RFR (XS): 8140683: Deduplicate Strings in UnixFileSystem canonical caches

[Paul Sandoz]

> On 28 Oct 2015, at 21:01, Claes Redestad <claes.redestad at oracle.com> wrote:
> 
> Hi,
> 
> while investigating startup and footprint for jigsaw, I found this unrelated oddity where java.io.UnixFileSystem is missing an opportunity to deduplicate file paths determined to be equal when putting them into its internal cache. Also avoid some recalculation of paths determined to be canonical for no good reason and we're golden:
> 
> webrev: http://cr.openjdk.java.net/~redestad/8140683/webrev.01
> bug: https://bugs.openjdk.java.net/browse/JDK-8140683
> 

I am not an expert in this area, but something does not feel right that you have modified things so the the key and value for a cache entry are the same. Why bother caching in that is the case? I am missing something obvious here?

Paul.