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102 lines
2.1 KiB
ReStructuredText
102 lines
2.1 KiB
ReStructuredText
.. highlight:: c
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PyHash API
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----------
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See also the :c:member:`PyTypeObject.tp_hash` member and :ref:`numeric-hash`.
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.. c:type:: Py_hash_t
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Hash value type: signed integer.
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.. versionadded:: 3.2
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.. c:type:: Py_uhash_t
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Hash value type: unsigned integer.
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.. versionadded:: 3.2
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.. c:macro:: PyHASH_MODULUS
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The `Mersenne prime <https://en.wikipedia.org/wiki/Mersenne_prime>`_ ``P = 2**n -1``, used for numeric hash scheme.
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.. versionadded:: 3.13
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.. c:macro:: PyHASH_BITS
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The exponent ``n`` of ``P`` in :c:macro:`PyHASH_MODULUS`.
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.. versionadded:: 3.13
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.. c:macro:: PyHASH_MULTIPLIER
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Prime multiplier used in string and various other hashes.
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.. versionadded:: 3.13
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.. c:macro:: PyHASH_INF
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The hash value returned for a positive infinity.
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.. versionadded:: 3.13
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.. c:macro:: PyHASH_IMAG
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The multiplier used for the imaginary part of a complex number.
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.. versionadded:: 3.13
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.. c:type:: PyHash_FuncDef
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Hash function definition used by :c:func:`PyHash_GetFuncDef`.
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.. c::member:: Py_hash_t (*const hash)(const void *, Py_ssize_t)
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Hash function.
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.. c:member:: const char *name
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Hash function name (UTF-8 encoded string).
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.. c:member:: const int hash_bits
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Internal size of the hash value in bits.
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.. c:member:: const int seed_bits
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Size of seed input in bits.
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.. versionadded:: 3.4
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.. c:function:: PyHash_FuncDef* PyHash_GetFuncDef(void)
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Get the hash function definition.
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.. seealso::
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:pep:`456` "Secure and interchangeable hash algorithm".
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.. versionadded:: 3.4
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.. c:function:: Py_hash_t Py_HashPointer(const void *ptr)
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Hash a pointer value: process the pointer value as an integer (cast it to
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``uintptr_t`` internally). The pointer is not dereferenced.
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The function cannot fail: it cannot return ``-1``.
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.. versionadded:: 3.13
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.. c:function:: Py_hash_t PyObject_GenericHash(PyObject *obj)
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Generic hashing function that is meant to be put into a type
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object's ``tp_hash`` slot.
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Its result only depends on the object's identity.
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.. impl-detail::
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In CPython, it is equivalent to :c:func:`Py_HashPointer`.
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.. versionadded:: 3.13
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