Queue interface. More...

#include <rdkafkacpp.h>

Public Member Functions
virtual ErrorCode	forward (Queue *dst)=0
	Forward/re-route queue to `dst`. If `dst` is `NULL`, the forwarding is removed. More...

virtual Message *	consume (int timeout_ms)=0
	Consume message or get error event from the queue. More...

virtual int	poll (int timeout_ms)=0
	Poll queue, serving any enqueued callbacks. More...

virtual void	io_event_enable (int fd, const void *payload, size_t size)=0
	Enable IO event triggering for queue. More...

Static Public Member Functions
static Queue *	create (Handle *handle)
	Create Queue object.

Detailed Description

Queue interface.

Create a new message queue. Message queues allows the application to re-route consumed messages from multiple topic+partitions into one single queue point. This queue point, containing messages from a number of topic+partitions, may then be served by a single consume() method, rather than one per topic+partition combination.

See the RdKafka::Consumer::start(), RdKafka::Consumer::consume(), and RdKafka::Consumer::consume_callback() methods that take a queue as the first parameter for more information.

Member Function Documentation

virtual ErrorCode RdKafka::Queue::forward ( Queue * dst )

pure virtual

Forward/re-route queue to dst. If dst is NULL, the forwarding is removed.

The internal refcounts for both queues are increased.

Remarks: Regardless of whether dst is NULL or not, after calling this function, src will not forward it's fetch queue to the consumer queue.

virtual Message* RdKafka::Queue::consume ( int timeout_ms )

pure virtual

Consume message or get error event from the queue.

Remarks: Use delete to free the message.

Returns

One of:

proper message (RdKafka::Message::err() is ERR_NO_ERROR)
error event (RdKafka::Message::err() is != ERR_NO_ERROR)
timeout due to no message or event in timeout_ms (RdKafka::Message::err() is ERR__TIMED_OUT)

virtual int RdKafka::Queue::poll ( int timeout_ms )

pure virtual

Poll queue, serving any enqueued callbacks.

Remarks: Must NOT be used for queues containing messages.

Returns: the number of events served or 0 on timeout.

virtual void RdKafka::Queue::io_event_enable	(	int	fd,
		const void *	payload,
		size_t	size
	)

pure virtual

Enable IO event triggering for queue.

To ease integration with IO based polling loops this API allows an application to create a separate file-descriptor that librdkafka will write payload (of size size) to whenever a new element is enqueued on a previously empty queue.

To remove event triggering call with fd = -1.

librdkafka will maintain a copy of the payload.

Remarks: When using forwarded queues the IO event must only be enabled on the final forwarded-to (destination) queue.

The documentation for this class was generated from the following file:

src-cpp/rdkafkacpp.h

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation