PIP 124: Add method to help user judge if consumer queue has message

[hezhangjian]

Motivation

Currently, I have an application that manages ten thousand of consumers, and a logic to schedule consumers's receive. It would be helpful to know if one of the consumers have message to recive.

Goal

To make Consumer can judge if there are unreceiving messages

API Changes

Add hasMessageInReceiverQueue on the Consumer interface.

Implementation

For ZeroQueueConsumerImpl return false, Others, judge the receiveQueueSize greater than zero.

Reject Alternatives

No alternatives yet.

[github-actions]

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