<?php
declare(strict_types=1);
namespace Doctrine\ORM\Tools\Pagination;
use ArrayIterator;
use Countable;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Internal\SQLResultCasing;
use Doctrine\ORM\NoResultException;
use Doctrine\ORM\Query;
use Doctrine\ORM\Query\Parameter;
use Doctrine\ORM\Query\Parser;
use Doctrine\ORM\Query\ResultSetMapping;
use Doctrine\ORM\QueryBuilder;
use IteratorAggregate;
use ReturnTypeWillChange;
use function array_key_exists;
use function array_map;
use function array_sum;
use function count;
/**
* The paginator can handle various complex scenarios with DQL.
*
* @template T
*/
class Paginator implements Countable, IteratorAggregate
{
use SQLResultCasing;
/** @var Query */
private $query;
/** @var bool */
private $fetchJoinCollection;
/** @var bool|null */
private $useOutputWalkers;
/** @var int */
private $count;
/**
* @param Query|QueryBuilder $query A Doctrine ORM query or query builder.
* @param bool $fetchJoinCollection Whether the query joins a collection (true by default).
*/
public function __construct($query, $fetchJoinCollection = true)
{
if ($query instanceof QueryBuilder) {
$query = $query->getQuery();
}
$this->query = $query;
$this->fetchJoinCollection = (bool) $fetchJoinCollection;
}
/**
* Returns the query.
*
* @return Query
*/
public function getQuery()
{
return $this->query;
}
/**
* Returns whether the query joins a collection.
*
* @return bool Whether the query joins a collection.
*/
public function getFetchJoinCollection()
{
return $this->fetchJoinCollection;
}
/**
* Returns whether the paginator will use an output walker.
*
* @return bool|null
*/
public function getUseOutputWalkers()
{
return $this->useOutputWalkers;
}
/**
* Sets whether the paginator will use an output walker.
*
* @param bool|null $useOutputWalkers
*
* @return $this
* @psalm-return static<T>
*/
public function setUseOutputWalkers($useOutputWalkers)
{
$this->useOutputWalkers = $useOutputWalkers;
return $this;
}
/**
* {@inheritdoc}
*
* @return int
*/
#[ReturnTypeWillChange]
public function count()
{
if ($this->count === null) {
try {
$this->count = (int) array_sum(array_map('current', $this->getCountQuery()->getScalarResult()));
} catch (NoResultException $e) {
$this->count = 0;
}
}
return $this->count;
}
/**
* {@inheritdoc}
*
* @return ArrayIterator
* @psalm-return ArrayIterator<array-key, T>
*/
#[ReturnTypeWillChange]
public function getIterator()
{
$offset = $this->query->getFirstResult();
$length = $this->query->getMaxResults();
if ($this->fetchJoinCollection && $length !== null) {
$subQuery = $this->cloneQuery($this->query);
if ($this->useOutputWalker($subQuery)) {
$subQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, LimitSubqueryOutputWalker::class);
} else {
$this->appendTreeWalker($subQuery, LimitSubqueryWalker::class);
$this->unbindUnusedQueryParams($subQuery);
}
$subQuery->setFirstResult($offset)->setMaxResults($length);
$foundIdRows = $subQuery->getScalarResult();
// don't do this for an empty id array
if ($foundIdRows === []) {
return new ArrayIterator([]);
}
$whereInQuery = $this->cloneQuery($this->query);
$ids = array_map('current', $foundIdRows);
$this->appendTreeWalker($whereInQuery, WhereInWalker::class);
$whereInQuery->setHint(WhereInWalker::HINT_PAGINATOR_ID_COUNT, count($ids));
$whereInQuery->setFirstResult(null)->setMaxResults(null);
$whereInQuery->setParameter(WhereInWalker::PAGINATOR_ID_ALIAS, $ids);
$whereInQuery->setCacheable($this->query->isCacheable());
$whereInQuery->expireQueryCache();
$result = $whereInQuery->getResult($this->query->getHydrationMode());
} else {
$result = $this->cloneQuery($this->query)
->setMaxResults($length)
->setFirstResult($offset)
->setCacheable($this->query->isCacheable())
->getResult($this->query->getHydrationMode());
}
return new ArrayIterator($result);
}
private function cloneQuery(Query $query): Query
{
$cloneQuery = clone $query;
$cloneQuery->setParameters(clone $query->getParameters());
$cloneQuery->setCacheable(false);
foreach ($query->getHints() as $name => $value) {
$cloneQuery->setHint($name, $value);
}
return $cloneQuery;
}
/**
* Determines whether to use an output walker for the query.
*/
private function useOutputWalker(Query $query): bool
{
if ($this->useOutputWalkers === null) {
return (bool) $query->getHint(Query::HINT_CUSTOM_OUTPUT_WALKER) === false;
}
return $this->useOutputWalkers;
}
/**
* Appends a custom tree walker to the tree walkers hint.
*
* @psalm-param class-string $walkerClass
*/
private function appendTreeWalker(Query $query, string $walkerClass): void
{
$hints = $query->getHint(Query::HINT_CUSTOM_TREE_WALKERS);
if ($hints === false) {
$hints = [];
}
$hints[] = $walkerClass;
$query->setHint(Query::HINT_CUSTOM_TREE_WALKERS, $hints);
}
/**
* Returns Query prepared to count.
*/
private function getCountQuery(): Query
{
$countQuery = $this->cloneQuery($this->query);
if (! $countQuery->hasHint(CountWalker::HINT_DISTINCT)) {
$countQuery->setHint(CountWalker::HINT_DISTINCT, true);
}
if ($this->useOutputWalker($countQuery)) {
$platform = $countQuery->getEntityManager()->getConnection()->getDatabasePlatform(); // law of demeter win
$rsm = new ResultSetMapping();
$rsm->addScalarResult($this->getSQLResultCasing($platform, 'dctrn_count'), 'count');
$countQuery->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, CountOutputWalker::class);
$countQuery->setResultSetMapping($rsm);
} else {
$this->appendTreeWalker($countQuery, CountWalker::class);
$this->unbindUnusedQueryParams($countQuery);
}
$countQuery->setFirstResult(null)->setMaxResults(null);
return $countQuery;
}
private function unbindUnusedQueryParams(Query $query): void
{
$parser = new Parser($query);
$parameterMappings = $parser->parse()->getParameterMappings();
/** @var Collection|Parameter[] $parameters */
$parameters = $query->getParameters();
foreach ($parameters as $key => $parameter) {
$parameterName = $parameter->getName();
if (! (isset($parameterMappings[$parameterName]) || array_key_exists($parameterName, $parameterMappings))) {
unset($parameters[$key]);
}
}
$query->setParameters($parameters);
}
}