contrib/python-zstandard/tests/test_compressor_fuzzing.py

shelve: fix crash on unshelve without .shelve metadata file

Follow up for c67c94c0e7ae and 38373da1af02.

The inline comment says "we should keep track of the unshelve node in case
we need to reuse it." Perhaps such case isn't tested, and this patch does
NOT add a test for the reuse of the unbundled revision.

Also, I have no idea what should be done if new revision is unbundled
because of "node not in repo".

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,
    random_input_data,
)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestCompressor_stream_reader_fuzzing(unittest.TestCase):
    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      source_read_size=strategies.integers(1, 16384),
                      read_sizes=strategies.data())
    def test_stream_source_read_variance(self, original, level, source_read_size,
                                         read_sizes):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(io.BytesIO(original), size=len(original),
                                read_size=source_read_size) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                chunk = reader.read(read_size)

                if not chunk:
                    break
                chunks.append(chunk)

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

    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
                      level=strategies.integers(min_value=1, max_value=5),
                      source_read_size=strategies.integers(1, 16384),
                      read_sizes=strategies.data())
    def test_buffer_source_read_variance(self, original, level, source_read_size,
                                         read_sizes):

        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        with cctx.stream_reader(original, size=len(original),
                                read_size=source_read_size) as reader:
            chunks = []
            while True:
                read_size = read_sizes.draw(strategies.integers(1, 16384))
                chunk = reader.read(read_size)
                if not chunk:
                    break
                chunks.append(chunk)

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


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestCompressor_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=1048576))
    def test_write_size_variance(self, original, level, write_size):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        b = io.BytesIO()
        with cctx.stream_writer(b, size=len(original), write_size=write_size) as compressor:
            compressor.write(original)

        self.assertEqual(b.getvalue(), ref_frame)


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestCompressor_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=1048576),
                      write_size=strategies.integers(min_value=1, max_value=1048576))
    def test_read_write_size_variance(self, original, level, read_size, write_size):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        source = io.BytesIO(original)
        dest = io.BytesIO()

        cctx.copy_stream(source, dest, size=len(original), read_size=read_size,
                         write_size=write_size)

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


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestCompressor_compressobj_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),
                      chunk_sizes=strategies.data())
    def test_random_input_sizes(self, original, level, chunk_sizes):
        refctx = zstd.ZstdCompressor(level=level)
        ref_frame = refctx.compress(original)

        cctx = zstd.ZstdCompressor(level=level)
        cobj = cctx.compressobj(size=len(original))

        chunks = []
        i = 0
        while True:
            chunk_size = chunk_sizes.draw(strategies.integers(1, 4096))
            source = original[i:i + chunk_size]
            if not source:
                break

            chunks.append(cobj.compress(source))
            i += chunk_size

        chunks.append(cobj.flush())

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


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
@make_cffi
class TestCompressor_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):
        refcctx = zstd.ZstdCompressor(level=level)
        ref_frame = refcctx.compress(original)

        source = io.BytesIO(original)

        cctx = zstd.ZstdCompressor(level=level)
        chunks = list(cctx.read_to_iter(source, size=len(original),
                                        read_size=read_size,
                                        write_size=write_size))

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


@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
class TestCompressor_multi_compress_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 = {}

        # Use a content dictionary because it is cheap to create.
        if use_dict:
            kwargs['dict_data'] = zstd.ZstdCompressionDict(original[0])

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

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

        self.assertEqual(len(result), len(original))

        # The frame produced via the batch APIs may not be bit identical to that
        # produced by compress() because compression parameters are adjusted
        # from the first input in batch mode. So the only thing we can do is
        # verify the decompressed data matches the input.
        dctx = zstd.ZstdDecompressor(**kwargs)

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