Jetty-12 MetaData cleanup needed

[gregw]

Target Jetty version(s)
Jetty-12

Enhancement Description

The MetaData class is badly in need of a clean up:

• Too many constructors, with multiple paths through to super constructor.
• The content-length handling is done poorly. It was meant to be an optimization to avoid HttpFields lookups when the content length is already known, but it now is more likely to cause a HttpFields lookup in every construction.
• The content-length is sometimes set to -1 and sometimes set tio Integer.MIN_VALUE. I think the later is probably meant to indicate that a HttpFields lookup should be done. Eitherway, this needs to be clarified and perhaps some named constants used to communicate the intent.
• Consideration could be given to using java-17 records

[gregw]

@lorban you want to tackle this, as you've already started. @sbordet anything to add?

[sbordet]

@gregw cannot be a record as they cannot be subclassed, while MetaData needs to be subclassed.

Other than that, I would like to get consistent naming, for example getFields() should be renamed to getHttpFields() or getHeaders() because then we have the concept of trailer(s).

• getFields() -> getHeaders()
• getTrailerSupplier() -> getTrailersSupplier() (plural)
• getURI() -> getHttpURI()
• getURIString() -> really necessary? How can the _uri be null?

[github-actions]

This issue has been automatically marked as stale because it has been a
full year without activity. It will be closed if no further activity occurs.
Thank you for your contributions.