Add timeline logging to grpc client

[bkonyi]

isTimelineLoggingEnabled is used to turn on/off the logging. Note that only RPCs sent after enabling the logging will be recorded.

Continuation of https://github.com/grpc/grpc-dart/pull/336/files

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ zichangg (f960ab2, 80a6c71, 3fa57f6)
• ✅ Ben Konyi (71142cf)

[kenzieschmoll]

Are responses added as metadata (instant events)? not as separate child timeline tasks like for HTTP events?

[bkonyi]

Are responses added as metadata (instant events)? not as separate child timeline tasks like for HTTP events?

Yes, that appears to be the case. I'm guessing we'd want child events for the responses?

[kenzieschmoll]

Are responses added as metadata (instant events)? not as separate child timeline tasks like for HTTP events?

Yes, that appears to be the case. I'm guessing we'd want child events for the responses?

IIRC, the http responses were added as separate TimelineTask events because it was possible that the response would come back after the request has completed. Is this possible for gRPC events? If so, we may want to use a similar implementation. But if not, then leaving the response as an instant event would also work.

[bkonyi]

Are responses added as metadata (instant events)? not as separate child timeline tasks like for HTTP events?

Yes, that appears to be the case. I'm guessing we'd want child events for the responses?

IIRC, the http responses were added as separate TimelineTask events because it was possible that the response would come back after the request has completed. Is this possible for gRPC events? If so, we may want to use a similar implementation. But if not, then leaving the response as an instant event would also work.

Yeah, I think it makes sense to be consistent, otherwise we'll be coming back to make that change later. I've updated to create a separate timeline task for the response with the request event as its parent.

[mraleph]

LGTM with two comments.

[bkonyi]

@mraleph addressed comments. Do you have write access to this repo? I'm unable to merge myself.

[mraleph]

@bkonyi thanks I will merge on green once checks cycle. I will publish a version to pub early next week.

[bkonyi]

Thanks Slava!