Add username to on_init

[burgalon]

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Summary

See #30
Currently the shim.authenticate does not pass a &mut self and so it is not possible to save the username for later use - i.e: initialization of upstream

Also the on_init does not pass username or the entire handshake but rather just the db.
Can we add the username to the on_init ?

[TCeason]

Yes, we can add a username on init.

But now we need database_name because of we will init_db in there.

The user name in shim.authenticate acctually will store in there.

So I think If use it as a base library, that's might be better off doing these things in own program.

BTW: what initialization of upstream this means? Is it convenient to explain a little bit?

[burgalon]

let's suppose we're doing a pass-through proxy for mysql, and we need to initialize an upstream mysql client with the same user that we were called with - in this case we need to initialize the self.upstream_client = Mysql(...) with the same username that we were connected to with.

[burgalon]

indeed it seems like the missing db is an issue

[sundy-li]

Currently the shim.authenticate does not pass a &mut self and so it is not possible to save the username for later use - i.e: initialization of upstream

I don't think so. You can use interior-mutability to modify self.

[sundy-li]

Also the on_init does not pass username or the entire handshake but rather just the db

on_init will be called only if the auth handshake is finished as ok. I think the user can be saved in your own struct rather than exporting this as an extra arg.

[sundy-li]

Closing seems it's not needed. Feel free to open it if it's not solved, thanks!