// understandingcollections/jmh/Deques.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Performance differences between Deques
package understandingcollections.jmh;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;
import java.util.concurrent.TimeUnit;
import java.util.*;

@State(Scope.Thread)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Warmup(iterations = 5, batchSize = 5000)
@Measurement(iterations = 5, batchSize = 5000)
@BenchmarkMode(Mode.SingleShotTime)
@Fork(1)
public class Deques {
  private Deque<String> deque;

  @Param({
    "java.util.LinkedList",
    "java.util.ArrayDeque",
    "java.util.concurrent.ConcurrentLinkedDeque",
    "java.util.concurrent.LinkedBlockingDeque",
  })
  private String type;

  @Param({
    "1",
    "10",
    "100",
    "1000",
    "10000",
    "100000"
  })
  private int size;

  @Setup
  public void setup() {
    try {
      deque = (Deque<String>)
        Class.forName(type).newInstance();
    } catch(Exception e) {
      System.err.println(
        "-> Cannot create: " + type);
      System.exit(99);
    }
    for(int i = 0; i < size; i++)
      deque.add(Integer.toString(i));
  }
  @Benchmark
  public Deque<String> addFirst() {
    deque.addFirst("test");
    return deque;
  }
  @Benchmark
  public Deque<String> addLast() {
    deque.addLast("test");
    return deque;
  }
  @Benchmark
  public void pollFirst(Blackhole bh) {
    bh.consume(deque.pollFirst());
  }
  @Benchmark
  public void pollLast(Blackhole bh) {
    bh.consume(deque.pollLast());
  }
}