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#define NPY_NO_DEPRECATED_API NPY_API_VERSION
#define _MULTIARRAYMODULE
#include "numpy/ndarraytypes.h"
#include "templ_common.h"
/*
* Helper function taking the size input and growing it (based on min_grow).
* The current scheme is a minimum growth and a general growth by 25%
* overallocation. This is then capped at 2**20 elements, as that propels us
* in the range of large page sizes (so it is presumably more than enough).
*
* It further multiplies it with `itemsize` and ensures that all results fit
* into an `npy_intp`.
* Returns -1 if any overflow occurred or the result would not fit.
* The user has to ensure the input is ssize_t but not negative.
*/
NPY_NO_EXPORT npy_intp
grow_size_and_multiply(npy_intp *size, npy_intp min_grow, npy_intp itemsize) {
/* min_grow must be a power of two: */
assert((min_grow & (min_grow - 1)) == 0);
npy_uintp new_size = (npy_uintp)*size;
npy_intp growth = *size >> 2;
if (growth <= min_grow) {
/* can never lead to overflow if we are using min_growth */
new_size += min_grow;
}
else {
if (growth > 1 << 20) {
/* limit growth to order of MiB (even hugepages are not larger) */
growth = 1 << 20;
}
new_size += growth + min_grow - 1;
new_size &= ~min_grow;
if (new_size > NPY_MAX_INTP) {
return -1;
}
}
*size = (npy_intp)new_size;
npy_intp alloc_size;
if (npy_mul_sizes_with_overflow(&alloc_size, (npy_intp)new_size, itemsize)) {
return -1;
}
return alloc_size;
}
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