347 lines
11 KiB
Python
347 lines
11 KiB
Python
# test the invariant that
|
|
# iff a==b then hash(a)==hash(b)
|
|
#
|
|
# Also test that hash implementations are inherited as expected
|
|
|
|
import datetime
|
|
import os
|
|
import sys
|
|
import unittest
|
|
from test.support.script_helper import assert_python_ok
|
|
from collections.abc import Hashable
|
|
|
|
IS_64BIT = sys.maxsize > 2**32
|
|
|
|
def lcg(x, length=16):
|
|
"""Linear congruential generator"""
|
|
if x == 0:
|
|
return bytes(length)
|
|
out = bytearray(length)
|
|
for i in range(length):
|
|
x = (214013 * x + 2531011) & 0x7fffffff
|
|
out[i] = (x >> 16) & 0xff
|
|
return bytes(out)
|
|
|
|
def pysiphash(uint64):
|
|
"""Convert SipHash24 output to Py_hash_t
|
|
"""
|
|
assert 0 <= uint64 < (1 << 64)
|
|
# simple unsigned to signed int64
|
|
if uint64 > (1 << 63) - 1:
|
|
int64 = uint64 - (1 << 64)
|
|
else:
|
|
int64 = uint64
|
|
# mangle uint64 to uint32
|
|
uint32 = (uint64 ^ uint64 >> 32) & 0xffffffff
|
|
# simple unsigned to signed int32
|
|
if uint32 > (1 << 31) - 1:
|
|
int32 = uint32 - (1 << 32)
|
|
else:
|
|
int32 = uint32
|
|
return int32, int64
|
|
|
|
def skip_unless_internalhash(test):
|
|
"""Skip decorator for tests that depend on SipHash24 or FNV"""
|
|
ok = sys.hash_info.algorithm in {"fnv", "siphash24"}
|
|
msg = "Requires SipHash24 or FNV"
|
|
return test if ok else unittest.skip(msg)(test)
|
|
|
|
|
|
class HashEqualityTestCase(unittest.TestCase):
|
|
|
|
def same_hash(self, *objlist):
|
|
# Hash each object given and fail if
|
|
# the hash values are not all the same.
|
|
hashed = list(map(hash, objlist))
|
|
for h in hashed[1:]:
|
|
if h != hashed[0]:
|
|
self.fail("hashed values differ: %r" % (objlist,))
|
|
|
|
def test_numeric_literals(self):
|
|
self.same_hash(1, 1, 1.0, 1.0+0.0j)
|
|
self.same_hash(0, 0.0, 0.0+0.0j)
|
|
self.same_hash(-1, -1.0, -1.0+0.0j)
|
|
self.same_hash(-2, -2.0, -2.0+0.0j)
|
|
|
|
def test_coerced_integers(self):
|
|
self.same_hash(int(1), int(1), float(1), complex(1),
|
|
int('1'), float('1.0'))
|
|
self.same_hash(int(-2**31), float(-2**31))
|
|
self.same_hash(int(1-2**31), float(1-2**31))
|
|
self.same_hash(int(2**31-1), float(2**31-1))
|
|
# for 64-bit platforms
|
|
self.same_hash(int(2**31), float(2**31))
|
|
self.same_hash(int(-2**63), float(-2**63))
|
|
self.same_hash(int(2**63), float(2**63))
|
|
|
|
def test_coerced_floats(self):
|
|
self.same_hash(int(1.23e300), float(1.23e300))
|
|
self.same_hash(float(0.5), complex(0.5, 0.0))
|
|
|
|
def test_unaligned_buffers(self):
|
|
# The hash function for bytes-like objects shouldn't have
|
|
# alignment-dependent results (example in issue #16427).
|
|
b = b"123456789abcdefghijklmnopqrstuvwxyz" * 128
|
|
for i in range(16):
|
|
for j in range(16):
|
|
aligned = b[i:128+j]
|
|
unaligned = memoryview(b)[i:128+j]
|
|
self.assertEqual(hash(aligned), hash(unaligned))
|
|
|
|
|
|
_default_hash = object.__hash__
|
|
class DefaultHash(object): pass
|
|
|
|
_FIXED_HASH_VALUE = 42
|
|
class FixedHash(object):
|
|
def __hash__(self):
|
|
return _FIXED_HASH_VALUE
|
|
|
|
class OnlyEquality(object):
|
|
def __eq__(self, other):
|
|
return self is other
|
|
|
|
class OnlyInequality(object):
|
|
def __ne__(self, other):
|
|
return self is not other
|
|
|
|
class InheritedHashWithEquality(FixedHash, OnlyEquality): pass
|
|
class InheritedHashWithInequality(FixedHash, OnlyInequality): pass
|
|
|
|
class NoHash(object):
|
|
__hash__ = None
|
|
|
|
class HashInheritanceTestCase(unittest.TestCase):
|
|
default_expected = [object(),
|
|
DefaultHash(),
|
|
OnlyInequality(),
|
|
]
|
|
fixed_expected = [FixedHash(),
|
|
InheritedHashWithEquality(),
|
|
InheritedHashWithInequality(),
|
|
]
|
|
error_expected = [NoHash(),
|
|
OnlyEquality(),
|
|
]
|
|
|
|
def test_default_hash(self):
|
|
for obj in self.default_expected:
|
|
self.assertEqual(hash(obj), _default_hash(obj))
|
|
|
|
def test_fixed_hash(self):
|
|
for obj in self.fixed_expected:
|
|
self.assertEqual(hash(obj), _FIXED_HASH_VALUE)
|
|
|
|
def test_error_hash(self):
|
|
for obj in self.error_expected:
|
|
self.assertRaises(TypeError, hash, obj)
|
|
|
|
def test_hashable(self):
|
|
objects = (self.default_expected +
|
|
self.fixed_expected)
|
|
for obj in objects:
|
|
self.assertIsInstance(obj, Hashable)
|
|
|
|
def test_not_hashable(self):
|
|
for obj in self.error_expected:
|
|
self.assertNotIsInstance(obj, Hashable)
|
|
|
|
|
|
# Issue #4701: Check that some builtin types are correctly hashable
|
|
class DefaultIterSeq(object):
|
|
seq = range(10)
|
|
def __len__(self):
|
|
return len(self.seq)
|
|
def __getitem__(self, index):
|
|
return self.seq[index]
|
|
|
|
class HashBuiltinsTestCase(unittest.TestCase):
|
|
hashes_to_check = [enumerate(range(10)),
|
|
iter(DefaultIterSeq()),
|
|
iter(lambda: 0, 0),
|
|
]
|
|
|
|
def test_hashes(self):
|
|
_default_hash = object.__hash__
|
|
for obj in self.hashes_to_check:
|
|
self.assertEqual(hash(obj), _default_hash(obj))
|
|
|
|
class HashRandomizationTests:
|
|
|
|
# Each subclass should define a field "repr_", containing the repr() of
|
|
# an object to be tested
|
|
|
|
def get_hash_command(self, repr_):
|
|
return 'print(hash(eval(%a)))' % repr_
|
|
|
|
def get_hash(self, repr_, seed=None):
|
|
env = os.environ.copy()
|
|
env['__cleanenv'] = True # signal to assert_python not to do a copy
|
|
# of os.environ on its own
|
|
if seed is not None:
|
|
env['PYTHONHASHSEED'] = str(seed)
|
|
else:
|
|
env.pop('PYTHONHASHSEED', None)
|
|
out = assert_python_ok(
|
|
'-c', self.get_hash_command(repr_),
|
|
**env)
|
|
stdout = out[1].strip()
|
|
return int(stdout)
|
|
|
|
def test_randomized_hash(self):
|
|
# two runs should return different hashes
|
|
run1 = self.get_hash(self.repr_, seed='random')
|
|
run2 = self.get_hash(self.repr_, seed='random')
|
|
self.assertNotEqual(run1, run2)
|
|
|
|
class StringlikeHashRandomizationTests(HashRandomizationTests):
|
|
repr_ = None
|
|
repr_long = None
|
|
|
|
# 32bit little, 64bit little, 32bit big, 64bit big
|
|
known_hashes = {
|
|
'djba33x': [ # only used for small strings
|
|
# seed 0, 'abc'
|
|
[193485960, 193485960, 193485960, 193485960],
|
|
# seed 42, 'abc'
|
|
[-678966196, 573763426263223372, -820489388, -4282905804826039665],
|
|
],
|
|
'siphash24': [
|
|
# NOTE: PyUCS2 layout depends on endianness
|
|
# seed 0, 'abc'
|
|
[1198583518, 4596069200710135518, 1198583518, 4596069200710135518],
|
|
# seed 42, 'abc'
|
|
[273876886, -4501618152524544106, 273876886, -4501618152524544106],
|
|
# seed 42, 'abcdefghijk'
|
|
[-1745215313, 4436719588892876975, -1745215313, 4436719588892876975],
|
|
# seed 0, 'äú∑ℇ'
|
|
[493570806, 5749986484189612790, -1006381564, -5915111450199468540],
|
|
# seed 42, 'äú∑ℇ'
|
|
[-1677110816, -2947981342227738144, -1860207793, -4296699217652516017],
|
|
],
|
|
'fnv': [
|
|
# seed 0, 'abc'
|
|
[-1600925533, 1453079729188098211, -1600925533,
|
|
1453079729188098211],
|
|
# seed 42, 'abc'
|
|
[-206076799, -4410911502303878509, -1024014457,
|
|
-3570150969479994130],
|
|
# seed 42, 'abcdefghijk'
|
|
[811136751, -5046230049376118746, -77208053 ,
|
|
-4779029615281019666],
|
|
# seed 0, 'äú∑ℇ'
|
|
[44402817, 8998297579845987431, -1956240331,
|
|
-782697888614047887],
|
|
# seed 42, 'äú∑ℇ'
|
|
[-283066365, -4576729883824601543, -271871407,
|
|
-3927695501187247084],
|
|
]
|
|
}
|
|
|
|
def get_expected_hash(self, position, length):
|
|
if length < sys.hash_info.cutoff:
|
|
algorithm = "djba33x"
|
|
else:
|
|
algorithm = sys.hash_info.algorithm
|
|
if sys.byteorder == 'little':
|
|
platform = 1 if IS_64BIT else 0
|
|
else:
|
|
assert(sys.byteorder == 'big')
|
|
platform = 3 if IS_64BIT else 2
|
|
return self.known_hashes[algorithm][position][platform]
|
|
|
|
def test_null_hash(self):
|
|
# PYTHONHASHSEED=0 disables the randomized hash
|
|
known_hash_of_obj = self.get_expected_hash(0, 3)
|
|
|
|
# Randomization is enabled by default:
|
|
self.assertNotEqual(self.get_hash(self.repr_), known_hash_of_obj)
|
|
|
|
# It can also be disabled by setting the seed to 0:
|
|
self.assertEqual(self.get_hash(self.repr_, seed=0), known_hash_of_obj)
|
|
|
|
@skip_unless_internalhash
|
|
def test_fixed_hash(self):
|
|
# test a fixed seed for the randomized hash
|
|
# Note that all types share the same values:
|
|
h = self.get_expected_hash(1, 3)
|
|
self.assertEqual(self.get_hash(self.repr_, seed=42), h)
|
|
|
|
@skip_unless_internalhash
|
|
def test_long_fixed_hash(self):
|
|
if self.repr_long is None:
|
|
return
|
|
h = self.get_expected_hash(2, 11)
|
|
self.assertEqual(self.get_hash(self.repr_long, seed=42), h)
|
|
|
|
|
|
class StrHashRandomizationTests(StringlikeHashRandomizationTests,
|
|
unittest.TestCase):
|
|
repr_ = repr('abc')
|
|
repr_long = repr('abcdefghijk')
|
|
repr_ucs2 = repr('äú∑ℇ')
|
|
|
|
@skip_unless_internalhash
|
|
def test_empty_string(self):
|
|
self.assertEqual(hash(""), 0)
|
|
|
|
@skip_unless_internalhash
|
|
def test_ucs2_string(self):
|
|
h = self.get_expected_hash(3, 6)
|
|
self.assertEqual(self.get_hash(self.repr_ucs2, seed=0), h)
|
|
h = self.get_expected_hash(4, 6)
|
|
self.assertEqual(self.get_hash(self.repr_ucs2, seed=42), h)
|
|
|
|
class BytesHashRandomizationTests(StringlikeHashRandomizationTests,
|
|
unittest.TestCase):
|
|
repr_ = repr(b'abc')
|
|
repr_long = repr(b'abcdefghijk')
|
|
|
|
@skip_unless_internalhash
|
|
def test_empty_string(self):
|
|
self.assertEqual(hash(b""), 0)
|
|
|
|
class MemoryviewHashRandomizationTests(StringlikeHashRandomizationTests,
|
|
unittest.TestCase):
|
|
repr_ = "memoryview(b'abc')"
|
|
repr_long = "memoryview(b'abcdefghijk')"
|
|
|
|
@skip_unless_internalhash
|
|
def test_empty_string(self):
|
|
self.assertEqual(hash(memoryview(b"")), 0)
|
|
|
|
class DatetimeTests(HashRandomizationTests):
|
|
def get_hash_command(self, repr_):
|
|
return 'import datetime; print(hash(%s))' % repr_
|
|
|
|
class DatetimeDateTests(DatetimeTests, unittest.TestCase):
|
|
repr_ = repr(datetime.date(1066, 10, 14))
|
|
|
|
class DatetimeDatetimeTests(DatetimeTests, unittest.TestCase):
|
|
repr_ = repr(datetime.datetime(1, 2, 3, 4, 5, 6, 7))
|
|
|
|
class DatetimeTimeTests(DatetimeTests, unittest.TestCase):
|
|
repr_ = repr(datetime.time(0))
|
|
|
|
|
|
class HashDistributionTestCase(unittest.TestCase):
|
|
|
|
def test_hash_distribution(self):
|
|
# check for hash collision
|
|
base = "abcdefghabcdefg"
|
|
for i in range(1, len(base)):
|
|
prefix = base[:i]
|
|
with self.subTest(prefix=prefix):
|
|
s15 = set()
|
|
s255 = set()
|
|
for c in range(256):
|
|
h = hash(prefix + chr(c))
|
|
s15.add(h & 0xf)
|
|
s255.add(h & 0xff)
|
|
# SipHash24 distribution depends on key, usually > 60%
|
|
self.assertGreater(len(s15), 8, prefix)
|
|
self.assertGreater(len(s255), 128, prefix)
|
|
|
|
if __name__ == "__main__":
|
|
unittest.main()
|