view contrib/python-zstandard/tests/test_data_structures_fuzzing.py @ 40121:73fef626dae3

zstandard: vendor python-zstandard 0.10.1

This was just released.

The upstream source distribution from PyPI was extracted. Unwanted
files were removed.

The clang-format ignore list was updated to reflect the new source
of files.

setup.py was updated to pass a new argument to python-zstandard's
function for returning an Extension instance. Upstream had to change
to use relative paths because Python 3.7's packaging doesn't
seem to like absolute paths when defining sources, includes, etc.
The default relative path calculation is relative to setup_zstd.py
which is different from the directory of Mercurial's setup.py.

The project contains a vendored copy of zstandard 1.3.6. The old
version was 1.3.4.

The API should be backwards compatible and nothing in core should
need adjusted. However, there is a new "chunker" API that we
may find useful in places where we want to emit compressed chunks
of a fixed size.

There are a pair of bug fixes in 0.10.0 with regards to
compressobj() and decompressobj() when block flushing is used. I
actually found these bugs when introducing these APIs in Mercurial!
But existing Mercurial code is not affected because we don't
perform block flushing.

# no-check-commit because 3rd party code has different style guidelines

Differential Revision: https://phab.mercurial-scm.org/D4911

import io
import os
import sys
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,
)


s_windowlog = strategies.integers(min_value=zstd.WINDOWLOG_MIN,
                                    max_value=zstd.WINDOWLOG_MAX)
s_chainlog = strategies.integers(min_value=zstd.CHAINLOG_MIN,
                                    max_value=zstd.CHAINLOG_MAX)
s_hashlog = strategies.integers(min_value=zstd.HASHLOG_MIN,
                                max_value=zstd.HASHLOG_MAX)
s_searchlog = strategies.integers(min_value=zstd.SEARCHLOG_MIN,
                                    max_value=zstd.SEARCHLOG_MAX)
s_searchlength = strategies.integers(min_value=zstd.SEARCHLENGTH_MIN,
                                     max_value=zstd.SEARCHLENGTH_MAX)
s_targetlength = strategies.integers(min_value=zstd.TARGETLENGTH_MIN,
                                     max_value=zstd.TARGETLENGTH_MAX)
s_strategy = strategies.sampled_from((zstd.STRATEGY_FAST,
                                        zstd.STRATEGY_DFAST,
                                        zstd.STRATEGY_GREEDY,
                                        zstd.STRATEGY_LAZY,
                                        zstd.STRATEGY_LAZY2,
                                        zstd.STRATEGY_BTLAZY2,
                                        zstd.STRATEGY_BTOPT,
                                        zstd.STRATEGY_BTULTRA))


@make_cffi
@unittest.skipUnless('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
class TestCompressionParametersHypothesis(unittest.TestCase):
    @hypothesis.given(s_windowlog, s_chainlog, s_hashlog, s_searchlog,
                        s_searchlength, s_targetlength, s_strategy)
    def test_valid_init(self, windowlog, chainlog, hashlog, searchlog,
                        searchlength, targetlength, strategy):
        zstd.ZstdCompressionParameters(window_log=windowlog,
                                       chain_log=chainlog,
                                       hash_log=hashlog,
                                       search_log=searchlog,
                                       min_match=searchlength,
                                       target_length=targetlength,
                                       compression_strategy=strategy)

    @hypothesis.given(s_windowlog, s_chainlog, s_hashlog, s_searchlog,
                        s_searchlength, s_targetlength, s_strategy)
    def test_estimated_compression_context_size(self, windowlog, chainlog,
                                                hashlog, searchlog,
                                                searchlength, targetlength,
                                                strategy):
        if searchlength == zstd.SEARCHLENGTH_MIN and strategy in (zstd.STRATEGY_FAST, zstd.STRATEGY_GREEDY):
            searchlength += 1
        elif searchlength == zstd.SEARCHLENGTH_MAX and strategy != zstd.STRATEGY_FAST:
            searchlength -= 1

        p = zstd.ZstdCompressionParameters(window_log=windowlog,
                                           chain_log=chainlog,
                                           hash_log=hashlog,
                                           search_log=searchlog,
                                           min_match=searchlength,
                                           target_length=targetlength,
                                           compression_strategy=strategy)
        size = p.estimated_compression_context_size()