Prior to this commit, `MediaType.parseMediaType` would already rely on
the internal LRU cache in `MimeTypeUtils` for better performance. With
that optimization, the parsing of raw media types is skipped for cached
elements.
But still, `MediaType.parseMediaType` would first get a cached
`MimeType` instance from that cache and then instantiate a
`new MediaType(type, subtype, parameters)`. This constructor not only
replays the `MimeType` checks on type/subtyme tokens and parameters, but
it also performs `MediaType`-specific checks on parameters.
Such checks are not required, as we're using an existing `MimeType`
instance in the first place.
This commit adds a new protected copy constructor (skipping checks) in
`MimeType` and uses it in `MediaType.parseMediaType` as a result.
This yields interesting performance improvements, with +400% throughput
and -40% allocation/call in benchmarks. This commit also introduces a
new JMH benchmark for future optimization work.
Closes gh-24769
Brian Clozel
612a63c0f1