contrib/python-zstandard/tests/test_decompressor_fuzzing.py

drawdag: don't crash when writing copy info to changesets

When writing copies to the changeset, localrepo.commitctx() will call
ctx.p1copies() and ctx.p2copies(). These crashed on simplecommitctx
because they ended up trying to access the manifest. drawdag doesn't
support copies at all, so we can simply override the methods to return
empty dicts.

Differential Revision: https://phab.mercurial-scm.org/D6565

import io
import os
import unittest

try:
    import hypothesis
    import hypothesis.strategies as strategies
except ImportError:
    raise unittest.SkipTest('hypothesis not available')

import zstandard as zstd

from . common import (
    make_cffi,
    NonClosingBytesIO,
    random_input_data,
)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestDecompressor_stream_reader_fuzzing(unittest.TestCase):
    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_sizes=strategies.data())
    def test_stream_source_read_variance(self, original, level, streaming,
                                         source_read_size, read_sizes):
        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            source.seek(0)
        else:
            frame = cctx.compress(original)
            source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()

        chunks = []
        with dctx.stream_reader(source, read_size=source_read_size) as reader:
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 131072))
                chunk = reader.read(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b''.join(chunks), original)

    # Similar to above except we have a constant read() size.
    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_size=strategies.integers(-1, 131072))
    def test_stream_source_read_size(self, original, level, streaming,
                                     source_read_size, read_size):
        if read_size == 0:
            read_size = 1

        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            source.seek(0)
        else:
            frame = cctx.compress(original)
            source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()

        chunks = []
        reader = dctx.stream_reader(source, read_size=source_read_size)
        while True:
            chunk = reader.read(read_size)
            if not chunk and read_size:
                break

            chunks.append(chunk)

        self.assertEqual(b''.join(chunks), original)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_sizes=strategies.data())
    def test_buffer_source_read_variance(self, original, level, streaming,
                                         source_read_size, read_sizes):
        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            frame = source.getvalue()
        else:
            frame = cctx.compress(original)

        dctx = zstd.ZstdDecompressor()
        chunks = []

        with dctx.stream_reader(frame, read_size=source_read_size) as reader:
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 131072))
                chunk = reader.read(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b''.join(chunks), original)

    # Similar to above except we have a constant read() size.
    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_size=strategies.integers(-1, 131072))
    def test_buffer_source_constant_read_size(self, original, level, streaming,
                                              source_read_size, read_size):
        if read_size == 0:
            read_size = -1

        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            frame = source.getvalue()
        else:
            frame = cctx.compress(original)

        dctx = zstd.ZstdDecompressor()
        chunks = []

        reader = dctx.stream_reader(frame, read_size=source_read_size)
        while True:
            chunk = reader.read(read_size)
            if not chunk and read_size:
                break

            chunks.append(chunk)

        self.assertEqual(b''.join(chunks), original)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576))
    def test_stream_source_readall(self, original, level, streaming,
                                         source_read_size):
        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            source.seek(0)
        else:
            frame = cctx.compress(original)
            source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()

        data = dctx.stream_reader(source, read_size=source_read_size).readall()
        self.assertEqual(data, original)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_sizes=strategies.data())
    def test_stream_source_read1_variance(self, original, level, streaming,
                                          source_read_size, read_sizes):
        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            source.seek(0)
        else:
            frame = cctx.compress(original)
            source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()

        chunks = []
        with dctx.stream_reader(source, read_size=source_read_size) as reader:
            while True:
                read_size = read_sizes.draw(strategies.integers(-1, 131072))
                chunk = reader.read1(read_size)
                if not chunk and read_size:
                    break

                chunks.append(chunk)

        self.assertEqual(b''.join(chunks), original)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      streaming=strategies.booleans(),
                      source_read_size=strategies.integers(1, 1048576),
                      read_sizes=strategies.data())
    def test_stream_source_readinto1_variance(self, original, level, streaming,
                                          source_read_size, read_sizes):
        cctx = zstd.ZstdCompressor(level=level)

        if streaming:
            source = io.BytesIO()
            writer = cctx.stream_writer(source)
            writer.write(original)
            writer.flush(zstd.FLUSH_FRAME)
            source.seek(0)
        else:
            frame = cctx.compress(original)
            source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()

        chunks = []
        with dctx.stream_reader(source, read_size=source_read_size) as reader:
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 131072))
                b = bytearray(read_size)
                count = reader.readinto1(b)

                if not count:
                    break

                chunks.append(bytes(b[0:count]))

        self.assertEqual(b''.join(chunks), original)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(
        original=strategies.sampled_from(random_input_data()),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 1048576),
        seek_amounts=strategies.data(),
        read_sizes=strategies.data())
    def test_relative_seeks(self, original, level, source_read_size, seek_amounts,
                            read_sizes):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        dctx = zstd.ZstdDecompressor()

        with dctx.stream_reader(frame, read_size=source_read_size) as reader:
            while True:
                amount = seek_amounts.draw(strategies.integers(0, 16384))
                reader.seek(amount, os.SEEK_CUR)

                offset = reader.tell()
                read_amount = read_sizes.draw(strategies.integers(1, 16384))
                chunk = reader.read(read_amount)

                if not chunk:
                    break

                self.assertEqual(original[offset:offset + len(chunk)], chunk)

    @hypothesis.settings(
        suppress_health_check=[hypothesis.HealthCheck.large_base_example])
    @hypothesis.given(
        originals=strategies.data(),
        frame_count=strategies.integers(min_value=2, max_value=10),
        level=strategies.integers(min_value=1, max_value=5),
        source_read_size=strategies.integers(1, 1048576),
        read_sizes=strategies.data())
    def test_multiple_frames(self, originals, frame_count, level,
                             source_read_size, read_sizes):

        cctx = zstd.ZstdCompressor(level=level)
        source = io.BytesIO()
        buffer = io.BytesIO()
        writer = cctx.stream_writer(buffer)

        for i in range(frame_count):
            data = originals.draw(strategies.sampled_from(random_input_data()))
            source.write(data)
            writer.write(data)
            writer.flush(zstd.FLUSH_FRAME)

        dctx = zstd.ZstdDecompressor()
        buffer.seek(0)
        reader = dctx.stream_reader(buffer, read_size=source_read_size,
                                    read_across_frames=True)

        chunks = []

        while True:
            read_amount = read_sizes.draw(strategies.integers(-1, 16384))
            chunk = reader.read(read_amount)

            if not chunk and read_amount:
                break

            chunks.append(chunk)

        self.assertEqual(source.getvalue(), b''.join(chunks))


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestDecompressor_stream_writer_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      write_size=strategies.integers(min_value=1, max_value=8192),
                      input_sizes=strategies.data())
    def test_write_size_variance(self, original, level, write_size, input_sizes):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        dctx = zstd.ZstdDecompressor()
        source = io.BytesIO(frame)
        dest = NonClosingBytesIO()

        with dctx.stream_writer(dest, write_size=write_size) as decompressor:
            while True:
                input_size = input_sizes.draw(strategies.integers(1, 4096))
                chunk = source.read(input_size)
                if not chunk:
                    break

                decompressor.write(chunk)

        self.assertEqual(dest.getvalue(), original)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestDecompressor_copy_stream_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      read_size=strategies.integers(min_value=1, max_value=8192),
                      write_size=strategies.integers(min_value=1, max_value=8192))
    def test_read_write_size_variance(self, original, level, read_size, write_size):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        source = io.BytesIO(frame)
        dest = io.BytesIO()

        dctx = zstd.ZstdDecompressor()
        dctx.copy_stream(source, dest, read_size=read_size, write_size=write_size)

        self.assertEqual(dest.getvalue(), original)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestDecompressor_decompressobj_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      chunk_sizes=strategies.data())
    def test_random_input_sizes(self, original, level, chunk_sizes):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()
        dobj = dctx.decompressobj()

        chunks = []
        while True:
            chunk_size = chunk_sizes.draw(strategies.integers(1, 4096))
            chunk = source.read(chunk_size)
            if not chunk:
                break

            chunks.append(dobj.decompress(chunk))

        self.assertEqual(b''.join(chunks), original)

    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      write_size=strategies.integers(min_value=1,
                                                     max_value=4 * zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE),
                      chunk_sizes=strategies.data())
    def test_random_output_sizes(self, original, level, write_size, chunk_sizes):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()
        dobj = dctx.decompressobj(write_size=write_size)

        chunks = []
        while True:
            chunk_size = chunk_sizes.draw(strategies.integers(1, 4096))
            chunk = source.read(chunk_size)
            if not chunk:
                break

            chunks.append(dobj.decompress(chunk))

        self.assertEqual(b''.join(chunks), original)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestDecompressor_read_to_iter_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      read_size=strategies.integers(min_value=1, max_value=4096),
                      write_size=strategies.integers(min_value=1, max_value=4096))
    def test_read_write_size_variance(self, original, level, read_size, write_size):
        cctx = zstd.ZstdCompressor(level=level)
        frame = cctx.compress(original)

        source = io.BytesIO(frame)

        dctx = zstd.ZstdDecompressor()
        chunks = list(dctx.read_to_iter(source, read_size=read_size, write_size=write_size))

        self.assertEqual(b''.join(chunks), original)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
class TestDecompressor_multi_decompress_to_buffer_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.lists(strategies.sampled_from(random_input_data()),
                                        min_size=1, max_size=1024),
                threads=strategies.integers(min_value=1, max_value=8),
                use_dict=strategies.booleans())
    def test_data_equivalence(self, original, threads, use_dict):
        kwargs = {}
        if use_dict:
            kwargs['dict_data'] = zstd.ZstdCompressionDict(original[0])

        cctx = zstd.ZstdCompressor(level=1,
                                   write_content_size=True,
                                   write_checksum=True,
                                   **kwargs)

        if not hasattr(cctx, 'multi_compress_to_buffer'):
            self.skipTest('multi_compress_to_buffer not available')

        frames_buffer = cctx.multi_compress_to_buffer(original, threads=-1)

        dctx = zstd.ZstdDecompressor(**kwargs)
        result = dctx.multi_decompress_to_buffer(frames_buffer)

        self.assertEqual(len(result), len(original))
        for i, frame in enumerate(result):
            self.assertEqual(frame.tobytes(), original[i])

        frames_list = [f.tobytes() for f in frames_buffer]
        result = dctx.multi_decompress_to_buffer(frames_list)

        self.assertEqual(len(result), len(original))
        for i, frame in enumerate(result):
            self.assertEqual(frame.tobytes(), original[i])