[OpenJDK 2D-Dev] RFR: 8186317: Cache font layout tables for use by harfbuzz

[Phil Race]

Dmitry commented on what JetBrains are doing but do I have any takers
to actually  review this change ?

-phil.

On 08/16/2017 02:07 PM, Phil Race wrote:
> Bug: https://bugs.openjdk.java.net/browse/JDK-8186317
> Webrev: http://cr.openjdk.java.net/~prr/8186317/
>
> In the ICU code path, we cache the layout tables in native memory so that
> when requested by ICU we can just hand the pointer, saving the overhead
> of copying the Java array for every call to layout.
>
> We weren't doing this for harfbuzz and this webrev fixes that.
>
> I noticed harfbuzz always retrieves the 'head' table so I decided to 
> add that to the list of
> cached tables.
>
> The overall result is something like 25-30% performance gain.
>
> -phil.