pub struct BoxCloneServiceLayer<In, T, U, E> { /* private fields */ }
util
only.Expand description
BoxCloneServiceLayer
turns a layer into a trait object, allowing both the Layer
itself
and the output Service
to be dynamic, while having consistent types.
This Layer
produces BoxCloneService
instances erasing the type of the
Service
produced by the wrapped Layer
.
This is similar to BoxLayer
except the layer and resulting
service implements Clone
.
§Example
BoxCloneServiceLayer
can, for example, be useful to create layers dynamically that otherwise wouldn’t have
the same types, when the underlying service must be clone (for example, when building a MakeService)
In this example, we include a Timeout
layer only if an environment variable is set. We can use
BoxCloneService
to return a consistent type regardless of runtime configuration:
use std::time::Duration;
use tower::{Service, ServiceBuilder, BoxError};
use tower::util::{BoxCloneServiceLayer, BoxCloneService};
fn common_layer<S, T>() -> BoxCloneServiceLayer<S, T, S::Response, BoxError>
where
S: Service<T> + Clone + Send + 'static,
S::Future: Send + 'static,
S::Error: Into<BoxError> + 'static,
{
let builder = ServiceBuilder::new()
.concurrency_limit(100);
if std::env::var("SET_TIMEOUT").is_ok() {
let layer = builder
.timeout(Duration::from_secs(30))
.into_inner();
BoxCloneServiceLayer::new(layer)
} else {
let layer = builder
.map_err(Into::into)
.into_inner();
BoxCloneServiceLayer::new(layer)
}
}
// We can clone the layer (this is true of BoxLayer as well)
let boxed_clone_layer = common_layer();
let cloned_layer = boxed_clone_layer.clone();
// Using the `BoxCloneServiceLayer` we can create a `BoxCloneService`
let service: BoxCloneService<Request, Response, BoxError> = ServiceBuilder::new().layer(boxed_clone_layer)
.service_fn(|req: Request| async {
Ok::<_, BoxError>(Response::new())
});
// And we can still clone the service
let cloned_service = service.clone();
Implementations§
Source§impl<In, T, U, E> BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> BoxCloneServiceLayer<In, T, U, E>
Trait Implementations§
Source§impl<In, T, U, E> Clone for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> Clone for BoxCloneServiceLayer<In, T, U, E>
Source§impl<In, T, U, E> Debug for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> Debug for BoxCloneServiceLayer<In, T, U, E>
Auto Trait Implementations§
impl<In, T, U, E> Freeze for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> !RefUnwindSafe for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> Send for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> Sync for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> Unpin for BoxCloneServiceLayer<In, T, U, E>
impl<In, T, U, E> !UnwindSafe for BoxCloneServiceLayer<In, T, U, E>
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,
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: 16 bytes