RFR JDK-8172921: Zip filesystem performance improvement and code cleanup

[Andrej Golovnin]

Hi Sherman,

src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipCoder.java

  72     public static ZipCoder get(String csn) {
  73         try {
  74         Charset cs = Charset.forName(csn);
  75         if (cs.name().equals("UTF-8")) {
  76             return utf8;
  77         }
  78         return new ZipCoder(cs);
  79         } catch (Throwable t) {
  80         t.printStackTrace();
  81         }
  82         return new ZipCoder(Charset.defaultCharset());
  83     }

Wouldn't it be better to use System.Logger instead of printStackTrace
in the line 80?

Best regards,
Andrej Golovnin

On Tue, Jan 17, 2017 at 11:39 PM, Xueming Shen <xueming.shen at oracle.com> wrote:
> Hi,
>
> Please review the following changes for zipfs implementation.
>
> issue: https://bugs.openjdk.java.net/browse/JDK-8172921
> webrev: http://cr.openjdk.java.net/~sherman/8172921/webrev/
>
>
> javac has moved to use zipfs (instead of ZipFile) to access jar files in
> jdk9. Here are
> some changes to improve the performance of access time and footprint (reduce
> the
> unnecessary object allocation ...) The improvement has been measured by the
> jmh
> benchmark test as
>
> http://cr.openjdk.java.net/~sherman/8172921/MyBenchmark.java
>
> with the benchmark sores (before-OLD/after-NEW) at:
>
> http://cr.openjdk.java.net/~sherman/8172921/scores
>
>
> The main change is to change the internal directory path representation from
> the
> zip specific format (directory name ends with "/", "/dir/" for directory
> ".dir" for
> example) to the "normalized" form with the tailing "/", which reduces the
> back and
> forth  conversion between the normal "unix style" path and the "zip style"
> path when
> doing path creation, path lookup and entry access, which also simplified the
> entry
> lookup logic.
>
> We are seeing pretty good performance improvement.
>
> There is another change, which involves the API change, for the
> "non-existing" path
> look up (which shows pretty bad numbers as ZFS_ExistsNG"), is not included
> in this
> patch. I hope we can address that as well in jdk9, but probably in another
> patch.
>
> Thanks,
> Sherman
>
>