diff contrib/python-zstandard/tests/test_compressor_fuzzing.py @ 31796:e0dc40530c5a

zstd: vendor python-zstandard 0.8.0

Commit 81e1f5bbf1fc54808649562d3ed829730765c540 from
https://github.com/indygreg/python-zstandard is imported without
modifications (other than removing unwanted files).

Updates relevant to Mercurial include:

* Support for multi-threaded compression (we can use this for
  bundle and wire protocol compression).
* APIs for batch compression and decompression operations using
  multiple threads and optimal memory allocation mechanism. (Can
  be useful for revlog perf improvements.)
* A ``BufferWithSegments`` type that models a single memory buffer
  containing N discrete items of known lengths. This type can be
  used for very efficient 0-copy data operations.

# no-check-commit

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/python-zstandard/tests/test_compressor_fuzzing.py	Sat Apr 01 15:24:03 2017 -0700
@@ -0,0 +1,143 @@
+import io
+import os
+
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+
+try:
+    import hypothesis
+    import hypothesis.strategies as strategies
+except ImportError:
+    raise unittest.SkipTest('hypothesis not available')
+
+import zstd
+
+from . common import (
+    make_cffi,
+    random_input_data,
+)
+
+
[e-mail]('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
+@make_cffi
+class TestCompressor_write_to_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.write_to(b, size=len(original), write_size=write_size) as compressor:
+            compressor.write(original)
+
+        self.assertEqual(b.getvalue(), ref_frame)
+
+
[e-mail]('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)
+
+
[e-mail]('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
+@make_cffi
+class TestCompressor_compressobj_fuzzing(unittest.TestCase):
+    @hypothesis.given(original=strategies.sampled_from(random_input_data()),
+                      level=strategies.integers(min_value=1, max_value=5),
+                      chunk_sizes=strategies.streaming(
+                          strategies.integers(min_value=1, max_value=4096)))
+    def test_random_input_sizes(self, original, level, chunk_sizes):
+        chunk_sizes = iter(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 = next(chunk_sizes)
+            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)
+
+
[e-mail]('ZSTD_SLOW_TESTS' in os.environ, 'ZSTD_SLOW_TESTS not set')
+@make_cffi
+class TestCompressor_read_from_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_from(source, size=len(original), read_size=read_size,
+                                     write_size=write_size))
+
+        self.assertEqual(b''.join(chunks), ref_frame)
+
+
[e-mail]('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_content_size=True,
+                                   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])