More memory-efficient internal representation for Strings: call for more data

[Aleksey Shipilev]

Hi Vitaly,

Please read the JEP proposal. String/char[] fusion (that's what you are
describing) is out of scope for this work. Baby steps. Careful baby steps.

-Aleksey.

On 03.12.2014 01:13, Vitaly Davidovich wrote:
> Any consideration towards removing the char[] (or byte[]) indirection
> altogether? .NET for example stores the bytes inline with the instance.
> 
> Sent from my phone
> 
> On Dec 2, 2014 4:59 PM, "Aleksey Shipilev" <aleksey.shipilev at oracle.com
> <mailto:aleksey.shipilev at oracle.com>> wrote:
> 
>     Hi,
> 
>     As you may already know, we are looking into more memory efficient
>     representation for Strings:
>      https://bugs.openjdk.java.net/browse/JDK-8054307
> 
>     As part of preliminary performance work for this JEP, we have to collect
>     the empirical data on usual characteristics of Strings and char[]-s
>     normal applications have, as well as figure out the early estimates for
>     the improvements based on that data. What we have so far is written
>     up here:
>      http://cr.openjdk.java.net/~shade/density/string-density-report.pdf
>     <http://cr.openjdk.java.net/%7Eshade/density/string-density-report.pdf>
> 
>     We would appreciate if people who are interested in this JEP can provide
>     the additional data on their applications. It is double-interesting to
>     have the data for the applications that process String data outside
>     Latin1 plane. Our current data says these cases are rather rare. Please
>     read the current report draft, and try to process your own heap dumps
>     using the instructions in the Appendix.
> 
>     Thanks,
>     -Aleksey.
>