tower_resilience_cache/
layer.rs

1use crate::{Cache, CacheConfig};
2use std::hash::Hash;
3use std::sync::Arc;
4use tower::Layer;
5
6/// A Tower [`Layer`] that applies response caching to a service.
7///
8/// This layer wraps a service with a [`Cache`] middleware that stores
9/// successful responses and returns cached values for subsequent requests
10/// with the same key.
11///
12/// # Examples
13///
14/// ```
15/// use tower_resilience_cache::CacheConfig;
16/// use tower::ServiceBuilder;
17/// use std::time::Duration;
18///
19/// # async fn example() {
20/// let cache_layer = CacheConfig::builder()
21///     .max_size(100)
22///     .ttl(Duration::from_secs(60))
23///     .key_extractor(|req: &String| req.clone())
24///     .build();
25///
26/// let service = ServiceBuilder::new()
27///     .layer(cache_layer)
28///     .service(my_service());
29/// # }
30/// # fn my_service() -> impl tower::Service<String, Response = String, Error = std::io::Error> {
31/// #     tower::service_fn(|req: String| async move { Ok::<_, std::io::Error>(req) })
32/// # }
33/// ```
34#[derive(Clone)]
35pub struct CacheLayer<Req, K> {
36    config: Arc<CacheConfig<Req, K>>,
37}
38
39impl<Req, K> CacheLayer<Req, K> {
40    /// Creates a new `CacheLayer` with the given configuration.
41    pub fn new(config: CacheConfig<Req, K>) -> Self {
42        Self {
43            config: Arc::new(config),
44        }
45    }
46}
47
48impl<S, Req, K> Layer<S> for CacheLayer<Req, K>
49where
50    K: Hash + Eq,
51    S: tower::Service<Req>,
52    S::Response: Clone,
53{
54    type Service = Cache<S, Req, K, S::Response>;
55
56    fn layer(&self, service: S) -> Self::Service {
57        Cache::new(service, Arc::clone(&self.config))
58    }
59}
tower_resilience_cache/layer.rs

tower_resilience_cache/
layer.rs
