RFR: 8358533: Improve performance of java.io.Reader.readAllLines

[Xueming Shen]

On Wed, 18 Jun 2025 01:34:14 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> src/java.base/share/classes/java/io/Reader.java line 469:
>> 
>>> 467:                     if (c == '\r' || c == '\n')
>>> 468:                         break;
>>> 469:                     term++;
>> 
>> It might be worth adding a test of unconventional sequences or \r and \n, including \r\r and \n\n, \r.
>> The current ReadAll test cover the conventional sequences on Linux and Windows.
>
> I agree. I was intending to follow up on @jaikiran's [comment](https://github.com/openjdk/jdk/pull/24728#discussion_r2112052404), probably in an update to this request.

I think we should treat "\r\n" as a single line terminator? for example

 "hello\r\nworld".lines().forEach(line -> out.format("[%s]\n", line));
=>
[hello]
[world]

instead of 

[hello]
[]
[world]

or I misread the impl?

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PR Review Comment: https://git.openjdk.org/jdk/pull/25863#discussion_r2153515129