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

Aleksey Shipilev aleksey.shipilev at
Tue Dec 2 22:15:29 UTC 2014

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.


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
> <mailto:aleksey.shipilev at>> wrote:
>     Hi,
>     As you may already know, we are looking into more memory efficient
>     representation for Strings:
>     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:
>     <>
>     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.

More information about the core-libs-dev mailing list