1 /* 2 Copyright 2014 The Kubernetes Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package volume 18 19 var _ MetricsProvider = &MetricsNil{} 20 21 // MetricsNil represents a MetricsProvider that does not support returning 22 // Metrics. It serves as a placeholder for Volumes that do not yet support 23 // metrics. 24 type MetricsNil struct{} 25 26 // SupportsMetrics returns false for the MetricsNil type. 27 func (*MetricsNil) SupportsMetrics() bool { 28 return false 29 } 30 31 // GetMetrics returns an empty Metrics and an error. 32 // See MetricsProvider.GetMetrics 33 func (*MetricsNil) GetMetrics() (*Metrics, error) { 34 return &Metrics{}, NewNotSupportedError() 35 } 36