Integers.java

/*
 * Copyright (c) 2014, 2021, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package org.openjdk.bench.java.lang;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
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.Warmup;
import org.openjdk.jmh.infra.Blackhole;

import java.util.Random;
import java.util.concurrent.TimeUnit;

/**
 * Test various java.lang.Integer operations
 */
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@State(Scope.Thread)
@Warmup(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 5, time = 1000, timeUnit = TimeUnit.MILLISECONDS)
@Fork(3)
public class Integers {

    @Param("500")
    private int size;

    private String[] strings;
    private int[] intsSmall;
    private int[] intsBig;

    @Setup
    public void setup() {
        Random r = new Random(0);
        strings = new String[size];
        intsSmall = new int[size];
        intsBig = new int[size];
        for (int i = 0; i < size; i++) {
            strings[i] = "" + (r.nextInt(10000) - (5000));
            intsSmall[i] = 100 * i + i + 103;
            intsBig[i] = ((100 * i + i) << 24) + 4543 + i * 4;
        }
    }

    @Benchmark
    public void parseInt(Blackhole bh) {
        for (String s : strings) {
            bh.consume(Integer.parseInt(s));
        }
    }

    /** Performs toString on small values, just a couple of digits. */
    @Benchmark
    public void toStringSmall(Blackhole bh) {
        for (int i : intsSmall) {
            bh.consume(Integer.toString(i));
        }
    }

    /** Performs toString on large values, roughly 10 digits. */
    @Benchmark
    public void toStringBig(Blackhole bh) {
        for (int i : intsBig) {
            bh.consume(Integer.toString(i));
        }
    }
}