import Backend from '@cansat-icarus/capture-lib/src/icarus/backend/index.js'

public class | source

Backend

Extends:

events~EventEmitter → Backend

Handles connection with the backend.

Responsible for establishing a WebSocket (socket.io) connection with the backend and handling its requests.

It also instantiates Replicator instances for data and log replication. The stateChange events from these are forwarded as: "replicator:data:state" and "replicator:log:state".

Constructor Summary

Public Constructor
public	constructor(name: String, logger: Bunyan, dataDB: PouchDB, logDB: PouchDB) Constructor.

Member Summary

Public Members
public	dataReplicator: Replicator Replicator instance for dataDB.
public	logReplicator: Replicator Replicator instance for logDB.
public	name: String Station name.

Private Members
private	_log: Bunyan Logger instance.
private	_socket: IO Current socket connection with the backend.
private	_state: String Current socket state.

Method Summary

Public Methods
public	async cleanup(): Promise Triggers Replicator#cleanup on the data and log replicators.
public	connect(url: String) Connects to backend at [url].
public	disconnect() Disconnects from the backend.

Protected Methods
protected	_updateState(state: String, extraData: Object) Updates the socket state.

Public Constructors

public constructor(name: String, logger: Bunyan, dataDB: PouchDB, logDB: PouchDB) source

Constructor.

Params:

Name	Type	Attribute	Description
name	String		Station name.
logger	Bunyan		Logger instance.
dataDB	PouchDB		Packet database.
logDB	PouchDB		Log entries database.

Public Members

public dataReplicator: Replicator source

Replicator instance for dataDB.

public logReplicator: Replicator source

Replicator instance for logDB.

public name: String source

Station name.

Private Members

private _log: Bunyan source

Logger instance.

private _socket: IO source

Current socket connection with the backend.

private _state: String source

Current socket state.

Public Methods

public async cleanup(): Promise source

Triggers Replicator#cleanup on the data and log replicators.

Return:

Promise

Emit:

*	state('cleanup')

public connect(url: String) source

Connects to backend at [url].

Params:

Name	Type	Attribute	Description
url	String		Backend URL.

Emit:

*	state(socketState): socket connection/disconnection.

public disconnect() source

Disconnects from the backend. Stops the socket. The replicators will keep running until a new connection makes them connect to a different database.

Emit:

*	state(socketState): socket connection/disconnection.

Protected Methods

protected _updateState(state: String, extraData: Object) source

Updates the socket state.

Params:

Name	Type	Attribute	Description
state	String		New Backend state.
extraData	Object	optional	Extra data related to the new state (error, no. of connection attempts...) to be included in logs.

Emit:

*	state(socketState): socket connection/disconnection.