Add Pagination classes to ODM

src/Pagination/AggregationCursorPaginator.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ODM\MongoDB\Pagination;
+
+use Doctrine\ODM\MongoDB\Aggregation\Builder;
+use Doctrine\ODM\MongoDB\Iterator\Iterator;
+
+/**
+ * @template-covariant TValue
+ * @template-extends Paginator<TValue>
+ */
+final class AggregationCursorPaginator extends Paginator
+{
+    public function __construct(
+        private readonly Builder $aggregation,
+        public readonly mixed $after = null,
+        public readonly int $perPage = 24,
+        public readonly string $field = 'id',
+    ) {
+    }
+
+    /** @return Iterator<TValue> */
+    protected function getResultsForCurrentPage(): Iterator
+    {
+        $builder = clone $this->aggregation;
+
+        if ($this->after) {
+            $builder
+                ->match()
+                    ->field($this->field)->gt($this->after);
+        }
+
+        return $builder
+            ->limit($this->perPage)
+            ->getAggregation()
+            ->getIterator();
+    }
+}

src/Pagination/AggregationOffsetPaginator.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ODM\MongoDB\Pagination;
+
+use Countable;
+use Doctrine\ODM\MongoDB\Aggregation\Builder;
+use Doctrine\ODM\MongoDB\Iterator\Iterator;
+
+use function ceil;
+use function iterator_to_array;
+
+/**
+ * @template-covariant TValue
+ * @template-extends Paginator<TValue>
+ */
+final class AggregationOffsetPaginator extends Paginator implements Countable
+{
+    private int $pageCount;
+
+    /** @psalm-param positive-int $page */
+    public function __construct(
+        private readonly Builder $aggregation,
+        public readonly int $page,
+        public readonly int $perPage = 24,
+    ) {
+    }
+
+    public function count(): int
+    {
+        return $this->pageCount ??= $this->getNumberOfPages();
+    }
+
+    private function getNumberOfPages(): int
+    {
+        $builder    = clone $this->aggregation;
+        $results    = $builder
+            ->hydrate(null)
+            ->count('numDocuments')
+            ->getAggregation()
+            ->getIterator();
+        $numResults = iterator_to_array($results)[0]['numDocuments'] ?? 0;
+
+        return (int) ceil($numResults / $this->perPage);
+    }
+
+    /** @return Iterator<TValue> */
+    protected function getResultsForCurrentPage(): Iterator
+    {
+        $builder = clone $this->aggregation;
+        $builder
+            ->skip(($this->page - 1) * $this->perPage)
+            ->limit($this->perPage);
+
+        return $builder->getAggregation()->getIterator();
+    }
+}

src/Pagination/Paginator.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ODM\MongoDB\Pagination;
+
+use Doctrine\ODM\MongoDB\Iterator\Iterator;
+use IteratorAggregate;
+
+/**
+ * @template-covariant TValue
+ * @template-implements IteratorAggregate<mixed, TValue>
+ */
+abstract class Paginator implements IteratorAggregate
+{
+    /** @return Iterator<TValue> */
+    abstract protected function getResultsForCurrentPage(): Iterator;
+
+    /** @return Iterator<TValue> */
+    final public function getIterator(): Iterator
+    {
+        return $this->getResultsForCurrentPage();
+    }
+}

src/Pagination/QueryCursorPaginator.php

@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ODM\MongoDB\Pagination;
+
+use Doctrine\ODM\MongoDB\Iterator\Iterator;
+use Doctrine\ODM\MongoDB\Query\Builder;
+
+/**
+ * @template-covariant TValue
+ * @template-extends Paginator<TValue>
+ */
+final class QueryCursorPaginator extends Paginator
+{
+    public function __construct(
+        private readonly Builder $query,
+        public readonly mixed $after = null,
+        public readonly int $perPage = 24,
+        public readonly string $field = 'id',
+    ) {
+    }
+
+    /** @return Iterator<TValue> */
+    protected function getResultsForCurrentPage(): Iterator
+    {
+        $builder = clone $this->query;
+
+        if ($this->after) {
+            $builder
+                ->field($this->field)->gt($this->after);
+        }
+
+        return $builder
+            ->limit($this->perPage)
+            ->getQuery()
+            ->getIterator();
+    }
+}

src/Pagination/QueryOffsetPaginator.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\ODM\MongoDB\Pagination;
+
+use Countable;
+use Doctrine\ODM\MongoDB\Iterator\Iterator;
+use Doctrine\ODM\MongoDB\Query\Builder;
+
+use function ceil;
+
+/**
+ * @template-covariant TValue
+ * @template-extends Paginator<TValue>
+ */
+final class QueryOffsetPaginator extends Paginator implements Countable
+{
+    private int $pageCount;
+
+    /** @psalm-param positive-int $page */
+    public function __construct(
+        private readonly Builder $query,
+        public readonly int $page,
+        public readonly int $perPage = 24,
+    ) {
+    }
+
+    public function count(): int
+    {
+        return $this->pageCount ??= $this->getNumberOfPages();
+    }
+
+    private function getNumberOfPages(): int
+    {
+        $builder = clone $this->query;
+
+        return (int) ceil($builder
+            ->hydrate(false)
+            ->count()
+            ->getQuery()
+            ->execute() / $this->perPage);
+    }
+
+    /** @return Iterator<TValue> */
+    protected function getResultsForCurrentPage(): Iterator
+    {
+        $builder = clone $this->query;
+        $builder
+            ->skip(($this->page - 1) * $this->perPage)
+            ->limit($this->perPage);
+
+        return $builder->getQuery()->getIterator();
+    }
+}

tests/Tests/Pagination/AggregationCursorPaginatorTest.php

@@ -0,0 +1,102 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\ODM\MongoDB\Pagination;
+
+use Doctrine\ODM\MongoDB\Aggregation\Builder;
+use Doctrine\ODM\MongoDB\Pagination\AggregationCursorPaginator;
+use Doctrine\ODM\MongoDB\Tests\BaseTestCase;
+use Documents\Tag;
+
+use function array_fill;
+use function iterator_to_array;
+
+class AggregationCursorPaginatorTest extends BaseTestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->prepareData();
+    }
+
+    protected function tearDown(): void
+    {
+        $this->dm->getDocumentCollection(Tag::class)->drop();
+
+        parent::tearDown();
+    }
+
+    public function testFirstPage(): void
+    {
+        $paginator = new AggregationCursorPaginator($this->createBuilder());
+
+        $results = iterator_to_array($paginator);
+        $this->assertCount(24, $results);
+
+        $this->assertSame('0', $results[0]->name);
+        $this->assertSame('3', $results[2]->name);
+    }
+
+    public function testThirdPage(): void
+    {
+        $last = $this->createBuilder()->skip(47)->limit(24)->getAggregation()->getSingleResult();
+
+        $results = iterator_to_array(new AggregationCursorPaginator($this->createBuilder(), $last->id));
+        $this->assertCount(24, $results);
+
+        $this->assertSame('49', $results[0]->name);
+    }
+
+    public function testPartialPage(): void
+    {
+        $last = $this->createBuilder()->skip(95)->limit(24)->getAggregation()->getSingleResult();
+
+        $paginator = new AggregationCursorPaginator($this->createBuilder(), $last->id);
+
+        $results = iterator_to_array($paginator);
+        $this->assertCount(3, $results);
+
+        $this->assertSame('97', $results[0]->name);
+    }
+
+    public function testDifferentPerPage(): void
+    {
+        $paginator = new AggregationCursorPaginator($this->createBuilder(), perPage: 12);
+
+        $results = iterator_to_array($paginator);
+        $this->assertCount(12, $results);
+    }
+
+    public function testDifferentField(): void
+    {
+        $paginator = new AggregationCursorPaginator($this->createBuilder(), after: '5', field: 'name');
+
+        $results = iterator_to_array($paginator);
+        $this->assertCount(24, $results);
+
+        $this->assertSame('6', $results[0]->name);
+    }
+
+    private function prepareData(): void
+    {
+        foreach (array_fill(0, 100, true) as $key => $t) {
+            $this->dm->persist(new Tag((string) $key));
+        }
+
+        $this->dm->flush();
+    }
+
+    private function createBuilder(): Builder
+    {
+        $builder = $this->dm->createAggregationBuilder(Tag::class);
+        $builder
+            ->hydrate(Tag::class)
+            ->match()
+                ->field('name')->notEqual('2')
+                ->sort('id', 1);
+
+        return $builder;
+    }
+}