/**
 * 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.
 */ import { validateNotNull } from '../../common/validations' ; import { MetricProducer , MetricProducerManager } from './types' ; /**
 * Keeps a set of MetricProducer that is used by exporters to determine the
 * metrics that need to be exported.
 */ class BaseMetricProducerManager implements MetricProducerManager { /** Singleton instance */ private static singletonInstance : MetricProducerManager ; private metricProducers : Set < MetricProducer > = new Set < MetricProducer > ( ) ; /** Gets the instance. */ static get instance ( ) : MetricProducerManager { return this . singletonInstance || ( this . singletonInstance = new this ( ) ) ; } param metricProducer add ( metricProducer ) { validateNotNull ( metricProducer , 'metricProducer' ) ; if ( ! this . metricProducers . has ( metricProducer ) ) { this . metricProducers . add ( metricProducer ) ; } } param metricProducer remove ( metricProducer ) { validateNotNull ( metricProducer , 'metricProducer' ) ; this . metricProducers . delete ( metricProducer ) ; } /**
     * Clears all MetricProducers.
     */ removeAll ( ) { this . metricProducers . clear ( ) ; } return { Set < MetricProducer > } getAllMetricProducer ( ) { return this . metricProducers ; } } export const metricProducerManagerInstance = BaseMetricProducerManager . instance ;