| /* |
| * Copyright 2018, 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 io.opencensus.implcore.metrics.export; |
| |
| import com.google.common.base.Preconditions; |
| import io.opencensus.metrics.MetricProducer; |
| import io.opencensus.metrics.export.MetricProducerManager; |
| import java.util.Collections; |
| import java.util.LinkedHashSet; |
| import java.util.Set; |
| import javax.annotation.concurrent.ThreadSafe; |
| |
| /** Implementation of {@link MetricProducerManager}. */ |
| @ThreadSafe |
| public final class MetricProducerManagerImpl extends MetricProducerManager { |
| |
| private volatile Set<MetricProducer> metricProducers = |
| Collections.unmodifiableSet(new LinkedHashSet<MetricProducer>()); |
| |
| @Override |
| public synchronized void add(MetricProducer metricProducer) { |
| Preconditions.checkNotNull(metricProducer, "metricProducer"); |
| // Updating the set of MetricProducers happens under a lock to avoid multiple add or remove |
| // operations to happen in the same time. |
| Set<MetricProducer> newMetricProducers = new LinkedHashSet<MetricProducer>(metricProducers); |
| if (!newMetricProducers.add(metricProducer)) { |
| // The element already present, no need to update the current set of MetricProducers. |
| return; |
| } |
| metricProducers = Collections.unmodifiableSet(newMetricProducers); |
| } |
| |
| @Override |
| public synchronized void remove(MetricProducer metricProducer) { |
| Preconditions.checkNotNull(metricProducer, "metricProducer"); |
| // Updating the set of MetricProducers happens under a lock to avoid multiple add or remove |
| // operations to happen in the same time. |
| Set<MetricProducer> newMetricProducers = new LinkedHashSet<MetricProducer>(metricProducers); |
| if (!newMetricProducers.remove(metricProducer)) { |
| // The element not present, no need to update the current set of MetricProducers. |
| return; |
| } |
| metricProducers = Collections.unmodifiableSet(newMetricProducers); |
| } |
| |
| @Override |
| public Set<MetricProducer> getAllMetricProducer() { |
| return metricProducers; |
| } |
| } |