close wallet connections methods

[abergasov]

For cases when connection to dirk go through short-living certifications, current implementation not allow re-load changed certificates because of in-memory pool of grpc connections. Even if certificate was re-loaded and wallet re-created, all connections trigger error because of cached connections

to avoid this added modification - move connection map from global to package to build in to struct PuddleConnectionProvider

to prevent of leak memory for unused old connections was added function CloseConnections

[mcdee]

I'm not convinced about have a per-wallet connection pool. We have people using this library with hundreds of wallets, and this would likely lead to resource exhaustion on either server or client. Could this be looked at whilst retaining the global connection pool?

I'd also change CloseConnections to just Close, as a more general "we're finished with this" call?

[abergasov]

Sure, I made a slight modification. Now, we can pass an optional parameter via the WithConnectionProviderName method, which will create a dedicated pool of connections for a specific wallet. This change keep backward compatibility for users with hundreds of wallets and does not impact their performance.

Otherwise, it will enable dedicated connections pool for wallets with specific certificate. So, the usage will be like:

Open(
    context.Background(),
    WithName("Test wallet"),
    WithCredentials(credentials.NewTLS(nil)),
    WithEndpoints([]*Endpoint{{host: "localhost", port: 12345}}),
    WithConnectionProviderName(uuid.NewString()), 
)

I'd also change CloseConnections to just Close, as a more general "we're finished with this" call?

Done, now wallet have just Close() method

[mcdee]

Apologies, I lost track of this PR. Please could you rebase it and address the last outstanding item here, and I'll merge it? Thanks.

[mcdee]

name is mandatory but connectionname is not. So I think that this should use connectionName if present, otherwise it should fall back to using name.