Class QoSFlowTracker

Tracks QoS message flows for reliable delivery.

Maintains separate maps for outbound (client→server) and inbound (server→client) flows. Enforces receive maximum for flow control.

Example

const tracker = new QoSFlowTracker(65535)

// Start QoS 1 outbound flow
tracker.startOutbound(publishPacket, Date.now())

// Process PUBACK
const result = tracker.handlePuback(pubackPacket)
if (result.success) {
  // Flow complete, ID can be released
}

Constructors

constructor

new QoSFlowTracker(receiveMaximum?: number): QoSFlowTracker
Create a QoS flow tracker.
Parameters
- receiveMaximum: number = 65535
  Maximum concurrent outbound QoS > 0 messages
Returns QoSFlowTracker
- Defined in state/qos-flow.ts:69

Accessors

inboundCount

get inboundCount(): number
Get current inbound QoS 2 flow count.

Returns number
- Defined in state/qos-flow.ts:240

outboundCount

get outboundCount(): number
Get current outbound flow count.

Returns number
- Defined in state/qos-flow.ts:89

Methods

canSendOutbound

canSendOutbound(): boolean
Check if we can send another QoS > 0 message.

Returns boolean
true if under receive maximum
- Defined in state/qos-flow.ts:82

clear

clear(): void
Clear all flows.

Returns void
- Defined in state/qos-flow.ts:370

getAllInbound

getAllInbound(): ReadonlyMap<number, QoS2InboundFlow>
Get all inbound flows (for session persistence).

Returns ReadonlyMap<number, QoS2InboundFlow>
- Defined in state/qos-flow.ts:304

getAllOutbound

getAllOutbound(): ReadonlyMap<number, OutboundFlow>
Get all outbound flows (for session persistence).

Returns ReadonlyMap<number, OutboundFlow>
- Defined in state/qos-flow.ts:229

getFlowsNeedingRetry

getFlowsNeedingRetry(timeout: number, now: number): OutboundFlow[]
Get flows that need retry (exceeded timeout).
Parameters
- timeout: number
  Retry timeout in milliseconds
- now: number
  Current timestamp
Returns OutboundFlow[]
Array of flows needing retry
- Defined in state/qos-flow.ts:341

getInbound

getInbound(packetId: number): QoS2InboundFlow | undefined
Get an inbound flow by packet ID.
Parameters
- packetId: number
Returns QoS2InboundFlow | undefined
- Defined in state/qos-flow.ts:297

getOutbound

getOutbound(packetId: number): OutboundFlow | undefined
Get an outbound flow by packet ID.
Parameters
- packetId: number
Returns OutboundFlow | undefined
- Defined in state/qos-flow.ts:222

handlePuback

handlePuback(packet: PubackPacket): AckResult
Handle PUBACK for outbound QoS 1.
Parameters
- packet: PubackPacket
  PUBACK packet received
Returns AckResult
Result with completed flow or error
- Defined in state/qos-flow.ts:142

handlePubcomp

handlePubcomp(packet: PubcompPacket): AckResult
Handle PUBCOMP for outbound QoS 2 (step 4).

Completes the QoS 2 flow.
Parameters
- packet: PubcompPacket
  PUBCOMP packet received
Returns AckResult
Result with completed flow or error
- Defined in state/qos-flow.ts:203

handlePubrec

handlePubrec(packet: PubrecPacket, timestamp: number): AckResult
Handle PUBREC for outbound QoS 2 (step 2).

Transitions flow from awaiting-pubrec to awaiting-pubcomp.
Parameters
- packet: PubrecPacket
  PUBREC packet received
- timestamp: number
  Timestamp for retry tracking
Returns AckResult
Result with updated flow or error
- Defined in state/qos-flow.ts:164

handlePubrel

handlePubrel(packet: PubrelPacket): QoS2InboundFlow | undefined
Handle PUBREL for inbound QoS 2 (step 3).

Completes the inbound QoS 2 flow.
Parameters
- packet: PubrelPacket
  PUBREL packet received
Returns QoS2InboundFlow | undefined
The completed flow or undefined if not found
- Defined in state/qos-flow.ts:275

hasInbound

hasInbound(packetId: number): boolean
Check if we have an inbound QoS 2 flow for a packet ID.

Used to detect duplicate QoS 2 PUBLISH.
Parameters
- packetId: number
Returns boolean
- Defined in state/qos-flow.ts:290

incrementRetry

incrementRetry(packetId: number, timestamp: number): OutboundFlow | undefined
Increment retry count for an outbound flow.
Parameters
- packetId: number
  Packet ID to update
- timestamp: number
  New send timestamp
Returns OutboundFlow | undefined
Updated flow or undefined if not found
- Defined in state/qos-flow.ts:319

restore

restore(
outbound: Iterable<OutboundFlow>,
inbound: Iterable<QoS2InboundFlow>,
): void
Restore flows from session state.
Parameters
- outbound: Iterable<OutboundFlow>
- inbound: Iterable<QoS2InboundFlow>
Returns void
- Defined in state/qos-flow.ts:358

startQoS1Outbound

startQoS1Outbound(packet: PublishPacket, timestamp: number): void
Start tracking an outbound QoS 1 flow.
Parameters
- packet: PublishPacket
  PUBLISH packet being sent
- timestamp: number
  Send timestamp
Returns void
- Defined in state/qos-flow.ts:99

startQoS2Inbound

startQoS2Inbound(packet: PublishPacket, timestamp: number): void
Start tracking an inbound QoS 2 flow.

Called when we receive a QoS 2 PUBLISH and send PUBREC.
Parameters
- packet: PublishPacket
  PUBLISH packet received
- timestamp: number
  Receive timestamp
Returns void
- Defined in state/qos-flow.ts:252

startQoS2Outbound

startQoS2Outbound(packet: PublishPacket, timestamp: number): void
Start tracking an outbound QoS 2 flow.
Parameters
- packet: PublishPacket
  PUBLISH packet being sent
- timestamp: number
  Send timestamp
Returns void
- Defined in state/qos-flow.ts:120

Class QoSFlowTracker

Example

Index

Constructors

Accessors

Methods

Constructors

constructor

Parameters

Returns QoSFlowTracker

Accessors

inboundCount

Returns number

outboundCount

Returns number

Methods

canSendOutbound

Returns boolean

clear

Returns void

getAllInbound

Returns ReadonlyMap<number, QoS2InboundFlow>

getAllOutbound

Returns ReadonlyMap<number, OutboundFlow>

getFlowsNeedingRetry

Parameters

Returns OutboundFlow[]

getInbound

Parameters

Returns QoS2InboundFlow | undefined

getOutbound

Parameters

Returns OutboundFlow | undefined

handlePuback

Parameters

Returns AckResult

handlePubcomp

Parameters

Returns AckResult

handlePubrec

Parameters

Returns AckResult

handlePubrel

Parameters

Returns QoS2InboundFlow | undefined

hasInbound

Parameters

Returns boolean

incrementRetry

Parameters

Returns OutboundFlow | undefined

restore

Parameters

Returns void

startQoS1Outbound

Parameters

Returns void

startQoS2Inbound

Parameters

Returns void

startQoS2Outbound

Parameters

Returns void

Settings

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