/**
* Execute a SPARQL query and return an SMWSparqlResultWrapper object
* that contains the results. Compared to SMWSparqlDatabase::doQuery(),
* this also supports the parameter "restricted=1" which 4Store provides
* to enforce strict resource bounds on query answering. The method also
* checks if these bounds have been met, and records this in the query
* result.
*
* @note The restricted option in 4Store mainly enforces the given soft
* limit more strictly. To disable/configure it, simply change the soft
* limit settings of your 4Store server.
*
* @param $sparql string with the complete SPARQL query (SELECT or ASK)
* @return SMWSparqlResultWrapper
*/
public function doQuery( $sparql ) {
//$result = parent::doQuery( $sparql );
curl_setopt( $this->m_curlhandle, CURLOPT_URL, $this->m_queryEndpoint );
curl_setopt( $this->m_curlhandle, CURLOPT_POST, true );
$parameterString = "query=" . urlencode( $sparql ) . "&restricted=1" .
( ( $this->m_defaultGraph !== '' )? '&default-graph-uri=' . urlencode( $this->m_defaultGraph ) : '' );
curl_setopt( $this->m_curlhandle, CURLOPT_POSTFIELDS, $parameterString );
$xmlResult = curl_exec( $this->m_curlhandle );
if ( curl_errno( $this->m_curlhandle ) == 0 ) {
$xmlParser = new SMWSparqlResultParser();
$result = $xmlParser->makeResultFromXml( $xmlResult );
} else {
$this->throwSparqlErrors( $this->m_updateEndpoint, $sparql );
$result = new SMWSparqlResultWrapper( array(), array(), array(), SMWSparqlResultWrapper::ERROR_UNREACHABLE );
}
foreach ( $result->getComments() as $comment ) {
if ( strpos( $comment, 'warning: hit complexity limit' ) === 0 ||
strpos( $comment, 'some results have been dropped' ) === 0 ) {
$result->setErrorCode( SMWSparqlResultWrapper::ERROR_INCOMPLETE );
} //else debug_zval_dump($comment);
}
return $result;
}
/**
* Build an SMWQueryResult object from a SMWSparqlResultWrapper. This
* function is used to generate instance query results, and the given
* result wrapper must have an according format (one result column that
* contains URIs of wiki pages).
*
* @param $sparqlResultWrapper SMWSparqlResultWrapper
* @param $query SMWQuery, SMWQueryResults hold a reference to original query
* @return SMWQueryResult
*/
protected function getQueryResultFromSparqlResult(SMWSparqlResultWrapper $sparqlResultWrapper, SMWQuery $query)
{
$resultDataItems = array();
foreach ($sparqlResultWrapper as $resultRow) {
if (count($resultRow) > 0) {
$dataItem = SMWExporter::findDataItemForExpElement($resultRow[0]);
if (!is_null($dataItem)) {
$resultDataItems[] = $dataItem;
}
}
}
if ($sparqlResultWrapper->numRows() > $query->getLimit()) {
array_pop($resultDataItems);
$hasFurtherResults = true;
} else {
$hasFurtherResults = false;
}
$result = new SMWQueryResult($query->getDescription()->getPrintrequests(), $query, $resultDataItems, $this->m_store, $hasFurtherResults);
switch ($sparqlResultWrapper->getErrorCode()) {
case SMWSparqlResultWrapper::ERROR_NOERROR:
break;
case SMWSparqlResultWrapper::ERROR_INCOMPLETE:
$result->addErrors(array(wfMessage('smw_db_sparqlqueryincomplete')->inContentLanguage()->text()));
break;
default:
$result->addErrors(array(wfMessage('smw_db_sparqlqueryproblem')->inContentLanguage()->text()));
break;
}
return $result;
}
