org.apache.aurora.scheduler.stats.CachedCounters.java Source code

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Here is the source code for org.apache.aurora.scheduler.stats.CachedCounters.java

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/**
 * 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 org.apache.aurora.scheduler.stats;

import java.util.concurrent.atomic.AtomicLong;

import javax.inject.Inject;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

import org.apache.aurora.common.stats.StatsProvider;

/**
 * A cache of stats, allowing counters to be fetched and reused based on their names.
 */
public class CachedCounters {
    private final LoadingCache<String, AtomicLong> cache;

    @VisibleForTesting
    @Inject
    public CachedCounters(final StatsProvider stats) {
        cache = CacheBuilder.newBuilder().build(new CacheLoader<String, AtomicLong>() {
            @Override
            public AtomicLong load(String key) {
                return stats.makeCounter(key);
            }
        });
    }

    public AtomicLong get(String name) {
        return cache.getUnchecked(name);
    }
}