pubsub: batch processing instead of 1 goroutine per message

[kokizzu]

Is your feature request related to a problem? Please describe.

currently I'm trying to do batch fetch from pubsub, transform, then insert to bigquery. but the pubsub library spawns a goroutine for each message, this causes bunch of memory consumption and inefficient processing

func (s *Subscription) Receive(ctx context.Context, f func(context.Context, *Message)) error {

Describe the solution you'd like

I need batch processing something like this

func (s *Subscription) ReceiveN(ctx context.Context, n items, f func(context.Context, []*Message)) error {

Describe alternatives you've considered

taking out the pubsub library and write own proper batch processing

Additional context

by doing this, it would be super efficient to do batch processing

[hongalex]

Thanks for filing an issue.

This is a duplicate of https://issuetracker.google.com/288595422, please +1 that issue if this is affecting you.