Restructure string intern check:
- Compute string hash and perform strtable lookup; if found, it
must already be a valid Symbol or valid WTF-8 data so no WTF-8
sanitization steps are needed. Return found string.
- Otherwise perform a "keepcheck" to see if the candidate string
can be used as is (i.e. it is valid Symbol or valid WTF-8).
If so, we know it's not in the strtable so intern the string.
- Otherwise the string needs WTF-8 sanitization. After sanitizing,
rehash the sanitized data, perform another strtable lookup and
return existing string or intern the sanitized string.
This speeds up string intern processing for (1) strings already in
the string table and (2) valid WTF-8 strings which should be the
vast majority of strings interned. Only strings that are invalid
WTF-8, i.e. contain uncombined surrogate pairs or outright data,
will need sanitization.
Other minor changes:
- Add some WTF-8 documentation to tentative 3.0 release notes.
- Add a 3.0 release entry.
Sami Vaarala