view contrib/python-zstandard/tests/test_train_dictionary.py @ 46480:05dd091dfa6a

wireprotopeer: clarify some variable names now that we allow snake_case

"encargsorres" is hard to parse ("encarg sorres" sounds like it might
be Spanish to me, and indeed Google Translate tells me that it's
Catalan for "order sands"). Let's clarify with some added underscores
and longer names.

Differential Revision: https://phab.mercurial-scm.org/D9973

import struct
import sys
import unittest

import zstandard as zstd

from .common import (
    generate_samples,
    make_cffi,
    random_input_data,
    TestCase,
)

if sys.version_info[0] >= 3:
    int_type = int
else:
    int_type = long


@make_cffi
class TestTrainDictionary(TestCase):
    def test_no_args(self):
        with self.assertRaises(TypeError):
            zstd.train_dictionary()

    def test_bad_args(self):
        with self.assertRaises(TypeError):
            zstd.train_dictionary(8192, u"foo")

        with self.assertRaises(ValueError):
            zstd.train_dictionary(8192, [u"foo"])

    def test_no_params(self):
        d = zstd.train_dictionary(8192, random_input_data())
        self.assertIsInstance(d.dict_id(), int_type)

        # The dictionary ID may be different across platforms.
        expected = b"\x37\xa4\x30\xec" + struct.pack("<I", d.dict_id())

        data = d.as_bytes()
        self.assertEqual(data[0:8], expected)

    def test_basic(self):
        d = zstd.train_dictionary(8192, generate_samples(), k=64, d=16)
        self.assertIsInstance(d.dict_id(), int_type)

        data = d.as_bytes()
        self.assertEqual(data[0:4], b"\x37\xa4\x30\xec")

        self.assertEqual(d.k, 64)
        self.assertEqual(d.d, 16)

    def test_set_dict_id(self):
        d = zstd.train_dictionary(
            8192, generate_samples(), k=64, d=16, dict_id=42
        )
        self.assertEqual(d.dict_id(), 42)

    def test_optimize(self):
        d = zstd.train_dictionary(
            8192, generate_samples(), threads=-1, steps=1, d=16
        )

        # This varies by platform.
        self.assertIn(d.k, (50, 2000))
        self.assertEqual(d.d, 16)


@make_cffi
class TestCompressionDict(TestCase):
    def test_bad_mode(self):
        with self.assertRaisesRegex(ValueError, "invalid dictionary load mode"):
            zstd.ZstdCompressionDict(b"foo", dict_type=42)

    def test_bad_precompute_compress(self):
        d = zstd.train_dictionary(8192, generate_samples(), k=64, d=16)

        with self.assertRaisesRegex(
            ValueError, "must specify one of level or "
        ):
            d.precompute_compress()

        with self.assertRaisesRegex(
            ValueError, "must only specify one of level or "
        ):
            d.precompute_compress(
                level=3, compression_params=zstd.CompressionParameters()
            )

    def test_precompute_compress_rawcontent(self):
        d = zstd.ZstdCompressionDict(
            b"dictcontent" * 64, dict_type=zstd.DICT_TYPE_RAWCONTENT
        )
        d.precompute_compress(level=1)

        d = zstd.ZstdCompressionDict(
            b"dictcontent" * 64, dict_type=zstd.DICT_TYPE_FULLDICT
        )
        with self.assertRaisesRegex(
            zstd.ZstdError, "unable to precompute dictionary"
        ):
            d.precompute_compress(level=1)