Prevent file uploading before condition.

[afwn90cj93201nixr2e1re]

How we can make it? For example: Backend some lang, which can create some redis keys: client requests is file upload available -> server under nginx check it and create redis key for example: uid_hash_timestamp 30s -> send url to client -> client starts file uploading by given url -> nginx check utl second part, for example (location upload/url_key_in_redis) -> if url exists go to file uploading module -> ok

If another client starts uploading to same url(which is not his) or url is not represent in redis we should immediately block request without any parsing (no nginx processing, no upload processing).