An MQTT message holds everything required for an MQTT PUBLISH message. More...

#include <message.h>

Public Types
using	ptr_t = std::shared_ptr< message >
	Smart/shared pointer to this class. More...

using	const_ptr_t = std::shared_ptr< const message >
	Smart/shared pointer to this class. More...

Public Member Functions
	message ()
	Constructs a message with an empty payload, and all other values set to defaults.

	message (string_ref topic, const void *payload, size_t len, int qos, bool retained)
	Constructs a message with the specified array as a payload, and all other values set to defaults. More...

	message (string_ref topic, const void *payload, size_t len)
	Constructs a message with the specified array as a payload, and all other values set to defaults. More...

	message (string_ref topic, binary_ref payload, int qos, bool retained)
	Constructs a message from a byte buffer. More...

	message (string_ref topic, binary_ref payload)
	Constructs a message from a byte buffer. More...

	message (string_ref topic, const MQTTAsync_message &msg)
	Constructs a message as a copy of the message structure. More...

	message (const message &other)
	Constructs a message as a copy of the other message. More...

	message (message &&other)
	Moves the other message to this one. More...

	~message ()
	Destroys a message and frees all associated resources.

message &	operator= (const message &rhs)
	Copies another message to this one. More...

message &	operator= (message &&rhs)
	Moves another message to this one. More...

void	set_topic (string_ref topic)
	Sets the topic string. More...

const string_ref &	get_topic_ref () const
	Gets the topic reference for the message. More...

const string &	get_topic () const
	Gets the topic for the message. More...

void	clear_payload ()
	Clears the payload, resetting it to be empty.

const binary_ref &	get_payload_ref () const
	Gets the payload reference.

const binary &	get_payload () const
	Gets the payload.

const string &	get_payload_str () const
	Gets the payload as a string.

int	get_qos () const
	Returns the quality of service for this message. More...

bool	is_duplicate () const
	Returns whether or not this message might be a duplicate of one which has already been received. More...

bool	is_retained () const
	Returns whether or not this message should be/was retained by the server. More...

void	set_payload (binary_ref payload)
	Sets the payload of this message to be the specified buffer. More...

void	set_payload (const void *payload, size_t n)
	Sets the payload of this message to be the specified byte array. More...

void	set_qos (int qos)
	Sets the quality of service for this message. More...

void	set_retained (bool retained)
	Whether or not the publish message should be retained by the broker. More...

string	to_string () const
	Returns a string representation of this messages payload. More...

Static Public Member Functions
static ptr_t	create (string_ref topic, const void *payload, size_t len, int qos, bool retained)
	Constructs a message with the specified array as a payload, and all other values set to defaults. More...

static ptr_t	create (string_ref topic, const void *payload, size_t len)
	Constructs a message with the specified array as a payload, and all other values set to defaults. More...

static ptr_t	create (string_ref topic, binary_ref payload, int qos, bool retained)
	Constructs a message from a byte buffer. More...

static ptr_t	create (string_ref topic, binary_ref payload)
	Constructs a message from a byte buffer. More...

static ptr_t	create (string_ref topic, const MQTTAsync_message &msg)
	Constructs a message as a copy of the C message struct. More...

static void	validate_qos (int qos)
	Determines if the QOS value is a valid one. More...

Static Public Attributes
static constexpr int	DFLT_QOS = 0
	The default QoS for a message.

static constexpr bool	DFLT_RETAINED = false
	The default retained flag.

Friends
class	async_client
	The client has special access. More...

class	message_test

Detailed Description

An MQTT message holds everything required for an MQTT PUBLISH message.

This holds the binary message payload, topic string, and all the additional meta-data for an MQTT message.

The topic and payload buffers are kept as references to const data, so they can be reassigned as needed, but the buffers can not be updated in-place. Normally they would be created externally then copied or moved into the message. The library to transport the messages never touchec the payloads or topics.

This also means that message objects are farily cheap to copy, since they don't copy the payloads. They simply copy the reference to the buffers. It is safe to pass these buffer references across threads since all references promise not to update the contents of the buffer.

Member Typedef Documentation

using mqtt::message::const_ptr_t = std::shared_ptr<const message>

Smart/shared pointer to this class.

using mqtt::message::ptr_t = std::shared_ptr<message>

Smart/shared pointer to this class.

Constructor & Destructor Documentation

mqtt::message::message	(	string_ref	topic,
		const void *	payload,
		size_t	len,
		int	qos,
		bool	retained
	)

Constructs a message with the specified array as a payload, and all other values set to defaults.

Parameters

topic	The message topic
payload	the bytes to use as the message payload
len	the number of bytes in the payload
qos	The quality of service for the message.
retained	Whether the message should be retained by the broker.

mqtt::message::message	(	string_ref	topic,
		const void *	payload,
		size_t	len
	)

inline

Constructs a message with the specified array as a payload, and all other values set to defaults.

Parameters

topic	The message topic
payload	the bytes to use as the message payload
len	the number of bytes in the payload

mqtt::message::message	(	string_ref	topic,
		binary_ref	payload,
		int	qos,
		bool	retained
	)

Constructs a message from a byte buffer.

Note that the payload accepts copy or move semantics.

Parameters

topic	The message topic
payload	A byte buffer to use as the message payload.
qos	The quality of service for the message.
retained	Whether the message should be retained by the broker.

mqtt::message::message	(	string_ref	topic,
		binary_ref	payload
	)

inline

Constructs a message from a byte buffer.

Note that the payload accepts copy or move semantics.

Parameters

topic	The message topic
payload	A byte buffer to use as the message payload.

mqtt::message::message	(	string_ref	topic,
		const MQTTAsync_message &	msg
	)

Constructs a message as a copy of the message structure.

Parameters

topic	The message topic
msg	A "C" MQTTAsync_message structure.

mqtt::message::message ( const message & other )

Constructs a message as a copy of the other message.

Parameters

other The message to copy into this one.

mqtt::message::message ( message && other )

Moves the other message to this one.

Parameters

other The message to move into this one.

Member Function Documentation

static ptr_t mqtt::message::create	(	string_ref	topic,
		const void *	payload,
		size_t	len,
		int	qos,
		bool	retained
	)

inlinestatic

Constructs a message with the specified array as a payload, and all other values set to defaults.

Parameters

topic	The message topic
payload	the bytes to use as the message payload
len	the number of bytes in the payload
qos	The quality of service for the message.
retained	Whether the message should be retained by the broker.

static ptr_t mqtt::message::create	(	string_ref	topic,
		const void *	payload,
		size_t	len
	)

inlinestatic

Constructs a message with the specified array as a payload, and all other values set to defaults.

Parameters

topic	The message topic
payload	the bytes to use as the message payload
len	the number of bytes in the payload

static ptr_t mqtt::message::create	(	string_ref	topic,
		binary_ref	payload,
		int	qos,
		bool	retained
	)

inlinestatic

Constructs a message from a byte buffer.

Note that the payload accepts copy or move semantics.

Parameters

topic	The message topic
payload	A byte buffer to use as the message payload.
qos	The quality of service for the message.
retained	Whether the message should be retained by the broker.

static ptr_t mqtt::message::create	(	string_ref	topic,
		binary_ref	payload
	)

inlinestatic

Constructs a message from a byte buffer.

Note that the payload accepts copy or move semantics.

Parameters

topic	The message topic
payload	A byte buffer to use as the message payload.

static ptr_t mqtt::message::create	(	string_ref	topic,
		const MQTTAsync_message &	msg
	)

inlinestatic

Constructs a message as a copy of the C message struct.

Parameters

topic	The message topic
msg	A "C" MQTTAsync_message structure.

int mqtt::message::get_qos ( ) const

inline

Returns the quality of service for this message.

Returns: The quality of service for this message.

const string& mqtt::message::get_topic ( ) const

inline

Gets the topic for the message.

Returns: The topic string for the message.

const string_ref& mqtt::message::get_topic_ref ( ) const

inline

Gets the topic reference for the message.

Returns: The topic reference for the message.

bool mqtt::message::is_duplicate ( ) const

inline

Returns whether or not this message might be a duplicate of one which has already been received.

Returns: true this message might be a duplicate of one which has already been received, false otherwise

bool mqtt::message::is_retained ( ) const

inline

Returns whether or not this message should be/was retained by the server.

Returns: true if this message should be/was retained by the server, false otherwise.

message& mqtt::message::operator= ( const message & rhs )

Copies another message to this one.

Parameters

rhs	The other message.

Returns: A reference to this message.

message& mqtt::message::operator= ( message && rhs )

Moves another message to this one.

Parameters

rhs	The other message.

Returns: A reference to this message.

void mqtt::message::set_payload ( binary_ref payload )

Sets the payload of this message to be the specified buffer.

Note that this accepts copy or move operations: set_payload(buf); set_payload(std::move(buf));

Parameters

payload A buffer to use as the message payload.

void mqtt::message::set_payload	(	const void *	payload,
		size_t	n
	)

inline

Sets the payload of this message to be the specified byte array.

Parameters

payload	the bytes to use as the message payload
n	the number of bytes in the payload

void mqtt::message::set_qos ( int qos )

inline

Sets the quality of service for this message.

Parameters

qos	The integer Quality of Service for the message

void mqtt::message::set_retained ( bool retained )

inline

Whether or not the publish message should be retained by the broker.

Parameters

retained true if the message should be retained by the broker, false if not.

void mqtt::message::set_topic ( string_ref topic )

inline

Sets the topic string.

Parameters

topic The topic on which the message is published.

string mqtt::message::to_string ( ) const

inline

Returns a string representation of this messages payload.

Returns: string

static void mqtt::message::validate_qos ( int qos )

inlinestatic

Determines if the QOS value is a valid one.

Parameters

qos	The QOS value.

Exceptions

std::invalid_argument If the qos value is invalid.

Friends And Related Function Documentation

friend class async_client

friend

The client has special access.

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

src/mqtt/message.h

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation