Struct HlsOriginBuilder 

pub struct HlsOriginBuilder { /* private fields */ }

Available on crate feature std only.

Fluent builder for HlsOrigin (issue #873) — replaces the old four-positional HlsOrigin::new (deleted; this crate is at 0.4.0 unpublished, so there is no compatibility burden), which could not express “classic HLS, no low latency” at all since part_target_ms was a mandatory positional argument.

let classic_ts = HlsOrigin::builder(Arc::clone(&trunk))
    .target_duration_secs(6.0)
    .window_segments(nz(4))
    .container(Container::MpegTs)
    // `.low_latency(..)` omitted entirely -> classic HLS.
    .build()
    .expect("both required fields were set");

Implementations

impl HlsOriginBuilder

pub fn target_duration_secs(self, target_duration_secs: f64) -> Self

#EXT-X-TARGETDURATION’s configured floor (RFC 8216bis §4.4.3.1) — required; HlsOriginBuilder::build errors if this is never called. The actually-rendered value is raised to the largest real segment duration seen, if that ever exceeds this (see render_playlist).

pub fn window_segments(self, window_segments: NonZeroUsize) -> Self

How many closed segments this origin advertises in a rendered Media Playlist — required; independent of media_plane::trunk::TrunkConfig::segment_capacity (the Trunk’s own retention bound): a caller may legitimately want a shorter advertised window than the Trunk retains for other consumers (e.g. a DVR SegmentEgress reading the same Trunk).

pub fn container(self, container: Container) -> Self

Which container this origin serves segments/parts as. Defaults to Container::Fmp4 if never called, matching every pre-#873 caller’s behaviour. Orthogonal to Self::low_latency — all four {Fmp4, MpegTs} x {classic, low-latency} combinations are valid.

pub fn low_latency(self, part_target_ms: u32) -> Self

Opt into LL-HLS: part_target_ms becomes #EXT-X-PART-INF’s PART-TARGET (milliseconds). Omit this call entirely for classic HLS — no #EXT-X-PART/#EXT-X-PART-INF/#EXT-X-SERVER-CONTROL/ #EXT-X-PRELOAD-HINT tags are then rendered, regardless of Self::container. This is what the old constructor’s mandatory part_target_ms positional could not express.

pub fn media_sequence_offset(self, offset: u64) -> Self

Add offset to every Media Sequence Number this origin shows: the playlist’s EXT-X-MEDIA-SEQUENCE, the numbers in segment/part URIs and the _HLS_msn it answers to. Default 0.

A fresh Trunk restarts its segment numbers at 1; the offset is the mechanism that keeps the Media Sequence Number a client sees increasing across a replacement origin (RFC 8216bis §6.2.2: it MUST NOT decrease). Pass previous.next_media_sequence() — not - 1: the number the previous origin’s open segment was shown with is skipped too, as its parts were already served (see HlsOrigin::next_media_sequence).

pub fn instance(self, token: u64) -> Self

Override the per-origin HlsOrigin::instance token (default: a fresh wall-clock-seeded one per build). For deterministic tests and for an embedder that wants names stable across a rebuild it knows is the same media.

pub fn build(self) -> Result<HlsOrigin, HlsOriginBuildError>

Build the HlsOrigin, subscribing its one SegmentCursor immediately (so the window starts empty but never misses a segment published from this point on).

Errors, never silently defaults, if Self::target_duration_secs or Self::window_segments was never called, for a zero Self::low_latency part target, or for an offset that cannot hold the u32 sequence range.

The advertised window is never shorter than three segments, whatever Self::window_segments says (RFC 8216bis §6.2.2: a live Playlist MUST NOT be shortened below three Target Durations). Part retention is not checked here: the part ring’s capacity belongs to the Trunk and is not observable from it; the playlist only advertises the parts of a closed segment while all of them are still resident.