40 lines
1.0 KiB
Python
40 lines
1.0 KiB
Python
import binascii
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import struct
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import pytest
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from ..helpers import Suite
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@pytest.mark.slow_integration_test
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def test_crc32():
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# FIXME: Stub
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# crc = 0xFFFFFFFF
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# byt = 0x61
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# => (crc >> 8) ^ _CRC32_Table[(crc & 0xFF) ^ byt]
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# (crc >> 8) = 0x00FFFFFF
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# => 0x00FFFFFF ^ _CRC32_Table[(crc & 0xFF) ^ byt]
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# (crc & 0xFF) = 0xFF
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# => 0x00FFFFFF ^ _CRC32_Table[0xFF ^ byt]
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# 0xFF ^ 0x61 = 0x9E
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# => 0x00FFFFFF ^ _CRC32_Table[0x9E]
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# _CRC32_Table[0x9E] = 0x17b7be43
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# => 0x00FFFFFF ^ 0x17b7be43
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code_py = """
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def _crc32_f(crc: u32, byt: u8) -> u32:
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return 16777215 ^ 397917763
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def testEntry(data: bytes) -> u32:
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return 4294967295 ^ _crc32_f(4294967295, data[0])
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"""
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exp_result = binascii.crc32(b'a')
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result = Suite(code_py).run_code(b'a')
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# exp_result returns a unsigned integer, as is proper
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exp_data = struct.pack('I', exp_result)
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# ints extracted from WebAssembly are always signed
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data = struct.pack('i', result.returned_value)
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assert exp_data == data
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