On Fri, 21 Nov 2025 14:58:55 GMT, Liam Miller-Cushon <[email protected]> wrote:
> This implements an API to return the byte length of a String encoded in a > given charset. See [JDK-8372353](https://bugs.openjdk.org/browse/JDK-8372353) > for background. > > --- > > > Benchmark (encoding) (stringLength) Mode Cnt > Score Error Units > StringLoopJmhBenchmark.getBytes ASCII 10 thrpt 5 > 406782650.595 ± 16960032.852 ops/s > StringLoopJmhBenchmark.getBytes ASCII 100 thrpt 5 > 172936926.189 ± 4532029.201 ops/s > StringLoopJmhBenchmark.getBytes ASCII 1000 thrpt 5 > 38830681.232 ± 2413274.766 ops/s > StringLoopJmhBenchmark.getBytes ASCII 100000 thrpt 5 > 458881.155 ± 12818.317 ops/s > StringLoopJmhBenchmark.getBytes LATIN1 10 thrpt 5 > 37193762.990 ± 3962947.391 ops/s > StringLoopJmhBenchmark.getBytes LATIN1 100 thrpt 5 > 55400876.236 ± 1267331.434 ops/s > StringLoopJmhBenchmark.getBytes LATIN1 1000 thrpt 5 > 11104514.001 ± 41718.545 ops/s > StringLoopJmhBenchmark.getBytes LATIN1 100000 thrpt 5 > 182535.414 ± 10296.120 ops/s > StringLoopJmhBenchmark.getBytes UTF16 10 thrpt 5 > 113474681.457 ± 8326589.199 ops/s > StringLoopJmhBenchmark.getBytes UTF16 100 thrpt 5 > 37854103.127 ± 4808526.773 ops/s > StringLoopJmhBenchmark.getBytes UTF16 1000 thrpt 5 > 4139833.009 ± 70636.784 ops/s > StringLoopJmhBenchmark.getBytes UTF16 100000 thrpt 5 > 57644.637 ± 1887.112 ops/s > StringLoopJmhBenchmark.getBytesLength ASCII 10 thrpt 5 > 946701647.247 ± 76938927.141 ops/s > StringLoopJmhBenchmark.getBytesLength ASCII 100 thrpt 5 > 396615374.479 ± 15167234.884 ops/s > StringLoopJmhBenchmark.getBytesLength ASCII 1000 thrpt 5 > 100464784.979 ± 794027.897 ops/s > StringLoopJmhBenchmark.getBytesLength ASCII 100000 thrpt 5 > 1215487.689 ± 1916.468 ops/s > StringLoopJmhBenchmark.getBytesLength LATIN1 10 thrpt 5 > 221265102.323 ± 17013983.056 ops/s > StringLoopJmhBenchmark.getBytesLength LATIN1 100 thrpt 5 > 137617873.887 ± 5842185.781 ops/s > StringLoopJmhBenchmark.getBytesLength LATIN1 1000 thrpt 5 > 92540259.130 ± 3839233.582 ops/s > StringLoopJmhBenchmark.ge... src/java.base/share/classes/java/lang/String.java line 2127: > 2125: * equivalent to this string, {@code false} otherwise > 2126: * > 2127: * @see #compareTo(String) For the **BOM**‑less **UTF‑16** charsets, this can simply return `value.length << (1 ‑ coder())`[^1]: Suggestion: if (cs instanceof sun.nio.cs.UTF_16LE || cs instanceof sun.nio.cs.UTF_16BE) { return value.length << (1 - coder()); } return getBytes(cs).length; [^1]: Lone surrogates get replaced with `U+FFFD` when encoding to **UTF‑16** by [`String::getBytes(Charset)`], and all of **LATIN1** can be encoded in **UTF‑16**. [`String::getBytes(Charset)`]: https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/String.html#getBytes(java.nio.charset.Charset) test/micro/org/openjdk/bench/java/lang/foreign/StringLoopJmhBenchmark.java line 74: > 72: stringData += (char) (Math.random() * 26) + 'a'; > 73: } > 74: stringData += c; Maybe avoid creating intermediate strings in a loop to avoid excess GC pressure? Suggestion: var stringDataBuilder = new StringBuilder(stringLength + 1); while (stringDataBuilder.length() < stringLength) { stringDataBuilder.append((char) (Math.random() * 26) + 'a'); } stringData = stringDataBuilder.append(c).toString(); ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/28454#discussion_r2552768341 PR Review Comment: https://git.openjdk.org/jdk/pull/28454#discussion_r2552801055
