Implemented tuple serialization

[sandbox] / serial / binary.py

diff --git a/serial/binary.py b/serial/binary.py
index 7ce58b7..fabcd47 100644 (file)
--- a/serial/binary.py
+++ b/serial/binary.py
@@ -18,6 +18,7 @@ TAG_BINARY = 0x20
 TAG_UTF8 = 0x21
 TAG_UTF16 = 0x22
 TAG_UTF32 = 0x23
+TAG_TUPLE = 0x30
 
 TaggedObject = collections.namedtuple(
     'TaggedObject',
@@ -54,6 +55,16 @@ def _make_string_serializer(encoder):
 
     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),
@@ -70,6 +81,7 @@ _TAGS_TO_SERIALIZERS = {
     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):
@@ -77,7 +89,7 @@ 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
 
@@ -89,25 +101,48 @@ def _make_struct_deserializer(tag, fmt):
     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):
-        length_b = b.read(size)
-        assert len(length_b) == size
-        length = unpacker(length_b)[0]
-        s = b.read(length)
-        assert len(s) == length
-        return TaggedObject(tag = tag, instance = decoder(s))
+        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),
@@ -124,15 +159,20 @@ _TAGS_TO_PARSERS = {
     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()