lean into examples

examples/request-logging/request-logging.go

@@ -0,0 +1,40 @@
+package main
+
+import "net/http"
+import "time"
+import "fmt"
+
+func runLogging(logs chan string) {
+    for log := range logs {
+        fmt.Println(log)
+    }
+}
+
+func wrapLogging(f http.HandlerFunc) http.HandlerFunc {
+    logs := make(chan string, 10000)
+    go runLogging(logs)
+    return func(w http.ResponseWriter, r *http.Request) {
+        start := time.Now()
+        f(w, r)
+        method := r.Method
+        path := r.URL.Path
+        elapsed := float64(time.Since(start)) / 1000000.0
+        logs <- fmt.Sprintf(
+            "method=%s path=%s elapsed=%f",
+            method, path, elapsed)
+    }
+}
+
+func hello(w http.ResponseWriter, r *http.Request) {
+    w.Header().Set("Content-Type", "text/plain")
+    time.Sleep(time.Millisecond * 50)
+    fmt.Fprintln(w, "Hello logged world")
+}
+
+func main() {
+    handler := wrapLogging(hello)
+    http.HandleFunc("/", handler)
+    http.ListenAndServe(":5000", nil)
+}
+
+// todo: logging status code?