Add metrics prefix

Author: mingyutang

ginmetrics/types.go

@@ -78,6 +78,16 @@ func (m *Monitor) SetDuration(duration []float64) {
 	m.reqDuration = duration
 }
 
+func (m *Monitor) SetMetricPrefix(prefix string) {
+	metricRequestTotal = prefix + metricRequestTotal
+	metricRequestUVTotal = prefix + metricRequestUVTotal
+	metricURIRequestTotal = prefix + metricURIRequestTotal
+	metricRequestBody = prefix + metricRequestBody
+	metricResponseBody = prefix + metricResponseBody
+	metricRequestDuration = prefix + metricRequestDuration
+	metricSlowRequest = prefix + metricSlowRequest
+}
+
 func (m *Monitor) SetMetricSuffix(suffix string) {
 	metricRequestTotal += suffix
 	metricRequestUVTotal += suffix