Lightweight client for talking to an MQTT server using methods that block until an operation completes. More...

#include <client.h>

Inheritance diagram for mqtt::client:

Public Types
using	ptr_t = std::shared_ptr< client >
	Smart pointer type for this object.

using	qos_collection = async_client::qos_collection
	Type for a collection of QOS values.

Public Member Functions
	client (const string &serverURI, const string &clientId, iclient_persistence *persistence=nullptr)
	Create a client that can be used to communicate with an MQTT server. More...

	client (const string &serverURI, const string &clientId, const string &persistDir)
	Create an async_client that can be used to communicate with an MQTT server. More...

	client (const string &serverURI, const string &clientId, int maxBufferedMessages, iclient_persistence *persistence=nullptr)
	Create a client that can be used to communicate with an MQTT server, which allows for off-line message buffering. More...

	client (const string &serverURI, const string &clientId, int maxBufferedMessages, const string &persistDir)
	Create a client that can be used to communicate with an MQTT server, which allows for off-line message buffering. More...

virtual	~client ()
	Virtual destructor.

virtual void	connect ()
	Connects to an MQTT server using the default options.

virtual void	connect (connect_options opts)
	Connects to an MQTT server using the specified options. More...

virtual void	reconnect ()
	Reconnects the client using options from the previous connect. More...

virtual void	disconnect ()
	Disconnects from the server.

virtual void	disconnect (int timeoutMS)
	Disconnects from the server. More...

template<class Rep , class Period >
void	disconnect (const std::chrono::duration< Rep, Period > &to)
	Disconnects from the server. More...

virtual string	get_client_id () const
	Gets the client ID used by this client. More...

virtual string	get_server_uri () const
	Gets the address of the server used by this client. More...

virtual std::chrono::milliseconds	get_timeout () const
	Return the maximum time to wait for an action to complete. More...

virtual topic	get_topic (const string &top)
	Get a topic object which can be used to publish messages on this client. More...

virtual bool	is_connected () const
	Determines if this client is currently connected to the server. More...

virtual void	publish (string_ref top, const void *payload, size_t n, int qos, bool retained)
	Publishes a message to a topic on the server and return once it is delivered. More...

virtual void	publish (string_ref top, const void *payload, size_t n)
	Publishes a message to a topic on the server and return once it is delivered. More...

virtual void	publish (const_message_ptr msg)
	Publishes a message to a topic on the server. More...

virtual void	publish (const message &msg)
	Publishes a message to a topic on the server. More...

virtual void	set_callback (callback &cb)
	Sets the callback listener to use for events that happen asynchronously. More...

virtual void	set_timeout (int timeoutMS)
	Set the maximum time to wait for an action to complete. More...

template<class Rep , class Period >
void	set_timeout (const std::chrono::duration< Rep, Period > &to)
	Set the maximum time to wait for an action to complete. More...

virtual void	subscribe (const string &topicFilter)
	Subscribe to a topic, which may include wildcards using a QoS of 1. More...

virtual void	subscribe (const string &topicFilter, int qos)
	Subscribe to a topic, which may include wildcards. More...

virtual void	subscribe (const string_collection &topicFilters)
	Subscribes to a one or more topics, which may include wildcards using a QoS of 1. More...

virtual void	subscribe (const string_collection &topicFilters, const qos_collection &qos)
	Subscribes to multiple topics, each of which may include wildcards. More...

virtual void	unsubscribe (const string &topicFilter)
	Requests the server unsubscribe the client from a topic. More...

virtual void	unsubscribe (const string_collection &topicFilters)
	Requests the server unsubscribe the client from one or more topics. More...

void	start_consuming ()
	Start consuming messages. More...

void	stop_consuming ()
	Stop consuming messages. More...

const_message_ptr	consume_message ()
	Read the next message from the queue. More...

bool	try_consume_message (const_message_ptr *msg)
	Try to read the next message from the queue without blocking. More...

template<typename Rep , class Period >
bool	try_consume_message_for (const_message_ptr *msg, const std::chrono::duration< Rep, Period > &relTime)
	Waits a limited time for a message to arrive. More...

template<class Clock , class Duration >
bool	try_consume_message_until (const_message_ptr *msg, const std::chrono::time_point< Clock, Duration > &absTime)
	Waits until a specific time for a message to occur. More...

Detailed Description

Lightweight client for talking to an MQTT server using methods that block until an operation completes.

Constructor & Destructor Documentation

mqtt::client::client	(	const string &	serverURI,
		const string &	clientId,
		iclient_persistence *	persistence = `nullptr`
	)

Create a client that can be used to communicate with an MQTT server.

This allows the caller to specify a user-defined persistence object, or use no persistence.

Parameters

serverURI	the address of the server to connect to, specified as a URI.
clientId	a client identifier that is unique on the server being connected to
persistence	The user persistence structure. If this is null, then no persistence is used.

mqtt::client::client	(	const string &	serverURI,
		const string &	clientId,
		const string &	persistDir
	)

Create an async_client that can be used to communicate with an MQTT server.

This uses file-based persistence in the specified directory.

Parameters

serverURI	the address of the server to connect to, specified as a URI.
clientId	a client identifier that is unique on the server being connected to
persistDir	The directory to use for persistence data

mqtt::client::client	(	const string &	serverURI,
		const string &	clientId,
		int	maxBufferedMessages,
		iclient_persistence *	persistence = `nullptr`
	)

Create a client that can be used to communicate with an MQTT server, which allows for off-line message buffering.

This allows the caller to specify a user-defined persistence object, or use no persistence.

Parameters

serverURI	the address of the server to connect to, specified as a URI.
clientId	a client identifier that is unique on the server being connected to
maxBufferedMessages	the maximum number of messages allowed to be buffered while not connected
persistence	The user persistence structure. If this is null, then no persistence is used.

mqtt::client::client	(	const string &	serverURI,
		const string &	clientId,
		int	maxBufferedMessages,
		const string &	persistDir
	)

Create a client that can be used to communicate with an MQTT server, which allows for off-line message buffering.

This uses file-based persistence in the specified directory.

Parameters

serverURI	the address of the server to connect to, specified as a URI.
clientId	a client identifier that is unique on the server being connected to
maxBufferedMessages	the maximum number of messages allowed to be buffered while not connected
persistDir	The directory to use for persistence data

Member Function Documentation

virtual void mqtt::client::connect ( connect_options opts )

inlinevirtual

Connects to an MQTT server using the specified options.

Parameters

opts

const_message_ptr mqtt::client::consume_message ( )

inline

Read the next message from the queue.

This blocks until a new message arrives.

Returns: The message and topic.

virtual void mqtt::client::disconnect ( int timeoutMS )

inlinevirtual

Disconnects from the server.

Parameters

timeoutMS the amount of time in milliseconds to allow for existing work to finish before disconnecting. A value of zero or less means the client will not quiesce.

template<class Rep , class Period >

void mqtt::client::disconnect ( const std::chrono::duration< Rep, Period > & to )

inline

Disconnects from the server.

Parameters

to	the amount of time in milliseconds to allow for existing work to finish before disconnecting. A value of zero or less means the client will not quiesce.

virtual string mqtt::client::get_client_id ( ) const

inlinevirtual

Gets the client ID used by this client.

Returns: The client ID used by this client.

virtual string mqtt::client::get_server_uri ( ) const

inlinevirtual

Gets the address of the server used by this client.

Returns: The address of the server used by this client, as a URI.

virtual std::chrono::milliseconds mqtt::client::get_timeout ( ) const

inlinevirtual

Return the maximum time to wait for an action to complete.

Returns: int

virtual topic mqtt::client::get_topic ( const string & top )

inlinevirtual

Get a topic object which can be used to publish messages on this client.

Parameters

top	The topic name

Returns: A topic attached to this client.

virtual bool mqtt::client::is_connected ( ) const

inlinevirtual

Determines if this client is currently connected to the server.

Returns: true if the client is currently connected, false if not.

virtual void mqtt::client::publish	(	string_ref	top,
		const void *	payload,
		size_t	n,
		int	qos,
		bool	retained
	)

inlinevirtual

Publishes a message to a topic on the server and return once it is delivered.

Parameters

top	The topic to publish
payload	The data to publish
n	The size in bytes of the data
qos	The QoS for message delivery
retained	Whether the broker should retain the message

virtual void mqtt::client::publish	(	string_ref	top,
		const void *	payload,
		size_t	n
	)

inlinevirtual

Publishes a message to a topic on the server and return once it is delivered.

Parameters

top	The topic to publish
payload	The data to publish
n	The size in bytes of the data

virtual void mqtt::client::publish ( const_message_ptr msg )

inlinevirtual

Publishes a message to a topic on the server.

Parameters

msg	The message

virtual void mqtt::client::publish ( const message & msg )

inlinevirtual

Publishes a message to a topic on the server.

This version will not timeout since that could leave the library with a reference to memory that could disappear while the library is still using it.

Parameters

msg	The message

virtual void mqtt::client::reconnect ( )

inlinevirtual

Reconnects the client using options from the previous connect.

The client must have previously called connect() for this to work.

virtual void mqtt::client::set_callback ( callback & cb )

virtual

Sets the callback listener to use for events that happen asynchronously.

Parameters

cb	The callback functions

virtual void mqtt::client::set_timeout ( int timeoutMS )

inlinevirtual

Set the maximum time to wait for an action to complete.

Parameters

timeoutMS The timeout in milliseconds

template<class Rep , class Period >

void mqtt::client::set_timeout ( const std::chrono::duration< Rep, Period > & to )

inline

Set the maximum time to wait for an action to complete.

Parameters

to	The timeout as a std::chrono duration.

void mqtt::client::start_consuming ( )

inline

Start consuming messages.

This initializes the client to receive messages through a queue that can be read synchronously.

void mqtt::client::stop_consuming ( )

inline

Stop consuming messages.

This shuts down the internal callback and discards any unread messages.

virtual void mqtt::client::subscribe ( const string & topicFilter )

inlinevirtual

Subscribe to a topic, which may include wildcards using a QoS of 1.

Parameters

topicFilter

virtual void mqtt::client::subscribe	(	const string &	topicFilter,
		int	qos
	)

inlinevirtual

Subscribe to a topic, which may include wildcards.

Parameters

topicFilter	A single topic to subscribe
qos	The QoS of the subscription

virtual void mqtt::client::subscribe ( const string_collection & topicFilters )

virtual

Subscribes to a one or more topics, which may include wildcards using a QoS of 1.

Parameters

topicFilters A set of topics to subscribe

virtual void mqtt::client::subscribe	(	const string_collection &	topicFilters,
		const qos_collection &	qos
	)

inlinevirtual

Subscribes to multiple topics, each of which may include wildcards.

Parameters

topicFilters	A collection of topics to subscribe
qos	A collection of QoS for each topic

bool mqtt::client::try_consume_message ( const_message_ptr * msg )

inline

Try to read the next message from the queue without blocking.

Parameters

msg	Pointer to the value to receive the message

Returns: true is a message was read, false if no message was available.

template<typename Rep , class Period >

bool mqtt::client::try_consume_message_for	(	const_message_ptr *	msg,
		const std::chrono::duration< Rep, Period > &	relTime
	)

inline

Waits a limited time for a message to arrive.

Parameters

msg	Pointer to the value to receive the message
relTime	The maximum amount of time to wait for a message.

Returns: true if a message was read, false if a timeout occurred.

template<class Clock , class Duration >

bool mqtt::client::try_consume_message_until	(	const_message_ptr *	msg,
		const std::chrono::time_point< Clock, Duration > &	absTime
	)

inline

Waits until a specific time for a message to occur.

Parameters

msg	Pointer to the value to receive the message
absTime	The time point to wait until, before timing out.

Returns: true if a message was read, false if a timeout occurred.

virtual void mqtt::client::unsubscribe ( const string & topicFilter )

inlinevirtual

Requests the server unsubscribe the client from a topic.

Parameters

topicFilter A single topic to unsubscribe.

virtual void mqtt::client::unsubscribe ( const string_collection & topicFilters )

inlinevirtual

Requests the server unsubscribe the client from one or more topics.

Parameters

topicFilters A collection of topics to unsubscribe.

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

src/mqtt/client.h

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation