VarintDecodingBenchmark Class — netty Architecture

Source Code

microbench/src/main/java/io/netty/handler/codec/protobuf/VarintDecodingBenchmark.java lines 36–195

@State(Scope.Benchmark)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@BenchmarkMode(org.openjdk.jmh.annotations.Mode.AverageTime)
@Fork(2)
@Warmup(iterations = 10, time = 400, timeUnit = java.util.concurrent.TimeUnit.MILLISECONDS)
@Measurement(iterations = 5, time = 400, timeUnit = java.util.concurrent.TimeUnit.MILLISECONDS)
public class VarintDecodingBenchmark extends AbstractMicrobenchmark {

    private static final int SEED = 0;

    // Ryzen 7950X is exceptionally good to predict branches, so we need to use A LOT of inputs!
    @Param({ "1", "128", "128000" })
    int inputs;

    public enum InputDistribution {
        SMALL,
        LARGE,
        MEDIUM,
        ALL
    }

    @Param
    InputDistribution inputDistribution;
    ByteBuf[] data;
    int index;

    @Setup
    public void init() {
        ByteBuf[] dataSet;
        switch (inputDistribution) {
        case SMALL:
            dataSet = new ByteBuf[] {
                    generateData(1, 1),
                    generateData(2, 2),
                    generateData(3, 3)
            };
            break;
        case LARGE:
            dataSet = new ByteBuf[] {
                    generateData(5, 5)
            };
            if (inputs > 1) {
                System.exit(1);
            }
            break;
        case MEDIUM:
            dataSet = new ByteBuf[] {
                    generateData(1, 5),
                    generateData(2, 5),
                    generateData(3, 5),
                    generateData(4, 5)
            };
            break;
        case ALL:
            dataSet = new ByteBuf[] {
                    generateData(1, 1),
                    generateData(2, 2),
                    generateData(3, 3),
                    generateData(1, 5),
                    generateData(2, 5),
                    generateData(3, 5),
                    generateData(4, 5),
                    generateData(5, 5)
            };
            break;
        default:
            throw new RuntimeException("Unknown distribution");
        }
        data = new ByteBuf[inputs];
        Random rnd = new Random(SEED);
        for (int i = 0; i < inputs; i++) {
            data[i] = dataSet[rnd.nextInt(dataSet.length)];
        }
        index = 0;
    }

    public static ByteBuf generateData(int varintLength, int capacity) {
        byte[] bytes = new byte[capacity];
        for (int i = 0; i < (varintLength - 1); i++) {
            bytes[i] = (byte) 150;
        }