<i18n dev> RFR: 8372353: API to compute the byte length of a String encoded in a given Charset [v17]

[Liam Miller-Cushon]

On Fri, 30 Jan 2026 15:56:20 GMT, Liam Miller-Cushon <cushon at openjdk.org> 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   92540259.1...
>
> Liam Miller-Cushon has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Rename getBytesLength to getByteLength

Thanks for the comments,

re: `getEncodedLength` or `encodedLength`, those options where considered, although I didn't write them up as alternatives in the CSR.

The main reason `getEncodedLength` wasn't used is that it doesn't make it clear that the unit of length is bytes. For UTF-8 a byte length is intuitive, for e.g. UTF-16 or UTF-32 the "encoded length" could also be the count of int16 (number of wchar_t) or int32.

Including a `get` prefix or not was also considered, one benefit of `get` is that it aligns with `getBytes`, and also it may help convey that the method is doing computation (it's often going to be O(1), compared to e.g. `length()` which is O(1)).

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PR Comment: https://git.openjdk.org/jdk/pull/28454#issuecomment-3860683771