misc: Replace sha1() by hash('sha1', ...) - #544

Hi @TimWolla thank you!

For a future change it might also be considered to move to a cheaper hash function.

Could we not use it already? What particular function(s) would work here?

Could we not use it already?

We probably can. For this PR I just proposed the minimally viable change, because I did not have the time to thoroughly investigate what replacement would be appropriate.

What particular function(s) would work here?

As suggested in the commit message, the xxHash family might be appropriate. An alternative might be using preg_replace() to replace any special characters by an "escape sequence". Something like the following:

preg_replace_callback('/[^a-zA-Z0-9]/', static function ($matches) {
  return sprintf('_%02x', ord($matches[0]));
}, $key);

This would be guaranteed to be collision resistant, because it's a bijection. It would also make the cache identifiers human-readable.

For future reference: symfony/symfony#47094

Hello @TimWolla, thanks for the original work and explanations.

After reading a bit about this topic (check this php.watch article for instance), I've decided to use the xxh128 hash, as Valinor requires PHP 8.1+.

I also moved the hash logic into one place only.

I'll wait for your approbation before merging.

NB: squash commit message to be used:

misc: use `xxh128` hash algorithm for cache keys

This algorithm is way faster than the originally used `sha1`.

This commit also moves the hash logic into one place, saving even more
processing time. 

Reference: https://php.watch/versions/8.1/xxHash

I'll wait for your approbation before merging.

Changes look good to me. You are the Valinor expert anyway 😄 The primary goal of this PR was not to be merged directly, but to start a discussion for you to make a good decision.

I wouldn't be an expert without the community around this tool, composed by many excellent PHP developers. 😉

Thanks again!