Enum TemplateEvent 

pub enum TemplateEvent {
    Learned {
        template_id: u16,
        protocol: TemplateProtocol,
    },
    Collision {
        template_id: u16,
        protocol: TemplateProtocol,
    },
    Evicted {
        template_id: u16,
        protocol: TemplateProtocol,
    },
    Expired {
        template_id: u16,
        protocol: TemplateProtocol,
    },
    MissingTemplate {
        template_id: u16,
        protocol: TemplateProtocol,
    },
}

Template lifecycle events.

These events are emitted during template cache operations and allow users to monitor and react to template state changes.

Variants

Learned

A new template was learned and added to the cache.

This event fires when a template definition packet is successfully parsed and the template is inserted into the cache for the first time.

Fields

template_id: u16

The template ID that was learned

protocol: TemplateProtocol

The protocol (V9 or IPFIX)

Collision

A template ID was reused, potentially with a different definition.

This event indicates that a template ID already in the cache was encountered again. This could be:

• The same template being re-sent (normal refresh)
• A different template using the same ID (collision - problematic)

In multi-source deployments without proper scoping, collisions indicate that different routers are using the same template ID with potentially different schemas. Use AutoScopedParser to avoid this issue.

Fields

template_id: u16

The template ID that collided

protocol: TemplateProtocol

The protocol (V9 or IPFIX)

Evicted

A template was evicted from the cache due to LRU policy.

When the cache reaches its maximum size, the least recently used template is evicted to make room for new templates. Frequent evictions may indicate that the cache size is too small or that there are too many active templates.

Fields

template_id: u16

The template ID that was evicted

protocol: TemplateProtocol

The protocol (V9 or IPFIX)

Expired

A template expired due to TTL timeout.

When TTL-based template expiration is enabled, templates that haven’t been used within the configured timeout are automatically removed from the cache. This is useful for handling exporters that may change their template definitions without notification.

Fields

template_id: u16

The template ID that expired

protocol: TemplateProtocol

The protocol (V9 or IPFIX)

MissingTemplate

Data packet arrived for a template that isn’t in the cache.

This typically occurs when:

• Data packets arrive before their template definition (out-of-order)
• Template was evicted from cache before data arrived
• Template definition packet was lost in transit

Users can implement retry logic or buffering strategies based on this event.

Fields

template_id: u16

The template ID that was not found

protocol: TemplateProtocol

The protocol (V9 or IPFIX)

Trait Implementations

impl Clone for TemplateEvent

fn clone(&self) -> TemplateEvent

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TemplateEvent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.