pkg/httputil: also track protocol versions of HTTP response in StatsTransport

cmd/camget/camget.go

@@ -159,6 +159,8 @@ func main() {
 
 	if *flagVerbose {
 		log.Printf("HTTP requests: %d\n", httpStats.Requests())
+		h1, h2 := httpStats.ProtoVersions()
+		log.Printf("    responses: %d (h1), %d (h2)\n", h1, h2)
 	}
 }
 

cmd/camput/camput.go

@@ -69,6 +69,8 @@ func init() {
 				log.Printf("Client stats: %s", stats.String())
 				if up.transport != nil {
 					log.Printf("  #HTTP reqs: %d", up.transport.Requests())
+					h1, h2 := up.transport.ProtoVersions()
+					log.Printf("   responses: %d (h1), %d (h2)\n", h1, h2)
 				}
 			}
 		}

pkg/httputil/transport.go

@@ -27,8 +27,9 @@ import (
 // StatsTransport wraps another RoundTripper (or uses the default one) and
 // counts the number of HTTP requests performed.
 type StatsTransport struct {
-	mu   sync.Mutex
-	reqs int
+	mu     sync.Mutex
+	reqs   int
+	h1, h2 int // responses by protocol type
 
 	// Transport optionally specifies the transport to use.
 	// If nil, http.DefaultTransport is used.
@@ -44,6 +45,13 @@ func (t *StatsTransport) Requests() int {
 	return t.reqs
 }
 
+// ProtoVersions returns how many HTTP/1 and HTTP/2 responses were seen.
+func (t *StatsTransport) ProtoVersions() (h1, h2 int) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.h1, t.h2
+}
+
 func (t *StatsTransport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
 	t.mu.Lock()
 	t.reqs++
@@ -70,6 +78,15 @@ func (t *StatsTransport) RoundTrip(req *http.Request) (resp *http.Response, err
 			log.Printf("(%d) %s %s = error: %v (in %v)", n, req.Method, req.URL, err, td)
 		}
 	}
+	if resp != nil {
+		t.mu.Lock()
+		defer t.mu.Unlock()
+		if resp.ProtoMajor == 2 {
+			t.h2++
+		} else {
+			t.h1++
+		}
+	}
 	return
 }