Java example source code file (ImmutableListCreationBenchmark.java)

This example Java source code file (ImmutableListCreationBenchmark.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

benchmark, immutablelistcreationbenchmark, list, object, param, util

The ImmutableListCreationBenchmark.java Java example source code

/*
 * Copyright (C) 2012 The Guava Authors
 *
 * 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 com.google.common.collect;

import com.google.caliper.Benchmark;
import com.google.caliper.Param;

import java.util.List;

/**
 * Benchmark for various ways to create an {@code ImmutableList}.
 *
 * @author Louis Wasserman
 */
public class ImmutableListCreationBenchmark {

  @Param({"10", "1000", "1000000"})
  int size;

  private static final Object OBJECT = new Object();

  @Benchmark int builderAdd(int reps) {
    int size = this.size;
    int dummy = 0;
    for (int rep = 0; rep < reps; rep++) {
      ImmutableList.Builder<Object> builder = ImmutableList.builder();
      for (int i = 0; i < size; i++) {
        builder.add(OBJECT);
      }
      dummy += builder.build().size();
    }
    return dummy;
  }

  @Benchmark int preSizedBuilderAdd(int reps) {
    int size = this.size;
    int dummy = 0;
    for (int rep = 0; rep < reps; rep++) {
      ImmutableList.Builder<Object> builder = new ImmutableList.Builder