RFR: JDK-8150496,(zipfs) Fix performance issues in zip-fs

[Aleksey Shipilev]

Hi Sherman,

On 05/03/2016 11:19 PM, Xueming Shen wrote:
> Again, thanks for the review. The webrev has been updated accordingly,
> as well as the MyBenchmark.java (to use Blackhole, as suggested)
> 
> http://cr.openjdk.java.net/~sherman/8150496/webrev/

Further nits, sorry for not catching them earlier:

 *) You can drop "public" from the ZipFileAttributes interface.

 *) Replace this:

 109         if (!writeable) {
 110             this.readOnly = true;
 111         }

with this?

 this.readOnly = !writeable;


 *) Parentheses to nail down eval order:
      if (w && zfs.isReadOnly() || x) {
    ...to:
      if ((w && zfs.isReadOnly()) || x) {

> http://cr.openjdk.java.net/~sherman/8150496/MyBenchmark.java

    @Benchmark
    public void ZFS_newInputStream() throws Throwable {
        for (Path p : entriesP) {
            if (Files.isRegularFile(p)) {
                int n = 0;
                try (InputStream is = Files.newInputStream(p)) {
                    n += is.available();
                }
            }
        }
    }

...to

    @Benchmark
    public void ZFS_newInputStream(Blackhole bh) throws Throwable {
        for (Path p : entriesP) {
            if (Files.isRegularFile(p)) {
                try (InputStream is = Files.newInputStream(p)) {
                    bh.consume(is.available());
                }
            }
        }
    }

Does performance still improve on fixed benchmark?

Thanks,
-Aleksey