Struct DtlsSessionCache 

pub struct DtlsSessionCache { /* private fields */ }

A bounded, TTL-expiring cache of DTLS sessions keyed by peer address.

Constrained devices perform expensive handshakes (especially with post-quantum key exchange), so session resumption significantly reduces latency and power consumption for repeated EST operations.

Capacity Management

The cache enforces a maximum number of sessions. When full, expired sessions are purged first. If still full, the oldest session is evicted.

Implementations

impl DtlsSessionCache

pub fn new(max_sessions: usize, ttl: Duration) -> Self

Creates a new session cache.

Arguments

• max_sessions - Maximum number of sessions to cache.
• ttl - Duration after which sessions expire and become eligible for eviction.

pub fn insert(&mut self, session: DtlsSession)

Inserts a session into the cache.

If the cache is at capacity, expired sessions are purged first. If still full, the oldest session is evicted to make room.

pub fn get(&mut self, peer_addr: &SocketAddr) -> Option<&DtlsSession>

Retrieves a cached session for the given peer address.

Returns None if no session exists or if the session has expired. Expired sessions are removed on access.

pub fn remove(&mut self, peer_addr: &SocketAddr) -> Option<DtlsSession>

Removes a session from the cache.

Returns the removed session, or None if no session existed for the given address.

pub fn cleanup_expired(&mut self) -> usize

Removes all expired sessions from the cache.

Returns the number of sessions removed.

pub fn len(&self) -> usize

Returns the number of currently cached sessions.

pub fn is_empty(&self) -> bool

Returns whether the cache is empty.

pub fn max_sessions(&self) -> usize

Returns the configured maximum number of sessions.

pub fn ttl(&self) -> Duration

Returns the configured TTL.

Trait Implementations

impl Debug for DtlsSessionCache

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

Formats the value using the given formatter.