Messaging API

Detailed Description

This API provides means for sending messages to the cloud using various protocols like Kafka, MQTT, and AMQP.

Typedefs
typedef void *	NvDsMsgApiHandle
	Defines the handle to be used with all methods in the NvDS_MsgApi interface. More...
typedef void(*	nvds_msgapi_send_cb_t )(void *user_ptr, NvDsMsgApiErrorType completion_flag)
	Type definition for send method callback. More...
typedef void(*	nvds_msgapi_connect_cb_t )(NvDsMsgApiHandle h_ptr, NvDsMsgApiEventType ds_evt)
	Type definition for handle method callback registered during connect. More...

Enumerations
enum	NvDsMsgApiEventType {   NVDS_MSGAPI_EVT_DISCONNECT,   NVDS_MSGAPI_EVT_SERVICE_DOWN }
	Defines various events associated with connections to remote entities. More...
enum	NvDsMsgApiErrorType {   NVDS_MSGAPI_OK,   NVDS_MSGAPI_ERR,   NVDS_MSGAPI_UNKNOWN_TOPIC }
	Defines completion status for operations in the NvDS_MsgApi interface. More...

Functions
NvDsMsgApiHandle	nvds_msgapi_connect (char *connection_str, nvds_msgapi_connect_cb_t connect_cb, char *config_path)
	Connects to a remote agent by calling into protocol adapter. More...
NvDsMsgApiErrorType	nvds_msgapi_send (NvDsMsgApiHandle h_ptr, char *topic, const uint8_t *payload, size_t nbuf)
	Send message over connection synchronously based on blocking semantics. More...
NvDsMsgApiErrorType	nvds_msgapi_send_async (NvDsMsgApiHandle h_ptr, char *topic, const uint8_t *payload, size_t nbuf, nvds_msgapi_send_cb_t send_callback, void *user_ptr)
	Send message over connection asynchronously based on non-blocking semantics. More...
void	nvds_msgapi_do_work (NvDsMsgApiHandle h_ptr)
	Calls into the adapter to allow for execution of undnerlying protocol logic. More...
NvDsMsgApiErrorType	nvds_msgapi_disconnect (NvDsMsgApiHandle h_ptr)
	Terminates existing connection. More...
char *	nvds_msgapi_getversion (void)
	Current version of NvDS_MsgApi interface supported by protocol adapter. More...

Typedef Documentation

typedef void(* nvds_msgapi_connect_cb_t)(NvDsMsgApiHandle h_ptr, NvDsMsgApiEventType ds_evt)

Type definition for handle method callback registered during connect.

using which events corresponding to connection are delivered

Parameters

[in]	h_ptr	Handle corresponding to event
[in]	ds_evt	Event type based on enum

Definition at line 82 of file nvds_msgapi.h.

typedef void(* nvds_msgapi_send_cb_t)(void *user_ptr, NvDsMsgApiErrorType completion_flag)

Type definition for send method callback.

Parameters

[in]	user_ptr	Pointer passed during async_send for context
[in]	completion_flag	Completion status of send operation.

Definition at line 73 of file nvds_msgapi.h.

typedef void* NvDsMsgApiHandle

Defines the handle to be used with all methods in the NvDS_MsgApi interface.

Definition at line 46 of file nvds_msgapi.h.

Enumeration Type Documentation

enum NvDsMsgApiErrorType

Defines completion status for operations in the NvDS_MsgApi interface.

Enumerator
NVDS_MSGAPI_OK
NVDS_MSGAPI_ERR
NVDS_MSGAPI_UNKNOWN_TOPIC

Definition at line 61 of file nvds_msgapi.h.

enum NvDsMsgApiEventType

Defines various events associated with connections to remote entities.

Enumerator
NVDS_MSGAPI_EVT_DISCONNECT	disconnection of connection handle
NVDS_MSGAPI_EVT_SERVICE_DOWN	remote service is down

Definition at line 51 of file nvds_msgapi.h.

Function Documentation

NvDsMsgApiHandle nvds_msgapi_connect	(	char *	connection_str,
		nvds_msgapi_connect_cb_t	connect_cb,
		char *	config_path
	)

Connects to a remote agent by calling into protocol adapter.

Parameters

[in]	connection_str	A connection string with format "url;port;topic".
[in]	connect_cb	A pointer to a callback function for events associated with the connection.
[in]	config_path	Pathname of a configuration file passed to the protocol adapter.

Returns

A connection handle.

NvDsMsgApiErrorType nvds_msgapi_disconnect

(

NvDsMsgApiHandle

h_ptr

)

Terminates existing connection.

Parameters

[in]

h_ptr

connection handle

Returns

Result of termination

void nvds_msgapi_do_work

(

NvDsMsgApiHandle

h_ptr

)

Calls into the adapter to allow for execution of undnerlying protocol logic.

As part of this routine, adapter should service outstanding incoming and outgoing. It can also perform periodic housekeeping tasks such s sending heartbeats. The method makes client control when the protocol logic gets executed. It should be called periodically by the client, as required by the adapter.

Parameters

[in]

h_ptr

connection handle

char* nvds_msgapi_getversion

(

void

)

Current version of NvDS_MsgApi interface supported by protocol adapter.

Returns

The version of the interface supported by the adapter based on MAJOR.MINOR format.

NvDsMsgApiErrorType nvds_msgapi_send	(	NvDsMsgApiHandle	h_ptr,
		char *	topic,
		const uint8_t *	payload,
		size_t	nbuf
	)

Send message over connection synchronously based on blocking semantics.

Parameters

[in]	h_ptr	connection handle
[in]	topic	topic to which send message
[in]	payload	message data
[in]	nbuf	number of bytes of data to send

Returns

Completion status of send operation

NvDsMsgApiErrorType nvds_msgapi_send_async	(	NvDsMsgApiHandle	h_ptr,
		char *	topic,
		const uint8_t *	payload,
		size_t	nbuf,
		nvds_msgapi_send_cb_t	send_callback,
		void *	user_ptr
	)

Send message over connection asynchronously based on non-blocking semantics.

Parameters

[in]	h_ptr	connection handle
[in]	topic	topic to which send message
[in]	payload	message data
[in]	nbuf	number of bytes of data to send
[in]	send_callback	callback to be invoked when operation complets
[in]	user_ptr	pointer to pass to callback for context

Returns

Completion status of send operation