Expand Up @@ -54,15 +54,17 @@ list_resize(PyListObject *self, Py_ssize_t newsize) * 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; Expand Down