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https://issues.apache.org/jira/browse/JENA-1290?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15874530#comment-15874530
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Andy Seaborne commented on JENA-1290:
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Alexis - thank you for the patch. It looks like the right thing to do to me.
> Slow Model.createList()
> -----------------------
>
> Key: JENA-1290
> URL: https://issues.apache.org/jira/browse/JENA-1290
> Project: Apache Jena
> Issue Type: Improvement
> Components: Core
> Affects Versions: Jena 3.0.1, Jena 3.2.0
> Environment: OpenJDK 1.8.0.121-b13
> Reporter: Alexis Armin Huf
> Priority: Minor
> Attachments: JENA-1290.patch, jena-slow-rdflist.tar.gz,
> mvn-clean-install.log.gz
>
>
> Model.createList(Iterator) is slow for large list sizes. Starting at 128
> nodes, creating a list from an ArrayList iterator takes ~3.6ms and the time
> goes up to 182ms for 1024 nodes. Creating the RDF list by hand and then doing
> .as(RDFList.class) for the 1024-nodes tests takes only 1.2ms. I will attach a
> MWE.
> Going through the code, the cause seems to be that RDFListImpl.with() , which
> is called for every member added, will always walk the entire list to get the
> last node. It mentions a possible cache for that, but it is not implemented.
> I wrote a patch for this issue replacing ModelCom.createList()
> implementation. I could not find tests for createList, so I added three
> simple ones to TestModel.
> PS: I'm having a classpath issue with jena-arq tests on mvn clean install, so
> I could only run tests for jena-core. Are there more specific instructions
> somewhere for building and testing jena?
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