purge

public function purge(int $purgeFlags): int {}

Purges messages handled by the producer.
The application will need to call poll() or flush() afterwards
to serve the delivery report callbacks of the purged messages.
Messages purged from internal queues fail with the delivery report error code
set to RD_KAFKA_RESP_ERR__PURGE_QUEUE, while purged messages that are in-flight
to or from the broker will fail with the error code set to RD_KAFKA_RESP_ERR__PURGE_INFLIGHT.

• RD_KAFKA_PURGE_F_QUEUE purge internal queue
• RD_KAFKA_PURGE_F_INFLIGHT purge messages in-flight to or from the broker
• RD_KAFKA_PURGE_F_NON_BLOCKING make the call non-blocking

$conf = SimpleKafkaClient\Configuration();
$conf->set('metadata.broker.list', 'kafka:9092');
$producer = new SimpleKafkaClient\Producer($conf);
// produce some messsages
$producer->purge(RD_KAFKA_PURGE_F_QUEUE);