traefik/vendor/go.opencensus.io/metric/metricproducer/manager.go
2019-04-26 11:26:04 +02:00

78 lines
2.2 KiB
Go

// Copyright 2019, OpenCensus 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.
package metricproducer
import (
"sync"
)
// Manager maintains a list of active producers. Producers can register
// with the manager to allow readers to read all metrics provided by them.
// Readers can retrieve all producers registered with the manager,
// read metrics from the producers and export them.
type Manager struct {
mu sync.RWMutex
producers map[Producer]struct{}
}
var prodMgr *Manager
var once sync.Once
// GlobalManager is a single instance of producer manager
// that is used by all producers and all readers.
func GlobalManager() *Manager {
once.Do(func() {
prodMgr = &Manager{}
prodMgr.producers = make(map[Producer]struct{})
})
return prodMgr
}
// AddProducer adds the producer to the Manager if it is not already present.
func (pm *Manager) AddProducer(producer Producer) {
if producer == nil {
return
}
pm.mu.Lock()
defer pm.mu.Unlock()
pm.producers[producer] = struct{}{}
}
// DeleteProducer deletes the producer from the Manager if it is present.
func (pm *Manager) DeleteProducer(producer Producer) {
if producer == nil {
return
}
pm.mu.Lock()
defer pm.mu.Unlock()
delete(pm.producers, producer)
}
// GetAll returns a slice of all producer currently registered with
// the Manager. For each call it generates a new slice. The slice
// should not be cached as registration may change at any time. It is
// typically called periodically by exporter to read metrics from
// the producers.
func (pm *Manager) GetAll() []Producer {
pm.mu.Lock()
defer pm.mu.Unlock()
producers := make([]Producer, len(pm.producers))
i := 0
for producer := range pm.producers {
producers[i] = producer
i++
}
return producers
}