The async for natsConnection_RequestString

[portsip]

Feature Request

Currently, I see there have the natsConnection_RequestString with a given timeout in MS, can it has an async version? Likes
natsConnection_RequestString(&reply, nc, "foo", "help", callback, 1000);
Once received the reply in 1000 MS or its timeout, the callback will be triggered.

Use Case:

For some large amounts of the sync call will cause the thread blocked

Proposed Change:

Add a callback parameter to the natsConnection_RequestString.

Who Benefits From The Change(s)?

Alternative Approaches

[derekcollison]

Is this for the server or a specific client language?

[portsip]

Is this for the server or a specific client language?

For the C language client.

Thanks

[derekcollison]

ok will move this over to there.

[kozlovic]

The C client already provides a way to create an async subscription that times out. See natsConnection_SubscribeTimeout. So you could create a subscription on a wildcard subject, and publish your requests using natsConnection_PublishRequestString with a unique token at the end of the reply subject.

Take note of the behavior of the async subscription timeout in the doc. That is, the callback will be invoked with a NULL message if no message is received in the timeout interval specified when creating the subscription. Receiving a message reset this interval, etc..