Struct miri::borrow_tracker::stacked_borrows::stack::StackCache
source · struct StackCache {
items: [Item; 32],
idx: [usize; 32],
}
Expand description
A very small cache of searches of a borrow stack, mapping Item
s to their position in said stack.
It may seem like maintaining this cache is a waste for small stacks, but (a) iterating over small fixed-size arrays is super fast, and (b) empirically this helps a lot, probably because runtime is dominated by large stacks.
Fields§
§items: [Item; 32]
§idx: [usize; 32]
Implementations§
source§impl StackCache
impl StackCache
sourcefn add(&mut self, idx: usize, item: Item)
fn add(&mut self, idx: usize, item: Item)
When a tag is used, we call this function to add or refresh it in the cache.
We use the position in the cache to represent how recently a tag was used; the first position is the most recently used tag. So an add shifts every element towards the end, and inserts the new element at the start. We lose the last element. This strategy is effective at keeping the most-accessed items in the cache, but it costs a linear shift across the entire cache when we add a new tag.
Trait Implementations§
source§impl Clone for StackCache
impl Clone for StackCache
source§fn clone(&self) -> StackCache
fn clone(&self) -> StackCache
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read moreAuto Trait Implementations§
impl Freeze for StackCache
impl RefUnwindSafe for StackCache
impl Send for StackCache
impl Sync for StackCache
impl Unpin for StackCache
impl UnwindSafe for StackCache
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§unsafe fn clone_to_uninit(&self, dst: *mut T)
unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)Layout§
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.
Size: 512 bytes