* enough to give linear-time amortized behavior over a long

* sequence of appends() in the presence of a poorly-performing

* system realloc().

* The growth pattern is: 0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...

* Add padding to make the allocated size multiple of 4.

* The growth pattern is: 0, 4, 8, 16, 24, 32, 40, 52, 64, 76, ...

* Note: new_allocated won't overflow because the largest possible value

* is PY_SSIZE_T_MAX * (9 / 8) + 6 which always fits in a size_t.

*/

new_allocated = (size_t)newsize + (newsize >> 3) + (newsize < 9 ? 3 : 6);

if (new_allocated > (size_t)PY_SSIZE_T_MAX / sizeof(PyObject *)) {

PyErr_NoMemory();

return -1;

}

new_allocated = ((size_t)newsize + (newsize >> 3) + 6) & ~(size_t)3;

/* Do not overallocate if the new size is closer to overalocated size

* than to the old size.

*/

if (newsize - Py_SIZE(self) > (Py_ssize_t)(new_allocated - newsize))

new_allocated = ((size_t)newsize + 3) & ~(size_t)3;

if (newsize == 0)

new_allocated = 0;