def test_write_content_size(self):
source = io.BytesIO(b'foobar' * 256)
no_size = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1)
cctx.copy_stream(source, no_size)
source.seek(0)
with_size = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1, write_content_size=True)
cctx.copy_stream(source, with_size)
# Source content size is unknown, so no content size written.
self.assertEqual(len(with_size.getvalue()), len(no_size.getvalue()))
source.seek(0)
with_size = io.BytesIO()
cctx.copy_stream(source, with_size, size=len(source.getvalue()))
# We specified source size, so content size header is present.
self.assertEqual(len(with_size.getvalue()),
len(no_size.getvalue()) + 1)
no_params = zstd.get_frame_parameters(no_size.getvalue())
with_params = zstd.get_frame_parameters(with_size.getvalue())
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 1536)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertFalse(with_params.has_checksum)
def test_write_content_size(self):
no_size = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1)
with cctx.write_to(no_size) as compressor:
self.assertEqual(compressor.write(b'foobar' * 256), 0)
with_size = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1, write_content_size=True)
with cctx.write_to(with_size) as compressor:
self.assertEqual(compressor.write(b'foobar' * 256), 0)
# Source size is not known in streaming mode, so header not
# written.
self.assertEqual(len(with_size.getvalue()), len(no_size.getvalue()))
# Declaring size will write the header.
with_size = io.BytesIO()
with cctx.write_to(with_size, size=len(b'foobar' * 256)) as compressor:
self.assertEqual(compressor.write(b'foobar' * 256), 0)
no_params = zstd.get_frame_parameters(no_size.getvalue())
with_params = zstd.get_frame_parameters(with_size.getvalue())
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 1536)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertFalse(with_params.has_checksum)
self.assertEqual(len(with_size.getvalue()),
len(no_size.getvalue()) + 1)
def test_no_dict_id(self):
samples = []
for i in range(128):
samples.append(b'foo' * 64)
samples.append(b'bar' * 64)
samples.append(b'foobar' * 64)
d = zstd.train_dictionary(1024, samples)
with_dict_id = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1, dict_data=d)
with cctx.write_to(with_dict_id) as compressor:
self.assertEqual(compressor.write(b'foobarfoobar'), 0)
cctx = zstd.ZstdCompressor(level=1, dict_data=d, write_dict_id=False)
no_dict_id = io.BytesIO()
with cctx.write_to(no_dict_id) as compressor:
self.assertEqual(compressor.write(b'foobarfoobar'), 0)
no_params = zstd.get_frame_parameters(no_dict_id.getvalue())
with_params = zstd.get_frame_parameters(with_dict_id.getvalue())
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 0)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, d.dict_id())
self.assertFalse(no_params.has_checksum)
self.assertFalse(with_params.has_checksum)
self.assertEqual(len(with_dict_id.getvalue()),
len(no_dict_id.getvalue()) + 4)
def test_multithreaded(self):
source = io.BytesIO()
source.write(b'a' * 1048576)
source.write(b'b' * 1048576)
source.write(b'c' * 1048576)
source.seek(0)
dest = io.BytesIO()
cctx = zstd.ZstdCompressor(threads=2)
r, w = cctx.copy_stream(source, dest)
self.assertEqual(r, 3145728)
self.assertEqual(w, 295)
params = zstd.get_frame_parameters(dest.getvalue())
self.assertEqual(params.content_size, 0)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
# Writing content size and checksum works.
cctx = zstd.ZstdCompressor(threads=2,
write_content_size=True,
write_checksum=True)
dest = io.BytesIO()
source.seek(0)
cctx.copy_stream(source, dest, size=len(source.getvalue()))
params = zstd.get_frame_parameters(dest.getvalue())
self.assertEqual(params.content_size, 3145728)
self.assertEqual(params.dict_id, 0)
self.assertTrue(params.has_checksum)
def test_invalid_input_sizes(self):
with self.assertRaisesRegexp(zstd.ZstdError,
'not enough data for frame'):
zstd.get_frame_parameters(b'')
with self.assertRaisesRegexp(zstd.ZstdError,
'not enough data for frame'):
zstd.get_frame_parameters(zstd.FRAME_HEADER)
def test_write_content_size(self):
cctx = zstd.ZstdCompressor(level=1)
no_size = cctx.compress(b'foobar' * 256)
cctx = zstd.ZstdCompressor(level=1, write_content_size=True)
with_size = cctx.compress(b'foobar' * 256)
self.assertEqual(len(with_size), len(no_size) + 1)
no_params = zstd.get_frame_parameters(no_size)
with_params = zstd.get_frame_parameters(with_size)
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 1536)
def test_write_checksum(self):
cctx = zstd.ZstdCompressor(level=1)
no_checksum = cctx.compress(b'foobar')
cctx = zstd.ZstdCompressor(level=1, write_checksum=True)
with_checksum = cctx.compress(b'foobar')
self.assertEqual(len(with_checksum), len(no_checksum) + 4)
no_params = zstd.get_frame_parameters(no_checksum)
with_params = zstd.get_frame_parameters(with_checksum)
self.assertFalse(no_params.has_checksum)
self.assertTrue(with_params.has_checksum)
def test_dictionary(self):
samples = []
for i in range(128):
samples.append(b'foo' * 64)
samples.append(b'bar' * 64)
samples.append(b'foobar' * 64)
d = zstd.train_dictionary(8192, samples)
buffer = io.BytesIO()
cctx = zstd.ZstdCompressor(level=9, dict_data=d)
with cctx.write_to(buffer) as compressor:
self.assertEqual(compressor.write(b'foo'), 0)
self.assertEqual(compressor.write(b'bar'), 0)
self.assertEqual(compressor.write(b'foo' * 16384), 634)
compressed = buffer.getvalue()
params = zstd.get_frame_parameters(compressed)
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1024)
self.assertEqual(params.dict_id, d.dict_id())
self.assertFalse(params.has_checksum)
self.assertEqual(
compressed[0:32],
b'\x28\xb5\x2f\xfd\x03\x00\x55\x7b\x6b\x5e\x54\x00'
b'\x00\x00\x02\xfc\xf4\xa5\xba\x23\x3f\x85\xb3\x54'
b'\x00\x00\x18\x6f\x6f\x66\x01\x00')
h = hashlib.sha1(compressed).hexdigest()
self.assertEqual(h, '1c5bcd25181bcd8c1a73ea8773323e0056129f92')
def test_write_content_size(self):
cctx = zstd.ZstdCompressor(level=1)
cobj = cctx.compressobj(size=len(b'foobar' * 256))
no_size = cobj.compress(b'foobar' * 256) + cobj.flush()
cctx = zstd.ZstdCompressor(level=1, write_content_size=True)
cobj = cctx.compressobj(size=len(b'foobar' * 256))
with_size = cobj.compress(b'foobar' * 256) + cobj.flush()
no_params = zstd.get_frame_parameters(no_size)
with_params = zstd.get_frame_parameters(with_size)
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 1536)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertFalse(with_params.has_checksum)
self.assertEqual(len(with_size), len(no_size) + 1)
def test_write_checksum(self):
cctx = zstd.ZstdCompressor(level=1)
cobj = cctx.compressobj()
no_checksum = cobj.compress(b'foobar') + cobj.flush()
cctx = zstd.ZstdCompressor(level=1, write_checksum=True)
cobj = cctx.compressobj()
with_checksum = cobj.compress(b'foobar') + cobj.flush()
no_params = zstd.get_frame_parameters(no_checksum)
with_params = zstd.get_frame_parameters(with_checksum)
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 0)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertTrue(with_params.has_checksum)
self.assertEqual(len(with_checksum), len(no_checksum) + 4)
def test_empty(self):
result = compress(b'', 1)
self.assertEqual(result, b'\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00')
params = zstd.get_frame_parameters(result)
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 524288)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
def test_no_dict_id(self):
samples = []
for i in range(128):
samples.append(b'foo' * 64)
samples.append(b'bar' * 64)
samples.append(b'foobar' * 64)
d = zstd.train_dictionary(1024, samples)
cctx = zstd.ZstdCompressor(level=1, dict_data=d)
with_dict_id = cctx.compress(b'foobarfoobar')
cctx = zstd.ZstdCompressor(level=1, dict_data=d, write_dict_id=False)
no_dict_id = cctx.compress(b'foobarfoobar')
self.assertEqual(len(with_dict_id), len(no_dict_id) + 4)
no_params = zstd.get_frame_parameters(no_dict_id)
with_params = zstd.get_frame_parameters(with_dict_id)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 1584102229)
def test_write_checksum(self):
no_checksum = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1)
with cctx.write_to(no_checksum) as compressor:
self.assertEqual(compressor.write(b'foobar'), 0)
with_checksum = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1, write_checksum=True)
with cctx.write_to(with_checksum) as compressor:
self.assertEqual(compressor.write(b'foobar'), 0)
no_params = zstd.get_frame_parameters(no_checksum.getvalue())
with_params = zstd.get_frame_parameters(with_checksum.getvalue())
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 0)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertTrue(with_params.has_checksum)
self.assertEqual(len(with_checksum.getvalue()),
len(no_checksum.getvalue()) + 4)
def test_multithreaded(self):
chunk_size = multithreaded_chunk_size(1)
source = b''.join([b'x' * chunk_size, b'y' * chunk_size])
cctx = zstd.ZstdCompressor(level=1, threads=2)
compressed = cctx.compress(source)
params = zstd.get_frame_parameters(compressed)
self.assertEqual(params.content_size, chunk_size * 2)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
dctx = zstd.ZstdDecompressor()
self.assertEqual(dctx.decompress(compressed), source)
def test_write_checksum(self):
source = io.BytesIO(b'foobar')
no_checksum = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1)
cctx.copy_stream(source, no_checksum)
source.seek(0)
with_checksum = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1, write_checksum=True)
cctx.copy_stream(source, with_checksum)
self.assertEqual(len(with_checksum.getvalue()),
len(no_checksum.getvalue()) + 4)
no_params = zstd.get_frame_parameters(no_checksum.getvalue())
with_params = zstd.get_frame_parameters(with_checksum.getvalue())
self.assertEqual(no_params.content_size, 0)
self.assertEqual(with_params.content_size, 0)
self.assertEqual(no_params.dict_id, 0)
self.assertEqual(with_params.dict_id, 0)
self.assertFalse(no_params.has_checksum)
self.assertTrue(with_params.has_checksum)
def test_read_large(self):
cctx = zstd.ZstdCompressor(level=1)
source = io.BytesIO()
source.write(b'f' * zstd.COMPRESSION_RECOMMENDED_INPUT_SIZE)
source.write(b'o')
source.seek(0)
# Creating an iterator should not perform any compression until
# first read.
it = cctx.read_from(source, size=len(source.getvalue()))
self.assertEqual(source.tell(), 0)
# We should have exactly 2 output chunks.
chunks = []
chunk = next(it)
self.assertIsNotNone(chunk)
self.assertEqual(source.tell(),
zstd.COMPRESSION_RECOMMENDED_INPUT_SIZE)
chunks.append(chunk)
chunk = next(it)
self.assertIsNotNone(chunk)
chunks.append(chunk)
self.assertEqual(source.tell(), len(source.getvalue()))
with self.assertRaises(StopIteration):
next(it)
# And again for good measure.
with self.assertRaises(StopIteration):
next(it)
# We should get the same output as the one-shot compression mechanism.
self.assertEqual(b''.join(chunks), cctx.compress(source.getvalue()))
params = zstd.get_frame_parameters(b''.join(chunks))
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 262144)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
# Now check the buffer protocol.
it = cctx.read_from(source.getvalue())
chunks = list(it)
self.assertEqual(len(chunks), 2)
self.assertEqual(b''.join(chunks), cctx.compress(source.getvalue()))
def test_compress_empty(self):
cctx = zstd.ZstdCompressor(level=1)
result = cctx.compress(b'')
self.assertEqual(result, b'\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00')
params = zstd.get_frame_parameters(result)
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 524288)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum, 0)
# TODO should be temporary until https://github.com/facebook/zstd/issues/506
# is fixed.
cctx = zstd.ZstdCompressor(write_content_size=True)
with self.assertRaises(ValueError):
cctx.compress(b'')
cctx.compress(b'', allow_empty=True)
def test_compressobj_large(self):
chunks = []
for i in range(255):
chunks.append(struct.Struct('>B').pack(i) * 16384)
cctx = zstd.ZstdCompressor(level=3)
cobj = cctx.compressobj()
result = cobj.compress(b''.join(chunks)) + cobj.flush()
self.assertEqual(len(result), 999)
self.assertEqual(result[0:4], b'\x28\xb5\x2f\xfd')
params = zstd.get_frame_parameters(result)
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1048576)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
def test_large_data(self):
source = io.BytesIO()
for i in range(255):
source.write(struct.Struct('>B').pack(i) * 16384)
source.seek(0)
dest = io.BytesIO()
cctx = zstd.ZstdCompressor()
r, w = cctx.copy_stream(source, dest)
self.assertEqual(r, 255 * 16384)
self.assertEqual(w, 999)
params = zstd.get_frame_parameters(dest.getvalue())
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1048576)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
def test_compression_params(self):
params = zstd.CompressionParameters(20, 6, 12, 5, 4, 10,
zstd.STRATEGY_FAST)
buffer = io.BytesIO()
cctx = zstd.ZstdCompressor(compression_params=params)
with cctx.write_to(buffer) as compressor:
self.assertEqual(compressor.write(b'foo'), 0)
self.assertEqual(compressor.write(b'bar'), 0)
self.assertEqual(compressor.write(b'foobar' * 16384), 0)
compressed = buffer.getvalue()
params = zstd.get_frame_parameters(compressed)
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1048576)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
h = hashlib.sha1(compressed).hexdigest()
self.assertEqual(h, '1ae31f270ed7de14235221a604b31ecd517ebd99')
def test_attributes(self):
params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x00\x00')
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1024)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
# Lowest 2 bits indicate a dictionary and length. Here, the dict id is 1 byte.
params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x01\x00\xff')
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1024)
self.assertEqual(params.dict_id, 255)
self.assertFalse(params.has_checksum)
# Lowest 3rd bit indicates if checksum is present.
params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x04\x00')
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 1024)
self.assertEqual(params.dict_id, 0)
self.assertTrue(params.has_checksum)
# Upper 2 bits indicate content size.
params = zstd.get_frame_parameters(zstd.FRAME_HEADER +
b'\x40\x00\xff\x00')
self.assertEqual(params.content_size, 511)
self.assertEqual(params.window_size, 1024)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
# Window descriptor is 2nd byte after frame header.
params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x00\x40')
self.assertEqual(params.content_size, 0)
self.assertEqual(params.window_size, 262144)
self.assertEqual(params.dict_id, 0)
self.assertFalse(params.has_checksum)
# Set multiple things.
params = zstd.get_frame_parameters(zstd.FRAME_HEADER +
b'\x45\x40\x0f\x10\x00')
self.assertEqual(params.content_size, 272)
self.assertEqual(params.window_size, 262144)
self.assertEqual(params.dict_id, 15)
self.assertTrue(params.has_checksum)
def test_invalid_frame(self):
with self.assertRaisesRegexp(zstd.ZstdError,
'Unknown frame descriptor'):
zstd.get_frame_parameters(b'foobarbaz')
def test_invalid_type(self):
with self.assertRaises(TypeError):
zstd.get_frame_parameters(None)
with self.assertRaises(TypeError):
zstd.get_frame_parameters(u'foobarbaz')