io.druid.query.MetricsEmittingExecutorService.java Source code

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Here is the source code for io.druid.query.MetricsEmittingExecutorService.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group Inc.
 *
 * 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.druid.query;

import com.google.common.util.concurrent.ForwardingListeningExecutorService;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.metamx.emitter.service.ServiceEmitter;
import com.metamx.emitter.service.ServiceMetricEvent;

import java.util.concurrent.Callable;

public class MetricsEmittingExecutorService extends ForwardingListeningExecutorService {
    private final ListeningExecutorService delegate;
    private final ServiceEmitter emitter;
    private final ServiceMetricEvent.Builder metricBuilder;

    public MetricsEmittingExecutorService(ListeningExecutorService delegate, ServiceEmitter emitter,
            ServiceMetricEvent.Builder metricBuilder) {
        super();

        this.delegate = delegate;
        this.emitter = emitter;
        this.metricBuilder = metricBuilder;
    }

    @Override
    protected ListeningExecutorService delegate() {
        return delegate;
    }

    @Override
    public <T> ListenableFuture<T> submit(Callable<T> tCallable) {
        emitMetrics();
        return delegate.submit(tCallable);
    }

    @Override
    public void execute(Runnable runnable) {
        emitMetrics();
        delegate.execute(runnable);
    }

    private void emitMetrics() {
        if (delegate instanceof PrioritizedExecutorService) {
            emitter.emit(metricBuilder.build("segment/scan/pending",
                    ((PrioritizedExecutorService) delegate).getQueueSize()));
        }
    }
}