How does mediawiki upload files to server

Question

I just found out that mediawiki does not use move_uploaded_file^Docs. So how does mediawiki upload file to the database?

Answer 1

There is an incredibly complex system of filesystem classes in the includes/upload and includes/filerepo folders. The relevant line, so far as I can tell, is line 216 of includes/filerepo/FSRepo.php:

if ( !rename( $srcPath, $dstPath ) ) {

If you really want to work out how the system works, I suggest you start with includes/upload/UploadFromFile.php and work your way through the network of objects. If you want your sanity, I suggest you don't.