add_early_handler

Adds an "early" handler to this for requests prefixed by path.

Note that "normal" and "early" handlers are matched up together, so if you add a normal handler for "/foo" and an early handler for "/foo/bar", then a request to "/foo/bar" (or any path below it) will run only the early handler. (But if you add both handlers at the same path, then both will get run.)

For requests under path (that have not already been assigned a status code by a [class@AuthDomain] or a signal handler), callback will be invoked after receiving the request headers, but before receiving the request body; the message's method and request-headers properties will be set.

Early handlers are generally used for processing requests with request bodies in a streaming fashion. If you determine that the request will contain a message body, normally you would call [method@MessageBody.set_accumulate] on the message's request-body to turn off request-body accumulation, and connect to the message's [signal@ServerMessage:SoupServer:got-chunk] signal to process each chunk as it comes in.

To complete the message processing after the full message body has been read, you can either also connect to [signal@ServerMessage: SoupServer:got-body], or else you can register a non-early handler for path as well. As long as you have not set the status-code by the time [signal@ServerMessage:SoupServer:got-body] is emitted, the non-early handler will be run as well.

Parameters:

this	a Server
path	the toplevel path for the handler
callback	callback to invoke for requests under path
destroy	destroy notifier to free user_data
user_data	data for callback