960a437d46
As previously reported by @flaushi in https://github.com/doctrine/doctrine2/pull/7471#discussion_r241949045, we discovered that binding a parameter causes a `ClassMetadataFactory#getClassMetadata()` call, which in turn leads to large performance regression when using any `object` type as parameter. Following two snippets lead to an internal `ClassMetadataFactory#getClassMetadata()` call, which in turn leads to an exception being thrown and garbage collected, plus multiple associated performance implications: ```php $query->setParameter('foo', new DateTime()); $query->getResult(); ``` ```php $query->setParameter('foo', new DateTime(), DateTimeType::NAME); $query->getResult(); ``` This is due to following portion of code:434820973c/lib/Doctrine/ORM/Query.php (L406-L409)
Notice how `$value = $this->processParameterValue($value);` happens before attempting to infer the type for the parameter value. That call leads to this segment being reached, which leads to the regression:434820973c/lib/Doctrine/ORM/AbstractQuery.php (L423-L433)
Assuming the bound parameter type is provided, we can completely skip attempting to introspect the given object: ```php $query->setParameter('foo', new DateTime(), DateTimeType::NAME); $query->getResult(); ``` Processing the parameter value is not needed in this case, so we can safely skip that logic for all known parameters. In order to not introduce a BC break or change the `AbstractQuery#processParameterValue()` implementation, we could filter out all parameters for which the type is given upfront, and later on merge them back in instead. The test expectation to be set is for `UnitOfWork#getSingleIdentifierValue()` to never be called.