Struct Info 

#[non_exhaustive]
pub struct Info {
    pub timescale: Timescale,
    pub max_age: Duration,
    pub priority: u8,
}

Publisher-side properties of a track.

These are fixed by the publisher when the track is created and don’t change while the track is alive. A subscriber learns them via broadcast::Consumer::track, which returns the publisher’s Info once the subscription is accepted.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

timescale: Timescale

Units per second for per-frame timestamps on this track.

Every track is timed; this defaults to Timescale::MILLI. On Lite05+ it is reported in TRACK_INFO and the publisher zigzag-delta encodes per-frame timestamps at this scale on the wire. Protocols whose wire can’t carry it (pre-Lite05 moq-lite, IETF moq-transport) fall back to local monotonic milliseconds.

max_age: Duration

How far behind the live edge a group may fall, in media timestamps, before it is stale. The newest group is always retained.

A retention bound rather than a delivery one, the inverse of an HTTP Cache-Control: max-age. Subscription::max_age is clamped to this, since a group can’t be waited for longer than it’s kept around. Reported in TRACK_INFO so relays re-serve with the same window. Defaults to DEFAULT_MAX_AGE.

Measured against timestamps rather than the wall clock, so a congestion stall (timestamps stop advancing) can’t age content out. Wall-clock reclamation of content nobody is accessing belongs to the cache pool’s own expiry window, not to this budget.

This is the Publisher Max Age on the wire, the publisher-side half of the budget Subscription::max_age sets for a subscriber.

Encoded as milliseconds in a QUIC varint, so a duration of 2^62 milliseconds or more cannot be put on the wire. Sub-millisecond precision is truncated (Duration::as_millis) at encode time.

priority: u8

The publisher’s priority for this track, used only to break ties between subscriptions of equal subscriber priority. Reported in TRACK_INFO (Lite05+). Higher is more urgent. Defaults to 127, the midpoint.

Implementations

impl Info

pub fn with_timescale(self, timescale: Timescale) -> Self

Set the per-frame timestamp scale, returning self for chaining.

Defaults to Timescale::MILLI. On Lite05+ this scale is reported in TRACK_INFO and used to encode per-frame timestamps on the wire.

pub fn with_max_age(self, max_age: Duration) -> Self

Set how old a non-latest group may get before eviction, returning self for chaining.

pub fn with_priority(self, priority: u8) -> Self

Set the publisher’s tie-break priority, returning self for chaining.

Trait Implementations

impl Clone for Info

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Info

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

Formats the value using the given formatter.

impl Default for Info

fn default() -> Self

Returns the “default value” for a type.