79 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
			
		
		
	
	
			79 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
 | 
						|
}
 |