106 lines
3.3 KiB
Python
106 lines
3.3 KiB
Python
# vim: set fileencoding=utf-8
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import os
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import random
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import unittest
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from bemani.protocol.lz77 import Lz77, Lz77Decompress
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from bemani.tests.helpers import get_fixture
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class TestLZ77Decompressor(unittest.TestCase):
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def test_ringbuffer_fuzz(self) -> None:
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dec = Lz77Decompress(b'')
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for _ in range(100):
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amount = random.randint(1, Lz77Decompress.RING_LENGTH)
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data = os.urandom(amount)
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# Save our ring position, write a chunk of data
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readpos = dec.write_pos
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dec._ring_write(data)
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# Read a chunk of data back from that buffer, see its the same
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newdata = b''.join(dec._ring_read(readpos, amount))
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self.assertEqual(data, newdata)
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# Verify integrity of ringbuffer
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self.assertEqual(len(dec.ring), Lz77Decompress.RING_LENGTH)
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class TestLz77RealCompressor(unittest.TestCase):
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def test_small_data_random(self) -> None:
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lz77 = Lz77()
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data = os.urandom(1 * 1024)
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_large_data_random(self) -> None:
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lz77 = Lz77()
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data = os.urandom(100 * 1024)
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_huge_data_random(self) -> None:
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lz77 = Lz77()
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data = os.urandom(1 * 1024 * 1024)
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_declaration(self) -> None:
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lz77 = Lz77()
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data = get_fixture("declaration.txt")
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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self.assertTrue(len(compresseddata) < len(data))
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_lorem_ipsum(self) -> None:
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lz77 = Lz77()
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data = get_fixture("lorem.txt")
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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self.assertTrue(len(compresseddata) < len(data))
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_texture(self) -> None:
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lz77 = Lz77()
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data = get_fixture("rawdata")
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compresseddata = lz77.compress(data)
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self.assertNotEqual(data, compresseddata)
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self.assertTrue(len(compresseddata) < len(data))
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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def test_known_compression(self) -> None:
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"""
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Specifically tests for ability to compress an overlap,
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verifies that we don't regress on known compressions.
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"""
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lz77 = Lz77()
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data = b"abcabcabcabc"
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compresseddata = lz77.compress(data)
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self.assertEqual(b"\x07abc\x006\x00\x00", compresseddata)
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decompresseddata = lz77.decompress(compresseddata)
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self.assertEqual(data, decompresseddata)
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