misc: Replace sha1() by hash('sha1', ...)

[TimWolla]

The dedicated sha1() function is proposed for deprecation with PHP 8.4: https://wiki.php.net/rfc/deprecations_php_8_4#deprecate_md5_sha1_md5_file_and_sha1_file

For a future change it might also be considered to move to a cheaper hash function. The xxHash family (available as xxh*) is faster and should be sufficiently collision resistant for use within the cache.

[romm]

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?

[TimWolla]

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.

[romm]

For future reference: symfony/symfony#47094