/**
* Create a new SMWSQLStore2Query object that can be used to obtain results
* for the given description. The result is stored in $this->m_queries
* using a numeric key that is returned as a result of the function.
* Returns -1 if no query was created.
* @todo The case of nominal classes (top-level SMWValueDescription) still
* makes some assumptions about the table structure, especially about the
* name of the joinfield (o_id). Better extend compileAttributeWhere to
* deal with this case.
*
* @param SMWDescription $description
*
* @return integer
*/
protected function compileQueries(SMWDescription $description)
{
$qid = SMWSQLStore2Query::$qnum;
$query = new SMWSQLStore2Query();
if ($description instanceof SMWSomeProperty) {
$this->compilePropertyCondition($query, $description->getProperty(), $description->getDescription());
// Compilation has set type to NOQUERY: drop condition.
if ($query->type == SMW_SQL2_NOQUERY) {
$qid = -1;
}
} elseif ($description instanceof SMWNamespaceDescription) {
// TODO: One instance of smw_ids on s_id always suffices (swm_id is KEY)! Doable in execution ... (PERFORMANCE)
$query->jointable = 'smw_ids';
$query->joinfield = "{$query->alias}.smw_id";
$query->where = "{$query->alias}.smw_namespace=" . $this->m_dbs->addQuotes($description->getNamespace());
} elseif ($description instanceof SMWConjunction || $description instanceof SMWDisjunction) {
$query->type = $description instanceof SMWConjunction ? SMW_SQL2_CONJUNCTION : SMW_SQL2_DISJUNCTION;
foreach ($description->getDescriptions() as $subdesc) {
$sub = $this->compileQueries($subdesc);
if ($sub >= 0) {
$query->components[$sub] = true;
}
}
// All subconditions failed, drop this as well.
if (count($query->components) == 0) {
$qid = -1;
}
} elseif ($description instanceof SMWClassDescription) {
$cqid = SMWSQLStore2Query::$qnum;
$cquery = new SMWSQLStore2Query();
$cquery->type = SMW_SQL2_CLASS_HIERARCHY;
$cquery->joinfield = array();
foreach ($description->getCategories() as $cat) {
$cid = $this->m_store->getSMWPageID($cat->getDBkey(), NS_CATEGORY, $cat->getInterwiki());
if ($cid != 0) {
$cquery->joinfield[] = $cid;
}
}
if (count($cquery->joinfield) == 0) {
// Empty result.
$query->type = SMW_SQL2_VALUE;
$query->jointable = '';
$query->joinfield = '';
} else {
// Instance query with dicjunction of classes (categories)
$query->jointable = 'smw_inst2';
$query->joinfield = "{$query->alias}.s_id";
$query->components[$cqid] = "{$query->alias}.o_id";
$this->m_queries[$cqid] = $cquery;
}
} elseif ($description instanceof SMWValueDescription) {
// Only type '_wpg' objects can appear on query level (essentially as nominal classes).
if ($description->getDatavalue()->getTypeID() == '_wpg') {
if ($description->getComparator() == SMW_CMP_EQ) {
$query->type = SMW_SQL2_VALUE;
$oid = $this->m_store->getSMWPageID($description->getDatavalue()->getDBkey(), $description->getDatavalue()->getNamespace(), $description->getDatavalue()->getInterwiki());
$query->joinfield = array($oid);
} else {
// Join with smw_ids needed for other comparators (apply to title string).
$query->jointable = 'smw_ids';
$query->joinfield = "{$query->alias}.smw_id";
$value = $description->getDatavalue()->getSortkey();
switch ($description->getComparator()) {
case SMW_CMP_LEQ:
$comp = '<=';
break;
case SMW_CMP_GEQ:
$comp = '>=';
break;
case SMW_CMP_NEQ:
$comp = '!=';
break;
case SMW_CMP_LIKE:
case SMW_CMP_NLKE:
$comp = ' LIKE ';
if ($description->getComparator() == SMW_CMP_NLKE) {
$comp = " NOT{$comp}";
}
$value = str_replace(array('%', '_', '*', '?'), array('\\%', '\\_', '%', '_'), $value);
break;
}
$query->where = "{$query->alias}.smw_sortkey{$comp}" . $this->m_dbs->addQuotes($value);
}
}
} elseif ($description instanceof SMWConceptDescription) {
// fetch concept definition and insert it here
$cid = $this->m_store->getSMWPageID($description->getConcept()->getDBkey(), SMW_NS_CONCEPT, '');
$row = $this->m_dbs->selectRow('smw_conc2', array('concept_txt', 'concept_features', 'concept_size', 'concept_depth', 'cache_date'), array('s_id' => $cid), 'SMWSQLStore2Queries::compileQueries');
if ($row === false) {
// No description found, concept does not exist.
// 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)
} else {
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 = 'smw_conccache';
$query->joinfield = "{$query->alias}.s_id";
$query->where = "{$query->alias}.o_id=" . $this->m_dbs->addQuotes($cid);
} elseif ($row->concept_txt) {
// Parse description and process it recursively.
if ($may_be_computed) {
$qp = new SMWQueryParser();
// No defaultnamespaces here; If any, these are already in the concept.
$desc = $qp->getQueryDescription($row->concept_txt);
$qid = $this->compileQueries($desc);
if ($qid != -1) {
$query = $this->m_queries[$qid];
} else {
// somehow the concept query is no longer valid; maybe some syntax changed (upgrade) or global settings were modified since storing it
smwfLoadExtensionMessages('SemanticMediaWiki');
$this->m_errors[] = wfMsg('smw_emptysubquery');
// not quite the right message, but this case is very rare; let us not make detailed messages for this
}
} else {
smwfLoadExtensionMessages('SemanticMediaWiki');
$this->m_errors[] = wfMsg('smw_concept_cache_miss', $description->getConcept()->getText());
}
}
// else: no cache, no description (this may happen); treat like empty concept
}
} else {
// (e.g. SMWThingDescription)
$qid = -1;
// no condition
}
if ($qid >= 0) {
// Success, keep query object, propagate sortkeys from subqueries.
$this->m_queries[$qid] = $query;
if ($query->type != SMW_SQL2_DISJUNCTION) {
// Sortkeys are killed by disjunctions (not all parts may have them),
// NOTE: preprocessing might try to push disjunctions downwards to safe sortkey, but this seems to be minor
foreach ($query->components as $cid => $field) {
$query->sortfields = array_merge($this->m_queries[$cid]->sortfields, $query->sortfields);
}
}
}
return $qid;
}
public function addDescription( SMWDescription $description ) {
if ( ! ( $description instanceof SMWThingDescription ) ) {
if ( $description instanceof SMWConjunction ) { // absorb sub-conjunctions
foreach ( $description->getDescriptions() as $subdesc ) {
$this->m_descriptions[] = $subdesc;
}
} else {
$this->m_descriptions[] = $description;
}
// move print descriptions downwards
///TODO: This may not be a good solution, since it does modify $description and since it does not react to future changes
$this->m_printreqs = array_merge( $this->m_printreqs, $description->getPrintRequests() );
$description->setPrintRequests( array() );
}
}
/**
* Given an SMWDescription that is just a conjunction or disjunction of
* SMWValueDescription objects, create a plain WHERE condition string for it.
*/
protected function compileAttributeWhere(SMWDescription $description, $jointable)
{
if ($description instanceof SMWValueDescription) {
$dv = $description->getDatavalue();
if (SMWSQLStore2::getStorageMode($dv->getTypeID()) == SMW_SQL2_SPEC2) {
$keys = $dv->getDBkeys();
$value = $keys[0];
$field = "{$jointable}.value_string";
} else {
// should be SMW_SQL2_ATTS2
if ($dv->isNumeric()) {
$value = $dv->getNumericValue();
$field = "{$jointable}.value_num";
} else {
$keys = $dv->getDBkeys();
$value = $keys[0];
$field = "{$jointable}.value_xsd";
}
}
switch ($description->getComparator()) {
case SMW_CMP_LEQ:
$comp = '<=';
break;
case SMW_CMP_GEQ:
$comp = '>=';
break;
case SMW_CMP_NEQ:
$comp = '!=';
break;
case SMW_CMP_LIKE:
if ($dv->getTypeID() == '_str') {
$comp = ' LIKE ';
$value = str_replace(array('%', '_', '*', '?'), array('\\%', '\\_', '%', '_'), $value);
} else {
// LIKE only supported for strings
$comp = '=';
}
break;
case SMW_CMP_EQ:
default:
$comp = '=';
break;
}
$result = "{$field}{$comp}" . $this->m_dbs->addQuotes($value);
} elseif ($description instanceof SMWConjunction || $description instanceof SMWDisjunction) {
$op = $description instanceof SMWConjunction ? ' AND ' : ' OR ';
$result = '';
foreach ($description->getDescriptions() as $subdesc) {
$result = $result . ($result != '' ? $op : '') . $this->compileAttributeWhere($subdesc, $jointable);
}
$result = "({$result})";
} else {
$result = '';
}
return $result;
}
