SocketPubSubService

@webda/fs

---

Class: SocketPubSubService<T, K>

Defined in: fs/src/socketpubsub.service.ts:62

Pub/sub backed by a unix-domain socket. Designed for single-host IPC: one peer binds the socket file and acts as broker, fanning each published message out to every connected client; other peers connect as clients. Any peer can publish — non-broker publishers send through the socket and the broker fanouts. Every connected peer (publisher included) receives every message, so the in-process semantics match the cross-process ones.

If the broker disconnects, surviving clients reconnect after a short randomized delay; one of them wins the bind race and becomes the new broker. Stale socket files left by killed brokers are detected via connect() returning ECONNREFUSED and unlinked before re-binding.

Wire format: 4-byte big-endian uint32 length prefix followed by a UTF-8 JSON payload.

Webda Modda

SocketPubSub

Extends

• default<T, K>

Type Parameters

T

T = any

K

K extends SocketPubSubParameters = SocketPubSubParameters

Constructors

Constructor

new SocketPubSubService<T, K>(name, params): SocketPubSubService<T, K>

Defined in: core/lib/services/service.d.ts:72

Service

Parameters

name

string

The name of the service

params

K

The parameters block define in the configuration file

Returns

SocketPubSubService<T, K>

Inherited from

PubSubService<T, K>.constructor

Properties

_compiledCapabilities

protected _compiledCapabilities: Record<string, any>

Defined in: core/lib/services/iservice.d.ts:39

Capabilities detected at compile-time from @WebdaCapability-tagged interfaces.

Populated during Service.resolve by reading the service's entry in webda.module.json. Each key is a capability name (e.g., "request-filter"), and the value is an empty object {} by default. Override getCapabilities to provide capability-specific configuration or to conditionally disable capabilities.

See

getCapabilities

Inherited from

PubSubService._compiledCapabilities

---

[WEBDA_EVENTS]

[WEBDA_EVENTS]: object

Defined in: core/lib/services/service.d.ts:50

Set the Webda events here

Inherited from

PubSubService.[WEBDA_EVENTS]

---

callbacks

protected callbacks: Set<Subscriber<T>>

Defined in: fs/src/socketpubsub.service.ts:84

Local callback registrations made via consume. The broker dispatches to these directly; client-mode peers feed them from the broker socket's incoming frames.

---

clientSocket?

protected optional clientSocket?: Socket

Defined in: fs/src/socketpubsub.service.ts:74

Outbound socket to the broker, when this peer is a client.

---

logger

protected logger: Logger

Defined in: core/lib/services/service.d.ts:59

Logger with class context

Inherited from

PubSubService.logger

---

metrics

protected metrics: object

Defined in: core/lib/queues/pubsubservice.d.ts:10

errors

errors: Counter

messages_pending

messages_pending: Gauge

messages_received

messages_received: Counter

messages_sent

messages_sent: Counter

processing_duration

processing_duration: Histogram

Inherited from

PubSubService.metrics

---

name

readonly name: string

Defined in: core/lib/services/iservice.d.ts:19

Inherited from

PubSubService.name

---

parameters

readonly parameters: K

Defined in: core/lib/services/iservice.d.ts:20

Inherited from

PubSubService.parameters

---

server?

protected optional server?: Server

Defined in: fs/src/socketpubsub.service.ts:70

Broker-mode listener. Set when this peer is the broker, undefined otherwise. Mutually exclusive with clientSocket.

---

stopping

protected stopping: boolean = false

Defined in: fs/src/socketpubsub.service.ts:89

Set during stop so disconnect handlers don't try to reconnect after we've torn down.

---

subscribers

protected subscribers: Set<Socket>

Defined in: fs/src/socketpubsub.service.ts:78

Active subscriber sockets the broker fans messages out to.

---

createConfiguration?

static optional createConfiguration?: (params) => any

Defined in: core/lib/services/iservice.d.ts:24

Create configuration set by the application on load

Parameters

params

any

Returns

any

Inherited from

PubSubService.createConfiguration

---

filterConfiguration?

static optional filterConfiguration?: (params) => any

Defined in: core/lib/services/iservice.d.ts:28

Create configuration set by the application on load

Parameters

params

any

Returns

any

Inherited from

PubSubService.filterConfiguration

---

Parameters

static Parameters: typeof ServiceParameters

Defined in: core/lib/services/service.d.ts:46

Service parameters

Inherited from

PubSubService.Parameters

Methods

__clean()

abstract __clean(): Promise<void>

Defined in: core/lib/services/service.d.ts:215

Clean the service data, can only be used in test mode

Returns

Promise<void>

Inherited from

PubSubService.__clean

---

addListener()

addListener<Key>(eventName, listener): this

Defined in: core/lib/events/asynceventemitter.d.ts:80

Type Parameters

Key

Key extends never

Parameters

eventName

Key

the event name

listener

(event) => void | Promise<void>

the event listener

Returns

this

this for chaining

See

EventEmitter.addListener

Inherited from

PubSubService.addListener

---

addRoute()

protected addRoute(url, methods, executer, openapi?, override?): void

Defined in: core/lib/services/service.d.ts:177

Add a route dynamicaly

Parameters

url

string

of the route can contains dynamic part like {uuid}

methods

HttpMethodType[]

the HTTP methods

executer

Function

Method to execute for this route

openapi?

OpenAPIWebdaDefinition

the OpenAPI specification

override?

boolean

whether to override existing

Returns

void

Inherited from

PubSubService.addRoute

---

authorizeClientEvent()

authorizeClientEvent(_event, _context): boolean

Defined in: core/lib/services/service.d.ts:153

Authorize a public event subscription

Parameters

_event

string

the event name

_context

OperationContext

the execution context

Returns

boolean

true if the condition is met

Inherited from

PubSubService.authorizeClientEvent

---

bindAsBroker()

protected bindAsBroker(path): Promise<void>

Defined in: fs/src/socketpubsub.service.ts:141

Bind the socket file and start listening. On every accepted connection we frame-decode incoming bytes, fanout the raw frame to all OTHER subscribers, and dispatch the parsed payload to local callbacks.

Parameters

path

string

filesystem path of the unix socket

Returns

Promise<void>

resolves once the listener is up

---

computeParameters()

computeParameters(): void

Defined in: core/lib/services/service.d.ts:77

Used to compute or derivate input parameter to attribute

Returns

void

Deprecated

Inherited from

PubSubService.computeParameters

---

connect()

protected connect(): Promise<void>

Defined in: fs/src/socketpubsub.service.ts:105

Connect to an existing broker, or bind ourselves as broker if there isn't one. Handles the EADDRINUSE race by retrying as a client.

Returns

Promise<void>

---

connectAsClient()

protected connectAsClient(path): Promise<void>

Defined in: fs/src/socketpubsub.service.ts:169

Open a client socket to the broker.

Parameters

path

string

filesystem path of the unix socket

Returns

Promise<void>

resolves once connected, rejects on the first connection error

---

consume()

consume(callback, eventPrototype?, onBind?): CancelablePromise

Defined in: fs/src/socketpubsub.service.ts:288

Parameters

callback

(event) => Promise<void>

invoked with each event received

eventPrototype?

() => T

optional class to rehydrate JSON into

onBind?

() => void

invoked once the subscription is registered

Returns

CancelablePromise

a cancelable subscription handle

Overrides

PubSubService.consume

---

dispatchToCallbacks()

protected dispatchToCallbacks(buf): void

Defined in: fs/src/socketpubsub.service.ts:227

Decode a JSON frame and run every registered callback against it. Errors thrown by callbacks are swallowed (logged + counted) so one bad subscriber doesn't break others.

Parameters

buf

Buffer

the unframed JSON payload bytes

Returns

void

---

emit()

emit<Key>(event, data): Promise<void>

Defined in: core/lib/services/service.d.ts:204

Emit the event with data and wait for Promise to finish if listener returned a Promise

Type Parameters

Key

Key extends never

Parameters

event

Key

the event name

data

object[Key]

the data to process

Returns

Promise<void>

Inherited from

PubSubService.emit

---

fanout()

protected fanout(buf, except?): void

Defined in: fs/src/socketpubsub.service.ts:213

Write a framed payload to every subscriber except the optional sender (used to avoid echoing a client's own message back to it via the broker — the client receives it via its local callback dispatch instead).

Parameters

buf

Buffer

the unframed JSON payload bytes

except?

Socket

optional socket to exclude from fanout

Returns

void

---

getCapabilities()

getCapabilities(): Record<string, any>

Defined in: core/lib/services/iservice.d.ts:61

Return the capabilities of this service.

By default returns capabilities detected at compile-time from

Returns

Record<string, any>

the result

Webda Capability-tagged

interfaces in webda.module.json.

Override to disable capabilities based on configuration:

getCapabilities() {
  const caps = super.getCapabilities();
  if (!this.parameters.enabled) delete caps["request-filter"];
  return caps;
}

Inherited from

PubSubService.getCapabilities

---

getClientEvents()

getClientEvents(): string[]

Defined in: core/lib/services/service.d.ts:144

Return the events that an external system can subscribe to

Returns

string[]

the list of results

Inherited from

PubSubService.getClientEvents

---

getMaxListeners()

getMaxListeners(): number

Defined in: core/lib/events/asynceventemitter.d.ts:84

Returns

number

Inherited from

PubSubService.getMaxListeners

---

getMetric()

getMetric<T>(type, configuration): T

Defined in: core/lib/services/service.d.ts:138

Add service name label

Type Parameters

T

T = Counter<string> | Gauge<string> | Histogram<string>

Parameters

type

CustomConstructor<T, [MetricConfiguration<T>]>

the type to look up

configuration

MetricConfiguration<T>

the configuration

Returns

T

the result

Inherited from

PubSubService.getMetric

---

getName()

getName(): string

Defined in: core/lib/services/service.d.ts:209

Get service name

Returns

string

the result string

Inherited from

PubSubService.getName

---

getOpenApiReplacements()

getOpenApiReplacements(): any

Defined in: core/lib/services/service.d.ts:182

Return variables for replacement in openapi

Returns

any

the result

Inherited from

PubSubService.getOpenApiReplacements

---

getOperationId()

getOperationId(id): string

Defined in: core/lib/services/service.d.ts:167

If undefined is returned it cancel the operation registration

Parameters

id

string

the identifier

Returns

string

the result

Inherited from

PubSubService.getOperationId

---

getParameters()

getParameters(): K

Defined in: core/lib/services/service.d.ts:82

Get the service parameters

Returns

K

the result

Inherited from

PubSubService.getParameters

---

getService()

getService<T>(name): ServicesMap[T]

Defined in: core/lib/services/service.d.ts:131

Get a service by name

Type Parameters

T

T extends keyof ServicesMap

Parameters

name

T

the name to use

Returns

ServicesMap[T]

the result map

Deprecated

Use useService, might reconsider

Inherited from

PubSubService.getService

---

getState()

getState(): ServiceStates

Defined in: core/lib/services/service.d.ts:55

Get the current state

Returns

ServiceStates

the result

Inherited from

PubSubService.getState

---

getUrl()

getUrl(url, _methods): string

Defined in: core/lib/services/service.d.ts:161

Return the full path url based on parameters

Parameters

url

string

relative url to service

_methods

HttpMethodType[]

in case we need filtering (like Store)

Returns

string

absolute url or undefined if need to skip the Route

Inherited from

PubSubService.getUrl

---

handleBrokerDisconnect()

protected handleBrokerDisconnect(): void

Defined in: fs/src/socketpubsub.service.ts:195

Schedule a reconnect attempt after a randomized backoff. The jitter keeps surviving clients from all racing to bind the new socket on the same tick.

Returns

void

---

init()

init(): Promise<SocketPubSubService<T, K>>

Defined in: fs/src/socketpubsub.service.ts:95

Returns

Promise<SocketPubSubService<T, K>>

this service

Overrides

PubSubService.init

---

initMetrics()

initMetrics(): void

Defined in: core/lib/queues/pubsubservice.d.ts:20

Returns

void

Inherited from

PubSubService.initMetrics

---

initOperations()

initOperations(): void

Defined in: core/lib/services/service.d.ts:186

Init the operations from

Returns

void

Operation

decorators on this service

Inherited from

PubSubService.initOperations

---

listeners()

listeners(eventName): Function[]

Defined in: core/lib/events/asynceventemitter.d.ts:139

Get all listeners for an event

Parameters

eventName

never

the event name

Returns

Function[]

the list of results

Inherited from

PubSubService.listeners

---

loadCapabilities()

protected loadCapabilities(): void

Defined in: core/lib/services/service.d.ts:120

Load capabilities from webda.module.json metadata into _compiledCapabilities.

Called during resolve after dependency injection. Reads the service's type name from parameters, looks it up in the application's module metadata (moddas or beans section), and populates _compiledCapabilities with an empty object for each declared capability name.

Fails silently if the application is not available (e.g., in unit tests where services are instantiated without a full application context).

Returns

void

Example

// If webda.module.json contains:
// { "moddas": { "MyApp/HawkService": { "capabilities": ["request-filter", "cors-filter"] } } }
// Then after resolve(), this.getCapabilities() returns:
// { "request-filter": {}, "cors-filter": {} }

See

getCapabilities

Inherited from

PubSubService.loadCapabilities

---

log()

log(level, ...args): void

Defined in: core/lib/services/service.d.ts:226

Parameters

level

WorkerLogLevel

to log

args

...any[]

additional arguments

Returns

void

Inherited from

PubSubService.log

---

off()

off<Key>(eventName, listener): this

Defined in: core/lib/events/asynceventemitter.d.ts:116

Type Parameters

Key

Key extends never

Parameters

eventName

Key

the event name

listener

(event) => void

the event listener

Returns

this

this for chaining

See

EventEmitter.off

Inherited from

PubSubService.off

---

on()

on<Key>(eventName, listener): this

Defined in: core/lib/events/asynceventemitter.d.ts:102

Type Parameters

Key

Key extends never

Parameters

eventName

Key

the event name

listener

(event) => void

the event listener

Returns

this

this for chaining

See

EventEmitter.once

Inherited from

PubSubService.on

---

once()

once<Key>(eventName, listener): this

Defined in: core/lib/events/asynceventemitter.d.ts:95

Type Parameters

Key

Key extends never

Parameters

eventName

Key

the event name

listener

(event) => void

the event listener

Returns

this

this for chaining

See

EventEmitter.once

Inherited from

PubSubService.once

---

removeAllListeners()

removeAllListeners<Key>(eventName?): this

Defined in: core/lib/events/asynceventemitter.d.ts:122

Type Parameters

Key

Key extends never

Parameters

eventName?

Key

the event name

Returns

this

this for chaining

See

EventEmitter.removeAllListeners

Inherited from

PubSubService.removeAllListeners

---

removeListener()

removeListener<Key>(eventName, listener): this

Defined in: core/lib/events/asynceventemitter.d.ts:109

Type Parameters

Key

Key extends never

Parameters

eventName

Key

the event name

listener

(event) => void

the event listener

Returns

this

this for chaining

See

EventEmitter.removeListener

Inherited from

PubSubService.removeListener

---

resolve()

resolve(): this

Defined in: core/lib/services/service.d.ts:98

Resolve parameters and load metadata. @Route-declared routes are scanned and registered by Router.discoverRoutes(services) from Core.init() once every service has resolved — nothing to do per-service here.

Returns

this

the result

Inherited from

PubSubService.resolve

---

sendMessage()

sendMessage(event): Promise<void>

Defined in: fs/src/socketpubsub.service.ts:256

Parameters

event

T

the event to publish

Returns

Promise<void>

Overrides

PubSubService.sendMessage

---

setMaxListeners()

setMaxListeners(n): this

Defined in: core/lib/events/asynceventemitter.d.ts:88

Parameters

n

number

Returns

this

Inherited from

PubSubService.setMaxListeners

---

size()

size(): Promise<number>

Defined in: fs/src/socketpubsub.service.ts:277

Returns

Promise<number>

0 — pub/sub is transient, no queueing

Overrides

PubSubService.size

---

stop()

stop(): Promise<void>

Defined in: fs/src/socketpubsub.service.ts:312

Returns

Promise<void>

Overrides

PubSubService.stop

---

toJSON()

toJSON(): string

Defined in: core/lib/services/service.d.ts:191

Prevent service to be serialized

Returns

string

the result

Inherited from

PubSubService.toJSON

---

toString()

toString(): string

Defined in: core/lib/services/service.d.ts:91

Return service representation

Returns

string

the result

Inherited from

PubSubService.toString

---

unserialize()

unserialize<L>(data, proto?): L

Defined in: core/lib/queues/pubsubservice.d.ts:32

Unserialize into class

Type Parameters

L

L

Parameters

data

string

the data to process

proto?

() => L

the proto

Returns

L

the result

Inherited from

PubSubService.unserialize