/**
* Simplify the query by flattening out subqueries.
* Modifies the passed query object directly.
*/
public function simplify(Query $query)
{
$arPatterns = $query->getResultPart();
self::dropEmpty($arPatterns);
$arPlan = $this->createPlan($arPatterns);
if (count($arPlan) == 0) {
$query->setResultPart($arPatterns);
return 0;
}
$this->executePlan($arPatterns, $arPlan);
$query->setResultPart($arPatterns);
}
/**
* Matches all graph Patterns against the dataset and generates an array which
* contains the result sets for every given GraphPattern.
*
* @param Array $graphlist the graphlist which contains the names of the named
* graphs which has to be queried.
* @return Array
*/
protected function matchPatterns($graphlist)
{
$patternlist = array();
// get the result part from the query
$resultPart = $this->query->getResultPart();
// for each GrapPattern in the result part
if ($resultPart) {
foreach ($resultPart as $graphPattern) {
$this->matchPattern($patternlist, $graphlist, $graphPattern);
}
}
return $patternlist;
}
/**
* renders the result part of a query object as a string
*/
static function renderResult(Query $query)
{
$s = '';
foreach ($query->getResultPart() as $gp) {
//dumpGp:
$s .= 'GP #' . $gp->getId();
if ($gp->getOptional() !== null) {
$s .= ' optionalTo(' . $gp->getOptional() . ')';
}
if ($gp->getUnion() !== null) {
$s .= ' unionWith(' . $gp->getUnion() . ')';
}
if ($gp->getSubpatternOf() !== null) {
$s .= ' subpatternOf(' . $gp->getSubpatternOf() . ')';
}
if (count($gp->getConstraints()) > 0) {
$s .= ' filter(' . count($gp->getConstraints()) . ')';
}
$s .= "\n";
if ($gp->getTriplePatterns()) {
foreach ($gp->getTriplePatterns() as $tp) {
$s .= ' ' . $tp->getSubject() . ', ' . $tp->getPredicate() . ', ' . $tp->getObject() . "\n";
}
}
}
return $s;
}
