 tags.LIST: _serialize_list,
85 return _TAGS_TO_SERIALIZERS[to.tag](to)
87 def _make_tag_only_parser(tag, value):
89 return 0, tags.TaggedObject(tag = tag, instance = value)
93 def _make_struct_deserializer(tag, fmt):
95 size = struct.calcsize(fmt)
96 unpacker = functools.partial(struct.unpack, fmt)
100 assert len(b) == size
101 return size, tags.TaggedObject(tag = tag, instance = unpacker(b)[0])
106 _LENGTH_FMT_SIZE = struct.calcsize(_LENGTH_FMT)
108 def _read_length_then_payload(b):
109 length_b = b.read(_LENGTH_FMT_SIZE)
110 assert len(length_b) == _LENGTH_FMT_SIZE
111 length = struct.unpack(_LENGTH_FMT, length_b)[0]
113 payload = b.read(length)
114 assert len(payload) == length
115 return _LENGTH_FMT_SIZE + length, payload
117 def _make_string_deserializer(tag, decoder):
119 size = struct.calcsize(fmt)
120 unpacker = functools.partial(struct.unpack, fmt)
123 bytes_read, payload = _read_length_then_payload(b)
124 return bytes_read, tags.TaggedObject(tag = tag, instance = decoder(payload))
128 def _deserialize_tuple(b):
129 bytes_read, payload = _read_length_then_payload(b)
131 payload_stream = io.BytesIO(payload)
136 while total_bytes_read < len(payload):
137 partial_bytes_read, item = _deserialize_partial(payload_stream)
138 total_bytes_read += partial_bytes_read
139 instance.append(item)
141 return bytes_read, tags.TaggedObject(tag = tags.TUPLE, instance = tuple(instance))
143 def _deserialize_list(b):
144 list_tag_bytes = b.read(1)
145 assert len(list_tag_bytes) == 1
146 list_tag = list_tag_bytes[0]
148 bytes_read, payload = _read_length_then_payload(b)
150 payload_stream = io.BytesIO(payload)
155 while total_bytes_read < len(payload):
156 partial_bytes_read, item = _TAGS_TO_PARSERS[list_tag](payload_stream)
157 total_bytes_read += partial_bytes_read
158 instance.append(item)
160 # TODO Return tags = (tags.LIST, list_tag) to function like a generic type
161 return bytes_read, tags.TaggedObject(tag = tags.LIST, instance = instance)
164 tags.NULL: _make_tag_only_parser(tags.NULL, None),
165 tags.TRUE: _make_tag_only_parser(tags.TRUE, True),
166 tags.FALSE: _make_tag_only_parser(tags.FALSE, False),
167 tags.UINT8: _make_struct_deserializer(tags.UINT8, 'B'),
168 tags.UINT16: _make_struct_deserializer(tags.UINT16, 'H'),
169 tags.UINT32: _make_struct_deserializer(tags.UINT32, 'I'),
170 tags.UINT64: _make_struct_deserializer(tags.UINT64, 'Q'),
171 tags.INT8: _make_struct_deserializer(tags.INT8, 'b'),
172 tags.INT16: _make_struct_deserializer(tags.INT16, 'h'),
173 tags.INT32: _make_struct_deserializer(tags.INT32, 'i'),
174 tags.INT64: _make_struct_deserializer(tags.INT64, 'q'),
175 tags.BINARY: _make_string_deserializer(tags.BINARY, lambda b: b),
176 tags.UTF8: _make_string_deserializer(tags.UTF8, lambda b: b.decode('utf-8')),
177 tags.UTF16: _make_string_deserializer(tags.UTF16, lambda b: b.decode('utf-16')),
178 tags.UTF32: _make_string_deserializer(tags.UTF32, lambda b: b.decode('utf-32')),
179 tags.TUPLE: _deserialize_tuple,
180 tags.LIST: _deserialize_list,
183 def _deserialize_partial(b):
186 bytes_read, to = _TAGS_TO_PARSERS[tag[0]](b)
187 return bytes_read + 1, to
190 if isinstance(b, bytes):
193 bytes_read, result = _deserialize_partial(b)
197 if len(remainder) == 0:
200 raise Exception('Unable to parse remainder: {}'.format(remainder))