Instrument response encoding time (#81)

Author: jemiahw

api/api_gomux.go

@@ -585,6 +585,7 @@ func (api *API) getEntitiesHandler(w http.ResponseWriter, r *http.Request) {
 	rc.gm.Val(metrics.ReadMatch, int64(len(entities)))
 
 	// Success: return matching entities (possibly empty list)
+	rc.inst.Start("encode-response")
 	if len(entities) > 0 && strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 		// use gzip compression if we have data to send back and the client accepts gzip
 		w.Header().Set("Content-Encoding", "gzip")
@@ -595,6 +596,7 @@ func (api *API) getEntitiesHandler(w http.ResponseWriter, r *http.Request) {
 		// no compression
 		json.NewEncoder(w).Encode(entities)
 	}
+	rc.inst.Stop("encode-response")
 }
 
 // //////////////////////////////////////////////////////////////////////////