Current File : //usr/include/python3.8/internal/pycore_long.h
#ifndef Py_INTERNAL_LONG_H
#define Py_INTERNAL_LONG_H
#ifdef __cplusplus
extern "C" {
#endif
#ifndef Py_BUILD_CORE
# error "this header requires Py_BUILD_CORE define"
#endif
/*
* Default int base conversion size limitation: Denial of Service prevention.
*
* Chosen such that this isn't wildly slow on modern hardware and so that
* everyone's existing deployed numpy test suite passes before
* https://github.com/numpy/numpy/issues/22098 is widely available.
*
* $ python -m timeit -s 's = "1"*4300' 'int(s)'
* 2000 loops, best of 5: 125 usec per loop
* $ python -m timeit -s 's = "1"*4300; v = int(s)' 'str(v)'
* 1000 loops, best of 5: 311 usec per loop
* (zen2 cloud VM)
*
* 4300 decimal digits fits a ~14284 bit number.
*/
#define _PY_LONG_DEFAULT_MAX_STR_DIGITS 4300
/*
* Threshold for max digits check. For performance reasons int() and
* int.__str__() don't checks values that are smaller than this
* threshold. Acts as a guaranteed minimum size limit for bignums that
* applications can expect from CPython.
*
* % python -m timeit -s 's = "1"*640; v = int(s)' 'str(int(s))'
* 20000 loops, best of 5: 12 usec per loop
*
* "640 digits should be enough for anyone." - gps
* fits a ~2126 bit decimal number.
*/
#define _PY_LONG_MAX_STR_DIGITS_THRESHOLD 640
#if ((_PY_LONG_DEFAULT_MAX_STR_DIGITS != 0) && \
(_PY_LONG_DEFAULT_MAX_STR_DIGITS < _PY_LONG_MAX_STR_DIGITS_THRESHOLD))
# error "_PY_LONG_DEFAULT_MAX_STR_DIGITS smaller than threshold."
#endif
#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_LONG_H */
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