Adding a produce() flag to free msg_opaque (like RD_KAFKA_MSG_F_FREE)

[arnaud-lb]

Description

In bindings for memory managed languages, freeing a msg_opaque is tricky.

Adding a flag to rd_kafka_produce() that allows librdkafka to free the msg_opaque, as RD_KAFKA_MSG_F_FREE does for the payload, would be very helpful.

The flag could be named RD_KAFKA_MSG_OPAQUE_F_FREE, and passing it to rd_kafka_produce() and variants would cause rd_kafka_msg_destroy() to free ->rkm_opaque.

Would you accept a PR with this change?

Checklist

• librdkafka version: e116a873bbe395b78d3b40171afa9c68dc93da78
• Feature request

[edenhill]

Why can't you free it in the delivery report callback?

[arnaud-lb]

We could, but will it be called in all cases, including when the rd_kafka_t is destroyed while a message is still queued ?

[arnaud-lb]

Actually I could handle this by keeping track of inflight msg_opaques and free them after rd_kafka_destroy()

[edenhill]

You can call purge() to force delivery callbacks for queued messages. Den mån 28 dec. 2020 17:42Arnaud Le Blanc <notifications@github.com> skrev:

…

We could, but will it be called in all cases, including when the rd_kafka_t is destroyed while a message is still queued ? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#3192 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAEAFPSZM3BKFDOZTDQMWGTSXCYQTANCNFSM4VMBW3GA> .

[arnaud-lb]

Oh, this is perfect! Thanks :)