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// This example demonstrates the use of Timeout, and Throttle middlewares.
//
// Timeout: cancel a request if processing takes longer than 2.5 seconds,
// server will respond with a http.StatusGatewayTimeout.
//
// Throttle: limit the number of in-flight requests along a particular
// routing path and backlog the others.
package main
import (
"context"
"fmt"
"math/rand"
"net/http"
"time"
"github.com/go-chi/chi/v5"
"github.com/go-chi/chi/v5/middleware"
)
func main() {
r := chi.NewRouter()
r.Use(middleware.RequestID)
r.Use(middleware.Logger)
r.Use(middleware.Recoverer)
r.Get("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("root."))
})
r.Get("/ping", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("pong"))
})
r.Get("/panic", func(w http.ResponseWriter, r *http.Request) {
panic("test")
})
// Slow handlers/operations.
r.Group(func(r chi.Router) {
// Stop processing after 2.5 seconds.
r.Use(middleware.Timeout(2500 * time.Millisecond))
r.Get("/slow", func(w http.ResponseWriter, r *http.Request) {
rand.Seed(time.Now().Unix())
// Processing will take 1-5 seconds.
processTime := time.Duration(rand.Intn(4)+1) * time.Second
select {
case <-r.Context().Done():
return
case <-time.After(processTime):
// The above channel simulates some hard work.
}
w.Write([]byte(fmt.Sprintf("Processed in %v seconds\n", processTime)))
})
})
// Throttle very expensive handlers/operations.
r.Group(func(r chi.Router) {
// Stop processing after 30 seconds.
r.Use(middleware.Timeout(30 * time.Second))
// Only one request will be processed at a time.
r.Use(middleware.Throttle(1))
r.Get("/throttled", func(w http.ResponseWriter, r *http.Request) {
select {
case <-r.Context().Done():
switch r.Context().Err() {
case context.DeadlineExceeded:
w.WriteHeader(504)
w.Write([]byte("Processing too slow\n"))
default:
w.Write([]byte("Canceled\n"))
}
return
case <-time.After(5 * time.Second):
// The above channel simulates some hard work.
}
w.Write([]byte("Processed\n"))
})
})
http.ListenAndServe(":3333", r)
}
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