Use two indexes instead of one for hashed urls

When using `OR` in a where clause, a composite index can't be used. We should use a `UNION` to take advantages of it.
Instead, create 2 indexes on each hashed urls and make 2 queries to find an url. It'll be faster than the previous solution.

app/DoctrineMigrations/Version20190601125843.php

@@ -30,27 +30,8 @@ class Version20190601125843 extends WallabagMigration
             ]);
         }
 
-        $entryTable->dropIndex('hashed_url_user_id');
-        $entryTable->addIndex(
-            [
-                'user_id',
-                'hashed_url',
-                'hashed_given_url',
-            ],
-            'hashed_urls_user_id',
-            [],
-            [
-                // specify length for index which is required by MySQL on text field
-                'lengths' => [
-                    // user_id
-                    null,
-                    // hashed_url
-                    40,
-                    // hashed_given_url
-                    40,
-                ],
-            ]
-        );
+        // 40 = length of sha1 field hashed_given_url
+        $entryTable->addIndex(['user_id', 'hashed_given_url'], 'hashed_given_url_user_id', [], ['lengths' => [null, 40]]);
     }
 
     /**
@@ -68,7 +49,6 @@ class Version20190601125843 extends WallabagMigration
             $entryTable->dropColumn('hashed_given_url');
         }
 
-        $entryTable->dropIndex('hashed_urls_user_id');
-        $entryTable->addIndex(['user_id', 'hashed_url'], 'hashed_url_user_id', [], ['lengths' => [null, 40]]);
+        $entryTable->dropIndex('hashed_given_url_user_id');
     }
 }

src/Wallabag/CoreBundle/Entity/Entry.php

@@ -27,7 +27,8 @@ use Wallabag\UserBundle\Entity\User;
  *     indexes={
  *         @ORM\Index(name="created_at", columns={"created_at"}),
  *         @ORM\Index(name="uid", columns={"uid"}),
- *         @ORM\Index(name="hashed_urls_user_id", columns={"user_id", "hashed_url", "hashed_given_url"}, options={"lengths"={null, 40, 40}})
+ *         @ORM\Index(name="hashed_url_user_id", columns={"user_id", "hashed_url"}, options={"lengths"={null, 40}}),
+ *         @ORM\Index(name="hashed_given_url_user_id", columns={"user_id", "hashed_given_url"}, options={"lengths"={null, 40}})
  *     }
  * )
  * @ORM\HasLifecycleCallbacks()

src/Wallabag/CoreBundle/Repository/EntryRepository.php

@@ -366,9 +366,20 @@ class EntryRepository extends EntityRepository
      */
     public function findByHashedUrlAndUserId($hashedUrl, $userId)
     {
+        // try first using hashed_url (to use the database index)
         $res = $this->createQueryBuilder('e')
             ->where('e.hashedUrl = :hashed_url')->setParameter('hashed_url', $hashedUrl)
-            ->orWhere('e.hashedGivenUrl = :hashed_given_url')->setParameter('hashed_given_url', $hashedUrl)
+            ->andWhere('e.user = :user_id')->setParameter('user_id', $userId)
+            ->getQuery()
+            ->getResult();
+
+        if (\count($res)) {
+            return current($res);
+        }
+
+        // then try using hashed_given_url (to use the database index)
+        $res = $this->createQueryBuilder('e')
+            ->where('e.hashedGivenUrl = :hashed_given_url')->setParameter('hashed_given_url', $hashedUrl)
             ->andWhere('e.user = :user_id')->setParameter('user_id', $userId)
             ->getQuery()
             ->getResult();

tests/Wallabag/CoreBundle/Controller/EntryControllerTest.php

@@ -265,6 +265,9 @@ class EntryControllerTest extends WallabagCoreTestCase
         $this->assertContains('/view/', $client->getResponse()->getTargetUrl());
     }
 
+    /**
+     * This test will require an internet connection.
+     */
     public function testPostNewOkUrlExistWithRedirection()
     {
         $this->logInAs('admin');