Struct SessionCache 

pub struct SessionCache { /* private fields */ }

LRU Session Cache with eviction

Implementations

impl SessionCache

pub fn new() -> Self

Create with default settings

impl SessionCache

pub fn with_capacity(max_entries: usize, ticket_lifetime: Duration) -> Self

Create with custom limits (for Device Profiles)

pub fn store( &mut self, session_id: SessionId, resumption_secret: &[u8; 32], cipher_suite: CipherSuite, )

Store a ticket after a successful handshake.

resumption_secret must be the same value Session::resumption_hint() exposes to the client — it is stored verbatim so both peers derive the same early-data key.

pub fn try_resume( &mut self, session_id: &SessionId, ) -> Option<([u8; 32], CipherSuite)>

Attempt to resume a session (0-RTT). One-shot: a successful lookup REMOVES the ticket, so a replayed ClientHello carrying the same resume_session_id finds nothing and falls back to a full 1-RTT handshake. This is the anti-replay guarantee for 0-RTT early-data (Phase 4.1).

Returns (raw resumption_secret, cipher_suite) — the verbatim secret stored at store time, ready to feed into crypto::kdf::derive_early_data_keying.

pub fn peek( &mut self, session_id: &SessionId, ) -> Option<([u8; 32], CipherSuite, Instant, Instant)>

Look up a still-valid ticket without consuming it (HS-03). Expired tickets are removed and None returned. The returned created_at/expires_at let the caller re-insert the ticket unchanged via reinsert_with_expiry if a resume that passed the binder check later fails (ZERORTT-2) — without extending the lifetime. Actual consumption is a separate explicit remove once the resume’s proof-of-possession (binder) has been verified.

pub fn reinsert_with_expiry( &mut self, session_id: SessionId, resumption_secret: &[u8; 32], cipher_suite: CipherSuite, created_at: Instant, expires_at: Instant, )

Re-insert a ticket that a resume attempt consumed but then failed to complete (ZERORTT-2 — e.g. a corrupted KEM ciphertext aborts the handshake after the ticket was removed). Restores the ticket with its original timestamps so the lifetime is not extended, and refuses to resurrect an already-expired ticket. Mirrors store’s eviction + LRU bookkeeping so evict_oldest stays consistent.

pub fn remove(&mut self, session_id: &SessionId) -> bool

Remove a specific ticket. Returns true iff a ticket was actually present — the resume path uses this to make eager consumption race-free: of two concurrent resumes of the same id, exactly one observes true and proceeds, so the same 0-RTT early-data cannot be accepted twice.

pub fn len(&self) -> usize

Number of cached tickets

pub fn is_empty(&self) -> bool

Returns true if no tickets are cached

pub fn clear(&mut self)

Clear all tickets

Trait Implementations

impl Default for SessionCache

fn default() -> Self

Returns the “default value” for a type.