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 def _serialize_object(to):
65 assert isinstance(to.instance, list)
67 # TODO Actually handle this case somehow
68 assert len(to.instance) > 0
70 # TODO Do this a better way
71 serialized_kvps = [(serialize(k), serialize(v)) for k,v in to.instance]
72 key_type_tag = serialized_kvps[0][0][0]
74 def check_and_strip_prefix(b):
76 assert key_type_tag == item_tag
79 payload = b''.join(check_and_strip_prefix(k) + v for k,v in serialized_kvps)
83 return struct.pack(fmt, tags.OBJECT, key_type_tag, len(payload)) + payload
85 _TAGS_TO_SERIALIZERS = {
86 tags.NULL: _make_tag_only_serializer(tags.NULL, None),
87 tags.TRUE: _make_tag_only_serializer(tags.TRUE, True),
88 tags.FALSE: _make_tag_only_serializer(tags.FALSE, False),
89 tags.UINT8: _make_struct_serializer('B'),
90 tags.UINT16: _make_struct_serializer('H'),
91 tags.UINT32: _make_struct_serializer('I'),
92 tags.UINT64: _make_struct_serializer('Q'),
93 tags.INT8: _make_struct_serializer('b'),
94 tags.INT16: _make_struct_serializer('h'),
95 tags.INT32: _make_struct_serializer('i'),
96 tags.INT64: _make_struct_serializer('q'),
97 tags.BINARY: _make_string_serializer(lambda s: s),
98 tags.UTF8: _make_string_serializer(lambda s: s.encode('utf-8')),
99 tags.UTF16: _make_string_serializer(lambda s: s.encode('utf-16')),
100 tags.UTF32: _make_string_serializer(lambda s: s.encode('utf-32')),
101 tags.TUPLE: _serialize_tuple,
102 tags.LIST: _serialize_list,
103 tags.OBJECT: _serialize_object,
107 return _TAGS_TO_SERIALIZERS[to.tag](to)
109 def _make_tag_only_parser(tag, value):
111 return 0, tags.TaggedObject(tag = tag, instance = value)
115 def _make_struct_deserializer(tag, fmt):
117 size = struct.calcsize(fmt)
118 unpacker = functools.partial(struct.unpack, fmt)
122 assert len(b) == size
123 return size, tags.TaggedObject(tag = tag, instance = unpacker(b)[0])
128 _LENGTH_FMT_SIZE = struct.calcsize(_LENGTH_FMT)
130 def _read_length_then_payload(b):
131 length_b = b.read(_LENGTH_FMT_SIZE)
132 assert len(length_b) == _LENGTH_FMT_SIZE
133 length = struct.unpack(_LENGTH_FMT, length_b)[0]
135 payload = b.read(length)
136 assert len(payload) == length
137 return _LENGTH_FMT_SIZE + length, payload
139 def _make_string_deserializer(tag, decoder):
141 size = struct.calcsize(fmt)
142 unpacker = functools.partial(struct.unpack, fmt)
145 bytes_read, payload = _read_length_then_payload(b)
146 return bytes_read, tags.TaggedObject(tag = tag, instance = decoder(payload))
150 def _deserialize_tuple(b):
151 bytes_read, payload = _read_length_then_payload(b)
153 payload_stream = io.BytesIO(payload)
158 while total_bytes_read < len(payload):
159 partial_bytes_read, item = _deserialize_partial(payload_stream)
160 total_bytes_read += partial_bytes_read
161 instance.append(item)
163 return bytes_read, tags.TaggedObject(tag = tags.TUPLE, instance = tuple(instance))
165 def _deserialize_list(b):
166 list_tag_bytes = b.read(1)
167 assert len(list_tag_bytes) == 1
168 list_tag = list_tag_bytes[0]
170 bytes_read, payload = _read_length_then_payload(b)
172 payload_stream = io.BytesIO(payload)
177 while total_bytes_read < len(payload):
178 partial_bytes_read, item = _TAGS_TO_PARSERS[list_tag](payload_stream)
179 total_bytes_read += partial_bytes_read
180 instance.append(item)
182 # TODO Return tags = (tags.LIST, list_tag) to function like a generic type
183 return bytes_read, tags.TaggedObject(tag = tags.LIST, instance = instance)
185 def _deserialize_object(b):
186 raise Exception('Not implemented')
189 tags.NULL: _make_tag_only_parser(tags.NULL, None),
190 tags.TRUE: _make_tag_only_parser(tags.TRUE, True),
191 tags.FALSE: _make_tag_only_parser(tags.FALSE, False),
192 tags.UINT8: _make_struct_deserializer(tags.UINT8, 'B'),
193 tags.UINT16: _make_struct_deserializer(tags.UINT16, 'H'),
194 tags.UINT32: _make_struct_deserializer(tags.UINT32, 'I'),
195 tags.UINT64: _make_struct_deserializer(tags.UINT64, 'Q'),
196 tags.INT8: _make_struct_deserializer(tags.INT8, 'b'),
197 tags.INT16: _make_struct_deserializer(tags.INT16, 'h'),
198 tags.INT32: _make_struct_deserializer(tags.INT32, 'i'),
199 tags.INT64: _make_struct_deserializer(tags.INT64, 'q'),
200 tags.BINARY: _make_string_deserializer(tags.BINARY, lambda b: b),
201 tags.UTF8: _make_string_deserializer(tags.UTF8, lambda b: b.decode('utf-8')),
202 tags.UTF16: _make_string_deserializer(tags.UTF16, lambda b: b.decode('utf-16')),
203 tags.UTF32: _make_string_deserializer(tags.UTF32, lambda b: b.decode('utf-32')),
204 tags.TUPLE: _deserialize_tuple,
205 tags.LIST: _deserialize_list,
206 tags.OBJECT: _deserialize_object,
209 def _deserialize_partial(b):
212 bytes_read, to = _TAGS_TO_PARSERS[tag[0]](b)
213 return bytes_read + 1, to
216 if isinstance(b, bytes):
219 bytes_read, result = _deserialize_partial(b)
223 if len(remainder) == 0:
226 raise Exception('Unable to parse remainder: {}'.format(remainder))