DeepCopy
DeepCopy copied to clipboard
myclabs
Make it faster
Last time I looked, I couldn't find any way to really squeeze much more perf. This is mainly due to the fact that DeepCopy deep copy an object. As such, you cannot assume the properties of that object as values can be dynamically added. The result is DeepCopy must rely on a brand new instance of ReflectionObject each time, even if you get two objects of the same class.
A way to change that would maybe to add a mode to clone class instances instead, i.e. to rely on ReflectionClass and cache it somehow.
But to be honest this is just an idea like that. I'm actually not sure if it's really worth it, maybe it would be better to start by having a benchmark and see if the perf gain is worth it.
A graph to give an idea of the performance impact: https://blackfire.io/profiles/b4b98b5d-f850-4853-b549-6ebe326a3451/graph
For ~150K it took ~10s for my data structures (which are not very big).
A way to change that would maybe to add a mode to clone class instances instead, i.e. to rely on ReflectionClass and cache it somehow.
That would mean that dynamically added properties would not be cloned?
That would mean that dynamically added properties would not be cloned?
There is cases, like in PhpUnit where this behaviour would not be desired. However in the case of alice of example, saving from stdClass and very rare cases (which already requires a lot of custom work), this behaviour is not needed.
Two things that could be done:
- Review where we could avoid unnecessary reflection
- Maybe we could experiment with the closure scopes instead of reflection. The result is not guaranteed as with reflection you know how to access to a value. With the closure you do not hence you may have some error handling to do to properly retrieve a value.
- Migrate to php7
- Have a mode where you rely on the reflection class instead of reflection object. Should be configurable as it means dynamic properties for example won't be cloned anymore.
- Maybe check Symfony PropertyAcccessor, IIRC there is some smart things done to retrieve the structure of a PHP object which could give some hints
Last be not least, performances should be monitored. Having a benchmark with a proper scenario would be cool.
@theofidry have a look at https://github.com/mnapoli/ReflectionBenchmark It might be worth running it again with PHP 7 though since performance has changed a lot.
Exactly what I was looking for :) Why not putting it in this project though?
Oh OK, but it already exists there I don't see a reason to duplicate it (and it's a generic benchmark so…). Or maybe you meant to add a benchmark of DeepCopy, in that case 👍
Anyway feel free to work on all that, that package is not my priority at the moment. I don't have admin access to the repository (this is the organisation of a former employer of mine) but I'm getting that sorted out soon, I'll add you as collaborator as soon as I can, that will be much more practical for you.
Or maybe you meant to add a benchmark of DeepCopy, in that case
Yeah that's what I was thinking of.
It would be great if you could retrieve access to it. I have almost no time for OSS lately but I'll need to have a break and make some progress soon. I'll get this [handle of the issues I posted] sorted then.
Without benchmarks any perception is biased, but for sure removing this: https://github.com/myclabs/DeepCopy/pull/107/files#diff-b80ac3509b6e72486b21cddfd9d9332aL58-L77 helped