Remove redundant otelhttp allocation (#5842)

There is no need to wrap `MeasurementOption` to a slice

Co-authored-by: Damien Mathieu <[email protected]>
Co-authored-by: Tyler Yahn <[email protected]>

Author: 3 people

instrumentation/net/http/otelhttp/handler.go

@@ -232,9 +232,9 @@ func (h *middleware) serveHTTP(w http.ResponseWriter, r *http.Request, next http
 		attributes = append(attributes, semconv.HTTPStatusCode(rww.statusCode))
 	}
 	o := metric.WithAttributeSet(attribute.NewSet(attributes...))
-	addOpts := []metric.AddOption{o} // Allocate vararg slice once.
-	h.requestBytesCounter.Add(ctx, bw.read.Load(), addOpts...)
-	h.responseBytesCounter.Add(ctx, rww.written, addOpts...)
+
+	h.requestBytesCounter.Add(ctx, bw.read.Load(), o)
+	h.responseBytesCounter.Add(ctx, rww.written, o)
 
 	// Use floating point division here for higher precision (instead of Millisecond method).
 	elapsedTime := float64(time.Since(requestStartTime)) / float64(time.Millisecond)

instrumentation/net/http/otelhttp/transport.go

@@ -172,11 +172,11 @@ func (t *Transport) RoundTrip(r *http.Request) (*http.Response, error) {
 		metricAttrs = append(metricAttrs, semconv.HTTPStatusCode(res.StatusCode))
 	}
 	o := metric.WithAttributeSet(attribute.NewSet(metricAttrs...))
-	addOpts := []metric.AddOption{o} // Allocate vararg slice once.
-	t.requestBytesCounter.Add(ctx, bw.read.Load(), addOpts...)
+
+	t.requestBytesCounter.Add(ctx, bw.read.Load(), o)
 	// For handling response bytes we leverage a callback when the client reads the http response
 	readRecordFunc := func(n int64) {
-		t.responseBytesCounter.Add(ctx, n, addOpts...)
+		t.responseBytesCounter.Add(ctx, n, o)
 	}
 
 	// traces