Actually - another filesystem question now that I think about it, if anyone is willing: If two users visit the site and end up overwriting the same cache file at the same time, isn't there a possibility the both of them writing to the file at the same time could corrupt the data? Is it wise to use flock() or LOCK_EX in the file_put_contents call? Again, I'm not an expert when it comes to filesystems, so I apologize if this is a stupid question.