axum: remove unnecessary Arc::clone
#2675
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jplatte
reviewed
Mar 24, 2024
axum/src/routing/path_router.rs
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| @@ -111,8 +111,7 @@ where | |||
| } | |||
|
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| fn set_node(&mut self, path: &str, id: RouteId) -> Result<(), String> { | |||
| let mut node = | |||
| Arc::try_unwrap(Arc::clone(&self.node)).unwrap_or_else(|node| (*node).clone()); | |||
| let mut node = (*self.node).clone(); | |||
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Could you still use fully qualified syntax here? Just so it's clear that this is a 'shallow' clone. I suspect we're not consistent about that overall, but would probably use fully qualified if we were to make things consistent.
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This was actually a deep clone.
However, I took a minute to think about how to actually do what the code probably wanted to do in the first place (which I guess I should have done at the start) and changed it to use Arc::make_mut. So as long as the router hasn't been cloned, it'll cheaply update it and otherwise fall back to a clone of Node.
jplatte
approved these changes
Mar 25, 2024
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Motivation
There was an unnecessary arc clone which is always dropped right afterward.
The
try_unwrapcall returnsOkonly if theArchas a strong count of exactly 1, but since we have just cloned it we know it will be more than 1. So thetry_unwrapnever works and the more expensiveclonealways happens anyway.Solution
I have removed the
Arcoperations.