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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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 *
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package org.openjdk.bench.java.lang.stable;

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.OperationsPerInvocation;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;

import java.util.Map;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/**
 * Benchmark measuring StableValue performance
 */
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Benchmark) // Share the same state instance (for contention)
@Warmup(iterations = 5, time = 1)
@Measurement(iterations = 5, time = 2)
@Fork(value = 2, jvmArgsAppend = {
        "--enable-preview"
})
@Threads(Threads.MAX)   // Benchmark under contention
public class StableFunctionSingleBenchmark {

    private static final int SIZE = 100;
    private static final Set<Integer> SET = IntStream.range(0, SIZE).boxed().collect(Collectors.toSet());

    private static final Map<Integer, Integer> MAP = StableValue.map(SET, Function.identity());
    private static final Function<Integer, Integer> FUNCTION = StableValue.function(SET, Function.identity());

    private final Map<Integer, Integer> map = StableValue.map(SET, Function.identity());
    private final Function<Integer, Integer> function = StableValue.function(SET, Function.identity());

    @Benchmark
    public int map() {
        return map.get(1);
    }

    @Benchmark
    public int function() {
        return function.apply(1);
    }

    @Benchmark
    public int staticSMap() {
        return MAP.get(1);
    }

    @Benchmark
    public int staticIntFunction() {
        return FUNCTION.apply(1);
    }

}
