Broker Class Reference

A class to store messages to be delivered using a comms model. This class should be used in combination with a specific comms model that implements the ICommsModel interface. More...

#include <Broker.hh>

Public Member Functions
	Broker ()
	Constructor.
MsgManager &	DataManager ()
	Get a mutable reference to the message manager.
void	DeliverMsgs ()
	Process all the messages in the inbound queue and deliver them to the destination clients.
void	Load (std::shared_ptr< const sdf::Element > _sdf)
	Configure the broker via SDF.
void	Lock ()
	Lock the mutex to access the message manager.
bool	OnBind (const gz::msgs::StringMsg_V &_req, gz::msgs::Boolean &_rep)
	This method associates an address with a client topic used as callback for receiving messages. This is a client requirement to start receiving messages.
void	OnMsg (const gz::msgs::Dataframe &_msg)
	Callback executed to process a communication request from one of the clients.
void	OnUnbind (const gz::msgs::StringMsg_V &_req)
	Unbind a given client address. The client associated to this address will not receive any more messages.
void	SetTime (const std::chrono::steady_clock::duration &_time)
	Set the current time.
void	Start ()
	Start handling comms services.
std::chrono::steady_clock::duration	Time () const
	Get the current time.
void	Unlock ()
	Unlock the mutex to access the message manager.

Detailed Description

A class to store messages to be delivered using a comms model. This class should be used in combination with a specific comms model that implements the ICommsModel interface.

See also

ICommsModel.hh The broker maintains two queues: inbound and outbound. When a client sends a communication request, we'll store it in the outbound queue of the sender's address. When the comms model decides that a message needs to be delivered to one of the destination, it'll be stored in the inbound queue of the destination's address.

The main goal of this class is to receive the comms requests, stamp the time, and place them in the appropriate outbound queue, as well as deliver the messages that are in the inbound queues.

The instance of the comms model is responsible for moving around the messages from the outbound queues to the inbound queues.

The broker can be configured with the following SDF parameters:

• Optional parameters: <broker> Element used to capture the broker parameters. This block can contain any of the next parameters: <messages_topic>: Topic name where the broker receives all the incoming messages. The default value is "/broker/msgs" <bind_service>: Service name used to bind an address. The default value is "/broker/bind" <unbind_service>: Service name used to unbind from an address. The default value is "/broker/unbind"

Here's an example: <plugin filename="gz-sim-perfect-comms-system" name="systems::PerfectComms"> <broker> <messages_topic>/broker/inbound</messages_topic> <bind_service>/broker/bind_address</bind_service> <unbind_service>/broker/unbind_address</unbind_service> </broker> </plugin>

Constructor & Destructor Documentation

Broker()

Broker

(

)

Constructor.

Member Function Documentation

DataManager()

MsgManager & DataManager

(

)

Get a mutable reference to the message manager.

Returns

The mutable reference.

DeliverMsgs()

void DeliverMsgs

(

)

Process all the messages in the inbound queue and deliver them to the destination clients.

Load()

void Load

(

std::shared_ptr< const sdf::Element >

_sdf

)

Configure the broker via SDF.

Parameters

[in]

_sdf

The SDF Element associated with the broker parameters.

Lock()

void Lock

(

)

Lock the mutex to access the message manager.

OnBind()

bool OnBind	(	const gz::msgs::StringMsg_V &	_req,
		gz::msgs::Boolean &	_rep
	)

This method associates an address with a client topic used as callback for receiving messages. This is a client requirement to start receiving messages.

Parameters

[in]	_req	Bind request containing the following content: _req[0] Client address. _req[1] Model name associated to the address. _req[2] Client subscription topic.
[out]	_rep	Unused

Returns

True when the bind service succeeded or false otherwise.

OnMsg()

void OnMsg

(

const gz::msgs::Dataframe &

_msg

)

Callback executed to process a communication request from one of the clients.

Parameters

[in]

_msg

The message from the client.

OnUnbind()

void OnUnbind

(

const gz::msgs::StringMsg_V &

_req

)

Unbind a given client address. The client associated to this address will not receive any more messages.

Parameters

[in]

_req

Bind request containing the following content: _req[0] Client address. _req[1] Client subscription topic.

SetTime()

void SetTime

(

const std::chrono::steady_clock::duration &

_time

)

Set the current time.

Parameters

[in]

_time

Current time.

Start()

void Start

(

)

Start handling comms services.

This function allows us to wait to advertise capabilities to clients until the broker has been entirely initialized.

Time()

std::chrono::steady_clock::duration Time

(

)

const

Get the current time.

Returns

Current time.

Unlock()

void Unlock

(

)

Unlock the mutex to access the message manager.

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

• Broker.hh