filter producer stats if topic is specified

nsqd/http.go

@@ -505,6 +505,28 @@ func (s *httpServer) doStats(w http.ResponseWriter, req *http.Request, ps httpro
 				break
 			}
 		}
+
+		filteredProducerStats := make([]ClientStats, 0)
+		for _, clientStat := range producerStats {
+			var found bool
+			var count uint64
+			for _, v := range clientStat.PubCounts {
+				if v.Topic == topicName {
+					count = v.Count
+					found = true
+					break
+				}
+			}
+			if !found {
+				continue
+			}
+			clientStat.PubCounts = []PubCount{PubCount{
+				Topic: topicName,
+				Count: count,
+			}}
+			filteredProducerStats = append(filteredProducerStats, clientStat)
+		}
+		producerStats = filteredProducerStats
 	}
 
 	ms := getMemStats()