Allow use of faster floating-point number parsing (Schubfach) with `StreamReadFeature.USE_FAST_DOUBLE_PARSER`

[cowtowncoder]

Jsoniter project (https://github.com/plokhotnyuk/jsoniter-scala) has many impressive performance optimizations; linked f.ex from here:

https://www.reddit.com/r/java/comments/darehu/jackson_release_210/f1ysf1e/

Of ones included, number-parsing would be relevant for this repo.

EDIT: also see (from the comment below)

"Unrelated to jsoniter but this recent port of Lemire's Double parser:

https://github.com/wrandelshofer/FastDoubleParser

and the original paper https://arxiv.org/abs/2101.11408 also relevant"

[cowtowncoder]

And specifically, for BigDecimal case:

https://github.com/plokhotnyuk/jsoniter-scala/blob/b51f90b87923305b6fa177a4da909ff43da3c7b7/jsoniter-scala-core/src/main/scala/com/github/plokhotnyuk/jsoniter_scala/core/JsonReader.scala#L1477-L1591

[anneloreegger]

I'd like to work on this issue, is it still available?

[cowtowncoder]

@anneloreegger Yes, this is available! I'll assign it to you (no obligation to work, just a marker so others know you are considering it).

[anneloreegger]

Just to be sure I understand the issue correctly. Shall I especially improve the parsingMethods inside the NumberInput-class? (especially parseBigDecimal)
And should this be done on 2.12 or master branch?
Thanks for the answers :)

[cowtowncoder]

@anneloreegger Yes, I think NumberInput has stubs that would allow for this. On 2.12 vs master -- ideally 2.12, if this seems doable on short term with well contained changes. But master if there were need to change API or internal interfaces.
I have not really investigated jsoniter's approach enough to know how involved this gets unfortunately.

[cowtowncoder]

NOTE: BigDecimal use case covered by #677 (for 2.13), will edit title