Alexis Armin Huf created JENA-1290:
--------------------------------------
Summary: 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 3.2.0, Jena 3.0.1
Environment: OpenJDK 1.8.0.121-b13
Reporter: Alexis Armin Huf
Priority: Minor
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 specific more instructions
somewhere for building and testing jena?
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
