DockerCLI/vendor/k8s.io/client-go/tools/cache/reflector_metrics.go

103 lines
3.2 KiB
Go

/*
Copyright 2016 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
// This file provides abstractions for setting the provider (e.g., prometheus)
// of metrics.
package cache
import (
"sync"
)
// GaugeMetric represents a single numerical value that can arbitrarily go up
// and down.
type GaugeMetric interface {
Set(float64)
}
// CounterMetric represents a single numerical value that only ever
// goes up.
type CounterMetric interface {
Inc()
}
// SummaryMetric captures individual observations.
type SummaryMetric interface {
Observe(float64)
}
type noopMetric struct{}
func (noopMetric) Inc() {}
func (noopMetric) Dec() {}
func (noopMetric) Observe(float64) {}
func (noopMetric) Set(float64) {}
type reflectorMetrics struct {
numberOfLists CounterMetric
listDuration SummaryMetric
numberOfItemsInList SummaryMetric
numberOfWatches CounterMetric
numberOfShortWatches CounterMetric
watchDuration SummaryMetric
numberOfItemsInWatch SummaryMetric
lastResourceVersion GaugeMetric
}
// MetricsProvider generates various metrics used by the reflector.
type MetricsProvider interface {
NewListsMetric(name string) CounterMetric
NewListDurationMetric(name string) SummaryMetric
NewItemsInListMetric(name string) SummaryMetric
NewWatchesMetric(name string) CounterMetric
NewShortWatchesMetric(name string) CounterMetric
NewWatchDurationMetric(name string) SummaryMetric
NewItemsInWatchMetric(name string) SummaryMetric
NewLastResourceVersionMetric(name string) GaugeMetric
}
type noopMetricsProvider struct{}
func (noopMetricsProvider) NewListsMetric(name string) CounterMetric { return noopMetric{} }
func (noopMetricsProvider) NewListDurationMetric(name string) SummaryMetric { return noopMetric{} }
func (noopMetricsProvider) NewItemsInListMetric(name string) SummaryMetric { return noopMetric{} }
func (noopMetricsProvider) NewWatchesMetric(name string) CounterMetric { return noopMetric{} }
func (noopMetricsProvider) NewShortWatchesMetric(name string) CounterMetric { return noopMetric{} }
func (noopMetricsProvider) NewWatchDurationMetric(name string) SummaryMetric { return noopMetric{} }
func (noopMetricsProvider) NewItemsInWatchMetric(name string) SummaryMetric { return noopMetric{} }
func (noopMetricsProvider) NewLastResourceVersionMetric(name string) GaugeMetric {
return noopMetric{}
}
var metricsFactory = struct {
metricsProvider MetricsProvider
setProviders sync.Once
}{
metricsProvider: noopMetricsProvider{},
}
// SetReflectorMetricsProvider sets the metrics provider
func SetReflectorMetricsProvider(metricsProvider MetricsProvider) {
metricsFactory.setProviders.Do(func() {
metricsFactory.metricsProvider = metricsProvider
})
}