def test_none_compression(self):
codecs = compression.registry.compressors
self.assertIn(None, codecs)
# check exception is raised when bytes are not passed in
with self.assertRaises(Exception) as cm:
compression.compress({})
self.assertIn("Can only compress bytes", str(cm.exception))
# perform roundtrip check
content_type, payload = compression.compress(TEST_DATA)
self.assertIsNone(content_type)
self.assertEqual(TEST_DATA, payload)
content_type, d = compression.decompress(payload)
self.assertIsNone(content_type)
self.assertEqual(d, TEST_DATA)
def test_snappy_compression(self):
convenience_name = "snappy"
mime_type = compression.COMPRESSION_SNAPPY
# check exception is raised when bytes are not passed in
with self.assertRaises(Exception) as cm:
compression.compress({}, mime_type)
self.assertIn("Can only compress bytes", str(cm.exception))
# perform roundtrip check
for c_name in (convenience_name, mime_type):
with self.subTest(f"Check snappy compression roundtrip using {c_name}"):
content_type, payload = compression.compress(TEST_DATA, c_name)
self.assertEqual(content_type, mime_type)
self.assertNotEqual(TEST_DATA, payload)
content_type, d = compression.decompress(payload, content_type)
self.assertEqual(content_type, mime_type)
self.assertEqual(d, TEST_DATA)
def test_compression_roundtrip(self):
codecs = compression.registry.compressors
for name, _settings in codecs.items():
with self.subTest(f"Check {name} compression roundtrip"):
convenience_name = name
mime_type = compression.registry.name_to_type[name]
# The convenience name or the content_type can be used when
# specifying compression method. Check both.
for c_label in (convenience_name, mime_type):
content_type, payload = compression.compress(TEST_DATA, c_label)
self.assertEqual(content_type, mime_type)
if c_label is None:
self.assertEqual(TEST_DATA, payload)
else:
self.assertNotEqual(TEST_DATA, payload)
content_type, d = compression.decompress(payload, content_type)
self.assertEqual(content_type, mime_type)
self.assertEqual(d, TEST_DATA)
def decode_payload(
data: bytes,
compression: Optional[str] = None,
content_type: Optional[str] = None,
content_encoding: Optional[str] = None,
type_identifier: Optional[int] = None,
) -> Any:
""" Decode a message payload
:param data: The message payload data to decode.
:param content_type: A string specifying the message content type. By
default the value is None.
:param compression: An optional string specifying a compression mime-type.
:param type_identifier: An integer that uniquely identifies a
registered message.
"""
if compression:
try:
_mime_type, data = decompress(data, compression)
except Exception as exc:
raise Exception(
f"Error decompressing payload using {compression}: {exc}"
) from None
try:
payload = loads(data,
content_type,
content_encoding,
type_identifier=type_identifier)
except Exception as exc:
raise Exception(
f"Error decoding payload with content-type={content_type}: {exc}"
) from None
return payload
def test_decompress_with_invalid_name_or_type(self):
with self.assertRaises(Exception) as cm:
compression.decompress(b"a", "invalid")
self.assertIn("Invalid compressor", str(cm.exception))
