IBX-7833: [PAPI] Implemented loading paginated relation list (#343)

For more details see https://issues.ibexa.co/browse/IBX-7833 and #343

Key changes:

* Added ContentService::loadRelationList public API which supports pagination

* Added ContentService::countRelations public API 

* [Tests] Added integration coverage for the new APIs

* Deprecated ContentService::loadRelations API

* Implemented persistence cache for the new APIs' results

phpstan-baseline.neon

@@ -16167,7 +16167,7 @@ parameters:
 
 		-
 			message: "#^Cannot call method fetchAll\\(\\) on Doctrine\\\\DBAL\\\\ForwardCompatibility\\\\Result\\|int\\|string\\.$#"
-			count: 17
+			count: 16
 			path: src/lib/Persistence/Legacy/Content/Gateway/DoctrineDatabase.php
 
 		-
@@ -63259,4 +63259,3 @@ parameters:
 			message: "#^Method Ibexa\\\\Tests\\\\Core\\\\Specification\\\\Content\\\\ContentTypeSpecificationTest\\:\\:providerForIsSatisfiedBy\\(\\) return type has no value type specified in iterable type array\\.$#"
 			count: 1
 			path: tests/lib/Specification/Content/ContentTypeSpecificationTest.php
-

src/contracts/Persistence/Content/Handler.php

@@ -283,6 +283,8 @@ public function removeRelation($relationId, $type, ?int $destinationContentId =
     /**
      * Loads relations from $sourceContentId. Optionally, loads only those with $type and $sourceContentVersionNo.
      *
+     * @deprecated 4.5.7 The "ContentService::loadRelations()" method is deprecated, will be removed in 5.0.
+     *
      * @param mixed $sourceContentId Source Content ID
      * @param mixed|null $sourceContentVersionNo Source Content Version, null if not specified
      * @param int|null $type {@see \Ibexa\Contracts\Core\Repository\Values\Content\Relation::COMMON,
@@ -294,6 +296,26 @@ public function removeRelation($relationId, $type, ?int $destinationContentId =
      */
     public function loadRelations($sourceContentId, $sourceContentVersionNo = null, $type = null);
 
+    /**
+     * Counts all outgoing relations for the given version.
+     */
+    public function countRelations(
+        int $sourceContentId,
+        ?int $sourceContentVersionNo = null,
+        ?int $type = null
+    ): int;
+
+    /**
+     * @return \Ibexa\Contracts\Core\Persistence\Content\Relation[]
+     */
+    public function loadRelationList(
+        int $sourceContentId,
+        int $limit,
+        int $offset = 0,
+        ?int $sourceContentVersionNo = null,
+        ?int $type = null
+    ): array;
+
     /**
      * Counts relations from $destinationContentId only against published versions. Optionally, count only those with $type.
      *

src/contracts/Repository/ContentService.php

@@ -30,6 +30,8 @@
  */
 interface ContentService
 {
+    public const DEFAULT_PAGE_SIZE = 25;
+
     /**
      * Loads a content info object.
      *
@@ -398,12 +400,36 @@ public function copyContent(ContentInfo $contentInfo, LocationCreateStruct $dest
      *
      * @throws \Ibexa\Contracts\Core\Repository\Exceptions\UnauthorizedException if the user is not allowed to read this version
      *
-     * @param \Ibexa\Contracts\Core\Repository\Values\Content\VersionInfo $versionInfo
+     * @deprecated 4.5.7 The "ContentService::loadRelations()" method is deprecated, will be removed in 5.0.
      *
      * @return \Ibexa\Contracts\Core\Repository\Values\Content\Relation[]
      */
     public function loadRelations(VersionInfo $versionInfo): iterable;
 
+    /**
+     * Loads all outgoing relations for the given version.
+     *
+     * If the user is not allowed to read specific version then a returned `RelationList` will contain `UnauthorizedRelationListItem`
+     *
+     * @throws \Ibexa\Contracts\Core\Repository\Exceptions\InvalidArgumentException
+     * @throws \Ibexa\Contracts\Core\Repository\Exceptions\BadStateException
+     *
+     * @see \Ibexa\Contracts\Core\Repository\Values\Content\RelationList\Item\UnauthorizedRelationListItem
+     */
+    public function loadRelationList(
+        VersionInfo $versionInfo,
+        int $offset = 0,
+        int $limit = self::DEFAULT_PAGE_SIZE
+    ): RelationList;
+
+    /**
+     * Counts all outgoing relations for the given version.
+     *
+     * @throws \Ibexa\Contracts\Core\Repository\Exceptions\InvalidArgumentException
+     * @throws \Ibexa\Contracts\Core\Repository\Exceptions\BadStateException
+     */
+    public function countRelations(VersionInfo $versionInfo): int;
+
     /**
      * Counts all incoming relations for the given content object.
      *

src/contracts/Repository/Decorator/ContentServiceDecorator.php

@@ -193,6 +193,16 @@ public function loadRelations(VersionInfo $versionInfo): iterable
         return $this->innerService->loadRelations($versionInfo);
     }
 
+    public function countRelations(VersionInfo $versionInfo): int
+    {
+        return $this->innerService->countRelations($versionInfo);
+    }
+
+    public function loadRelationList(VersionInfo $versionInfo, int $offset = 0, int $limit = self::DEFAULT_PAGE_SIZE): RelationList
+    {
+        return $this->innerService->loadRelationList($versionInfo, $offset, $limit);
+    }
+
     public function countReverseRelations(ContentInfo $contentInfo): int
     {
         return $this->innerService->countReverseRelations($contentInfo);

src/lib/Persistence/Cache/ContentHandler.php

@@ -31,6 +31,10 @@ class ContentHandler extends AbstractInMemoryPersistenceHandler implements Conte
     private const CONTENT_VERSION_LIST_IDENTIFIER = 'content_version_list';
     private const CONTENT_VERSION_INFO_IDENTIFIER = 'content_version_info';
     private const CONTENT_VERSION_IDENTIFIER = 'content_version';
+    private const CONTENT_RELATIONS_COUNT_WITH_VERSION_TYPE_IDENTIFIER = 'content_relations_count_with_by_version_type_suffix';
+    private const CONTENT_RELATION_IDENTIFIER = 'content_relation';
+    private const CONTENT_RELATIONS_LIST_IDENTIFIER = 'content_relations_list';
+    private const CONTENT_RELATIONS_LIST_WITH_VERSION_TYPE_IDENTIFIER = 'content_relations_list_with_by_version_type_suffix';
     private const CONTENT_REVERSE_RELATIONS_COUNT_IDENTIFIER = 'content_reverse_relations_count';
     private const RELATION_IDENTIFIER = 'relation';
 
@@ -517,6 +521,97 @@ public function loadRelations($sourceContentId, $sourceContentVersionNo = null,
         return $this->persistenceHandler->contentHandler()->loadRelations($sourceContentId, $sourceContentVersionNo, $type);
     }
 
+    public function countRelations(int $sourceContentId, ?int $sourceContentVersionNo = null, ?int $type = null): int
+    {
+        $cacheItem = $this->cache->getItem(
+            $this->cacheIdentifierGenerator->generateKey(
+                self::CONTENT_RELATIONS_COUNT_WITH_VERSION_TYPE_IDENTIFIER,
+                [$sourceContentId, $sourceContentVersionNo, $type],
+                true
+            )
+        );
+
+        if ($cacheItem->isHit()) {
+            $this->logger->logCacheHit(['content' => $sourceContentId, 'version' => $sourceContentVersionNo, 'type' => $type]);
+
+            return $cacheItem->get();
+        }
+
+        $this->logger->logCacheMiss(['content' => $sourceContentId, 'version' => $sourceContentVersionNo, 'type' => $type]);
+        $relationsCount = $this->persistenceHandler->contentHandler()->countRelations(
+            $sourceContentId,
+            $sourceContentVersionNo,
+            $type
+        );
+        $cacheItem->set($relationsCount);
+        $tags = [
+            $this->cacheIdentifierGenerator->generateTag(
+                self::CONTENT_IDENTIFIER,
+                [$sourceContentId]
+            ),
+        ];
+
+        $cacheItem->tag($tags);
+        $this->cache->save($cacheItem);
+
+        return $relationsCount;
+    }
+
+    public function loadRelationList(
+        int $sourceContentId,
+        int $limit,
+        int $offset = 0,
+        ?int $sourceContentVersionNo = null,
+        ?int $type = null
+    ): array {
+        return $this->getListCacheValue(
+            $this->cacheIdentifierGenerator->generateKey(
+                self::CONTENT_RELATIONS_LIST_WITH_VERSION_TYPE_IDENTIFIER,
+                [$sourceContentId, $limit, $offset, $sourceContentVersionNo, $type],
+                true
+            ),
+            function () use ($sourceContentId, $limit, $offset, $sourceContentVersionNo, $type): array {
+                return $this->persistenceHandler->contentHandler()->loadRelationList(
+                    $sourceContentId,
+                    $limit,
+                    $offset,
+                    $sourceContentVersionNo,
+                    $type
+                );
+            },
+            function (Relation $relation): array {
+                return [
+                    $this->cacheIdentifierGenerator->generateTag(
+                        self::CONTENT_RELATION_IDENTIFIER,
+                        [$relation->destinationContentId]
+                    ),
+                    $this->cacheIdentifierGenerator->generateTag(
+                        self::CONTENT_IDENTIFIER,
+                        [$relation->destinationContentId]
+                    ),
+                ];
+            },
+            function (Relation $relation): array {
+                return [
+                    $this->cacheIdentifierGenerator->generateKey(self::CONTENT_IDENTIFIER, [$relation->destinationContentId], true),
+                ];
+            },
+            function () use ($sourceContentId): array {
+                return [
+                    $this->cacheIdentifierGenerator->generateTag(
+                        self::CONTENT_RELATIONS_LIST_IDENTIFIER,
+                        [$sourceContentId]
+                    ),
+                    $this->cacheIdentifierGenerator->generateTag(
+                        self::CONTENT_IDENTIFIER,
+                        [$sourceContentId]
+                    ),
+                ];
+            },
+            [$sourceContentId, $limit, $offset, $sourceContentVersionNo, $type]
+        );
+    }
+
     /**
      * {@inheritdoc}
      */

src/lib/Persistence/Legacy/Content/Gateway.php

@@ -361,7 +361,29 @@ abstract public function loadRelations(
     ): array;
 
     /**
-     * Count number of related to/from $contentId.
+     * Counts number of related to/from $contentId.
+     */
+    abstract public function countRelations(
+        int $contentId,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): int;
+
+    /**
+     * Loads paginated data of related to/from $contentId.
+     *
+     * @return array<array<string, mixed>>
+     */
+    abstract public function listRelations(
+        int $contentId,
+        int $limit,
+        int $offset = 0,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): array;
+
+    /**
+     * Counts number of related to/from $contentId.
      */
     abstract public function countReverseRelations(int $contentId, ?int $relationType = null): int;
 

src/lib/Persistence/Legacy/Content/Gateway/DoctrineDatabase.php

@@ -1387,18 +1387,61 @@ public function loadRelations(
         ?int $relationType = null
     ): array {
         $query = $this->queryBuilder->createRelationFindQueryBuilder();
+        $query = $this->prepareRelationQuery($query, $contentId, $contentVersionNo, $relationType);
+
+        return $query->execute()->fetchAllAssociative();
+    }
+
+    public function countRelations(
+        int $contentId,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): int {
+        $query = $this->connection->createQueryBuilder();
+        $query->select($this->databasePlatform->getCountExpression('l.id'))
+            ->from(self::CONTENT_RELATION_TABLE, 'l');
+
+        $query = $this->prepareRelationQuery($query, $contentId, $contentVersionNo, $relationType);
+
+        return (int)$query->execute()->fetchOne();
+    }
+
+    public function listRelations(
+        int $contentId,
+        int $limit,
+        int $offset = 0,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): array {
+        $query = $this->queryBuilder->createRelationFindQueryBuilder();
+        $query = $this->prepareRelationQuery($query, $contentId, $contentVersionNo, $relationType);
+
+        $query->setFirstResult($offset)
+            ->setMaxResults($limit);
+
+        $query->orderBy('l.id', 'DESC');
+
+        return $query->execute()->fetchAllAssociative();
+    }
+
+    private function prepareRelationQuery(
+        DoctrineQueryBuilder $query,
+        int $contentId,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): DoctrineQueryBuilder {
         $expr = $query->expr();
         $query
             ->innerJoin(
                 'l',
-                'ezcontentobject',
-                'ezcontentobject_to',
-                $expr->andX(
-                    'l.to_contentobject_id = ezcontentobject_to.id',
-                    'ezcontentobject_to.status = :status'
+                self::CONTENT_ITEM_TABLE,
+                'c_to',
+                $expr->and(
+                    'l.to_contentobject_id = c_to.id',
+                    'c_to.status = :status'
                 )
             )
-            ->where(
+            ->andWhere(
                 'l.from_contentobject_id = :content_id'
             )
             ->setParameter(
@@ -1409,18 +1452,18 @@ public function loadRelations(
             ->setParameter('content_id', $contentId, ParameterType::INTEGER);
 
         // source version number
-        if (null !== $contentVersionNo) {
+        if ($contentVersionNo !== null) {
             $query
                 ->andWhere('l.from_contentobject_version = :version_no')
                 ->setParameter('version_no', $contentVersionNo, ParameterType::INTEGER);
         } else {
             // from published version only
             $query
                 ->innerJoin(
-                    'ezcontentobject_to',
-                    'ezcontentobject',
+                    'c_to',
+                    self::CONTENT_ITEM_TABLE,
                     'c',
-                    $expr->andX(
+                    $expr->and(
                         'c.id = l.from_contentobject_id',
                         'c.current_version = l.from_contentobject_version'
                     )
@@ -1442,7 +1485,7 @@ public function loadRelations(
                 ->setParameter('relation_type', $relationType, ParameterType::INTEGER);
         }
 
-        return $query->execute()->fetchAll(FetchMode::ASSOCIATIVE);
+        return $query;
     }
 
     public function countReverseRelations(int $toContentId, ?int $relationType = null): int

src/lib/Persistence/Legacy/Content/Gateway/ExceptionConversion.php

@@ -392,6 +392,38 @@ public function loadRelations(
         }
     }
 
+    public function countRelations(
+        int $contentId,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): int {
+        try {
+            return $this->innerGateway->countRelations($contentId, $contentVersionNo, $relationType);
+        } catch (DBALException | PDOException $e) {
+            throw DatabaseException::wrap($e);
+        }
+    }
+
+    public function listRelations(
+        int $contentId,
+        int $limit,
+        int $offset = 0,
+        ?int $contentVersionNo = null,
+        ?int $relationType = null
+    ): array {
+        try {
+            return $this->innerGateway->listRelations(
+                $contentId,
+                $limit,
+                $offset,
+                $contentVersionNo,
+                $relationType
+            );
+        } catch (DBALException | PDOException $e) {
+            throw DatabaseException::wrap($e);
+        }
+    }
+
     public function countReverseRelations(int $contentId, ?int $relationType = null): int
     {
         try {