If a Processor Plugin returns an empty message is the message dropped?

[Degiorgio]

Hello,

If I have Processor plugin, thats returns an empty service.MessageBatch, something like this:

func (p *someplugin) Process(_ context.Context, m *service.Message) (service.MessageBatch, error) {
         ....
	return []*service.Message{}, nil
}

Is it safe to assume that the message is dropped? (i.e. processors downstream of this processor won't be called?)

Another question I have, is the constructor of processor plugin called once or per message?

[mihaitodor]

Hey! 👋

Is it safe to assume that the message is dropped? (i.e. processors downstream of this processor won't be called?)

Yes, any message which passes through that processor will be deleted (just like using a mapping processor with root = deleted()) and an ack will be sent to the input if the input supports acknowledgements (see kafka or nats).

is the constructor of processor plugin called once or per message?

No, it's called once on startup. If you want to perform some initialisation before processing every message, then you have to call that logic inside the Process() method.