import hashlib
import io
import struct
import sys
try:
import unittest2 as unittest
except ImportError:
import unittest
import zstd
from .common import (
make_cffi,
OpCountingBytesIO,
)
if sys.version_info[0] >= 3:
next = lambda it: it.__next__()
else:
next = lambda it: it.next()
def multithreaded_chunk_size(level, source_size=0):
params = zstd.get_compression_parameters(level, source_size)
return 1 << (params.window_log + 2)
@make_cffi
class TestCompressor(unittest.TestCase):
def test_level_bounds(self):
with self.assertRaises(ValueError):
zstd.ZstdCompressor(level=0)
with self.assertRaises(ValueError):
zstd.ZstdCompressor(level=23)
@make_cffi
class TestCompressor_compress(unittest.TestCase):
def test_multithreaded_unsupported(self):
samples = []
for i in range(128):
samples.append(b'foo' * 64)
samples.append(b'bar' * 64)
d = zstd.train_dictionary(8192, samples)
cctx = zstd.ZstdCompressor(dict_data=d, threads=2)
with self.assertRaisesRegexp(zstd.ZstdError, 'compress\(\) cannot be used with both dictionaries and multi-threaded compression'):
cctx.compress(b'foo')
params = zstd.get_compression_parameters(3)
cctx = zstd.ZstdCompressor(compression_params=params, threads=2)
with self.assertRaisesRegexp(zstd.ZstdError, 'compress\(\) cannot be used with both compression parameters and multi-threaded compression'):
cctx.compress(b'foo')
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_compress_large(self):
chunks = []
for i in range(255):
chunks.append(struct.Struct('>B').pack(i) * 16384)
cctx = zstd.ZstdCompressor(level=3)
result = cctx.compress(b''.join(chunks))
self.assertEqual(len(result), 999)
self.assertEqual(result[0:4], b'\x28\xb5\x2f\xfd')
# This matches the test for read_from() below.
cctx = zstd.ZstdCompressor(level=1)
result = cctx.compress(b'f' * zstd.COMPRESSION_RECOMMENDED_INPUT_SIZE + b'o')
self.assertEqual(result, b'\x28\xb5\x2f\xfd\x00\x40\x54\x00\x00'
b'\x10\x66\x66\x01\x00\xfb\xff\x39\xc0'
b'\x02\x09\x00\x00\x6f')
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_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_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_compress_dict_multiple(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)
cctx = zstd.ZstdCompressor(level=1, dict_data=d)
for i in range(32):
cctx.compress(b'foo bar foobar foo bar foobar')
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)
@make_cffi
class TestCompressor_compressobj(unittest.TestCase):
def test_compressobj_empty(self):
cctx = zstd.ZstdCompressor(level=1)
cobj = cctx.compressobj()
self.assertEqual(cobj.compress(b''), b'')
self.assertEqual(cobj.flush(),
b'\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00')
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_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_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_compress_after_finished(self):
cctx = zstd.ZstdCompressor()
cobj = cctx.compressobj()
cobj.compress(b'foo')
cobj.flush()
with self.assertRaisesRegexp(zstd.ZstdError, 'cannot call compress\(\) after compressor'):
cobj.compress(b'foo')
with self.assertRaisesRegexp(zstd.ZstdError, 'compressor object already finished'):
cobj.flush()
def test_flush_block_repeated(self):
cctx = zstd.ZstdCompressor(level=1)
cobj = cctx.compressobj()
self.assertEqual(cobj.compress(b'foo'), b'')
self.assertEqual(cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK),
b'\x28\xb5\x2f\xfd\x00\x48\x18\x00\x00foo')
self.assertEqual(cobj.compress(b'bar'), b'')
# 3 byte header plus content.
self.assertEqual(cobj.flush(), b'\x19\x00\x00bar')
def test_flush_empty_block(self):
cctx = zstd.ZstdCompressor(write_checksum=True)
cobj = cctx.compressobj()
cobj.compress(b'foobar')
cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK)
# No-op if no block is active (this is internal to zstd).
self.assertEqual(cobj.flush(zstd.COMPRESSOBJ_FLUSH_BLOCK), b'')
trailing = cobj.flush()
# 3 bytes block header + 4 bytes frame checksum
self.assertEqual(len(trailing), 7)
header = trailing[0:3]
self.assertEqual(header, b'\x01\x00\x00')
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)
cctx = zstd.ZstdCompressor(level=1, threads=2)
cobj = cctx.compressobj()
chunks = []
while True:
d = source.read(8192)
if not d:
break
chunks.append(cobj.compress(d))
chunks.append(cobj.flush())
compressed = b''.join(chunks)
self.assertEqual(len(compressed), 295)
@make_cffi
class TestCompressor_copy_stream(unittest.TestCase):
def test_no_read(self):
source = object()
dest = io.BytesIO()
cctx = zstd.ZstdCompressor()
with self.assertRaises(ValueError):
cctx.copy_stream(source, dest)
def test_no_write(self):
source = io.BytesIO()
dest = object()
cctx = zstd.ZstdCompressor()
with self.assertRaises(ValueError):
cctx.copy_stream(source, dest)
def test_empty(self):
source = io.BytesIO()
dest = io.BytesIO()
cctx = zstd.ZstdCompressor(level=1)
r, w = cctx.copy_stream(source, dest)
self.assertEqual(int(r), 0)
self.assertEqual(w, 9)
self.assertEqual(dest.getvalue(),
b'\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00')
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_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_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_read_write_size(self):
source = OpCountingBytesIO(b'foobarfoobar')
dest = OpCountingBytesIO()
cctx = zstd.ZstdCompressor()
r, w = cctx.copy_stream(source, dest, read_size=1, write_size=1)
self.assertEqual(r, len(source.getvalue()))
self.assertEqual(w, 21)
self.assertEqual(source._read_count, len(source.getvalue()) + 1)
self.assertEqual(dest._write_count, len(dest.getvalue()))
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 compress(data, level):
buffer = io.BytesIO()
cctx = zstd.ZstdCompressor(level=level)
with cctx.write_to(buffer) as compressor:
compressor.write(data)
return buffer.getvalue()
@make_cffi
class TestCompressor_write_to(unittest.TestCase):
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_multiple_compress(self):
buffer = io.BytesIO()
cctx = zstd.ZstdCompressor(level=5)
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'x' * 8192), 0)
result = buffer.getvalue()
self.assertEqual(result,
b'\x28\xb5\x2f\xfd\x00\x50\x75\x00\x00\x38\x66\x6f'
b'\x6f\x62\x61\x72\x78\x01\x00\xfc\xdf\x03\x23')
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_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_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_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_memory_size(self):
cctx = zstd.ZstdCompressor(level=3)
buffer = io.BytesIO()
with cctx.write_to(buffer) as compressor:
size = compressor.memory_size()
self.assertGreater(size, 100000)
def test_write_size(self):
cctx = zstd.ZstdCompressor(level=3)
dest = OpCountingBytesIO()
with cctx.write_to(dest, write_size=1) as compressor:
self.assertEqual(compressor.write(b'foo'), 0)
self.assertEqual(compressor.write(b'bar'), 0)
self.assertEqual(compressor.write(b'foobar'), 0)
self.assertEqual(len(dest.getvalue()), dest._write_count)
def test_flush_repeated(self):
cctx = zstd.ZstdCompressor(level=3)
dest = OpCountingBytesIO()
with cctx.write_to(dest) as compressor:
self.assertEqual(compressor.write(b'foo'), 0)
self.assertEqual(dest._write_count, 0)
self.assertEqual(compressor.flush(), 12)
self.assertEqual(dest._write_count, 1)
self.assertEqual(compressor.write(b'bar'), 0)
self.assertEqual(dest._write_count, 1)
self.assertEqual(compressor.flush(), 6)
self.assertEqual(dest._write_count, 2)
self.assertEqual(compressor.write(b'baz'), 0)
self.assertEqual(dest._write_count, 3)
def test_flush_empty_block(self):
cctx = zstd.ZstdCompressor(level=3, write_checksum=True)
dest = OpCountingBytesIO()
with cctx.write_to(dest) as compressor:
self.assertEqual(compressor.write(b'foobar' * 8192), 0)
count = dest._write_count
offset = dest.tell()
self.assertEqual(compressor.flush(), 23)
self.assertGreater(dest._write_count, count)
self.assertGreater(dest.tell(), offset)
offset = dest.tell()
# Ending the write here should cause an empty block to be written
# to denote end of frame.
trailing = dest.getvalue()[offset:]
# 3 bytes block header + 4 bytes frame checksum
self.assertEqual(len(trailing), 7)
header = trailing[0:3]
self.assertEqual(header, b'\x01\x00\x00')
def test_multithreaded(self):
dest = io.BytesIO()
cctx = zstd.ZstdCompressor(threads=2)
with cctx.write_to(dest) as compressor:
compressor.write(b'a' * 1048576)
compressor.write(b'b' * 1048576)
compressor.write(b'c' * 1048576)
self.assertEqual(len(dest.getvalue()), 295)
@make_cffi
class TestCompressor_read_from(unittest.TestCase):
def test_type_validation(self):
cctx = zstd.ZstdCompressor()
# Object with read() works.
for chunk in cctx.read_from(io.BytesIO()):
pass
# Buffer protocol works.
for chunk in cctx.read_from(b'foobar'):
pass
with self.assertRaisesRegexp(ValueError, 'must pass an object with a read'):
for chunk in cctx.read_from(True):
pass
def test_read_empty(self):
cctx = zstd.ZstdCompressor(level=1)
source = io.BytesIO()
it = cctx.read_from(source)
chunks = list(it)
self.assertEqual(len(chunks), 1)
compressed = b''.join(chunks)
self.assertEqual(compressed, b'\x28\xb5\x2f\xfd\x00\x48\x01\x00\x00')
# And again with the buffer protocol.
it = cctx.read_from(b'')
chunks = list(it)
self.assertEqual(len(chunks), 1)
compressed2 = b''.join(chunks)
self.assertEqual(compressed2, compressed)
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_read_write_size(self):
source = OpCountingBytesIO(b'foobarfoobar')
cctx = zstd.ZstdCompressor(level=3)
for chunk in cctx.read_from(source, read_size=1, write_size=1):
self.assertEqual(len(chunk), 1)
self.assertEqual(source._read_count, len(source.getvalue()) + 1)
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)
cctx = zstd.ZstdCompressor(threads=2)
compressed = b''.join(cctx.read_from(source))
self.assertEqual(len(compressed), 295)
class TestCompressor_multi_compress_to_buffer(unittest.TestCase):
def test_multithreaded_unsupported(self):
cctx = zstd.ZstdCompressor(threads=2)
with self.assertRaisesRegexp(zstd.ZstdError, 'function cannot be called on ZstdCompressor configured for multi-threaded compression'):
cctx.multi_compress_to_buffer([b'foo'])
def test_invalid_inputs(self):
cctx = zstd.ZstdCompressor()
with self.assertRaises(TypeError):
cctx.multi_compress_to_buffer(True)
with self.assertRaises(TypeError):
cctx.multi_compress_to_buffer((1, 2))
with self.assertRaisesRegexp(TypeError, 'item 0 not a bytes like object'):
cctx.multi_compress_to_buffer([u'foo'])
def test_empty_input(self):
cctx = zstd.ZstdCompressor()
with self.assertRaisesRegexp(ValueError, 'no source elements found'):
cctx.multi_compress_to_buffer([])
with self.assertRaisesRegexp(ValueError, 'source elements are empty'):
cctx.multi_compress_to_buffer([b'', b'', b''])
def test_list_input(self):
cctx = zstd.ZstdCompressor(write_content_size=True, write_checksum=True)
original = [b'foo' * 12, b'bar' * 6]
frames = [cctx.compress(c) for c in original]
b = cctx.multi_compress_to_buffer(original)
self.assertIsInstance(b, zstd.BufferWithSegmentsCollection)
self.assertEqual(len(b), 2)
self.assertEqual(b.size(), 44)
self.assertEqual(b[0].tobytes(), frames[0])
self.assertEqual(b[1].tobytes(), frames[1])
def test_buffer_with_segments_input(self):
cctx = zstd.ZstdCompressor(write_content_size=True, write_checksum=True)
original = [b'foo' * 4, b'bar' * 6]
frames = [cctx.compress(c) for c in original]
offsets = struct.pack('=QQQQ', 0, len(original[0]),
len(original[0]), len(original[1]))
segments = zstd.BufferWithSegments(b''.join(original), offsets)
result = cctx.multi_compress_to_buffer(segments)
self.assertEqual(len(result), 2)
self.assertEqual(result.size(), 47)
self.assertEqual(result[0].tobytes(), frames[0])
self.assertEqual(result[1].tobytes(), frames[1])
def test_buffer_with_segments_collection_input(self):
cctx = zstd.ZstdCompressor(write_content_size=True, write_checksum=True)
original = [
b'foo1',
b'foo2' * 2,
b'foo3' * 3,
b'foo4' * 4,
b'foo5' * 5,
]
frames = [cctx.compress(c) for c in original]
b = b''.join([original[0], original[1]])
b1 = zstd.BufferWithSegments(b, struct.pack('=QQQQ',
0, len(original[0]),
len(original[0]), len(original[1])))
b = b''.join([original[2], original[3], original[4]])
b2 = zstd.BufferWithSegments(b, struct.pack('=QQQQQQ',
0, len(original[2]),
len(original[2]), len(original[3]),
len(original[2]) + len(original[3]), len(original[4])))
c = zstd.BufferWithSegmentsCollection(b1, b2)
result = cctx.multi_compress_to_buffer(c)
self.assertEqual(len(result), len(frames))
for i, frame in enumerate(frames):
self.assertEqual(result[i].tobytes(), frame)
def test_multiple_threads(self):
# threads argument will cause multi-threaded ZSTD APIs to be used, which will
# make output different.
refcctx = zstd.ZstdCompressor(write_content_size=True, write_checksum=True)
reference = [refcctx.compress(b'x' * 64), refcctx.compress(b'y' * 64)]
cctx = zstd.ZstdCompressor(write_content_size=True, write_checksum=True)
frames = []
frames.extend(b'x' * 64 for i in range(256))
frames.extend(b'y' * 64 for i in range(256))
result = cctx.multi_compress_to_buffer(frames, threads=-1)
self.assertEqual(len(result), 512)
for i in range(512):
if i < 256:
self.assertEqual(result[i].tobytes(), reference[0])
else:
self.assertEqual(result[i].tobytes(), reference[1])