[infinispan-issues] [JBoss JIRA] (ISPN-4678) Trim down ExpandableMarshalledValueByteStream to the actual data length before storing in cache

[Martin Gencur (JIRA)]

    [ https://issues.jboss.org/browse/ISPN-4678?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12999359#comment-12999359 ] 

Martin Gencur commented on ISPN-4678:
-------------------------------------

Hmm, growing by 1.5 factor instead of 2 is possible. This would require a perf. test to actually see what is better, and for different types of data. I wouldn't like to over-engineer this, though. Maybe growing by factor of 2 is still better than 1.5. 
Also, I still think it makes sense to store only the actual data, not more. The time it takes to copy the byte array seems very small compared to the whole chain of invocations that happen in Infinispan. And it also appears that storing smaller data has a very positive effect on performance.

> Trim down ExpandableMarshalledValueByteStream to the actual data length before storing in cache
> -----------------------------------------------------------------------------------------------
>
>                 Key: ISPN-4678
>                 URL: https://issues.jboss.org/browse/ISPN-4678
>             Project: Infinispan
>          Issue Type: Enhancement
>          Components: Core
>    Affects Versions: 7.0.0.Beta1
>            Reporter: Martin Gencur
>            Assignee: Martin Gencur
>
> When storeAsBinary configuration flag is used, the ExpandableMarshalledValueByteStream is used to serialize objects to byte arrays. 
> However, for value size up to 4kB, almost half of the space for each cache entry can be wasted because the ByteStream is stored as is - with the additional space for future expansion.
> For value size greater than 4kB, only additional 25% of actual value size can be wasted. But as these values can be quite large, the wasted space gets bigger too.
> It is not necessary to store ExpandableMarshalledValueByteStream as is and can be shrinked to actual data size before storing in cache.



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