RFR: 8222532: (zipfs) Performance regression when writing ZipFileSystem entries in parallel

[Claes Redestad]

Hi Lance,

On 2019-04-22 21:26, Lance Andersen wrote:
> Hi Claes,
> 
> Thank you for your efforts here.
> 
> I have gone through your changes, comparing to the original code prior 
> to JDK-8034802 and your changes look good.  It would be good if someone 
> else can  also help sanity check but you did a nice job of adding the 
> functionality back.

thanks for reviewing! And yes, I'd appreciate more reviews, too. :-)

> 
> Before you push, please update the copyright for ZipFileSystemProvider.

Sure

Thanks!

/Claes
> 
> Best,
> Lance
>> On Apr 18, 2019, at 9:10 AM, Claes Redestad <claes.redestad at oracle.com 
>> <mailto:claes.redestad at oracle.com>> wrote:
>>
>> Hi,
>>
>> JDK-8034802 changed zipfs to defer deflation to only happen when
>> closing/syncing the ZipFileSystem. Previously it happened eagerly when
>> closing output streams retrieved via Files.newOutputStream. While this
>> behavior change could have positive effects in some cases (since
>> reading/writing entries don't need to inflate/deflate on the fly), it
>> also broke the ability to deflate entries in parallel.
>>
>> This patch reverts the behavior so that entries are deflated (by
>> default) when individual entry output streams are closed. File channels
>> retain the behavior that entries are inflated into an internal byte
>> array.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8222532
>> Webrev: http://cr.openjdk.java.net/~redestad/8222532/open.00/
>>
>> Testing: tier1-3, verified recuperation of performance in reproducer to
>> pre-JDK-8034802 levels.
>>
>> Thanks!
>>
>> /Claes
> 
> <http://oracle.com/us/design/oracle-email-sig-198324.gif>
> <http://oracle.com/us/design/oracle-email-sig-198324.gif><http://oracle.com/us/design/oracle-email-sig-198324.gif>
> <http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance Andersen| 
> Principal Member of Technical Staff | +1.781.442.2037
> Oracle Java Engineering
> 1 Network Drive
> Burlington, MA 01803
> Lance.Andersen at oracle.com <mailto:Lance.Andersen at oracle.com>
> 
> 
>