ullun/
middleware.rs

1//! Middleware types and traits
2
3use crate::error::{Error, Result};
4use crate::request::Request;
5use crate::response::Response;
6use async_trait::async_trait;
7use std::sync::Arc;
8
9/// Middleware trait
10#[async_trait]
11pub trait Middleware: Send + Sync + 'static {
12    async fn handle(&self, req: Request, next: Next) -> Result<Response>;
13}
14
15/// Next middleware in chain
16#[derive(Clone)]
17pub struct Next {
18    middlewares: Arc<Vec<Arc<dyn Middleware>>>,
19    index: usize,
20}
21
22impl Next {
23    pub fn new(middlewares: Arc<Vec<Arc<dyn Middleware>>>) -> Self {
24        Self {
25            middlewares,
26            index: 0,
27        }
28    }
29
30    pub async fn run(mut self, req: Request) -> Result<Response> {
31        if self.index < self.middlewares.len() {
32            let middleware = self.middlewares[self.index].clone();
33            self.index += 1;
34            middleware.handle(req, self).await
35        } else {
36            // End of chain without handler match
37            Err(Error::not_found("Route not found"))
38        }
39    }
40}
41
42/// Share one middleware instance between several registrations, e.g. a
43/// `RateLimiter` whose budget spans multiple groups
44#[async_trait]
45impl<M: Middleware + ?Sized> Middleware for Arc<M> {
46    async fn handle(&self, req: Request, next: Next) -> Result<Response> {
47        (**self).handle(req, next).await
48    }
49}
50
51/// A handler wrapped in its own middleware stack (used by route groups)
52pub(crate) struct Layered {
53    middlewares: Vec<Arc<dyn Middleware>>,
54    inner: crate::handler::DynHandler,
55}
56
57impl Layered {
58    pub(crate) fn new(
59        middlewares: Vec<Arc<dyn Middleware>>,
60        inner: crate::handler::DynHandler,
61    ) -> Self {
62        Self { middlewares, inner }
63    }
64}
65
66#[async_trait]
67impl crate::handler::Handler for Layered {
68    async fn call(&self, req: Request) -> Result<Response> {
69        let inner = self.inner.clone();
70        let mut chain = self.middlewares.clone();
71        chain.push(Arc::new(move |req: Request, _next: Next| {
72            let inner = inner.clone();
73            async move { inner.call(req).await }
74        }));
75        Next::new(Arc::new(chain)).run(req).await
76    }
77}
78
79/// Implement Middleware for async functions
80#[async_trait]
81impl<F, Fut> Middleware for F
82where
83    F: Fn(Request, Next) -> Fut + Send + Sync + 'static,
84    Fut: std::future::Future<Output = Result<Response>> + Send + 'static,
85{
86    async fn handle(&self, req: Request, next: Next) -> Result<Response> {
87        (self)(req, next).await
88    }
89}
90
91/// Logger middleware
92pub async fn logger(req: Request, next: Next) -> Result<Response> {
93    let method = req.method.clone();
94    let uri = req.uri.clone();
95    let start = std::time::Instant::now();
96
97    let response = next.run(req).await;
98
99    let duration = start.elapsed();
100    println!("{} {} - {:?}", method, uri, duration);
101
102    response
103}
104
105/// CORS middleware with preflight support
106pub fn cors(
107    allowed_origins: Vec<String>,
108) -> impl Fn(
109    Request,
110    Next,
111) -> std::pin::Pin<Box<dyn std::future::Future<Output = Result<Response>> + Send>>
112       + Clone {
113    move |req: Request, next: Next| {
114        let origins = allowed_origins.clone();
115        Box::pin(async move {
116            // Handle preflight OPTIONS requests
117            if req.method == http::Method::OPTIONS {
118                let mut response = Response::new(http::StatusCode::NO_CONTENT);
119
120                if !origins.is_empty() {
121                    let origin = if origins.contains(&"*".to_string()) {
122                        "*".to_string()
123                    } else {
124                        // In production, should check Origin header against allowed list
125                        origins[0].clone()
126                    };
127                    response = response.with_header("Access-Control-Allow-Origin", origin);
128                    response = response.with_header(
129                        "Access-Control-Allow-Methods",
130                        "GET, POST, PUT, DELETE, PATCH, OPTIONS",
131                    );
132                    response = response.with_header(
133                        "Access-Control-Allow-Headers",
134                        "Content-Type, Authorization",
135                    );
136                    response = response.with_header("Access-Control-Max-Age", "86400");
137                }
138
139                return Ok(response);
140            }
141
142            // Regular request - add CORS headers to response
143            let mut response = next.run(req).await?;
144
145            if !origins.is_empty() {
146                let origin = if origins.contains(&"*".to_string()) {
147                    "*".to_string()
148                } else {
149                    origins[0].clone()
150                };
151                response = response.with_header("Access-Control-Allow-Origin", origin);
152                response = response.with_header("Access-Control-Allow-Credentials", "true");
153            }
154
155            Ok(response)
156        })
157    }
158}
ullun/middleware.rs

ullun/
middleware.rs
