/**
* @since 2.2
*
* @param Description $description
*
* @return QuerySegment
*/
public function interpretDescription(Description $description)
{
$query = new QuerySegment();
$conceptId = $this->querySegmentListBuilder->getStore()->getObjectIds()->getSMWPageID($description->getConcept()->getDBkey(), SMW_NS_CONCEPT, '', '');
$hash = 'concept-' . $conceptId;
$this->querySegmentListBuilder->getCircularReferenceGuard()->mark($hash);
if ($this->querySegmentListBuilder->getCircularReferenceGuard()->isCircularByRecursionFor($hash)) {
$this->querySegmentListBuilder->addError(wfMessage('smw-query-condition-circular', $description->getQueryString())->text());
return $query;
}
$db = $this->querySegmentListBuilder->getStore()->getConnection('mw.db.queryengine');
$row = $this->getConceptForId($db, $conceptId);
// No description found, concept does not exist.
if ($row === false) {
$this->querySegmentListBuilder->getCircularReferenceGuard()->unmark('concept-' . $conceptId);
// keep the above query object, it yields an empty result
// TODO: announce an error here? (maybe not, since the query processor can check for
// non-existing concept pages which is probably the main reason for finding nothing here)
return $query;
}
global $smwgQConceptCaching, $smwgQMaxSize, $smwgQMaxDepth, $smwgQFeatures, $smwgQConceptCacheLifetime;
$may_be_computed = $smwgQConceptCaching == CONCEPT_CACHE_NONE || $smwgQConceptCaching == CONCEPT_CACHE_HARD && ~(~($row->concept_features + 0) | $smwgQFeatures) == 0 && $smwgQMaxSize >= $row->concept_size && $smwgQMaxDepth >= $row->concept_depth;
if ($row->cache_date && ($row->cache_date > strtotime("now") - $smwgQConceptCacheLifetime * 60 || !$may_be_computed)) {
// Cached concept, use cache unless it is dead and can be revived.
$query->joinTable = SMWSQLStore3::CONCEPT_CACHE_TABLE;
$query->joinfield = "{$query->alias}.s_id";
$query->where = "{$query->alias}.o_id=" . $db->addQuotes($conceptId);
} elseif ($row->concept_txt) {
// Parse description and process it recursively.
if ($may_be_computed) {
$qid = $this->querySegmentListBuilder->getQuerySegmentFrom($this->getConceptQueryDescriptionFrom($row->concept_txt));
if ($qid != -1) {
$query = $this->querySegmentListBuilder->findQuerySegment($qid);
} else {
// somehow the concept query is no longer valid; maybe some syntax changed (upgrade) or global settings were modified since storing it
$this->querySegmentListBuilder->addError(wfMessage('smw_emptysubquery')->text());
// not the right message, but this case is very rare; let us not make detailed messages for this
}
} else {
$this->querySegmentListBuilder->addError(wfMessage('smw_concept_cache_miss', $description->getConcept()->getTitle()->getText())->text());
}
}
// else: no cache, no description (this may happen); treat like empty concept
$this->querySegmentListBuilder->getCircularReferenceGuard()->unmark($hash);
return $query;
}
