/**
* Uses the primary key list and the maximal result row from the
* previous iteration to build an SQL condition sufficient for
* selecting the next page of results. All except the final key use
* `=` conditions while the final key uses a `>` condition
*
* Example output:
* array( '( foo = 42 AND bar > 7 ) OR ( foo > 42 )' )
*
* @return array The SQL conditions necessary to select the next set
* of rows in the batched query
*/
protected function buildConditions()
{
if (!$this->current) {
return $this->conditions;
}
$maxRow = end($this->current);
$maximumValues = [];
foreach ($this->primaryKey as $column) {
$maximumValues[$column] = $this->db->addQuotes($maxRow->{$column});
}
$pkConditions = [];
// For example: If we have 3 primary keys
// first run through will generate
// col1 = 4 AND col2 = 7 AND col3 > 1
// second run through will generate
// col1 = 4 AND col2 > 7
// and the final run through will generate
// col1 > 4
while ($maximumValues) {
$pkConditions[] = $this->buildGreaterThanCondition($maximumValues);
array_pop($maximumValues);
}
$conditions = $this->conditions;
$conditions[] = sprintf('( %s )', implode(' ) OR ( ', $pkConditions));
return $conditions;
}
/**
* Invalidate the cache of a list of pages from a single namespace.
* This is intended for use by subclasses.
*
* @param IDatabase $dbw
* @param int $namespace Namespace number
* @param array $dbkeys
*/
public static function invalidatePages(IDatabase $dbw, $namespace, array $dbkeys)
{
if ($dbkeys === []) {
return;
}
$dbw->onTransactionIdle(function () use($dbw, $namespace, $dbkeys) {
$services = MediaWikiServices::getInstance();
$lbFactory = $services->getDBLoadBalancerFactory();
// Determine which pages need to be updated.
// This is necessary to prevent the job queue from smashing the DB with
// large numbers of concurrent invalidations of the same page.
$now = $dbw->timestamp();
$ids = $dbw->selectFieldValues('page', 'page_id', ['page_namespace' => $namespace, 'page_title' => $dbkeys, 'page_touched < ' . $dbw->addQuotes($now)], __METHOD__);
if (!$ids) {
return;
}
$batchSize = $services->getMainConfig()->get('UpdateRowsPerQuery');
$ticket = $lbFactory->getEmptyTransactionTicket(__METHOD__);
foreach (array_chunk($ids, $batchSize) as $idBatch) {
$dbw->update('page', ['page_touched' => $now], ['page_id' => $idBatch, 'page_touched < ' . $dbw->addQuotes($now)], __METHOD__);
$lbFactory->commitAndWaitForReplication(__METHOD__, $ticket);
}
}, __METHOD__);
}
/**
* SQL clause to skip forbidden log types for this user
*
* @param IDatabase $db
* @param string $audience Public/user
* @param User $user User to check, or null to use $wgUser
* @return string|bool String on success, false on failure.
*/
public static function getExcludeClause($db, $audience = 'public', User $user = null)
{
global $wgLogRestrictions;
if ($audience != 'public' && $user === null) {
global $wgUser;
$user = $wgUser;
}
// Reset the array, clears extra "where" clauses when $par is used
$hiddenLogs = array();
// Don't show private logs to unprivileged users
foreach ($wgLogRestrictions as $logType => $right) {
if ($audience == 'public' || !$user->isAllowed($right)) {
$hiddenLogs[] = $logType;
}
}
if (count($hiddenLogs) == 1) {
return 'log_type != ' . $db->addQuotes($hiddenLogs[0]);
} elseif ($hiddenLogs) {
return 'log_type NOT IN (' . $db->makeList($hiddenLogs) . ')';
}
return false;
}
/**
* Build a SQL expression for a closed interval (i.e. BETWEEN).
*
* By specifying a null $start or $end, it is also possible to create
* half-bounded or unbounded intervals using this function.
*
* @param IDatabase $db Database connection
* @param string $var Field name
* @param mixed $start First value to include or null
* @param mixed $end Last value to include or null
*/
private static function intervalCond(IDatabase $db, $var, $start, $end)
{
if ($start === null && $end === null) {
return "{$var} IS NOT NULL";
} elseif ($end === null) {
return "{$var} >= {$db->addQuotes($start)}";
} elseif ($start === null) {
return "{$var} <= {$db->addQuotes($end)}";
} else {
return "{$var} BETWEEN {$db->addQuotes($start)} AND {$db->addQuotes($end)}";
}
}
/**
* Generates condition for the query used in a batch count visiting watchers.
*
* @param IDatabase $db
* @param array $targetsWithVisitThresholds array of pairs (LinkTarget, last visit threshold)
* @return string
*/
private function getVisitingWatchersCondition(IDatabase $db, array $targetsWithVisitThresholds)
{
$missingTargets = [];
$namespaceConds = [];
foreach ($targetsWithVisitThresholds as list($target, $threshold)) {
if ($threshold === null) {
$missingTargets[] = $target;
continue;
}
/* @var LinkTarget $target */
$namespaceConds[$target->getNamespace()][] = $db->makeList(['wl_title = ' . $db->addQuotes($target->getDBkey()), $db->makeList(['wl_notificationtimestamp >= ' . $db->addQuotes($db->timestamp($threshold)), 'wl_notificationtimestamp IS NULL'], LIST_OR)], LIST_AND);
}
$conds = [];
foreach ($namespaceConds as $namespace => $pageConds) {
$conds[] = $db->makeList(['wl_namespace = ' . $namespace, '(' . $db->makeList($pageConds, LIST_OR) . ')'], LIST_AND);
}
if ($missingTargets) {
$lb = new LinkBatch($missingTargets);
$conds[] = $lb->constructSet('wl', $db);
}
return $db->makeList($conds, LIST_OR);
}
/**
* Creates a query condition part for getting only items before or after the given link target
* (while ordering using $sort mode)
*
* @param IDatabase $db
* @param LinkTarget $target
* @param string $op comparison operator to use in the conditions
* @return string
*/
private function getFromUntilTargetConds(IDatabase $db, LinkTarget $target, $op)
{
return $db->makeList(["wl_namespace {$op} " . $target->getNamespace(), $db->makeList(['wl_namespace = ' . $target->getNamespace(), "wl_title {$op}= " . $db->addQuotes($target->getDBkey())], LIST_AND)], LIST_OR);
}