ZipfianLoopingPrecomputedSequenceLoadingBenchmark.java

package org.cache2k.benchmark.jmh.suite.eviction.symmetrical;

/*
 * #%L
 * Benchmarks: JMH suite.
 * %%
 * Copyright (C) 2013 - 2017 headissue GmbH, Munich
 * %%
 * 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.
 * #L%
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import org.cache2k.benchmark.LoadingBenchmarkCache;
import org.cache2k.benchmark.jmh.BenchmarkBase;
import org.cache2k.benchmark.util.ZipfianPattern;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Level;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.Param;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.TearDown;

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Benchmark of a loading cache with penalty on a zipfian sequence.
 *
 * <p>Pattern is precomputed and Integer objects are created. This yields about 5M op/s
 * for Caffeine. Problems: Memory consumption makes it hard to determine the real occupied
 * memory, loops in threads may can follow closely leading to a higher hit rate.
 *
 * <p>As improvement {@link ZipfianHoppingPrecomputedSequenceLoadingBenchmark} is but
 * still needs memory for the pattern.
 *
 * @author Jens Wilke
 * @see ZipfianHoppingPrecomputedSequenceLoadingBenchmark
 * @see ZipfianSequenceLoadingBenchmark
 */
public class ZipfianLoopingPrecomputedSequenceLoadingBenchmark extends BenchmarkBase {

  public static final int PATTERN_COUNT = 2_000_000;

  private static final AtomicInteger offsetCount = new AtomicInteger();

  @Param({"10", "80"})
  public int factor = 0;

  @Param({"100000"})
  public int entryCount = 100_000;

  private Integer[] pattern;

  private final ZipfianSequenceLoadingBenchmark.DataSource source = new ZipfianSequenceLoadingBenchmark.DataSource();

  @State(Scope.Thread)
  public static class ThreadState {

    long index = PATTERN_COUNT / 16 * offsetCount.getAndIncrement();

    @TearDown(Level.Iteration)
    public void tearDown() {
      HitCountRecorder.recordOpCount(index);
    }
  }

  LoadingBenchmarkCache<Integer, Integer> cache;

  @Setup(Level.Iteration)
  public void setup() throws Exception {
    cache = getFactory().createLoadingCache(Integer.class, Integer.class, entryCount, source);
    ZipfianPattern _generator = new ZipfianPattern(1802, entryCount * factor);
    pattern = new Integer[PATTERN_COUNT];
    for (int i = 0; i < PATTERN_COUNT; i++) {
      pattern[i] = _generator.next();
    }
  }

  @TearDown(Level.Iteration)
  public void tearDown() {
    HitCountRecorder.recordMissCount(source.missCount.longValue());
    recordMemoryAndDestroy(cache);
    cache = null;
  }

  @Benchmark
  @BenchmarkMode(Mode.Throughput)
  public long operation(ThreadState threadState) {
    Integer k = pattern[(int) (threadState.index++ % PATTERN_COUNT)];
    Integer v = cache.get(k);
    return k + v;
  }

}