On Wed, 13 Sep 2023 14:56:15 GMT, 温绍锦 <d...@openjdk.org> wrote:
> In many scenarios, DateTimeFormatter::format is a slower operation. > > For example, the following business scenarios > 1. The json library > gson/jackson/[fastjson2](https://github.com/alibaba/fastjson2) formats > Instant/LocalDate/LocalTime/LocalDateTime/ZonedDateTim into strings. > 2. In data integration scenarios, for projects like > [datax](https://github.com/alibaba/datax)/[canal](https://github.com/alibaba/canal), > if the input type is Date/Instant and the output type is String, formatting > is required. > > This PR provides format performance optimization for commonly used date > patterns. > > ISO_INSTANT > ISO_LOCAL_TIME > ISO_LOCAL_DATE > ISO_LOCAL_DATETIME > HH:mm:ss > HH:mm:ss.SSS > yyyy-MM-dd > yyyy-MM-dd HH:mm:ss > yyyy-MM-dd'T'HH:mm:ss > yyyy-MM-dd HH:mm:ss.SSS > yyyy-MM-dd'T'HH:mm:ss.SSS Performance comparison data is as follows: ## 1. Script bash configure make images sh make/devkit/createJMHBundle.sh bash configure --with-jmh=build/jmh/jars make test TEST="micro:java.time.format.DateTimeFormatterBench.*" ## 2. MacBookPro benchmark -Benchmark (pattern) Mode Cnt Score Error Units (baseline) -DateTimeFormatterBench.formatInstants HH:mm:ss thrpt 15 14.888 ? 0.109 ops/ms -DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt 15 10.132 ? 0.046 ops/ms -DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt 15 8.993 ? 0.039 ops/ms -DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt 15 7.400 ? 0.035 ops/ms -DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt 15 21.460 ? 0.056 ops/ms -DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt 15 14.439 ? 0.264 ops/ms -DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt 15 12.742 ? 0.055 ops/ms -DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt 15 9.059 ? 0.124 ops/ms +Benchmark (pattern) Mode Cnt Score Error Units (optimized) +DateTimeFormatterBench.formatInstants HH:mm:ss thrpt 15 28.082 ? 0.284 ops/ms (+88.62%) +DateTimeFormatterBench.formatInstants HH:mm:ss.SSS thrpt 15 25.483 ? 0.109 ops/ms (+151.51%) +DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss thrpt 15 19.950 ? 0.444 ops/ms (+121.83%) +DateTimeFormatterBench.formatInstants yyyy-MM-dd'T'HH:mm:ss.SSS thrpt 15 18.391 ? 0.327 ops/ms (+148.52%) +DateTimeFormatterBench.formatZonedDateTime HH:mm:ss thrpt 15 57.870 ? 0.641 ops/ms (+169.66%) +DateTimeFormatterBench.formatZonedDateTime HH:mm:ss.SSS thrpt 15 43.783 ? 0.300 ops/ms (+203.22%) +DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss thrpt 15 36.220 ? 0.194 ops/ms (+184.25%) +DateTimeFormatterBench.formatZonedDateTime yyyy-MM-dd'T'HH:mm:ss.SSS thrpt 15 32.512 ? 0.583 ops/ms (+258.89%) ------------- PR Comment: https://git.openjdk.org/jdk/pull/15722#issuecomment-1717870613
