contrib/python-zstandard/tests/test_data_structures.py

wireproto: support for pullbundles

Pullbundles are similar to clonebundles, but served as normal inline
bundle streams. They are almost transparent to the client -- the only
visible effect is that the client might get less changes than what it
asked for, i.e. not all requested head revisions are provided.

The client announces support for the necessary retries with the
partial-pull capability. After receiving a partial bundle, it updates
the set of revisions shared with the server and drops all now-known
heads from the request list. It will then rerun getbundle until
no changes are received or all remote heads are present.

Extend badserverext to support per-socket limit, i.e. don't assume that
the same limits should be applied to all sockets.

Differential Revision: https://phab.mercurial-scm.org/D1856

import sys
import unittest

import zstandard as zstd

from . common import (
    make_cffi,
)


@make_cffi
class TestCompressionParameters(unittest.TestCase):
    def test_bounds(self):
        zstd.ZstdCompressionParameters(window_log=zstd.WINDOWLOG_MIN,
                                       chain_log=zstd.CHAINLOG_MIN,
                                       hash_log=zstd.HASHLOG_MIN,
                                       search_log=zstd.SEARCHLOG_MIN,
                                       min_match=zstd.SEARCHLENGTH_MIN + 1,
                                       target_length=zstd.TARGETLENGTH_MIN,
                                       compression_strategy=zstd.STRATEGY_FAST)

        zstd.ZstdCompressionParameters(window_log=zstd.WINDOWLOG_MAX,
                                       chain_log=zstd.CHAINLOG_MAX,
                                       hash_log=zstd.HASHLOG_MAX,
                                       search_log=zstd.SEARCHLOG_MAX,
                                       min_match=zstd.SEARCHLENGTH_MAX - 1,
                                       compression_strategy=zstd.STRATEGY_BTULTRA)

    def test_from_level(self):
        p = zstd.ZstdCompressionParameters.from_level(1)
        self.assertIsInstance(p, zstd.CompressionParameters)

        self.assertEqual(p.window_log, 19)

        p = zstd.ZstdCompressionParameters.from_level(-4)
        self.assertEqual(p.window_log, 19)
        self.assertEqual(p.compress_literals, 0)

    def test_members(self):
        p = zstd.ZstdCompressionParameters(window_log=10,
                                           chain_log=6,
                                           hash_log=7,
                                           search_log=4,
                                           min_match=5,
                                           target_length=8,
                                           compression_strategy=1)
        self.assertEqual(p.window_log, 10)
        self.assertEqual(p.chain_log, 6)
        self.assertEqual(p.hash_log, 7)
        self.assertEqual(p.search_log, 4)
        self.assertEqual(p.min_match, 5)
        self.assertEqual(p.target_length, 8)
        self.assertEqual(p.compression_strategy, 1)

        p = zstd.ZstdCompressionParameters(compression_level=2)
        self.assertEqual(p.compression_level, 2)

        p = zstd.ZstdCompressionParameters(threads=4)
        self.assertEqual(p.threads, 4)

        p = zstd.ZstdCompressionParameters(threads=2, job_size=1048576,
                                       overlap_size_log=6)
        self.assertEqual(p.threads, 2)
        self.assertEqual(p.job_size, 1048576)
        self.assertEqual(p.overlap_size_log, 6)

        p = zstd.ZstdCompressionParameters(compression_level=2)
        self.assertEqual(p.compress_literals, 1)

        p = zstd.ZstdCompressionParameters(compress_literals=False)
        self.assertEqual(p.compress_literals, 0)

        p = zstd.ZstdCompressionParameters(compression_level=-1)
        self.assertEqual(p.compression_level, -1)
        self.assertEqual(p.compress_literals, 0)

        p = zstd.ZstdCompressionParameters(compression_level=-2, compress_literals=True)
        self.assertEqual(p.compression_level, -2)
        self.assertEqual(p.compress_literals, 1)

        p = zstd.ZstdCompressionParameters(force_max_window=True)
        self.assertEqual(p.force_max_window, 1)

        p = zstd.ZstdCompressionParameters(enable_ldm=True)
        self.assertEqual(p.enable_ldm, 1)

        p = zstd.ZstdCompressionParameters(ldm_hash_log=7)
        self.assertEqual(p.ldm_hash_log, 7)

        p = zstd.ZstdCompressionParameters(ldm_min_match=6)
        self.assertEqual(p.ldm_min_match, 6)

        p = zstd.ZstdCompressionParameters(ldm_bucket_size_log=7)
        self.assertEqual(p.ldm_bucket_size_log, 7)

        p = zstd.ZstdCompressionParameters(ldm_hash_every_log=8)
        self.assertEqual(p.ldm_hash_every_log, 8)

    def test_estimated_compression_context_size(self):
        p = zstd.ZstdCompressionParameters(window_log=20,
                                           chain_log=16,
                                           hash_log=17,
                                           search_log=1,
                                           min_match=5,
                                           target_length=16,
                                           compression_strategy=zstd.STRATEGY_DFAST)

        # 32-bit has slightly different values from 64-bit.
        self.assertAlmostEqual(p.estimated_compression_context_size(), 1294072,
                               delta=250)


@make_cffi
class TestFrameParameters(unittest.TestCase):
    def test_invalid_type(self):
        with self.assertRaises(TypeError):
            zstd.get_frame_parameters(None)

        # Python 3 doesn't appear to convert unicode to Py_buffer.
        if sys.version_info[0] >= 3:
            with self.assertRaises(TypeError):
                zstd.get_frame_parameters(u'foobarbaz')
        else:
            # CPython will convert unicode to Py_buffer. But CFFI won't.
            if zstd.backend == 'cffi':
                with self.assertRaises(TypeError):
                    zstd.get_frame_parameters(u'foobarbaz')
            else:
                with self.assertRaises(zstd.ZstdError):
                    zstd.get_frame_parameters(u'foobarbaz')

    def test_invalid_input_sizes(self):
        with self.assertRaisesRegexp(zstd.ZstdError, 'not enough data for frame'):
            zstd.get_frame_parameters(b'')

        with self.assertRaisesRegexp(zstd.ZstdError, 'not enough data for frame'):
            zstd.get_frame_parameters(zstd.FRAME_HEADER)

    def test_invalid_frame(self):
        with self.assertRaisesRegexp(zstd.ZstdError, 'Unknown frame descriptor'):
            zstd.get_frame_parameters(b'foobarbaz')

    def test_attributes(self):
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x00\x00')
        self.assertEqual(params.content_size, zstd.CONTENTSIZE_UNKNOWN)
        self.assertEqual(params.window_size, 1024)
        self.assertEqual(params.dict_id, 0)
        self.assertFalse(params.has_checksum)

        # Lowest 2 bits indicate a dictionary and length. Here, the dict id is 1 byte.
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x01\x00\xff')
        self.assertEqual(params.content_size, zstd.CONTENTSIZE_UNKNOWN)
        self.assertEqual(params.window_size, 1024)
        self.assertEqual(params.dict_id, 255)
        self.assertFalse(params.has_checksum)

        # Lowest 3rd bit indicates if checksum is present.
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x04\x00')
        self.assertEqual(params.content_size, zstd.CONTENTSIZE_UNKNOWN)
        self.assertEqual(params.window_size, 1024)
        self.assertEqual(params.dict_id, 0)
        self.assertTrue(params.has_checksum)

        # Upper 2 bits indicate content size.
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x40\x00\xff\x00')
        self.assertEqual(params.content_size, 511)
        self.assertEqual(params.window_size, 1024)
        self.assertEqual(params.dict_id, 0)
        self.assertFalse(params.has_checksum)

        # Window descriptor is 2nd byte after frame header.
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x00\x40')
        self.assertEqual(params.content_size, zstd.CONTENTSIZE_UNKNOWN)
        self.assertEqual(params.window_size, 262144)
        self.assertEqual(params.dict_id, 0)
        self.assertFalse(params.has_checksum)

        # Set multiple things.
        params = zstd.get_frame_parameters(zstd.FRAME_HEADER + b'\x45\x40\x0f\x10\x00')
        self.assertEqual(params.content_size, 272)
        self.assertEqual(params.window_size, 262144)
        self.assertEqual(params.dict_id, 15)
        self.assertTrue(params.has_checksum)

    def test_input_types(self):
        v = zstd.FRAME_HEADER + b'\x00\x00'

        mutable_array = bytearray(len(v))
        mutable_array[:] = v

        sources = [
            memoryview(v),
            bytearray(v),
            mutable_array,
        ]

        for source in sources:
            params = zstd.get_frame_parameters(source)
            self.assertEqual(params.content_size, zstd.CONTENTSIZE_UNKNOWN)
            self.assertEqual(params.window_size, 1024)
            self.assertEqual(params.dict_id, 0)
            self.assertFalse(params.has_checksum)