co.cask.cdap.metrics.collect.AggregatedMetricsEmitter.java Source code

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Here is the source code for co.cask.cdap.metrics.collect.AggregatedMetricsEmitter.java

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/*
 * Copyright  2014 Cask Data, 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 co.cask.cdap.metrics.collect;

import co.cask.cdap.metrics.transport.MetricsRecord;
import co.cask.cdap.metrics.transport.TagMetric;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.ImmutableList;
import org.slf4j.LoggerFactory;

import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * A {@link co.cask.cdap.common.metrics.MetricsCollector} and {@link MetricsEmitter} that aggregates metric values
 * during collection and emit the aggregated values when emit.
 */
final class AggregatedMetricsEmitter implements MetricsEmitter {

    private static final org.slf4j.Logger LOG = LoggerFactory.getLogger(AggregatedMetricsEmitter.class);
    private static final long CACHE_EXPIRE_MINUTES = 1;

    private final String context;
    private final String runId;
    private final String name;
    private final AtomicInteger value;
    private final LoadingCache<String, AtomicInteger> tagValues;

    AggregatedMetricsEmitter(String context, String runId, String name) {
        this.context = context;
        this.runId = runId;
        this.name = name;
        this.value = new AtomicInteger();
        this.tagValues = CacheBuilder.newBuilder().expireAfterAccess(CACHE_EXPIRE_MINUTES, TimeUnit.MINUTES)
                .build(new CacheLoader<String, AtomicInteger>() {
                    @Override
                    public AtomicInteger load(String key) throws Exception {
                        return new AtomicInteger();
                    }
                });
        if (name == null || name.isEmpty()) {
            LOG.warn("Creating emmitter with " + (name == null ? "null" : "empty") + " name, " + "for context "
                    + context + " and runId " + runId);
        }
    }

    void increment(int value, String... tags) {
        this.value.addAndGet(value);
        for (String tag : tags) {
            tagValues.getUnchecked(tag).addAndGet(value);
        }
    }

    @Override
    public MetricsRecord emit(long timestamp) {
        ImmutableList.Builder<TagMetric> builder = ImmutableList.builder();
        int value = this.value.getAndSet(0);
        for (Map.Entry<String, AtomicInteger> entry : tagValues.asMap().entrySet()) {
            builder.add(new TagMetric(entry.getKey(), entry.getValue().getAndSet(0)));
        }
        return new MetricsRecord(context, runId, name, builder.build(), timestamp, value);
    }
}