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			93 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
	
		
			3 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
import sys
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import unittest
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from test.support import import_helper
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_testcapi = import_helper.import_module('_testcapi')
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SIZEOF_VOID_P = _testcapi.SIZEOF_VOID_P
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SIZEOF_PY_HASH_T = SIZEOF_VOID_P
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class CAPITest(unittest.TestCase):
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    def test_hash_getfuncdef(self):
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        # Test PyHash_GetFuncDef()
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        hash_getfuncdef = _testcapi.hash_getfuncdef
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        func_def = hash_getfuncdef()
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        match func_def.name:
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            case "fnv":
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                self.assertEqual(func_def.hash_bits, 8 * SIZEOF_PY_HASH_T)
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                self.assertEqual(func_def.seed_bits, 16 * SIZEOF_PY_HASH_T)
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            case "siphash13":
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                self.assertEqual(func_def.hash_bits, 64)
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                self.assertEqual(func_def.seed_bits, 128)
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            case "siphash24":
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                self.assertEqual(func_def.hash_bits, 64)
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                self.assertEqual(func_def.seed_bits, 128)
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            case _:
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                self.fail(f"unknown function name: {func_def.name!r}")
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        # compare with sys.hash_info
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        hash_info = sys.hash_info
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        self.assertEqual(func_def.name, hash_info.algorithm)
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        self.assertEqual(func_def.hash_bits, hash_info.hash_bits)
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        self.assertEqual(func_def.seed_bits, hash_info.seed_bits)
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    def test_hash_pointer(self):
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        # Test Py_HashPointer()
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        hash_pointer = _testcapi.hash_pointer
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        UHASH_T_MASK = ((2 ** (8 * SIZEOF_PY_HASH_T)) - 1)
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        HASH_T_MAX = (2 ** (8 * SIZEOF_PY_HASH_T - 1) - 1)
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        def python_hash_pointer(x):
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            # Py_HashPointer() rotates the pointer bits by 4 bits to the right
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            x = (x >> 4) | ((x & 15) << (8 * SIZEOF_VOID_P - 4))
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            # Convert unsigned uintptr_t (Py_uhash_t) to signed Py_hash_t
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            if HASH_T_MAX < x:
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                x = (~x) + 1
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                x &= UHASH_T_MASK
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                x = (~x) + 1
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            return x
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        if SIZEOF_VOID_P == 8:
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            values = (
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                0xABCDEF1234567890,
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                0x1234567890ABCDEF,
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                0xFEE4ABEDD1CECA5E,
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            )
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        else:
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            values = (
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                0x12345678,
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                0x1234ABCD,
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                0xDEADCAFE,
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            )
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        for value in values:
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            expected = python_hash_pointer(value)
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            with self.subTest(value=value):
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                self.assertEqual(hash_pointer(value), expected,
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                                 f"hash_pointer({value:x}) = "
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                                 f"{hash_pointer(value):x} != {expected:x}")
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        # Py_HashPointer(NULL) returns 0
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        self.assertEqual(hash_pointer(0), 0)
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        # Py_HashPointer((void*)(uintptr_t)-1) doesn't return -1 but -2
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        VOID_P_MAX = -1 & (2 ** (8 * SIZEOF_VOID_P) - 1)
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        self.assertEqual(hash_pointer(VOID_P_MAX), -2)
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    def test_hash_buffer(self):
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        hash_buffer = _testcapi.hash_buffer
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        def check(data):
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            self.assertEqual(hash_buffer(data), hash(data))
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        check(b'')
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        check(b'abc')
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        check(b'x' * 1024)
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if __name__ == "__main__":
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    unittest.main()
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