Make inbox optional

[lubien]

Hi there!

I've been using a fork of your library on Fly.io for logs for a while but I had to make a few changes.

My proposal here would be to make inbox optional defaulting to true (the current behavior). I've already had this implemented here: 162cd94

If it's something you'd like I could make a pull request and add tests if needed

[mmmries]

Hi @lubien I'm glad that the library has been useful! Can you provide a bit more context about why skipping the inbox is useful for the work you're doing? My thought was that creating an inbox is relatively cheap (you could have hundred or thousands of clients each with their own inbox without any noticeable load) and it will only be used if the client decides to do a request/reply.

Are you seeing performance problems with having the client create an inbox even if you don't intend to use it?

[lubien]

Rather than performance, our use case doesn't really needs it and doesn't support those. We just use NATs for one way messages passing the logs so for us having this inbox broke the usage of this lib so we ended up forking and making this optional.

[mmmries]

Hey @lubien I'm doing some summer cleanup on the repo and saw that we never came to an understanding on this suggestion. I'm open to supporting this, but I'm still not clear on why the automatic creation of an inbox can cause problems for your use-case. The only thing it's really doing is generating a random/unique string and then subscribing to subject matching that unique string. Are you connecting with credentials that don't allow subscribing?

If we want to allow this flag to be set, we will need to also prevent users from calling Gnat.request since requests use the inbox subscription to create a reply subject and get the response back. It's definitely doable, but I just don't understand the use case for it.