Enum ClientEvent 

#[non_exhaustive]
pub enum ClientEvent {
    SetupComplete {
        negotiated_version: u64,
    },
    ControlMessage {
        direction: Direction,
        message: AnyControlMessage,
        stream_id: Option<u64>,
        raw: Option<Vec<u8>>,
    },
    StreamOpened {
        direction: Direction,
        stream_kind: StreamKind,
        stream_id: u64,
    },
    DataStreamHeader {
        stream_id: u64,
        direction: Direction,
        header: AnySubgroupHeader,
    },
    PublishStateNotify {
        request_id: u64,
        stream_id: u64,
        parameters: Vec<KeyValuePair>,
    },
    FetchStreamHeader {
        stream_id: u64,
        direction: Direction,
        header: AnyFetchHeader,
    },
    SubgroupObjectReceived {
        stream_id: u64,
        direction: Direction,
        subgroup_header: SubgroupHeader,
        object: SubgroupObject,
    },
    FetchHeaderReceived {
        stream_id: u64,
        direction: Direction,
        header: FetchHeader,
    },
    DatagramReceived {
        direction: Direction,
        header: AnyDatagramHeader,
        payload_len: usize,
    },
    StreamClosed {
        stream_id: u64,
        error_code: u64,
    },
    Draining {
        new_session_uri: Vec<u8>,
    },
    Closed {
        code: u32,
        reason: Vec<u8>,
    },
    Error {
        error: String,
    },
}

Events emitted by a MoQT connection.

This enum is #[non_exhaustive] – new variants may be added in minor releases. Downstream match arms should include a wildcard _ => branch.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

SetupComplete

MoQT setup handshake completed.

Fields

negotiated_version: u64

The negotiated MoQT version (from ALPN in draft-20).

ControlMessage

A control message was sent or received.

Fields

direction: Direction

Whether the message was sent or received.

message: AnyControlMessage

The decoded control message.

stream_id: Option<u64>

The transport-level identifier of the stream the message travelled on when that stream is a request stream, and None when it is the control stream.

Draft-20 responses carry no request id: the stream is the correlation. Without this an observer sees a SUBSCRIBE_OK with nothing to say which SUBSCRIBE it answers, and cannot tell a message on the control stream from one on a request stream.

raw: Option<Vec<u8>>

The raw wire bytes of the framed message (type + length + payload). None if raw capture is not available.

StreamOpened

A data stream was opened.

Fields

direction: Direction

Whether we opened (Send) or accepted (Receive) the stream.

stream_kind: StreamKind

The type of data stream.

stream_id: u64

Transport-level stream identifier.

DataStreamHeader

A data stream header was decoded after the stream opened.

Fields

stream_id: u64

Transport-level stream identifier.

direction: Direction

Whether we opened (Send) or accepted (Receive) the stream.

header: AnySubgroupHeader

The parsed subgroup header.

PublishStateNotify

The publisher reported that a subscription’s state changed, other than in answer to a REQUEST_UPDATE this endpoint sent.

PUBLISH_STATE_NOTIFY, new in draft-20 (Section 10.10). Nothing is owed in reply — “it is a unilateral notification: the receiver does not respond with REQUEST_OK or REQUEST_ERROR, and the message is not subject to the MAX_REQUEST_UPDATES limit” — and “no action is required by the recipient”. It is an event rather than a return value for that reason: there is nothing for a caller to do with it except notice.

It also arrives as an ordinary ClientEvent::ControlMessage, as every message does. This variant is the decoded form, so an observer does not have to reach through AnyControlMessage to find out which subscription changed.

Fields

request_id: u64

The Request ID of the subscription whose state changed.

The message itself carries no Request ID field: Section 10.10 makes the bidirectional stream the correlation, exactly as it is for SUBSCRIBE_OK, PUBLISH_DONE and FETCH_OK. This is the request that stream belongs to.

stream_id: u64

The transport-level identifier of that stream.

parameters: Vec<KeyValuePair>

The parameters whose values changed. A parameter that is absent is unchanged; the publisher “MUST include the LARGEST_OBJECT parameter” if known, so a receiver can place the change in the track.

FetchStreamHeader

A fetch response stream header was decoded.

Fields

stream_id: u64

Transport-level stream identifier.

direction: Direction

Whether we opened (Send) or accepted (Receive) the stream.

header: AnyFetchHeader

The parsed fetch header.

SubgroupObjectReceived

A subgroup object header was decoded on a subgroup stream.

Fields

stream_id: u64

Transport-level stream identifier.

direction: Direction

Direction (Send when emitted from a writer, Receive from a reader).

subgroup_header: SubgroupHeader

The decoded subgroup header (for context).

object: SubgroupObject

The decoded subgroup object.

FetchHeaderReceived

A fetch header was decoded on a fetch stream.

Fields

stream_id: u64

Transport-level stream identifier.

direction: Direction

Direction (Send when emitted from a writer, Receive from a reader).

header: FetchHeader

The decoded fetch header.

DatagramReceived

A datagram was sent or received.

Fields

direction: Direction

Whether sent or received.

header: AnyDatagramHeader

The parsed datagram header.

payload_len: usize

Size of the payload in bytes.

StreamClosed

A data stream was closed.

Fields

stream_id: u64

Transport-level stream identifier.

error_code: u64

Error code (0 = clean close).

Draining

Session entered draining state (GOAWAY received).

Fields

new_session_uri: Vec<u8>

The new session URI from the GOAWAY message.

Closed

Connection was closed.

Fields

code: u32

Application error code.

reason: Vec<u8>

Human-readable reason.

Error

A transport or protocol error occurred.

Fields

error: String

Error description.

Trait Implementations

impl Clone for ClientEvent

fn clone(&self) -> ClientEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClientEvent

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

Formats the value using the given formatter.