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https://issues.apache.org/jira/browse/JCR-1604?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12597401#action_12597401
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Stefan Guggisberg commented on JCR-1604:
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1) and 2) were introduced quite a while ago after some extensive
profiling/performance testing. equals() and hashCode() turned out to consume a
lot of CPU time (since names, as part of property id's, are used as hashmap
keys) and the said carefully chosen modifications helped improve overall
performance significantly.
unless there's some real issue with those i'd prefer to not apply the proposed
hanges, i.e. keep NameImpl as is.
> NameImpl improvements
> ---------------------
>
> Key: JCR-1604
> URL: https://issues.apache.org/jira/browse/JCR-1604
> Project: Jackrabbit
> Issue Type: Improvement
> Components: jackrabbit-jcr-commons
> Reporter: Jukka Zitting
> Priority: Minor
> Attachments: NameImpl.patch
>
>
> I'd like to propose the following changes to NameImpl in
> jackrabbit-jcr-commons:
> 1) Don't intern the namespace string. Most often the namespace string is in
> any case coming from a namespace registry, so there aren't that many copies
> of the same strings lying around. Also, I don't think the performance impact
> on NameImpl.equals() is significant even if there are multiple copies of the
> same namespace string.
> 2) Don't memorize the hash code. Since String already memorizes its hash
> code, the cost of NameImpl.hashCode() is just a few bytecode instructions. I
> don't think the performance benefit is worth the extra complexity and memory
> overhead.
> 3) Don't memoize the string representation. NameImpl.toString() method is
> typically only invoked when debugging or when serializing name values. In
> both cases the CPU overhead of recreating the string is insignificant and
> IMHO not worth the memory overhead .
> I'll attach the patch.
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