tor_memquota_cost/
memory_cost.rs

1//! `HasMemoryCost` and typed memory cost tracking
2
3/// Types whose memory usage is known (and stable)
4///
5/// ### Important guarantees
6///
7/// Implementors of this trait must uphold the guarantees in the API of
8/// [`memory_cost`](HasMemoryCost::memory_cost).
9///
10/// If these guarantees are violated, memory tracking may go wrong,
11/// with seriously bad implications for the whole program,
12/// including possible complete denial of service.
13///
14/// (Nevertheless, memory safety will not be compromised,
15/// so trait this is not `unsafe`.)
16pub trait HasMemoryCost {
17    /// Returns the memory cost of `self`, in bytes
18    ///
19    /// ### Return value must be stable
20    ///
21    /// It is vital that the return value does not change, for any particular `self`,
22    /// unless `self` is mutated through `&mut self` or similar.
23    /// Otherwise, memory accounting may go awry.
24    ///
25    /// If `self` has interior mutability. the changing internal state
26    /// must not change the memory cost.
27    ///
28    /// ### Panics - forbidden
29    ///
30    /// This method must not panic.
31    /// Otherwise, memory accounting may go awry.
32    fn memory_cost(&self, _: crate::EnabledToken) -> usize;
33}
tor_memquota_cost/memory_cost.rs

tor_memquota_cost/
memory_cost.rs
