Merge branch 'master' of github.com:kerkeslager/sandbox

diff --git a/serial/binary.py b/serial/binary.py
new file mode 100644 (file)
index 0000000..7ce58b7
--- /dev/null
+++ b/serial/binary.py
@@ -0,0 +1,142 @@
+import collections
+import functools
+import io
+import struct
+
+TAG_NULL = 0x00
+TAG_TRUE = 0x01
+TAG_FALSE = 0x02
+TAG_UINT8 = 0x03
+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
+
+TaggedObject = collections.namedtuple(
+    'TaggedObject',
+    [
+        'tag',
+        'instance',
+    ],
+)
+
+def _make_tag_only_serializer(tag, expected_value):
+    tag = bytes([tag])
+
+    def serializer(to):
+        assert to.instance == expected_value
+        return tag
+
+    return serializer
+
+def _make_struct_serializer(fmt):
+    fmt = '!B' + fmt
+    packer = functools.partial(struct.pack, fmt)
+
+    def serializer(to):
+        return packer(to.tag, to.instance)
+
+    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
+
+_TAGS_TO_SERIALIZERS = {
+    TAG_NULL: _make_tag_only_serializer(TAG_NULL, None),
+    TAG_TRUE: _make_tag_only_serializer(TAG_TRUE, True),
+    TAG_FALSE: _make_tag_only_serializer(TAG_FALSE, False),
+    TAG_UINT8: _make_struct_serializer('B'),
+    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')),
+}
+
+def serialize(to):
+    return _TAGS_TO_SERIALIZERS[to.tag](to)
+
+def _make_tag_only_parser(tag, value):
+    def parser(b):
+        return TaggedObject(tag = tag, instance = value)
+
+    return parser
+
+def _make_struct_deserializer(tag, fmt):
+    fmt = '!' + fmt
+    size = struct.calcsize(fmt)
+    unpacker = functools.partial(struct.unpack, fmt)
+
+    def parser(b):
+        b = b.read(size)
+        assert len(b) == size
+        return TaggedObject(tag = tag, instance = unpacker(b)[0])
+
+    return parser
+
+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))
+
+    return parser
+
+_TAGS_TO_PARSERS = {
+    TAG_NULL: _make_tag_only_parser(TAG_NULL, None),
+    TAG_TRUE: _make_tag_only_parser(TAG_TRUE, True),
+    TAG_FALSE: _make_tag_only_parser(TAG_FALSE, False),
+    TAG_UINT8: _make_struct_deserializer(TAG_UINT8, 'B'),
+    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')),
+}
+
+def deserialize(b):
+    if isinstance(b, bytes):
+        b = io.BytesIO(b)
+
+    tag = b.read(1)[0]
+
+    result = _TAGS_TO_PARSERS[tag](b)
+
+    remainder = b.read()
+
+    if len(remainder) == 0:
+        return result
+
+    raise Exception('Unable to parse remainder: {}'.format(remainder))

diff --git a/serial/test_binary.py b/serial/test_binary.py
new file mode 100644 (file)
index 0000000..8bc3811
--- /dev/null
+++ b/serial/test_binary.py
@@ -0,0 +1,53 @@
+import unittest
+
+import binary
+
+EXAMPLE_REPRESENTATIONS = [
+    (binary.TAG_NULL, None, b'\x00'),
+    (binary.TAG_TRUE, True, b'\x01'),
+    (binary.TAG_FALSE, False, b'\x02'),
+    (binary.TAG_UINT8, 7, b'\x03\x07'),
+    (binary.TAG_UINT16, 7, b'\x04\x00\x07'),
+    (binary.TAG_UINT32, 7, b'\x05\x00\x00\x00\x07'),
+    (binary.TAG_UINT64, 7, b'\x06\x00\x00\x00\x00\x00\x00\x00\x07'),
+    (binary.TAG_INT8, 7, b'\x10\x07'),
+    (binary.TAG_INT16, 7, b'\x11\x00\x07'),
+    (binary.TAG_INT32, 7, b'\x12\x00\x00\x00\x07'),
+    (binary.TAG_INT64, 7, b'\x13\x00\x00\x00\x00\x00\x00\x00\x07'),
+    (binary.TAG_UINT8, 254, b'\x03\xfe'),
+    (binary.TAG_UINT16, 65534, b'\x04\xff\xfe'),
+    (binary.TAG_UINT32, 4294967294, b'\x05\xff\xff\xff\xfe'),
+    (binary.TAG_UINT64, 18446744073709551614, b'\x06\xff\xff\xff\xff\xff\xff\xff\xfe'),
+    (binary.TAG_INT8, -2, b'\x10\xfe'),
+    (binary.TAG_INT16, -2, b'\x11\xff\xfe'),
+    (binary.TAG_INT32, -2, b'\x12\xff\xff\xff\xfe'),
+    (binary.TAG_INT64, -2, b'\x13\xff\xff\xff\xff\xff\xff\xff\xfe'),
+    (binary.TAG_BINARY, b'\xde\xad\xbe\xef', b'\x20\x00\x00\x00\x04\xde\xad\xbe\xef'),
+    (binary.TAG_UTF8, 'Lol!', b'\x21\x00\x00\x00\x04Lol!'),
+    (binary.TAG_UTF16, 'かわ', b'\x22\x00\x00\x00\x06\xff\xfeK0\x8f0'),
+    (binary.TAG_UTF32, '漢', b'\x23\x00\x00\x00\x08\xff\xfe\x00\x00"o\x00\x00'),
+]
+
+class SerializeTests(unittest.TestCase):
+    def test_serialize(self):
+        for tag, instance, representation in EXAMPLE_REPRESENTATIONS:
+            self.assertEqual(
+                binary.serialize(binary.TaggedObject(
+                    tag = tag,
+                    instance = instance,
+                )),
+                representation,
+            )
+
+class DeserializeTests(unittest.TestCase):
+    def test_deserialize(self):
+        for tag, instance, representation in EXAMPLE_REPRESENTATIONS:
+            self.assertEqual(
+                binary.deserialize(representation),
+                binary.TaggedObject(
+                    tag = tag,
+                    instance = instance,
+                ),
+            )
+
+unittest.main()