DateRegexBenchmark.java

@State(Scope.Benchmark)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
public class DateRegexBenchmark {

    private static final String MESSAGE = "2015-12-15T07:36:25+00:00 sundaysister kernel[0]: **** [IOBluetoothHostControllerUSBTransport][ClearFeatureInterruptEndpointHalt] -- successfully posting another read for the mInt0InterruptPipe -- mInterruptPipeInOutstandingIOCount = 1 -- this = 0xb800";

    private static Pattern VERY_DESCRIPTIVE;
    private static Pattern DESCRIPTIVE;
    private static Pattern OPEN;

    @Setup
    public void prepare() {
        VERY_DESCRIPTIVE = Pattern.compile("^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\+\\d{2}:\\d{2}");
        DESCRIPTIVE = Pattern.compile(".{4}-.{2}-.{2}T.{2}:.{2}:.{2}\\+.{2}:.{2}");
        OPEN = Pattern.compile(".*-.*-.*T.*:.*:.*\\+");
    }

    @Benchmark
    public void veryDescriptiveMatch(Blackhole bh) {
        bh.consume(VERY_DESCRIPTIVE.matcher(MESSAGE).matches());
    }

    @Benchmark
    public void descriptiveMatch(Blackhole bh) {
        bh.consume(DESCRIPTIVE.matcher(MESSAGE).matches());
    }

    @Benchmark
    public void openMatch(Blackhole bh) {
        bh.consume(OPEN.matcher(MESSAGE).matches());
    }

}