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

rd_kafka_resp_err_t rd_kafka_message_t::err

Non-zero for error signaling.

rd_kafka_topic_t* rd_kafka_message_t::rkt

Topic

int32_t rd_kafka_message_t::partition

Partition

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

size_t rd_kafka_message_t::len

Depends on the value of err :

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

void* rd_kafka_message_t::key

Depends on the value of err :

• err==0: Optional message key

size_t rd_kafka_message_t::key_len

Depends on the value of err :

• err==0: Optional message key length

int64_t rd_kafka_message_t::offset

Consume:

• Message offset (or offset for error if err!=0 if applicable).
• dr_msg_cb: Message offset assigned by broker. If produce.offset.report is set then each message will have this field set, otherwise only the last message in each produced internal batch will have this field set, otherwise 0.

void* rd_kafka_message_t::_private

Consume:

• rdkafka private pointer: DO NOT MODIFY
• dr_msg_cb: msg_opaque from produce() call

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

• src/rdkafka.h