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comparison Python/sysmodule.c @ 61873:0bc8ffe6ba9a

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Issue #8188: Introduce a new scheme for computing hashes of numbers (instances of int, float, complex, decimal.Decimal and fractions.Fraction) that makes it easy to maintain the invariant that hash(x) == hash(y) whenever x and y have equal value.
author Mark Dickinson <dickinsm@gmail.com>
date Sun, 23 May 2010 13:33:13 +0000
parents 795762b5e0d6
children 600c23127207
comparison
equal deleted inserted replaced
61872:b0dee32a1c6b 61873:0bc8ffe6ba9a
567 } 567 }
568 Py_SetRecursionLimit(new_limit); 568 Py_SetRecursionLimit(new_limit);
569 Py_INCREF(Py_None); 569 Py_INCREF(Py_None);
570 return Py_None; 570 return Py_None;
571 } 571 }
572
573 static PyTypeObject Hash_InfoType;
574
575 PyDoc_STRVAR(hash_info_doc,
576 "hash_info\n\
577 \n\
578 A struct sequence providing parameters used for computing\n\
579 numeric hashes. The attributes are read only.");
580
581 static PyStructSequence_Field hash_info_fields[] = {
582 {"width", "width of the type used for hashing, in bits"},
583 {"modulus", "prime number giving the modulus on which the hash "
584 "function is based"},
585 {"inf", "value to be used for hash of a positive infinity"},
586 {"nan", "value to be used for hash of a nan"},
587 {"imag", "multiplier used for the imaginary part of a complex number"},
588 {NULL, NULL}
589 };
590
591 static PyStructSequence_Desc hash_info_desc = {
592 "sys.hash_info",
593 hash_info_doc,
594 hash_info_fields,
595 5,
596 };
597
598 PyObject *
599 get_hash_info(void)
600 {
601 PyObject *hash_info;
602 int field = 0;
603 hash_info = PyStructSequence_New(&Hash_InfoType);
604 if (hash_info == NULL)
605 return NULL;
606 PyStructSequence_SET_ITEM(hash_info, field++,
607 PyLong_FromLong(8*sizeof(long)));
608 PyStructSequence_SET_ITEM(hash_info, field++,
609 PyLong_FromLong(_PyHASH_MODULUS));
610 PyStructSequence_SET_ITEM(hash_info, field++,
611 PyLong_FromLong(_PyHASH_INF));
612 PyStructSequence_SET_ITEM(hash_info, field++,
613 PyLong_FromLong(_PyHASH_NAN));
614 PyStructSequence_SET_ITEM(hash_info, field++,
615 PyLong_FromLong(_PyHASH_IMAG));
616 if (PyErr_Occurred()) {
617 Py_CLEAR(hash_info);
618 return NULL;
619 }
620 return hash_info;
621 }
622
572 623
573 PyDoc_STRVAR(setrecursionlimit_doc, 624 PyDoc_STRVAR(setrecursionlimit_doc,
574 "setrecursionlimit(n)\n\ 625 "setrecursionlimit(n)\n\
575 \n\ 626 \n\
576 Set the maximum depth of the Python interpreter stack to n. This\n\ 627 Set the maximum depth of the Python interpreter stack to n. This\n\
1480 PyLong_FromSsize_t(PY_SSIZE_T_MAX)); 1531 PyLong_FromSsize_t(PY_SSIZE_T_MAX));
1481 SET_SYS_FROM_STRING("float_info", 1532 SET_SYS_FROM_STRING("float_info",
1482 PyFloat_GetInfo()); 1533 PyFloat_GetInfo());
1483 SET_SYS_FROM_STRING("int_info", 1534 SET_SYS_FROM_STRING("int_info",
1484 PyLong_GetInfo()); 1535 PyLong_GetInfo());
1536 /* initialize hash_info */
1537 if (Hash_InfoType.tp_name == 0)
1538 PyStructSequence_InitType(&Hash_InfoType, &hash_info_desc);
1539 SET_SYS_FROM_STRING("hash_info",
1540 get_hash_info());
1485 SET_SYS_FROM_STRING("maxunicode", 1541 SET_SYS_FROM_STRING("maxunicode",
1486 PyLong_FromLong(PyUnicode_GetMax())); 1542 PyLong_FromLong(PyUnicode_GetMax()));
1487 SET_SYS_FROM_STRING("builtin_module_names", 1543 SET_SYS_FROM_STRING("builtin_module_names",
1488 list_builtin_module_names()); 1544 list_builtin_module_names());
1489 { 1545 {