Improve fairing example.

examples/fairings/src/main.rs

@@ -2,8 +2,9 @@
 
 use std::io::Cursor;
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::Arc;
 
-use rocket::{Request, State, Data, Response};
+use rocket::{Rocket, Request, State, Data, Response};
 use rocket::fairing::{AdHoc, Fairing, Info, Kind};
 use rocket::http::{Method, ContentType, Status};
 
@@ -11,10 +12,10 @@ struct Token(i64);
 
 #[cfg(test)] mod tests;
 
-#[derive(Default)]
+#[derive(Default, Clone)]
 struct Counter {
-    get: AtomicUsize,
-    post: AtomicUsize,
+    get: Arc<AtomicUsize>,
+    post: Arc<AtomicUsize>,
 }
 
 #[rocket::async_trait]
@@ -22,7 +23,7 @@ impl Fairing for Counter {
     fn info(&self) -> Info {
         Info {
             name: "GET/POST Counter",
-            kind: Kind::Request | Kind::Response
+            kind: Kind::Attach | Kind::Request
         }
     }
 
@@ -34,20 +35,15 @@ impl Fairing for Counter {
         }
     }
 
-    async fn on_response<'r>(&self, req: &'r Request<'_>, res: &mut Response<'r>) {
-        if res.status() != Status::NotFound {
-            return
+    async fn on_attach(&self, rocket: Rocket) -> Result<Rocket, Rocket> {
+        #[get("/counts")]
+        fn counts(counts: State<'_, Counter>) -> String {
+            let get_count = counts.get.load(Ordering::Relaxed);
+            let post_count = counts.post.load(Ordering::Relaxed);
+            format!("Get: {}\nPost: {}", get_count, post_count)
         }
 
-        if req.method() == Method::Get && req.uri().path() == "/counts" {
-            let get_count = self.get.load(Ordering::Relaxed);
-            let post_count = self.post.load(Ordering::Relaxed);
-
-            let body = format!("Get: {}\nPost: {}", get_count, post_count);
-            res.set_status(Status::Ok);
-            res.set_header(ContentType::Plain);
-            res.set_sized_body(body.len(), Cursor::new(body));
-        }
+        Ok(rocket.manage(self.clone()).mount("/", routes![counts]))
     }
 }