I'm confused on `trySend` vs `trySendBlocking` in `callbackFlow`. I presume it's about backpressure...

# coroutines

[ursus]

I'm confused on trySend vs trySendBlocking in callbackFlow. I presume it's about backpressure right? If so, to mimic rxjava Observable, I want trySendBlocking right?

[louiscad]

Did you read their respective KDoc? I think it's all explained there.

[elizarov]

If want to drop extra element on backpressue, you do trySend, to block in case of backpressue -> trySendBlocking

[ursus]

If I might ask, does the backpressure sort of happen right away or are there some internal buffers?

From rxjava I faintly remember that yes Observable doesnt support backpressure, i.e. blocks caller, however I do remember there being some 64 sized buffer in it or something like that, so it should not happen that often

[elizarov]

Default is 64, you can configure with buffer(n)

[ursus]

so callbackflow with trySendBlocking behaves exactly as rxjava.. now I need to figure out why IDE warns me about Inapropriate blocking call when using it 😀

[louiscad]

Because it can block, and that might not be what you want.
Using conflate() or properly configured buffer(…) along with trySend(…) is often a better solution (but it depends on use case and requirements).

[ursus]

why does the method exist then

[louiscad]

I guess there are use cases for it that I'm not aware of.