flow_guard/
integration.rs

1/* * Created and Developed by: Cleiton Augusto Correa Bezerra
2 * FlowGuard - Tower/Axum Integration Layer
3 */
4
5use crate::error::FlowError;
6use crate::{FlowGuard, LimitStrategy};
7use futures_util::future::BoxFuture;
8use std::sync::Arc;
9use std::task::{Context, Poll};
10use tower::{Layer, Service};
11
12// --- 1. A LAYER ---
13pub struct FlowGuardLayer<S: LimitStrategy> {
14    guard: Arc<FlowGuard<S>>,
15}
16
17// Implementação manual de Clone para não exigir que S seja Clone
18impl<S: LimitStrategy> Clone for FlowGuardLayer<S> {
19    fn clone(&self) -> Self {
20        Self {
21            guard: self.guard.clone(),
22        }
23    }
24}
25
26impl<S: LimitStrategy + 'static> FlowGuardLayer<S> {
27    pub fn new(strategy: S) -> Self {
28        Self {
29            guard: Arc::new(FlowGuard::new(strategy)),
30        }
31    }
32}
33
34impl<S, L> Layer<S> for FlowGuardLayer<L>
35where
36    L: LimitStrategy + 'static,
37{
38    type Service = FlowGuardService<S, L>;
39
40    fn layer(&self, inner: S) -> Self::Service {
41        FlowGuardService {
42            inner,
43            guard: self.guard.clone(),
44        }
45    }
46}
47
48// --- 2. O SERVICE ---
49pub struct FlowGuardService<S, L: LimitStrategy> {
50    inner: S,
51    guard: Arc<FlowGuard<L>>,
52}
53
54impl<S: Clone, L: LimitStrategy> Clone for FlowGuardService<S, L> {
55    fn clone(&self) -> Self {
56        Self {
57            inner: self.inner.clone(),
58            guard: self.guard.clone(),
59        }
60    }
61}
62
63impl<S, L, Req> Service<Req> for FlowGuardService<S, L>
64where
65    S: Service<Req> + Clone + Send + 'static,
66    S::Future: Send + 'static,
67    L: LimitStrategy + 'static,
68    Req: Send + 'static,
69{
70    type Response = S::Response;
71    type Error = FlowError<S::Error>;
72    type Future = BoxFuture<'static, Result<Self::Response, Self::Error>>;
73
74    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
75        // Mapeia o erro do serviço interno para o nosso sistema de erros do FlowGuard
76        self.inner.poll_ready(cx).map_err(FlowError::AppError)
77    }
78
79    fn call(&mut self, req: Req) -> Self::Future {
80        let mut inner = self.inner.clone();
81        let guard = self.guard.clone();
82
83        Box::pin(async move {
84            // O FlowGuard decide se executa ou bloqueia (Backpressure dinâmico)
85            guard.run(inner.call(req)).await
86        })
87    }
88}
flow_guard/integration.rs

flow_guard/
integration.rs
