Performance penalty when comparing $page object instead of $page->id

[slkwrm]

Hey guys. Does

<?php $p === $page

have bigger overhead then

<?php p->id === $page->id

Is there any difference in performance?

[apeisa]

Hey guys. Does

<?php $p === $page

have bigger overhead then

<?php p->id === $page->id

Is there any difference in performance?

I don't think so (if you remember to use === instead of ==). But not sure about this, Ryan probably knows more. Here is some information, but not much about performance: http://php.net/manual/en/language.oop5.object-comparison.php

[ryan]

Regarding whether to use "===" or "==": if you are comparing Page object to object, you would want to use the "===" rather than "==". That tells PHP to check that they are in fact the same instance (i.e. occupying the same block of memory). There may be a slight performance benefit to using "===" to compare object-to-object rather than comparing ID because $page->id triggers some action in the class, where as "===" is likely handled all in PHP's core code (in C).

Regardless, I prefer to compare the ID. It doesn't matter if you use "===" or "==" when comparing the ID. There is also a side benefit in comparing the ID because there is a possibility that you could have two instances of the same page in memory. PW tries to prevent this from happening by keeping a memory cache of everything that gets loaded. But if you have a $page in your code's scope and not in PW's scope (due to some action that clears PW's memory cache), and the page gets loaded again from a $pages->find (for example), then it's feasible you could have two instances of the same page... yours and PW's. In such a case, comparing $p === $page would return false, whereas $p->id == $page->id would return true. For this reason, I think it may be better to compare the ID.

Actions that clear the cache are: saving or deleting pages. If your block of code doesn't do any page saving or deleting (or manual cache clearing)… or calling anything that does, then comparing object-to-object with "===" is a fine way to go. But if you don't want to have to think about such things, then maybe better to just compare the IDs.

[slkwrm]

Apeisa, Ryan, thank you. Now this topic is clear for me. Btw, wanted to express my appriciation to Ryan for such a clear code with comprehensive comments. PW source code is a really good read

[ryan]

Slkwrm, thanks – you are too kind. The commenting is good alright some spots, but needs a lot of work in others.