minor symfony#12825 [Serializer] add caution for normalize Datetime object with GetSetMethodNormalizer (spike31)

wouterj · wouterj · commit 5016771e2c7d · 2020-10-22T13:37:58.000+02:00
This PR was merged into the 3.4 branch. Discussion ---------- [Serializer] add caution for normalize Datetime object with GetSetMethodNormalizer I noticed an issue with the GetSetMethodNormalizer, not a real issue, but just a warning about its use. If we normalize an object which returns a Datetime, without defining the DatetimeNormalizer; on many objects at the same time, we explode the memory of PHP and time of use. Example : ```php $serializer = new Serializer([new GetSetMethodNormalizer()]); $objects = []; for ($i = 0, $n = 100;$i<$n; $i++) { $objects[] = new MyObject(new \DateTime('now')); } $serializer->normalize($objects); dd('memory_get_peak_usage', (memory_get_peak_usage(true) / 1024 / 1024) . ' MiB'); ``` "memory_get_peak_usage" "46 MiB" ```php $serializer = new Serializer([new DateTimeNormalizer(), new GetSetMethodNormalizer()]); $objects = []; for ($i = 0, $n = 100;$i<$n; $i++) { $objects[] = new MyObject(new \DateTime('now')); } $serializer->normalize($objects); dd('memory_get_peak_usage', (memory_get_peak_usage(true) / 1024 / 1024) . ' MiB'); ``` "memory_get_peak_usage" "14 MiB" ------ For i = 1000 => 334 Mib 🌊 Commits ------- 369ea13 add caution for datetime object
diff --git a/serializer.rst b/serializer.rst
@@ -116,6 +116,12 @@ Custom normalizers and/or encoders can also be loaded by tagging them as
 :ref:`serializer.encoder <reference-dic-tags-serializer-encoder>`. It's also
 possible to set the priority of the tag in order to decide the matching order.
 
+.. caution::
+
+    Always make sure to load the ``DateTimeNormalizer`` when serializing the
+    ``DateTime`` or ``DateTimeImmutable`` classes to avoid excessive memory
+    usage and exposing internal details.
+
 Here is an example on how to load the
 :class:`Symfony\\Component\\Serializer\\Normalizer\\GetSetMethodNormalizer`, a
 faster alternative to the `ObjectNormalizer` when data objects always use
