Performance: only load files once

[kkmuffme]

FileProvider.php function getContents

When logging the $file_path directly before:

return (string)file_get_contents($file_path);

I can see the same files getting opened multiple times between 2-100s of times. 90% of file_get_contents calls here are duplicates, which means psalm could be 4% faster if that didn't happen.

We check if the file was opened before, but this is useless, since it's always empty:

if (isset($this->open_files[$file_path_lc])) {
            return $this->open_files[$file_path_lc];
}

Changing $open_files to a static and using self::$open_files should fix this.
I tried this - however weirdly enough, $open_files still is always empty.

Any idea why this is happening though? (I can provide a PR with the static, however it has the same issue)

[psalm-github-bot]

Hey @kkmuffme, can you reproduce the issue on https://psalm.dev ?

[kkmuffme]

No, this is an psalm internal issue.