sample file for logging incoming requests and timing between requests

path_timing_server.go

package main

import (
	"log"
	"net/http"
	"time"
)

func main() {
	// Map to record timings between different paths
	type prev struct {
		t0, tLast time.Time
	}
	m := make(map[string]*prev)

	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		p := r.URL.Path
		q, prs := m[p]
		if !prs {
			q = &prev{
				t0:    time.Now(),
				tLast: time.Now(),
			}
		}

		// Calculate total time and time since last request.
		// Update q.tLast for next calculation.
		t := time.Now()
		total := t.Sub(q.t0)
		d := t.Sub(q.tLast)
		q.tLast = t
		m[p] = q
		log.Printf("total=%v delta=%v path=%s\n", total, d, r.URL.Path)

		// see if we can return various responses and see how that
		// effects the retry timers and things.
		// http.StatusTooManyRequests, eg.
		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte("error"))
	})

	log.Println("listening on port :9200")
	log.Fatal(http.ListenAndServe(":9200", nil))
}