Struct SessionStateMachine 

pub struct SessionStateMachine {
    state: SessionState,
}

Pure state machine for MoQT session lifecycle. Transitions: Connecting -> SetupExchange -> Active -> Draining -> Closed.

Fields

state: SessionState

Implementations

impl SessionStateMachine

pub fn new() -> Self

Create a new state machine starting in the Connecting state.

pub fn state(&self) -> SessionState

Returns the current session state.

pub fn on_connect(&mut self) -> Result<(), SessionError>

Transition: Connecting -> SetupExchange.

pub fn on_setup_complete(&mut self) -> Result<(), SessionError>

Transition: SetupExchange -> Active.

pub fn on_goaway(&mut self) -> Result<(), SessionError>

Transition: Active -> Draining (GOAWAY received).

pub fn on_close(&mut self) -> Result<(), SessionError>

Transition: SetupExchange|Active|Draining -> Closed.

draft-20 Section 3.5: “The Transport Session can be terminated at any point.”

SetupExchange is accepted, and draft-20 removes the code that made the case obvious rather than the case itself. Draft-19’s Section 3.5 listed VERSION_NEGOTIATION_FAILED (0x15), “The client didn’t offer a version supported by the server” — a failure reachable only from SetupExchange, before any session is Active. Draft-20 deleted the row, because from draft-15 on there is no version on the wire to fail to negotiate: the draft is the ALPN and a mismatch ends the TLS handshake before a MoQT session exists. What survives is every other reason a setup exchange can end — a PATH from a server, a malformed SETUP, a peer that goes away — and a session that could not close in SetupExchange could record none of them.

Connecting is still refused: no transport session has been established, so there is nothing to terminate.

Trait Implementations

impl Default for SessionStateMachine

fn default() -> Self

Returns the “default value” for a type.