#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 */