rd_kafka_message_t Struct Reference

A Kafka message as returned by the rd_kafka_consume*() family of functions as well as provided to the Producer dr_msg_cb(). More...

#include <rdkafka.h>

Data Fields
rd_kafka_resp_err_t	err
rd_kafka_topic_t *	rkt
int32_t	partition
void *	payload
size_t	len
void *	key
size_t	key_len
int64_t	offset
void *	_private

Detailed Description

A Kafka message as returned by the rd_kafka_consume*() family of functions as well as provided to the Producer dr_msg_cb().

For the consumer this object has two purposes:

• provide the application with a consumed message. (err == 0)
• report per-topic+partition consumer errors (err != 0)

The application must check err to decide what action to take.

When the application is finished with a message it must call rd_kafka_message_destroy() unless otherwise noted.

Field Documentation

err

rd_kafka_resp_err_t rd_kafka_message_t::err

Non-zero for error signaling.

rkt

rd_kafka_topic_t* rd_kafka_message_t::rkt

Topic

partition

int32_t rd_kafka_message_t::partition

Partition

payload

void* rd_kafka_message_t::payload

Producer: original message payload. Consumer: Depends on the value of err :

• err==0: Message payload.
• err!=0: Error string

len

size_t rd_kafka_message_t::len

Depends on the value of err :

• err==0: Message payload length
• err!=0: Error string length

key

void* rd_kafka_message_t::key

Depends on the value of err :

• err==0: Optional message key

key_len

size_t rd_kafka_message_t::key_len

Depends on the value of err :

• err==0: Optional message key length

offset

int64_t rd_kafka_message_t::offset

Consumer:

• Message offset (or offset for error if err!=0 if applicable). Producer, dr_msg_cb: Message offset assigned by broker. May be RD_KAFKA_OFFSET_INVALID for retried messages when idempotence is enabled.

_private

void* rd_kafka_message_t::_private

Consumer:

• rdkafka private pointer: DO NOT MODIFY, DO NOT COPY. Producer:
• dr_msg_cb: msg_opaque from produce() call or RD_KAFKA_V_OPAQUE from producev().

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

• src/rdkafka.h