Drupal\Core\Config\FileStorage::getAllCollectionNamesHelper should use some caching

This is a very dirty patch to see how tests will react on it.

This is TOP 10 calls during installation after fix applied.

You can see that both, Drupal\Core\Config\FileStorage->getAllCollectionNamesHelper() and php::SplFileInfo->isDir() disappears from the list.

• Drupal\Core\Config\FileStorage->getAllCollectionNamesHelper() calls went from 36'392 → 4'551
• php::SplFileInfo->isDir() calls went from 13'937'541 → 23'710

I measured installation time by time drush site:install --existing-config and results are:

• Before: real 8m 38.06s
• After: real 7m 9.09s

It's roughly ~15% increase in site installation speed.

The last submitted patch, 2: drupal-3389567-2.patch, failed testing. View results →

It looks like some code will break. Can we decorate that service specifically for installation process? Because I don't think this caching is actually needed for regular runtime process, but it's a very significant improvement for installation. I don't see any cases where configurations are changed on disc during installation, hence, this caching should not do any harm.

Is it happening during installation only?

This profiling results for drush site:install --existing-config with a specific website configuration. It is not an issue on default profiles (because they are simple and small) or a smaller website (which have fewer configs). But a multilingual website, with something like 10 languages, a lot of content types, fields, etc., configs grows in size very fast, and this is where the issue starts. The profiler is clearly shows, that the more configurations you have, the more calls for Drupal\Core\Config\FileStorage->getAllCollectionNamesHelper() which is bottlenecked by a php::SplFileInfo->isDir() - the unique calls of which is hundreds times fewer than the actual one. In my example, it means for one unique file, it calls this check 587 times.

This issue reproduced everywhere, on different developers PCs and CI's.

I feel we need to fund out why we're call getAllCollectionNames() and work from there.

static cache is workaround, as file cache should be applied in other place

bottlenecked by a php::SplFileInfo->isDir() - the unique calls of which is hundreds times fewer than the actual one. In my example, it means for one unique file, it calls this check 587 times.

it means filecache miss