Module notification_forwarder 

Notification Forwarder object (type 51, Clause 12.51).

A forwarder originates no events. It takes the event notifications this device receives, and those its own objects address to the local Device, and sends each one on to the destinations it holds: the configured Recipient_List and the expiring Subscribed_Recipients. The server does the sending; see forwarding_targets for which notifications a forwarder takes and where it sends them.

Rows

The object serves every required row of Table 12-58, plus Description and, when the application configures one, Port_Filter. Over the network:

• Recipient_List takes the same writes as a Notification Class’s, capped at MAX_RECIPIENT_LIST_DESTINATIONS destinations.
• Subscribed_Recipients is a SubscribedRecipients store: entries run out after their Time Remaining and are edited by AddListElement and RemoveListElement.
• Process_Identifier_Filter takes an Unsigned32, or NULL to forward every process identifier; Local_Forwarding_Only and Out_Of_Service take a BOOLEAN.
• Port_Filter takes writes of its Enabled members only (Clause 12.51.11): the array keeps its size and Port_IDs.
• Reliability is always NO_FAULT_DETECTED and is not writable.

Restarts

Clauses 12.51.8 and 12.51.9 ask for both lists to survive a restart. A forwarder built with NotificationForwarderObject::with_persistence saves Recipient_List and Subscribed_Recipients together, each subscription with the minutes it has left, when a write changes either list, when an entry lapses, and at most once a minute while the minutes the entries serve fall; it restores both when built again. A restored entry counts down from its saved minutes: no fewer than it had left when the device stopped, about a minute more at most, and never more than its last subscription gave it, so restarts do not keep an entry alive.

Saves run on the forwarder’s own writer thread, never while the database guard is held (crate::durable), and a list write that cannot be saved is refused with DEVICE / OPERATIONAL_PROBLEM, leaving the old list. A failed save is logged and counted (ForwarderSaveCounters); one the operation task made is retried a minute later.

A written Recipient_List wins over the one the application configures: once a write has set the list and it was saved, a rebuilt forwarder serves the saved list and ignores add_destination calls. Until then the configured destinations apply at every start; they are not saved. A forwarder built with NotificationForwarderObject::new keeps both lists in memory only.

Re-exports

pub use crate::notification_class::MAX_RECIPIENT_LIST_DESTINATIONS;

Structs

FileNotificationForwarderPersistence

A file holding one forwarder’s lists, replaced whole on each save.

ForwarderSaveCounters

Lifetime totals of one forwarder’s saves, shared with the object: take it with save_counters before the object joins a database, and read it at any time after. Each total saturates at u64::MAX.

ForwarderSnapshot

What a forwarder keeps across a restart: both of its lists.

ForwardingInput

One event notification offered to this device’s forwarders.

ForwardingTargets

Where this device’s forwarders send one notification.

NotificationForwarderObject

BACnet Notification Forwarder object (type 51). See the module documentation.

Traits

NotificationForwarderPersistence

Application-owned storage for one Notification Forwarder’s lists.

Functions

forwarding_targets

Select the forwarders that take input and their destinations, leaving out the forwarders in skip (those that already took this notification earlier in a chain within this device).