/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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 org.apache.groovy.bench;

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.State;
import org.openjdk.jmh.annotations.Warmup;

import java.util.concurrent.TimeUnit;

/**
 * Benchmark comparing Java, Groovy, and Groovy {@code @CompileStatic} array operations.
 */
@Warmup(iterations = 3, time = 2, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 5, time = 2, timeUnit = TimeUnit.SECONDS)
@Fork(2)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@State(Scope.Thread)
public class AryBench {

    @Param({"10", "100", "1000", "1000000"})
    private int n;

    /**
     * Baseline Java array operations.
     * @return the sum of first and last elements
     */
    @Benchmark
    public int java() {
        return JavaAry.ary(n);
    }

    /**
     * Groovy dynamic array operations.
     * @return the sum of first and last elements
     */
    @Benchmark
    public int groovy() {
        return Ary.ary(n);
    }

    /**
     * Groovy {@code @CompileStatic} array operations.
     * @return the sum of first and last elements
     */
    @Benchmark
    public int groovyCS() {
        return Ary.aryCS(n);
    }

    private static class JavaAry {
        static int ary(int n) {
            int[] x = new int[n];
            int[] y = new int[n];

            for (int i = 0; i < n; i++)
                x[i] = i + 1;
            for (int k = 0; k < 1000; k++ )
                for (int j = n-1; j >= 0; j--)
                    y[j] += x[j];

            return y[0] + y[n-1];
        }
    }

}
