UpdateHub / updatehub / 32295731778

66%

Build Type

push

github

Committed by otavio

Commit Message

refactor: replace async-trait with native async functions in traits

Rust stabilized async functions in traits in 1.75 and the MSRV is already 1.88,
so the macro carries its own weight for nothing. Removing it drops a proc-macro
from the build graph and the `Box<dyn Future>` that each of the 30 annotated
blocks allocated on every call, which the state machine paid on every
transition.

All but one of those blocks asked for `?Send`, and that is what a native async
function gives on its own. `CommunicationState` used the `Send` variant, but
nothing ever needed its future to be `Send`, so the bound goes away with no
other change.

Two things the expansion was hiding:

`StateChangeImpl::handle` now needs `where Self: Sized`. A native async function
makes a trait dyn-incompatible, and `State::inner_state` returns `&dyn
StateChangeImpl`. The bound keeps `handle` out of the vtable and costs nothing,
because `inner_state` only reaches `name`, `is_handling_download` and
`is_preemptive_state`.

`Download::handle` took `mut self` and never mutated it. The macro moved the
binding somewhere `unused_mut` could not see it.

async-trait stays in Cargo.lock as an indirect dependency of other crates.

Coverage Stats

0 of 1 new or added line in 1 file covered. (0.0%)

456 existing lines in 24 files now uncovered.

3261 of 5239 relevant lines covered (62.24%)

951.75 hits per line