Struct RelaySeenCache 

pub struct RelaySeenCache { /* private fields */ }

Bounded, insertion-ordered record of recently handled message ids.

Implementations

impl RelaySeenCache

pub fn new() -> Self

Creates a cache with the default sizing.

pub fn with_config(config: RelaySeenConfig) -> Self

Creates a cache with explicit sizing.

pub fn observe(&mut self, message_id: &str) -> SeenOutcome

Records message_id, reporting whether it had been seen already.

This is the single entry point: checking and recording are one step so no caller can test an id and then forget to record it, which would forward every copy.

pub fn forget(&mut self, message_id: &str)

Forgets message_id, so a later copy is treated as new again.

For a frame that was recorded as handled and then dropped without ever being transmitted — displaced from a queue, abandoned for waiting too long, refused room on the way back. The record would otherwise refuse every later copy for the rest of the retention window, including the sender’s own retransmissions, which carry the same id: a route closed for ten minutes by a few seconds of congestion, with nothing on the air to justify it.

Safe only because nothing was transmitted. An id forgotten after the frame reached a neighbor could be forwarded a second time — by every node — which is how a flood becomes a storm, so callers must be certain the frame travelled nowhere.

One exception, and only at the point of acceptance: the mesh relay governor forgets and immediately re-records an id when it accepts the sender’s own re-send of a frame it already carried. The entry is gone for no observable moment, so no echo can slip through, and a re-send the governor refuses never reaches this call.

pub fn contains(&self, message_id: &str) -> bool

Whether message_id is currently suppressed, without recording it.

pub fn expire(&mut self, now: Instant)

Drops entries older than the retention window.

Called automatically by Self::observe; exposed so an idle node can release memory from its process tick.

pub fn len(&self) -> usize

Number of ids currently tracked.

pub fn is_empty(&self) -> bool

Whether the cache holds no ids.

pub fn duplicates_suppressed(&self) -> u64

How many arrivals were suppressed as already-handled.

pub fn capacity_evictions(&self) -> u64

How many ids were dropped for capacity rather than age.

Expected to stay at zero: an id evicted while copies of it are still in flight would be forwarded again. A rising count means the cache is too small for the traffic the node is seeing.

pub fn clear(&mut self)

Removes every entry.

Trait Implementations

impl Debug for RelaySeenCache

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

Formats the value using the given formatter.

impl Default for RelaySeenCache

fn default() -> Self

Returns the “default value” for a type.