Add a new API Wallet::new_with_online().

[monaka]

I'm developing RESTful http interface for RGB-Lib.
This PR is for my app.

As you might know, web frameworks tends to be stateless.
So I want to keep my Wallet instance over sessions.
But as far as I trided, the instance of Wallet structure couldn't store in reference count traits like Rc<> or Arc<>.

I also tried instancing Wallet per session.
Results were "panicked" because of thread generation in _go_online().

This PR enables to inject Online object when a Wallet instance is created.
This approach is kept a backward compatibility. All tests are passed.

Signed-off-by: Masaki Muranaka [email protected]

[monaka]

I found lint errors by clippy. But they are not caused by my patches.

[monaka]

After tracking #17, I realized another approach is required to fix my pain point.
I close this PR as "won't fix".

[zoedberg]

Hi @monaka,

I believe this API will not solve your issues.

First, it cannot work as it has been implemented. The Online object is not an object meant to be manually constructed or shared across different wallets. Its purpose is to prevent lib users to call APIs that require the wallet to have called go_online first.

Second, the issue you're facing in shiro-backend, as I tried to explain here, comes from a very clear limitation: it is not possible to create more than a wallet instance on the same data directory (in the same process in your case, but also using different processes you will end up with other painful bugs).

So to fix the issues you’re facing you need to store the wallet instance and reuse it. I know this can be frustrating, but we cannot do much until RGB-WG/rgb-node#222 gets addressed.

[monaka]

@zoedberg Thank you for you suggestion.
I got the reason why this PR is useless before closing this.
Your comment makes me more clear.

And in fact, I tried to share an instance of struct Wallet before.
It was failed by another error message.
I'm going to create a tiny crate that reproduces errors.
I'll share it within tomorrow.