Http2PseudoHeadersLookupBenchmark Class — netty Architecture

Source Code

microbench/src/main/java/io/netty/handler/codec/http2/Http2PseudoHeadersLookupBenchmark.java lines 37–121

@State(Scope.Benchmark)
@Warmup(iterations = 10, time = 200, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 200, timeUnit = TimeUnit.MILLISECONDS)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
public class Http2PseudoHeadersLookupBenchmark extends AbstractMicrobenchmark {

    @Param({ "true", "false" })
    public boolean same;

    private AsciiString[] asciiStrings;
    private String[] strings;

    private DefaultHttp2Headers headers;
    @Setup
    public void init() {
        // this benchmark is assuming a good happy path:
        // 1. ascii strings have hashCode cached
        // 2. String doesn't have AsciiString::hashCode cached -> cannot be compared directly with AsciiStrings!
        // 3. the call-sites are never observing the 2 types together
        PseudoHeaderName[] pseudoHeaderNames = PseudoHeaderName.values();
        asciiStrings = new AsciiString[pseudoHeaderNames.length];
        strings = new String[pseudoHeaderNames.length];
        for (int i = 0; i < pseudoHeaderNames.length; i++) {
            PseudoHeaderName pseudoHeaderName = pseudoHeaderNames[i];
            asciiStrings[i] = same? pseudoHeaderName.value() : new AsciiString(pseudoHeaderName.value().array(), true);
            byte[] chars = asciiStrings[i].array();
            strings[i] = same? pseudoHeaderName.value().toString() : new String(chars, 0, 0, chars.length);
            // force hashCode caching
            asciiStrings[i].hashCode();
            pseudoHeaderName.hashCode();
            pseudoHeaderName.toString().hashCode();
            strings[i].hashCode();
        }
        this.headers = new DefaultHttp2Headers();
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public void getAsciiStringPseudoHeader(Blackhole bh) {
        for (AsciiString asciiString : asciiStrings) {
            bh.consume(PseudoHeaderName.getPseudoHeader(asciiString));
        }
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public void getStringPseudoHeader(Blackhole bh) {
        for (String string : strings) {
            bh.consume(PseudoHeaderName.getPseudoHeader(string));
        }
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public void addAsciiStringInHttp2Headers(Blackhole bh) {
        DefaultHttp2Headers headers = this.headers;
        for (AsciiString asciiString : asciiStrings) {
            boolean hasPrefix = PseudoHeaderName.hasPseudoHeaderFormat(asciiString);
            if (hasPrefix) {
                boolean isPseudoHeader = PseudoHeaderName.isPseudoHeader(asciiString);
                if (isPseudoHeader) {
                    bh.consume(headers.add(asciiString, "0"));
                    headers.clear();
                }
            }
        }
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public void addStringInHttp2Headers(Blackhole bh) {
        DefaultHttp2Headers headers = this.headers;
        for (String asciiString : strings) {
            boolean hasPrefix = PseudoHeaderName.hasPseudoHeaderFormat(asciiString);
            if (hasPrefix) {
                boolean isPseudoHeader = PseudoHeaderName.isPseudoHeader(asciiString);
                if (isPseudoHeader) {
                    bh.consume(headers.add(asciiString, "0"));
                    headers.clear();
                }