Struct Connection 

pub struct Connection { /* private fields */ }

Handle to a live FIX session.

Cloning is cheap; all clones refer to the same session. The session is closed when the transport drops, the counterparty logs out, a heartbeat timeout is detected, or Connection::logout completes.

Dropping every handle logs out

The reactor stops when the last clone is dropped: it reads that as “nobody can drive this session any more” and performs a graceful Logout rather than leaving a task holding a socket forever. A consumer that wants the session to outlive its handle must keep one alive — typically by holding it until Connection::wait_closed returns.

Implementations

impl Connection

pub fn session_id(&self) -> &SessionId

Returns the session identifier.

pub async fn send(&self, message: OutboundMessage) -> Result<(), EngineError>

Sends an application message on the session.

The engine stamps the standard header (including MsgSeqNum) and trailer; the message only needs body fields. It is checked here, before it is queued, so a message the session layer will not carry is refused to the caller rather than dropped later.

Arguments

• message - The application message to send

Errors

• EngineError::ReservedMsgType for an administrative MsgType. Logon, Logout, SequenceReset and the rest belong to the session state machine; one sent here would bypass the typestate and the engine’s phase tracking — a Logout sent this way never arms the logout timeout.
• EngineError::ReservedTag for a body field that repeats a tag the engine stamps itself (see crate::outbound::RESERVED_TAGS), which would put two occurrences of it in the frame.
• EngineError::InvalidField for a value with no legal wire form.
• EngineError::Closed if the session is already closed.

Accepted is not sent

Ok means the message was queued for the reactor, not that it reached the counterparty. A message queued while a Logout is already pending is dropped with a warning — the session is on its way out and a new application message would arrive after the Logout the counterparty has already seen. Use Connection::wait_closed to observe the end of the session and next_sender_seq to observe progress.

pub async fn logout(&self) -> Result<(), EngineError>

Initiates a graceful logout.

A Logout message is sent to the counterparty; the session closes when the Logout acknowledgement arrives or the logout timeout elapses. Use Connection::wait_closed to observe completion.

Errors

Returns EngineError::Closed if the session is already closed.

pub async fn wait_closed(&self)

Waits until the session is closed.

Fires on transport drop, counterparty logout, heartbeat timeout, or completion of a locally initiated logout. Returns immediately if the session is already closed.

It fires after the inbound application messages already queued have been through from_app and on_logout has run, so a handler still in flight when the session ends delays this by however long it takes to finish, up to an internal drain bound.

pub fn is_closed(&self) -> bool

Returns true if the session is closed.

pub fn is_timed_out(&self) -> bool

Returns true if the session has detected a heartbeat timeout (a TestRequest went unanswered for a full heartbeat interval).

pub fn next_sender_seq(&self) -> u64

Returns the next outgoing (sender) sequence number.

pub fn next_target_seq(&self) -> u64

Returns the next expected incoming (target) sequence number.

Trait Implementations

impl Clone for Connection

fn clone(&self) -> Connection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Connection

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

Formats the value using the given formatter.