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])