BloombergLP::rmqa::MessageGuard Class Reference

Controls acknowledgements passed to broker for consumed messages. More...

#include <rmqa_messageguard.h>

Inheritance diagram for BloombergLP::rmqa::MessageGuard:

Collaboration diagram for BloombergLP::rmqa::MessageGuard:

Classes
class	Factory

Public Types
typedef bsl::function< void(const rmqt::ConsumerAck &)>	MessageGuardCallback

Public Member Functions
	MessageGuard (const rmqt::Message &message, const rmqt::Envelope &envelope, const MessageGuardCallback &ackCallback, rmqp::Consumer *consumer)
	MessageGuard (const MessageGuard &obj)
	~MessageGuard () BSLS_KEYWORD_OVERRIDE
const rmqt::Message &	message () const BSLS_KEYWORD_OVERRIDE
	Access the received message. More...
const rmqt::Envelope &	envelope () const BSLS_KEYWORD_OVERRIDE
	Access the received message envelope (delivery details) More...
void	ack () BSLS_KEYWORD_OVERRIDE
void	nack (bool requeue=true) BSLS_KEYWORD_OVERRIDE
virtual rmqp::Consumer *	consumer () const BSLS_KEYWORD_OVERRIDE
	Pointer to the Consumer, e.g. to cancel the message flow. More...
rmqp::TransferrableMessageGuard	transferOwnership () BSLS_KEYWORD_OVERRIDE

Protected Types
enum	State { READY , TRANSFERRED , RESOLVED }

Protected Member Functions
State	state () const

Friends
bsl::ostream &	operator<< (bsl::ostream &os, const MessageGuard &mg)
	Stream out.

Detailed Description

Controls acknowledgements passed to broker for consumed messages.

A MessageGuard is passed to the rmqa::Consumer callback function (defined in rmqp::Consumer) for each message. The object allows acknowledging either positively or negatively, with options to requeue. If a MessageGuard object is allowed to destruct before ack/nack is called a nack with requeue is automatically signaled to the broker.

Member Enumeration Documentation

State

enum BloombergLP::rmqa::MessageGuard::State

protected

Ready - not resolved yet Invalid - ownership moved Resolved - message (n)acked.

Constructor & Destructor Documentation

MessageGuard() [1/2]

BloombergLP::rmqa::MessageGuard::MessageGuard	(	const rmqt::Message &	message,
		const rmqt::Envelope &	envelope,
		const MessageGuardCallback &	ackCallback,
		rmqp::Consumer *	consumer
	)

Constructs a new valid guard

Parameters

message	Consumed message
envelope	Consumed delivery metadata
ackCallback	Callback called when resolving message
consumer	Pointer to the Consumer

MessageGuard() [2/2]

BloombergLP::rmqa::MessageGuard::MessageGuard

(

const MessageGuard &

obj

)

During copying obj is invalidated and thereafter cannot be used to (n)ack.

~MessageGuard()

BloombergLP::rmqa::MessageGuard::~MessageGuard ( )

virtual

If not processed (ack()/nack() called), message will be nacked automatically.

Reimplemented from BloombergLP::rmqp::MessageGuard.

Member Function Documentation

ack()

void BloombergLP::rmqa::MessageGuard::ack ( )

virtual

Acknowledge the received message. Callable only once. Should only be called after the message has been fully processed

A message acknowledgement is fire-and-forget. If the broker does not receive this (e.g. due to connection drop), the message will be redelivered to another consumer.

Implements BloombergLP::rmqp::MessageGuard.

consumer()

rmqp::Consumer * BloombergLP::rmqa::MessageGuard::consumer ( ) const

virtual

Pointer to the Consumer, e.g. to cancel the message flow.

Implements BloombergLP::rmqp::MessageGuard.

envelope()

const rmqt::Envelope & BloombergLP::rmqa::MessageGuard::envelope ( ) const

virtual

Access the received message envelope (delivery details)

Implements BloombergLP::rmqp::MessageGuard.

message()

const rmqt::Message & BloombergLP::rmqa::MessageGuard::message ( ) const

virtual

Access the received message.

Implements BloombergLP::rmqp::MessageGuard.

nack()

void BloombergLP::rmqa::MessageGuard::nack ( bool  requeue = true )

virtual

Negative acknowledge the received message. Callable only once.

Parameters

requeue

true requeues the message on the broker for redelivery , if false, then the message will be either dead lettered (if a dead letter exchange is specified) or dropped if not.

Implements BloombergLP::rmqp::MessageGuard.

transferOwnership()

rmqp::TransferrableMessageGuard BloombergLP::rmqa::MessageGuard::transferOwnership ( )

virtual

Transfers ownership of the message processing to a MessageGuard that is copyable (shared pointer semantics) RETURN a shared pointer to a valid message guard,

Note

if the MessageGuard has already been resolved or transferred (ack/nack) a warning will be printed

Implements BloombergLP::rmqp::MessageGuard.

Reimplemented in BloombergLP::rmqa::TracingMessageGuard.

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

• src/rmq/rmqa/rmqa_messageguard.h
• src/rmq/rmqa/rmqa_messageguard.cpp