RFR: 8294293: Remove unused _width and _newlines field in outputStream

[Robbin Ehn]

On Fri, 23 Sep 2022 15:59:39 GMT, Johan Sjölen <jsjolen at openjdk.org> wrote:

> 1. `_width` is unused so I deleted it
> 2. `_newlines` was used in one place, and only to check if any new lines had been seen. I removed `_newlines` and instead used `update_position`'s unused return value to indicate whether any newlines has been seen. This required expanding the call of `xmlTextStream::write` in `defaultStream`.
> 
> This removes some cruft from `outputStream` and saves us 8 bytes on the size of `outputStream`.
> 
> I also noted that `_position` isn't number of chars into a line, but rather a "visual position". It's a bit surprising, which is why I added this comment. This can be seen in the `\t` case in `update_position`.

Looks good, thanks!

src/hotspot/share/utilities/ostream.hpp line 91:

> 89:    int position() const { return _position; }
> 90:    julong count() const { return _precount + _position; }
> 91:    void set_count(julong count) { _precount = count - _position; }

These julong should probably be uint64_t.
But it may cause some more changes, e.g. _file_end in CompileLog should then also probably also be uint64_t.
We can look at that in another RFE.

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Marked as reviewed by rehn (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10411