From 091ea974eb483abddedb3aa87475c751766e6fa8 Mon Sep 17 00:00:00 2001
From: Alejandro Celaya <alejandro@alejandrocelaya.com>
Date: Sat, 23 Feb 2019 07:29:07 +0100
Subject: [PATCH] Simplified implementation iterating unlocated visits

---
 .../Adapter/PaginableQueryAdapter.php         | 34 ----------
 .../src/Paginator/ImplicitLoopPaginator.php   | 38 -----------
 .../Paginator/ImplicitLoopPaginatorTest.php   | 65 -------------------
 .../Core/src/Repository/VisitRepository.php   | 23 ++++---
 4 files changed, 13 insertions(+), 147 deletions(-)
 delete mode 100644 module/Common/src/Paginator/Adapter/PaginableQueryAdapter.php
 delete mode 100644 module/Common/src/Paginator/ImplicitLoopPaginator.php
 delete mode 100644 module/Common/test/Paginator/ImplicitLoopPaginatorTest.php

diff --git a/module/Common/src/Paginator/Adapter/PaginableQueryAdapter.php b/module/Common/src/Paginator/Adapter/PaginableQueryAdapter.php
deleted file mode 100644
index d6de1ada..00000000
--- a/module/Common/src/Paginator/Adapter/PaginableQueryAdapter.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace Shlinkio\Shlink\Common\Paginator\Adapter;
-
-use Doctrine\ORM\Query;
-use Zend\Paginator\Adapter\AdapterInterface;
-
-class PaginableQueryAdapter implements AdapterInterface
-{
-    /** @var Query */
-    private $query;
-    /** @var int */
-    private $totalItems;
-
-    public function __construct(Query $query, int $totalItems)
-    {
-        $this->query = $query;
-        $this->totalItems = $totalItems;
-    }
-
-    public function getItems($offset, $itemCountPerPage): iterable
-    {
-        return $this->query
-            ->setMaxResults($itemCountPerPage)
-            ->setFirstResult($offset)
-            ->iterate();
-    }
-
-    public function count(): int
-    {
-        return $this->totalItems;
-    }
-}
diff --git a/module/Common/src/Paginator/ImplicitLoopPaginator.php b/module/Common/src/Paginator/ImplicitLoopPaginator.php
deleted file mode 100644
index 9019f248..00000000
--- a/module/Common/src/Paginator/ImplicitLoopPaginator.php
+++ /dev/null
@@ -1,38 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace Shlinkio\Shlink\Common\Paginator;
-
-use IteratorAggregate;
-use Zend\Paginator\Paginator;
-
-class ImplicitLoopPaginator implements IteratorAggregate
-{
-    /** @var Paginator */
-    private $paginator;
-    /** @var callable */
-    private $valueParser;
-
-    public function __construct(Paginator $paginator, callable $valueParser = null)
-    {
-        $this->paginator = $paginator;
-        $this->valueParser = $valueParser ?? function ($value) {
-            return $value;
-        };
-    }
-
-    public function getIterator(): iterable
-    {
-        $totalPages = $this->paginator->count();
-        $processedPages = 0;
-
-        do {
-            $processedPages++;
-            $this->paginator->setCurrentPageNumber($processedPages);
-
-            foreach ($this->paginator as $key => $value) {
-                yield $key => ($this->valueParser)($value);
-            }
-        } while ($processedPages < $totalPages);
-    }
-}
diff --git a/module/Common/test/Paginator/ImplicitLoopPaginatorTest.php b/module/Common/test/Paginator/ImplicitLoopPaginatorTest.php
deleted file mode 100644
index 0e494afb..00000000
--- a/module/Common/test/Paginator/ImplicitLoopPaginatorTest.php
+++ /dev/null
@@ -1,65 +0,0 @@
-<?php
-declare(strict_types=1);
-
-namespace ShlinkioTest\Shlink\Common\Paginator;
-
-use PHPUnit\Framework\TestCase;
-use Shlinkio\Shlink\Common\Paginator\ImplicitLoopPaginator;
-use Zend\Paginator\Adapter\ArrayAdapter;
-use Zend\Paginator\Paginator;
-use function Functional\map;
-use function range;
-
-class ImplicitLoopPaginatorTest extends TestCase
-{
-    private const TOTAL_ITEMS = 10;
-
-    /** @var Paginator */
-    private $paginator;
-
-    protected function setUp(): void
-    {
-        $this->paginator = new Paginator(new ArrayAdapter(range(1, self::TOTAL_ITEMS)));
-    }
-
-    /**
-     * @test
-     * @dataProvider provideItemsPerPage
-     */
-    public function allElementsAreIteratedRegardlessThePageSize(int $itemsPerPage): void
-    {
-        $this->paginator->setItemCountPerPage($itemsPerPage);
-        $implicitLoopPaginator = new ImplicitLoopPaginator($this->paginator);
-
-        $iteratedItems = 0;
-        foreach ($implicitLoopPaginator as $item) {
-            $iteratedItems++;
-        }
-
-        $this->assertEquals(self::TOTAL_ITEMS, $iteratedItems);
-    }
-
-    public function provideItemsPerPage(): iterable
-    {
-        return map(range(1, 20), function (int $i) {
-            return [$i];
-        });
-    }
-
-    /** @test */
-    public function valuesWrappedInPaginatorAreProperlyParsed(): void
-    {
-        $valueParser = function (int $item) {
-            return $item * 3;
-        };
-        $this->paginator->setItemCountPerPage(5);
-        $implicitLoopPaginator = new ImplicitLoopPaginator($this->paginator, $valueParser);
-
-        $items = [];
-        foreach ($implicitLoopPaginator as $item) {
-            $items[] = $item;
-        }
-
-        $this->assertEquals([3, 6, 9, 12, 15, 18, 21, 24, 27, 30], $items);
-    }
-}
diff --git a/module/Core/src/Repository/VisitRepository.php b/module/Core/src/Repository/VisitRepository.php
index dfa5498f..9c65877c 100644
--- a/module/Core/src/Repository/VisitRepository.php
+++ b/module/Core/src/Repository/VisitRepository.php
@@ -5,12 +5,8 @@ namespace Shlinkio\Shlink\Core\Repository;
 
 use Doctrine\ORM\EntityRepository;
 use Doctrine\ORM\QueryBuilder;
-use Shlinkio\Shlink\Common\Paginator\Adapter\PaginableQueryAdapter;
-use Shlinkio\Shlink\Common\Paginator\ImplicitLoopPaginator;
 use Shlinkio\Shlink\Common\Util\DateRange;
 use Shlinkio\Shlink\Core\Entity\Visit;
-use Zend\Paginator\Paginator;
-use function array_shift;
 
 class VisitRepository extends EntityRepository implements VisitRepositoryInterface
 {
@@ -19,18 +15,25 @@ class VisitRepository extends EntityRepository implements VisitRepositoryInterfa
      */
     public function findUnlocatedVisits(int $blockSize = self::DEFAULT_BLOCK_SIZE): iterable
     {
-        $count = $this->count(['visitLocation' => null]);
         $dql = <<<DQL
 SELECT v FROM Shlinkio\Shlink\Core\Entity\Visit AS v WHERE v.visitLocation IS NULL
 DQL;
         $query = $this->getEntityManager()->createQuery($dql);
+        $remainingVisitsToProcess = $this->count(['visitLocation' => null]);
+        $offset = 0;
 
-        $paginator = new Paginator(new PaginableQueryAdapter($query, $count));
-        $paginator->setItemCountPerPage($blockSize);
+        while ($remainingVisitsToProcess > 0) {
+            $iterator = $query->setMaxResults($blockSize)
+                              ->setFirstResult($offset)
+                              ->iterate();
 
-        return new ImplicitLoopPaginator($paginator, function (array $value) {
-            return array_shift($value);
-        });
+            foreach ($iterator as $key => [$value]) {
+                yield $key => $value;
+            }
+
+            $remainingVisitsToProcess -= $blockSize;
+            $offset += $blockSize;
+        }
     }
 
     /**