Add a partial paginator to prevent SQL COUNT queries

features/hydra/collection.feature

@@ -164,6 +164,50 @@ Feature: Collections support
     }
     """
 
+  Scenario: Enable the partial pagination client side
+    When I send a "GET" request to "/dummies?page=7&partial=1"
+    Then the response status code should be 200
+    And the response should be in JSON
+    And the header "Content-Type" should be equal to "application/ld+json; charset=utf-8"
+    And the JSON should be valid according to this schema:
+    """
+    {
+      "type": "object",
+      "properties": {
+        "@context": {"pattern": "^/contexts/Dummy$"},
+        "@id": {"pattern": "^/dummies$"},
+        "@type": {"pattern": "^hydra:Collection$"},
+        "hydra:totalItems": {"type":"number", "maximum": 30},
+        "hydra:member": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "properties": {
+              "@id": {
+                "oneOf": [
+                  {"pattern": "^/dummies/19$"},
+                  {"pattern": "^/dummies/20$"},
+                  {"pattern": "^/dummies/21$"}
+                ]
+              }
+            }
+          },
+          "maxItems": 3
+        },
+        "hydra:view": {
+          "type": "object",
+          "properties": {
+            "@id": {"pattern": "^/dummies\\?partial=1&page=7$"},
+            "@type": {"pattern": "^hydra:PartialCollectionView$"},
+            "hydra:next": {"pattern": "^/dummies\\?partial=1&page=8$"},
+            "hydra:previous": {"pattern": "^/dummies\\?partial=1&page=6$"}
+          },
+          "additionalProperties": false
+        }
+      }
+    }
+    """
+
   Scenario: Disable the pagination client side
     When I send a "GET" request to "/dummies?pagination=0"
     Then the response status code should be 200

phpstan.neon

@@ -14,3 +14,4 @@ parameters:
         - '#Parameter \#2 \$dqlPart of method Doctrine\\ORM\\QueryBuilder::add\(\) expects Doctrine\\ORM\\Query\\Expr\\Base, Doctrine\\ORM\\Query\\Expr\\Join\[\] given#' # Fixed in Doctrine's master
         - '#Call to an undefined method Doctrine\\Common\\Persistence\\ObjectManager::getConnection\(\)#'
         - '#Parameter \#1 \$callable of static method Doctrine\\Common\\Annotations\\AnnotationRegistry::registerLoader\(\) expects callable, mixed\[\] given#'
+        - '#Method ApiPlatform\\Core\\Bridge\\Doctrine\\Orm\\Extension\\QueryResult(Item|Collection)ExtensionInterface::getResult\(\) invoked with 3 parameters, 1 required#'

src/Bridge/Doctrine/Orm/AbstractPaginator.php

@@ -0,0 +1,75 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\Core\Bridge\Doctrine\Orm;
+
+use ApiPlatform\Core\DataProvider\PartialPaginatorInterface;
+use ApiPlatform\Core\Exception\InvalidArgumentException;
+use Doctrine\ORM\Query;
+use Doctrine\ORM\Tools\Pagination\Paginator as DoctrinePaginator;
+
+abstract class AbstractPaginator implements \IteratorAggregate, PartialPaginatorInterface
+{
+    protected $paginator;
+    protected $iterator;
+    protected $firstResult;
+    protected $maxResults;
+
+    /**
+     * @throws InvalidArgumentException
+     */
+    public function __construct(DoctrinePaginator $paginator)
+    {
+        $query = $paginator->getQuery();
+
+        if (null === ($firstResult = $query->getFirstResult()) || null === $maxResults = $query->getMaxResults()) {
+            throw new InvalidArgumentException(sprintf('"%1$s::setFirstResult()" or/and "%1$s::setMaxResults()" was/were not applied to the query.', Query::class));
+        }
+
+        $this->paginator = $paginator;
+        $this->firstResult = $firstResult;
+        $this->maxResults = $maxResults;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getCurrentPage(): float
+    {
+        return floor($this->firstResult / $this->maxResults) + 1.;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getItemsPerPage(): float
+    {
+        return (float) $this->maxResults;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getIterator(): \Traversable
+    {
+        return $this->iterator ?? $this->iterator = $this->paginator->getIterator();
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function count(): int
+    {
+        return iterator_count($this->getIterator());
+    }
+}

src/Bridge/Doctrine/Orm/CollectionDataProvider.php

@@ -65,7 +65,7 @@ public function getCollection(string $resourceClass, string $operationName = nul
             $extension->applyToCollection($queryBuilder, $queryNameGenerator, $resourceClass, $operationName);
 
             if ($extension instanceof QueryResultCollectionExtensionInterface && $extension->supportsResult($resourceClass, $operationName)) {
-                return $extension->getResult($queryBuilder);
+                return $extension->getResult($queryBuilder, $resourceClass, $operationName);
             }
         }
 

src/Bridge/Doctrine/Orm/Extension/PaginationExtension.php

@@ -13,6 +13,7 @@
 
 namespace ApiPlatform\Core\Bridge\Doctrine\Orm\Extension;
 
+use ApiPlatform\Core\Bridge\Doctrine\Orm\AbstractPaginator;
 use ApiPlatform\Core\Bridge\Doctrine\Orm\Paginator;
 use ApiPlatform\Core\Bridge\Doctrine\Orm\Util\QueryChecker;
 use ApiPlatform\Core\Bridge\Doctrine\Orm\Util\QueryNameGeneratorInterface;
@@ -44,8 +45,11 @@ final class PaginationExtension implements QueryResultCollectionExtensionInterfa
     private $enabledParameterName;
     private $itemsPerPageParameterName;
     private $maximumItemPerPage;
+    private $partial;
+    private $clientPartial;
+    private $partialParameterName;
 
-    public function __construct(ManagerRegistry $managerRegistry, RequestStack $requestStack, ResourceMetadataFactoryInterface $resourceMetadataFactory, bool $enabled = true, bool $clientEnabled = false, bool $clientItemsPerPage = false, int $itemsPerPage = 30, string $pageParameterName = 'page', string $enabledParameterName = 'pagination', string $itemsPerPageParameterName = 'itemsPerPage', int $maximumItemPerPage = null)
+    public function __construct(ManagerRegistry $managerRegistry, RequestStack $requestStack, ResourceMetadataFactoryInterface $resourceMetadataFactory, bool $enabled = true, bool $clientEnabled = false, bool $clientItemsPerPage = false, int $itemsPerPage = 30, string $pageParameterName = 'page', string $enabledParameterName = 'pagination', string $itemsPerPageParameterName = 'itemsPerPage', int $maximumItemPerPage = null, bool $partial = false, bool $clientPartial = false, string $partialParameterName = 'partial')
     {
         $this->managerRegistry = $managerRegistry;
         $this->requestStack = $requestStack;
@@ -58,6 +62,9 @@ public function __construct(ManagerRegistry $managerRegistry, RequestStack $requ
         $this->enabledParameterName = $enabledParameterName;
         $this->itemsPerPageParameterName = $itemsPerPageParameterName;
         $this->maximumItemPerPage = $maximumItemPerPage;
+        $this->partial = $partial;
+        $this->clientPartial = $clientPartial;
+        $this->partialParameterName = $partialParameterName;
     }
 
     /**
@@ -108,14 +115,55 @@ public function supportsResult(string $resourceClass, string $operationName = nu
     /**
      * {@inheritdoc}
      */
-    public function getResult(QueryBuilder $queryBuilder)
+    public function getResult(QueryBuilder $queryBuilder/*, string $resourceClass, string $operationName = null*/)
     {
+        $resourceClass = $operationName = null;
+
+        if (func_num_args() >= 2) {
+            $resourceClass = func_get_arg(1);
+        } else {
+            @trigger_error(sprintf('Method %s() will have a 2nd `string $resourceClass` argument in version 3.0. Not defining it is deprecated since 2.2.', __METHOD__), E_USER_DEPRECATED);
+        }
+
+        if (func_num_args() >= 3) {
+            $operationName = func_get_arg(2);
+        } else {
+            @trigger_error(sprintf('Method %s() will have a 3rd `string $operationName = null` argument in version 3.0. Not defining it is deprecated since 2.2.', __METHOD__), E_USER_DEPRECATED);
+        }
+
         $doctrineOrmPaginator = new DoctrineOrmPaginator($queryBuilder, $this->useFetchJoinCollection($queryBuilder));
         $doctrineOrmPaginator->setUseOutputWalkers($this->useOutputWalkers($queryBuilder));
 
+        $resourceMetadata = null === $resourceClass ? null : $this->resourceMetadataFactory->create($resourceClass);
+
+        if ($this->isPartialPaginationEnabled($this->requestStack->getCurrentRequest(), $resourceMetadata, $operationName)) {
+            return new class($doctrineOrmPaginator) extends AbstractPaginator {
+            };
+        }
+
         return new Paginator($doctrineOrmPaginator);
     }
 
+    private function isPartialPaginationEnabled(Request $request = null, ResourceMetadata $resourceMetadata = null, string $operationName = null): bool
+    {
+        $enabled = $this->partial;
+        $clientEnabled = $this->clientPartial;
+
+        if ($resourceMetadata) {
+            $enabled = $resourceMetadata->getCollectionOperationAttribute($operationName, 'pagination_partial', $enabled, true);
+
+            if ($request) {
+                $clientEnabled = $resourceMetadata->getCollectionOperationAttribute($operationName, 'pagination_client_partial', $clientEnabled, true);
+            }
+        }
+
+        if ($clientEnabled && $request) {
+            $enabled = filter_var($request->query->get($this->partialParameterName, $enabled), FILTER_VALIDATE_BOOLEAN);
+        }
+
+        return $enabled;
+    }
+
     private function isPaginationEnabled(Request $request, ResourceMetadata $resourceMetadata, string $operationName = null): bool
     {
         $enabled = $resourceMetadata->getCollectionOperationAttribute($operationName, 'pagination_enabled', $this->enabled, true);

src/Bridge/Doctrine/Orm/Extension/QueryResultCollectionExtensionInterface.php

@@ -34,8 +34,10 @@ public function supportsResult(string $resourceClass, string $operationName = nu
 
     /**
      * @param QueryBuilder $queryBuilder
+     * @param string       $resourceClass
+     * @param string|null  $operationName
      *
      * @return mixed
      */
-    public function getResult(QueryBuilder $queryBuilder);
+    public function getResult(QueryBuilder $queryBuilder/*, string $resourceClass, string $operationName = null*/);
 }

src/Bridge/Doctrine/Orm/Extension/QueryResultItemExtensionInterface.php

@@ -33,8 +33,10 @@ public function supportsResult(string $resourceClass, string $operationName = nu
 
     /**
      * @param QueryBuilder $queryBuilder
+     * @param string       $resourceClass
+     * @param string|null  $operationName
      *
      * @return mixed
      */
-    public function getResult(QueryBuilder $queryBuilder);
+    public function getResult(QueryBuilder $queryBuilder/*, string $resourceClass, string $operationName = null*/);
 }

src/Bridge/Doctrine/Orm/Paginator.php

@@ -14,95 +14,32 @@
 namespace ApiPlatform\Core\Bridge\Doctrine\Orm;
 
 use ApiPlatform\Core\DataProvider\PaginatorInterface;
-use Doctrine\ORM\Tools\Pagination\Paginator as DoctrineOrmPaginator;
 
 /**
  * Decorates the Doctrine ORM paginator.
  *
  * @author Kévin Dunglas <[email protected]>
  */
-final class Paginator implements \IteratorAggregate, PaginatorInterface
+final class Paginator extends AbstractPaginator implements PaginatorInterface
 {
-    private $paginator;
-
-    /**
-     * @var int
-     */
-    private $firstResult;
-
-    /**
-     * @var int
-     */
-    private $maxResults;
-
     /**
      * @var int
      */
     private $totalItems;
 
-    /**
-     * @var \Traversable
-     */
-    private $iterator;
-
-    public function __construct(DoctrineOrmPaginator $paginator)
-    {
-        $this->paginator = $paginator;
-        $query = $paginator->getQuery();
-        $this->firstResult = $query->getFirstResult();
-        $this->maxResults = $query->getMaxResults();
-        $this->totalItems = count($paginator);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getCurrentPage(): float
-    {
-        return floor($this->firstResult / $this->maxResults) + 1.;
-    }
-
     /**
      * {@inheritdoc}
      */
     public function getLastPage(): float
     {
-        return ceil($this->totalItems / $this->maxResults) ?: 1.;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getItemsPerPage(): float
-    {
-        return (float) $this->maxResults;
+        return ceil($this->getTotalItems() / $this->maxResults) ?: 1.;
     }
 
     /**
      * {@inheritdoc}
      */
     public function getTotalItems(): float
     {
-        return (float) $this->totalItems;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getIterator()
-    {
-        if (null === $this->iterator) {
-            $this->iterator = $this->paginator->getIterator();
-        }
-
-        return $this->iterator;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function count()
-    {
-        return count($this->getIterator());
+        return (float) ($this->totalItems ?? $this->totalItems = count($this->paginator));
     }
 }

src/Bridge/Doctrine/Orm/SubresourceDataProvider.php

@@ -178,15 +178,15 @@ public function getSubresource(string $resourceClass, array $identifiers, array
                 $extension->applyToCollection($queryBuilder, $queryNameGenerator, $resourceClass, $operationName);
 
                 if ($extension instanceof QueryResultCollectionExtensionInterface && $extension->supportsResult($resourceClass, $operationName)) {
-                    return $extension->getResult($queryBuilder);
+                    return $extension->getResult($queryBuilder, $resourceClass, $operationName);
                 }
             }
         } else {
             foreach ($this->itemExtensions as $extension) {
                 $extension->applyToItem($queryBuilder, $queryNameGenerator, $resourceClass, $identifiers, $operationName, $context);
 
                 if ($extension instanceof QueryResultItemExtensionInterface && $extension->supportsResult($resourceClass, $operationName)) {
-                    return $extension->getResult($queryBuilder);
+                    return $extension->getResult($queryBuilder, $resourceClass, $operationName);
                 }
             }
         }

src/Bridge/Symfony/Bundle/DependencyInjection/ApiPlatformExtension.php

@@ -145,13 +145,16 @@ private function handleConfig(ContainerBuilder $container, array $config, array
         $container->setParameter('api_platform.collection.order', $config['collection']['order']);
         $container->setParameter('api_platform.collection.order_parameter_name', $config['collection']['order_parameter_name']);
         $container->setParameter('api_platform.collection.pagination.enabled', $config['collection']['pagination']['enabled']);
+        $container->setParameter('api_platform.collection.pagination.partial', $config['collection']['pagination']['partial']);
         $container->setParameter('api_platform.collection.pagination.client_enabled', $config['collection']['pagination']['client_enabled']);
         $container->setParameter('api_platform.collection.pagination.client_items_per_page', $config['collection']['pagination']['client_items_per_page']);
+        $container->setParameter('api_platform.collection.pagination.client_partial', $config['collection']['pagination']['client_partial']);
         $container->setParameter('api_platform.collection.pagination.items_per_page', $config['collection']['pagination']['items_per_page']);
         $container->setParameter('api_platform.collection.pagination.maximum_items_per_page', $config['collection']['pagination']['maximum_items_per_page']);
         $container->setParameter('api_platform.collection.pagination.page_parameter_name', $config['collection']['pagination']['page_parameter_name']);
         $container->setParameter('api_platform.collection.pagination.enabled_parameter_name', $config['collection']['pagination']['enabled_parameter_name']);
         $container->setParameter('api_platform.collection.pagination.items_per_page_parameter_name', $config['collection']['pagination']['items_per_page_parameter_name']);
+        $container->setParameter('api_platform.collection.pagination.partial_parameter_name', $config['collection']['pagination']['partial_parameter_name']);
         $container->setParameter('api_platform.http_cache.etag', $config['http_cache']['etag']);
         $container->setParameter('api_platform.http_cache.max_age', $config['http_cache']['max_age']);
         $container->setParameter('api_platform.http_cache.shared_max_age', $config['http_cache']['shared_max_age']);