/*

 * Copyright (c) 2019, 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package org.openjdk.bench.java.util;

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 java.util.Arrays;

import java.util.HashMap;

import java.util.LinkedHashMap;

import java.util.Map;

import java.util.concurrent.TimeUnit;

@BenchmarkMode(Mode.AverageTime)

@OutputTimeUnit(TimeUnit.NANOSECONDS)

@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)

@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)

@Fork(3)

@State(Scope.Thread)

public class HashMapToArray {

    @Param({"0", "1", "10", "1000", "100000"})

    public int size;

    @Param({"HashMap", "LinkedHashMap"})

    public String mapType;

    private Map<Integer, Integer> map;

    @Setup

    public void setup() {

        switch (mapType) {

            case "HashMap":

                map = new HashMap<>();

                break;

            case "LinkedHashMap":

                map = new LinkedHashMap<>();

                break;

            default:

                throw new IllegalStateException();

        }

        for (int i = 0; i < size; i++) {

            map.put(i, i * i);

        }

    }

    @Benchmark

    public Object[] testKeySetToArray() {

        return map.keySet().toArray();

    }

    @Benchmark

    public Object[] testKeySetToArrayTyped() {

        return map.keySet().toArray(new Integer[0]);

    }

    @Benchmark

    public Object[] testValuesToArray() {

        return map.values().toArray();

    }

    @Benchmark

    public Object[] testValuesToArrayTyped() {

        return map.values().toArray(new Integer[0]);

    }

}