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Vector can currently panic when pushing an element or reserving space

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for only half of the maximum size available on the architecture. This
allows vectors to keep expanding with those two methods until the amount
of bytes exceeds usize.
This commit is contained in:
bcoopers 2015-03-29 16:07:24 -04:00
parent fa3d778626
commit c93760da9d
1 changed files with 11 additions and 5 deletions
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16
src/libcollections/vec.rs
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@ -306,9 +306,12 @@ impl<T> Vec<T> {
pub fn reserve(&mut self, additional: usize) {
if self.cap - self.len < additional {
let err_msg = "Vec::reserve: `usize` overflow";
let new_cap = self.len.checked_add(additional).expect(err_msg)
.checked_next_power_of_two().expect(err_msg);
self.grow_capacity(new_cap);
let new_min_cap = self.len.checked_add(additional).expect(err_msg);
match new_min_cap.checked_next_power_of_two() {
None => self.grow_capacity(new_min_cap),
Some(x) => self.grow_capacity(x),
}
}
}
@ -639,8 +642,11 @@ impl<T> Vec<T> {
#[inline(never)]
fn resize<T>(vec: &mut Vec<T>) {
let old_size = vec.cap * mem::size_of::<T>();
let size = max(old_size, 2 * mem::size_of::<T>()) * 2;
if old_size > size { panic!("capacity overflow") }
if old_size == std::usize::MAX { panic!("capacity overflow") }
let mut size = max(old_size, 2 * mem::size_of::<T>()) * 2;
if old_size > size {
size = std::usize::MAX;
}
unsafe {
let ptr = alloc_or_realloc(*vec.ptr, old_size, size);
if ptr.is_null() { ::alloc::oom() }