RFR: 8340232: Optimize DataInputStream::readUTF

[Shaojin Wen]

On Mon, 16 Sep 2024 13:15:02 GMT, Chen Liang <liach at openjdk.org> wrote:

>> Similar to ObjectInputStream, use JLA.countPositives and JLA.inflateBytesToChars to speed up readUTF
>
> src/java.base/share/classes/java/io/DataInputStream.java line 590:
> 
>> 588:         if (bytearr == null) {
>> 589:             bytearr = new byte[utflen];
>> 590:             allocate = true;
> 
> Can we rename this boolean to `trusted` and set it to `false` when we assign it back to `dis.bytearr`? Even though that assignment will be redundant, calling it `trusted` is helpful to avoid causing security problems if we reorganize this code in the future.

When ascii != utflen, bytearr will be reused, and the name of `trusted` is not clear here.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/20903#discussion_r1761486696