Start instance of base class, load configuration and establish database connection. Please don't call the constructor direcly, use the singleton pattern instead.
Returns full path to global file object. Takes global file object name on disk as first argument. Please note that the object doesn't have to exist to get the path to a object.
Moves global file to store. Takes the real name (~ file name on user's disk) as first argument, the path to the uploaded file as second argument. Returns the new name on disk (uniqid + real name).
Tests given global file for uniqueness. Takes the global file name as first argument and the id as second argument as an option.
The second argument is used to compare if the uploaded global file name equals the former global file name that is already on disk. When the global file name is identical, we allow to replace this file.
Returns boolean true if global file name is unique.
Updates global file. Takes the global file id as first argument, a field=>value array with the new global file data as second argument. Returns amount of affected rows.
