[jira] [Commented] (MARMOTTA-401) Cache keys for triples with literal nodes are not created correctly

["ASF subversion and git services (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MARMOTTA-401?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13864274#comment-13864274 ] 

ASF subversion and git services commented on MARMOTTA-401:
----------------------------------------------------------

Commit 3b2452239d92428282ff21ac4f73a8fe3fd59f76 in branch refs/heads/maintenance-3.1.x from [~wastl]
[ https://git-wip-us.apache.org/repos/asf?p=marmotta.git;h=3b24522 ]

backport for MARMOTTA-401 (yet another take at MARMOTTA-401)
(cherry picked from commit 7c1f7d7667dc4fca8a751ece877333d3c23eaded)

Signed-off-by: Jakob Frank <ja...@apache.org>


> Cache keys for triples with literal nodes are not created correctly
> -------------------------------------------------------------------
>
>                 Key: MARMOTTA-401
>                 URL: https://issues.apache.org/jira/browse/MARMOTTA-401
>             Project: Marmotta
>          Issue Type: Bug
>          Components: KiWi Triple Store
>    Affects Versions: 3.1-incubating
>            Reporter: Alan
>            Assignee: Sebastian Schaffert
>            Priority: Critical
>             Fix For: 3.1.1, 3.2
>
>
> From Allan Melville at the development mailinglist:
> I have encountered a situation where by the same cache key is generated for
> different triple statements. The current key generation is based on hash
> codes ( see IntArray.createSPOCKey(s, p, o, c)), which unfortunately is not
> guaranteed to be unique across different node types.
> In my particular example I have a KiWiLiteral node with a URI string value.
> I also have another KiWiUriResource node with the same value for its URI
> (messy I know :( ).
> {code:xml}
> <rdf:Description rdf:about="http://vocabulary.curriculum.edu.au/access/10">
>         <rdf:type rdf:resource="http://www.w3.org/2004/02/skos/core#Concept"/>
>         <skos:prefLabel xml:lang="en">Visual independence</skos:prefLabel>
>         <skos:topConceptOf
> rdf:resource="http://vocabulary.curriculum.edu.au/access"/>
>         <skos:topConceptOf>http://vocabulary.curriculum.edu.au/access</skos:topConceptOf>
> {code}
> KiWiLiteral.hashCode() is solely based on its label/content and
> KiWiUriResource.hashCode() is solely based on its URI hence to two
> different nodes generate the same hashCode, which in its self is fine, but
> the IntArray.createSPOCKey(s, p, o, c) generates the same key and thus the
> KiWiValueFactory.tripleRegistry may return the wrong KiWiTriple (see
> KiWiValueFactory.createStatement(s, p, o, c, con)).
> Proposed solution:
> 1) Update the hashCode in the KiWiNode types to be more unique?
> 2) Adjust the IntArray.createSPOCKey implementation?
> 3) other?



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