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 raise Exception('Not implemented')
67 _TAGS_TO_SERIALIZERS = {
68 tags.NULL: _make_tag_only_serializer(tags.NULL, None),
69 tags.TRUE: _make_tag_only_serializer(tags.TRUE, True),
70 tags.FALSE: _make_tag_only_serializer(tags.FALSE, False),
71 tags.UINT8: _make_struct_serializer('B'),
72 tags.UINT16: _make_struct_serializer('H'),
73 tags.UINT32: _make_struct_serializer('I'),
74 tags.UINT64: _make_struct_serializer('Q'),
75 tags.INT8: _make_struct_serializer('b'),
76 tags.INT16: _make_struct_serializer('h'),
77 tags.INT32: _make_struct_serializer('i'),
78 tags.INT64: _make_struct_serializer('q'),
79 tags.BINARY: _make_string_serializer(lambda s: s),
80 tags.UTF8: _make_string_serializer(lambda s: s.encode('utf-8')),
81 tags.UTF16: _make_string_serializer(lambda s: s.encode('utf-16')),
82 tags.UTF32: _make_string_serializer(lambda s: s.encode('utf-32')),
83 tags.TUPLE: _serialize_tuple,
84 tags.LIST: _serialize_list,
85 tags.OBJECT: _serialize_object,
89 return _TAGS_TO_SERIALIZERS[to.tag](to)
91 def _make_tag_only_parser(tag, value):
93 return 0, tags.TaggedObject(tag = tag, instance = value)
97 def _make_struct_deserializer(tag, fmt):
99 size = struct.calcsize(fmt)
100 unpacker = functools.partial(struct.unpack, fmt)
104 assert len(b) == size
105 return size, tags.TaggedObject(tag = tag, instance = unpacker(b)[0])
110 _LENGTH_FMT_SIZE = struct.calcsize(_LENGTH_FMT)
112 def _read_length_then_payload(b):
113 length_b = b.read(_LENGTH_FMT_SIZE)
114 assert len(length_b) == _LENGTH_FMT_SIZE
115 length = struct.unpack(_LENGTH_FMT, length_b)[0]
117 payload = b.read(length)
118 assert len(payload) == length
119 return _LENGTH_FMT_SIZE + length, payload
121 def _make_string_deserializer(tag, decoder):
123 size = struct.calcsize(fmt)
124 unpacker = functools.partial(struct.unpack, fmt)
127 bytes_read, payload = _read_length_then_payload(b)
128 return bytes_read, tags.TaggedObject(tag = tag, instance = decoder(payload))
132 def _deserialize_tuple(b):
133 bytes_read, payload = _read_length_then_payload(b)
135 payload_stream = io.BytesIO(payload)
140 while total_bytes_read < len(payload):
141 partial_bytes_read, item = _deserialize_partial(payload_stream)
142 total_bytes_read += partial_bytes_read
143 instance.append(item)
145 return bytes_read, tags.TaggedObject(tag = tags.TUPLE, instance = tuple(instance))
147 def _deserialize_list(b):
148 list_tag_bytes = b.read(1)
149 assert len(list_tag_bytes) == 1
150 list_tag = list_tag_bytes[0]
152 bytes_read, payload = _read_length_then_payload(b)
154 payload_stream = io.BytesIO(payload)
159 while total_bytes_read < len(payload):
160 partial_bytes_read, item = _TAGS_TO_PARSERS[list_tag](payload_stream)
161 total_bytes_read += partial_bytes_read
162 instance.append(item)
164 # TODO Return tags = (tags.LIST, list_tag) to function like a generic type
165 return bytes_read, tags.TaggedObject(tag = tags.LIST, instance = instance)
167 def _deserialize_object(b):
168 raise Exception('Not implemented')
171 tags.NULL: _make_tag_only_parser(tags.NULL, None),
172 tags.TRUE: _make_tag_only_parser(tags.TRUE, True),
173 tags.FALSE: _make_tag_only_parser(tags.FALSE, False),
174 tags.UINT8: _make_struct_deserializer(tags.UINT8, 'B'),
175 tags.UINT16: _make_struct_deserializer(tags.UINT16, 'H'),
176 tags.UINT32: _make_struct_deserializer(tags.UINT32, 'I'),
177 tags.UINT64: _make_struct_deserializer(tags.UINT64, 'Q'),
178 tags.INT8: _make_struct_deserializer(tags.INT8, 'b'),
179 tags.INT16: _make_struct_deserializer(tags.INT16, 'h'),
180 tags.INT32: _make_struct_deserializer(tags.INT32, 'i'),
181 tags.INT64: _make_struct_deserializer(tags.INT64, 'q'),
182 tags.BINARY: _make_string_deserializer(tags.BINARY, lambda b: b),
183 tags.UTF8: _make_string_deserializer(tags.UTF8, lambda b: b.decode('utf-8')),
184 tags.UTF16: _make_string_deserializer(tags.UTF16, lambda b: b.decode('utf-16')),
185 tags.UTF32: _make_string_deserializer(tags.UTF32, lambda b: b.decode('utf-32')),
186 tags.TUPLE: _deserialize_tuple,
187 tags.LIST: _deserialize_list,
188 tags.OBJECT: _deserialize_object,
191 def _deserialize_partial(b):
194 bytes_read, to = _TAGS_TO_PARSERS[tag[0]](b)
195 return bytes_read + 1, to
198 if isinstance(b, bytes):
201 bytes_read, result = _deserialize_partial(b)
205 if len(remainder) == 0:
208 raise Exception('Unable to parse remainder: {}'.format(remainder))