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/*
* Copyright (C) 2010 Google 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 benchmarks.regression;
import com.google.caliper.Param;
import com.google.caliper.SimpleBenchmark;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.PriorityQueue;
import java.util.Random;
public class PriorityQueueBenchmark extends SimpleBenchmark {
@Param({"100", "1000", "10000"}) private int queueSize;
@Param({"0", "25", "50", "75", "100"}) private int hitRate;
private PriorityQueue<Integer> pq;
private PriorityQueue<Integer> usepq;
private List<Integer> seekElements;
private Random random = new Random(189279387L);
@Override protected void setUp() throws Exception {
pq = new PriorityQueue<Integer>();
usepq = new PriorityQueue<Integer>();
seekElements = new ArrayList<Integer>();
List<Integer> allElements = new ArrayList<Integer>();
int numShared = (int)(queueSize * ((double)hitRate / 100));
// the total number of elements we require to engineer a hit rate of hitRate%
int totalElements = 2 * queueSize - numShared;
for (int i = 0; i < totalElements; i++) {
allElements.add(i);
}
// shuffle these elements so that we get a reasonable distribution of missed elements
Collections.shuffle(allElements, random);
// add shared elements
for (int i = 0; i < numShared; i++) {
pq.add(allElements.get(i));
seekElements.add(allElements.get(i));
}
// add priority queue only elements (these won't be touched)
for (int i = numShared; i < queueSize; i++) {
pq.add(allElements.get(i));
}
// add non-priority queue elements (these will be misses)
for (int i = queueSize; i < totalElements; i++) {
seekElements.add(allElements.get(i));
}
usepq = new PriorityQueue<Integer>(pq);
// shuffle again so that elements are accessed in a different pattern than they were
// inserted
Collections.shuffle(seekElements, random);
}
public boolean timeRemove(int reps) {
boolean dummy = false;
int elementsSize = seekElements.size();
// At most allow the queue to empty 10%.
int resizingThreshold = queueSize / 10;
for (int i = 0; i < reps; i++) {
// Reset queue every so often. This will be called more often for smaller
// queueSizes, but since a copy is linear, it will also cost proportionally
// less, and hopefully it will approximately balance out.
if (i % resizingThreshold == 0) {
usepq = new PriorityQueue<Integer>(pq);
}
dummy = usepq.remove(seekElements.get(i % elementsSize));
}
return dummy;
}
}