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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
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 *
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package org.openjdk.bench.java.lang.foreign;

import java.lang.foreign.MemorySegment;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.CompilerControl;
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.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;

import java.lang.foreign.Arena;
import java.nio.ByteBuffer;
import java.util.concurrent.TimeUnit;

import static java.lang.foreign.ValueLayout.JAVA_BYTE;

@BenchmarkMode(Mode.AverageTime)
@Warmup(iterations = 5, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MILLISECONDS)
@State(org.openjdk.jmh.annotations.Scope.Thread)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Fork(value = 1, jvmArgsAppend = {
        "-Dforeign.restricted=permit",
        "--enable-native-access", "ALL-UNNAMED",
        "--enable-preview"})
public class TestLoadBytes {
    @Param("1024")
    private int size;

    private byte[] srcArray;
    private ByteBuffer srcBufferNative;
    private MemorySegment srcSegmentImplicit;

    @Setup
    public void setup() {
        srcArray = new byte[size];
        for (int i = 0; i < srcArray.length; i++) {
            srcArray[i] = (byte) i;
        }

        srcBufferNative = ByteBuffer.allocateDirect(size);
        Arena scope = Arena.ofAuto();
        srcSegmentImplicit = scope.allocate(size, 1);
    }

    @Benchmark
    public int arrayScalar() {
        int size = 0;
        for (int i = 0; i < srcArray.length; i ++) {
            var v = srcArray[i];
            size += v;
        }
        return size;
    }

    @Benchmark
    public int arrayScalarConst() {
        int size = 0;
        for (int i = 0; i < 1024; i ++) {
            var v = srcArray[i];
            size += v;
        }
        return size;
    }

    @Benchmark
    public int bufferNativeScalar() {
        int size = 0;
        for (int i = 0; i < srcArray.length; i++) {
            var v = srcBufferNative.get(i);
            size += v;
        }
        return size;
    }

    @Benchmark
    public int bufferNativeScalarConst() {
        int size = 0;
        for (int i = 0; i < 1024; i++) {
            var v = srcBufferNative.get(i);
            size += v;
        }
        return size;
    }

    @Benchmark
    public int segmentNativeScalar() {
        int size = 0;
        for (int i = 0; i < srcArray.length; i++) {
            var v = srcSegmentImplicit.get(JAVA_BYTE, i);
            size += v;
        }
        return size;
    }

    @Benchmark
    public int segmentNativeScalarConst() {
        int size = 0;
        for (int i = 0; i < 1024; i++) {
            var v = srcSegmentImplicit.get(JAVA_BYTE, i);
            size += v;
        }
        return size;
    }
}
