SL MQTT Client API

Modules
	SL MQTT Client Events
	SL MQTT Oper Paramters
Classes
struct	SlMqttClientCbs_t
struct	SlMqttWill_t
struct	SlMqttServer_t
struct	SlMqttClientLibCfg_t
struct	SlMqttClientCtxCfg_t
Functions
_i32	sl_ExtLib_MqttClientInit (const SlMqttClientLibCfg_t *cfg)
_i32	sl_ExtLib_MqttClientExit ()
void *	sl_ExtLib_MqttClientCtxCreate (const SlMqttClientCtxCfg_t *ctx_cfg, const SlMqttClientCbs_t *msg_cbs, void *app_hndl)
_i32	sl_ExtLib_MqttClientCtxDelete (void *cli_ctx)
_i32	sl_ExtLib_MqttClientSet (void *cli_ctx, _i32 param, const void *value, _u32 len)
_i32	sl_ExtLib_MqttClientGet (void *cli_ctx, _i32 param, void *value, _u32 len)
_i32	sl_ExtLib_MqttClientConnect (void *cli_ctx, bool clean, _u16 keep_alive_time)
_i32	sl_ExtLib_MqttClientDisconnect (void *cli_ctx)
_i32	sl_ExtLib_MqttClientSub (void *cli_ctx, char *const *topics, _u8 *qos, _i32 count)
_i32	sl_ExtLib_MqttClientUnsub (void *cli_ctx, char *const *topics, _i32 count)
_i32	sl_ExtLib_MqttClientSend (void *cli_ctx, const char *topic, const void *data, _i32 len, char qos, bool retain)

---

Function Documentation

_i32 sl_ExtLib_MqttClientConnect	(	void *	cli_ctx,
		bool	clean,
		_u16	keep_alive_time
	)

CONNECT to the server. This routine establishes a connection with the server for MQTT transactions. The caller should specify a time-period with-in which the implementation should send a message to the server to keep-alive the connection.

Parameters:

[in]	cli_ctx	refers to the handle to the client context
[in]	clean	assert to make a clean start and purge the previous session
[in]	keep_alive_time	the maximum time within which client should send a message to server. The unit of the interval is in seconds.

Returns:

on success, variable header of CONNACK message in network byte order. Lowest Byte[Byte0] contains CONNACK Return Code. Byte1 Contains Session Present Bit. on failure returns(-1)

void* sl_ExtLib_MqttClientCtxCreate	(	const SlMqttClientCtxCfg_t *	ctx_cfg,
		const SlMqttClientCbs_t *	msg_cbs,
		void *	app_hndl
	)

Create a new client context to connect to a server. A context has to be created prior to invoking the client services.

Parameters:

[in]	ctx_cfg	refers to client context configuration parameters
[in]	msg_cbs	refers to callbacks into application
[in]	app	refers to the application callback to be returned on callback

_i32 sl_ExtLib_MqttClientCtxDelete

(

void *

cli_ctx

)

Deletes the specified client context.

       \param[in] cli_ctx refers to client context to be deleted
       \return Success (0) or Failure (< 0)

_i32 sl_ExtLib_MqttClientDisconnect

(

void *

cli_ctx

)

DISCONNECT from the server. The caller must use this service to close the connection with the server.

Parameters:

[in]

cli_ctx

refers to the handle to the client context

Returns:

Success (0) or Failure (< 0)

_i32 sl_ExtLib_MqttClientExit

(

)

Exit the SL MQTT Implementation.

       \return Success (0) or Failure (-1)

_i32 sl_ExtLib_MqttClientGet	(	void *	cli_ctx,
		_i32	param,
		void *	value,
		_u32	len
	)

_i32 sl_ExtLib_MqttClientInit

(

const SlMqttClientLibCfg_t *

cfg

)

Initialize the SL MQTT Implementation. A caller must initialize the MQTT implementation prior to using its services.

Parameters:

[in]

cfg

refers to client lib configuration parameters

Returns:

Success (0) or Failure (-1)

_i32 sl_ExtLib_MqttClientSend	(	void *	cli_ctx,
		const char *	topic,
		const void *	data,
		_i32	len,
		char	qos,
		bool	retain
	)

PUBLISH a named message to the server. In addition to the PUBLISH specific parameters, the caller can indicate whether the routine should block until the time, the message has been acknowleged by the server. This is applicable only for non-QoS0 messages.

In case, the app has chosen not to await for the ACK from the server, the SL MQTT implementation will notify the app about the subscription through the callback routine.

Parameters:

[in]	cli_ctx	refers to the handle to the client context
[in]	topic	topic of the data to be published. It is NULL terminated.
[in]	data	binary data to be published
[in]	len	length of the data
[in]	qos	QoS for the publish message
[in]	retain	assert if server should retain the message
[in]	flags	Command flag. Refer to sl_mqtt_cl_cmdflags

Returns:

Success(transaction Message ID) or Failure(< 0)

_i32 sl_ExtLib_MqttClientSet	(	void *	cli_ctx,
		_i32	param,
		const void *	value,
		_u32	len
	)

Set parameters in SL MQTT implementation. The caller must configure these paramters prior to invoking any MQTT transaction.

Note:

The implementation does not copy the contents referred. Therefore, the caller must ensure that contents are persistent in the memory.

Parameters:

[in]	cli_ctx	refers to the handle to the client context
[in]	param	identifies parameter to set. Refer to SL MQTT Oper Paramters
[in]	value	refers to the place-holder of value to be set
[in]	len	length of the value of the parameter

Returns:

Success (0) or Failure (-1)

_i32 sl_ExtLib_MqttClientSub	(	void *	cli_ctx,
		char *const *	topics,
		_u8 *	qos,
		_i32	count
	)

SUBSCRIBE a set of topics. To receive data about a set of topics from the server, the app through this routine must subscribe to those topic names with the server. The caller can indicate whether the routine should block until a time, the message has been acknowledged by the server.

In case, the app has chosen not to await for the ACK from the server, the SL MQTT implementation will notify the app about the subscription through the callback routine.

Parameters:

[in]	cli_ctx	refers to the handle to the client context
[in]	topics	set of topic names to subscribe. It is an array of pointers to NUL terminated strings.
[in,out]	qos	array of qos values for each topic in the same order of the topic array. If configured to await for SUB-ACK from server, the array will contain qos responses for topics from the server.
[in]	count	number of such topics

Returns:

Success(transaction Message ID) or Failure(< 0)

_i32 sl_ExtLib_MqttClientUnsub	(	void *	cli_ctx,
		char *const *	topics,
		_i32	count
	)

UNSUBSCRIBE a set of topics. The app should use this service to stop receiving data for the named topics from the server. The caller can indicate whether the routine should block until a time, the message has been acknowleged by the server.

In case, the app has chosen not to await for the ACK from the server, the SL MQTT implementation will notify the app about the subscription through the callback routine.

Parameters:

[in]	cli_ctx	refers to the handle to the client context
[in]	topics	set of topics to be unsubscribed. It is an array of pointers to NUL terminated strings.
[in]	count	number of topics to be unsubscribed

Returns:

Success(transaction Message ID) or Failure(< 0)