Class TopicAliasManager

constructor

• new TopicAliasManager(
      outboundMaximum?: number,
      inboundMaximum?: number,
  ): TopicAliasManager

  Create a topic alias manager.

  Parameters

  • outboundMaximum: number = 0

    Maximum outbound alias (from CONNACK)

  • inboundMaximum: number = 0

    Maximum inbound alias (from our CONNECT)

  Returns TopicAliasManager

Readonlyinbound

Readonlyoutbound

clear

• clear(): void

  Clear all mappings (on disconnect).

  Returns void

getOrAssignOutbound

• getOrAssignOutbound(topic: string): OutboundAliasResult | undefined

  Get or assign an outbound alias for a topic.

  Returns existing alias if topic is already mapped, or assigns a new alias if slots are available. Returns undefined if aliases are disabled or all slots are used.

  Parameters

  • topic: string

    Topic to get/assign alias for

  Returns OutboundAliasResult | undefined

  Object with alias and whether topic should be sent

resolveInbound

• resolveInbound(topic: string, alias?: number): string

  Resolve an inbound PUBLISH's topic using aliases.

  According to MQTT 5.0 §3.3.2.3.4:

  • If topic is non-empty and alias present: set alias → topic
  • If topic is empty and alias present: lookup alias
  • If topic is empty and no alias: protocol error

  Parameters

  • topic: string

    Topic from PUBLISH packet (may be empty)

  • Optionalalias: number

    Topic alias from PUBLISH properties (optional)

  Returns string

  Resolved topic name

  Throws

  TopicAliasError if resolution fails