On Fri, 4 Mar 2022 17:54:20 GMT, Jim Laskey <jlas...@openjdk.org> wrote:
> Several attempts have been made to improve Formatter's numeric performance by
> caching the current Locale zero. Such fixes, however, ignore the real issue,
> which is the slowness of fetching DecimalFormatSymbols. By directly caching
> DecimalFormatSymbols in the Formatter, this enhancement streamlines the
> process of accessing Locale DecimalFormatSymbols and specifically
> getZeroDigit(). The result is a general improvement in the performance of
> numeric formatting.
>
>
> @Benchmark
> public void bigDecimalDefaultLocale() {
> result = String.format("%1$f %1$f %1$f %1$f %1$f %1$f %1$f %1$f %1$f
> %1$f", X);
> }
>
> @Benchmark
> public void bigDecimalLocaleAlternate() {
> result = String.format(THAI, "%1$f %1$f %1$f %1$f %1$f %1$f %1$f %1$f
> %1$f %1$f", X);
> other = String.format(DEFAULT, "%1$f %1$f %1$f %1$f %1$f %1$f %1$f %1$f
> %1$f %1$f", X);
> }
>
> @Benchmark
> public void bigDecimalThaiLocale() {
> result = String.format(THAI, "%1$f %1$f %1$f %1$f %1$f %1$f %1$f %1$f
> %1$f %1$f", X);
> }
>
> @Benchmark
> public void integerDefaultLocale() {
> result = String.format("%1$d %1$d %1$d %1$d %1$d %1$d %1$d %1$d %1$d
> %1$d", x);
> }
>
> @Benchmark
> public void integerLocaleAlternate() {
> result = String.format(THAI, "%1$d %1$d %1$d %1$d %1$d %1$d %1$d %1$d
> %1$d %1$d", x);
> other = String.format(DEFAULT, "%1$d %1$d %1$d %1$d %1$d %1$d %1$d %1$d
> %1$d %1$d", x);
> }
>
> @Benchmark
> public void integerThaiLocale() {
> result = String.format(THAI, "%1$d %1$d %1$d %1$d %1$d %1$d %1$d %1$d
> %1$d %1$d", x);
> }
>
>
> Before:
> Benchmark Mode Cnt Score Error Units
> MyBenchmark.bigDecimalDefaultLocale thrpt 25 75498.923 ± 3686.966 ops/s
> MyBenchmark.bigDecimalLocaleAlternate thrpt 25 39068.721 ± 162.983 ops/s
> MyBenchmark.bigDecimalThaiLocale thrpt 25 77256.530 ± 294.743 ops/s
> MyBenchmark.integerDefaultLocale thrpt 25 344093.071 ± 6189.002 ops/s
> MyBenchmark.integerLocaleAlternate thrpt 25 165685.488 ± 440.857 ops/s
> MyBenchmark.integerThaiLocale thrpt 25 327461.302 ± 1168.243 ops/s
>
> After:
> Benchmark Mode Cnt Score Error Units
> MyBenchmark.bigDecimalDefaultLocale thrpt 25 94735.293 ± 674.587 ops/s
> MyBenchmark.bigDecimalLocaleAlternate thrpt 25 44215.547 ± 291.664 ops/s
> MyBenchmark.bigDecimalThaiLocale thrpt 25 91390.997 ± 658.677 ops/s
> MyBenchmark.integerDefaultLocale thrpt 25 363722.977 ± 2864.554 ops/s
> MyBenchmark.integerLocaleAlternate thrpt 25 165789.514 ± 779.656 ops/s
> MyBenchmark.integerThaiLocale thrpt 25 351400.818 ± 1030.246 ops/s
Good to see the performance improvement. Since you are adding a new public
method, a CSR is needed for this change.
src/java.base/share/classes/java/text/DecimalFormatSymbols.java line 194:
> 192: * Gets the locale used to create this table.
> 193: *
> 194: * @return the the locale used to create this table
`table` does not read right here, also `@since 19` is needed.
src/java.base/share/classes/java/util/Formatter.java line 2016:
> 2014: static DecimalFormatSymbols getDecimalFormatSymbols(Locale locale) {
> 2015: DecimalFormatSymbols dfs = DFS;
> 2016: if (dfs != null && dfs.getLocale() == locale) {
`Locale` should be compared using `equals()`.
src/java.base/share/classes/java/util/Formatter.java line 2026:
> 2024: // Caching zero.
> 2025: static char getZero(Locale locale) {
> 2026: return locale == null ? '0' :
> getDecimalFormatSymbols(locale).getZeroDigit();
While we are at it, it would be beneficial to cache locale-dependent grouping
and decimal separators too.
-------------
PR: https://git.openjdk.java.net/jdk/pull/7703
