feat(moq-net): add OriginProducer::dynamic + infallible OriginConsumer::request_broadcast

[kixelated]

Summary

Ports the origin-level dynamic-fallback API from dev to main: OriginProducer::dynamic() (from #1772) and an infallible OriginConsumer::request_broadcast (from #1890).

On dev these ride on a chain of disruptive reshapes that are deliberately quarantined there (TrackInfo/TrackConsumer #1631, RAII OriginPublish #1640, lite-05 wire #1847). Rather than drag those into main, this reimplements the feature additively against main's existing primitives. It turned out the dynamic machinery is self-contained on kio + OriginNodes, so the port is small and touches no existing API — subscribe_track and the rest of the origin/track surface are unchanged.

What changed

moq-net

• OriginProducer::dynamic() -> OriginDynamic — serves whole broadcasts on demand. Served broadcasts are never announced, so they only resolve a consumer's exact-path request when no live announcement exists (the origin-level analogue of BroadcastProducer::dynamic).
• OriginConsumer::request_broadcast(path) -> kio::Pending<BroadcastRequested> — looks up an announced broadcast (resolves immediately), else registers a fallback request that resolves once an OriginDynamic handler accepts it. Concurrent requests for the same path coalesce.
• New types: OriginDynamic, BroadcastRequest, BroadcastRequested.
• Error::Unroutable at wire code 30 (matches dev; codes 28/29 stay reserved for dev's compression/timestamp errors so the wire code is identical across branches).

kio (additive)

• Future + Pending (future.rs, ported verbatim — depends only on Waiter).
• Consumer::write(), so the requester can enqueue into the shared dynamic queue (mirrors Producer::write).

Infallibility

request_broadcast is infallible on its own terms — it returns a kio::Pending future, not a Result. An announced path resolves immediately; an unannounced path stays pending until served, then resolves to the broadcast or to Error::Unroutable (no route) / Error::Dropped (origin gone). This required no change to subscribe_track, which stays -> Result<...> as on main.

API notes

This adds new public moq-net surface but is purely additive (no existing signature changes), so it's main-appropriate per Branch Targeting. New public items: OriginProducer::dynamic, OriginConsumer::request_broadcast, OriginDynamic, BroadcastRequest, BroadcastRequested, Error::Unroutable, kio::{Future, Pending}, kio::Consumer::write.

One deliberate divergence from dev: BroadcastRequest::accept takes a BroadcastConsumer directly instead of dev's Consume<T> trait. That trait is part of the #1640 RAII reshape and pulling it in would change publish_broadcast's signature, which is out of scope here.

Follow-ups (Cross-Package Sync) — intentionally not in this PR

• js/net mirror + doc/concept
• FFI/libmoq + py/swift/kt/go wrapper surface (dev's feat(moq-net): add OriginDynamic for unannounced fallback broadcasts #1772 mirrored this)
• relay wiring to use the dynamic fallback router

Test plan

• cargo test -p kio -p moq-net — passes, including 8 new dynamic_* tests (ported and adapted to main's API) and the kio Pending test
• cargo fmt + cargo clippy -p kio -p moq-net (via nix) clean
• reverse-deps compile: moq-relay, moq-native, hang, moq-mux, moq-ffi, moq-cli
• full just check (JS + native matrix) not run — change is Rust-only and additive

🤖 Generated with Claude Code

(Written by Claude)

[coderabbitai]

Caution

Review failed

Pull request was closed or merged during review

Walkthrough

Adds a kio Future trait and Pending adapter for std::future::Future, plus Consumer::write for mutable state access. Re-exports the new kio types from rs/kio/src/lib.rs. In moq-net, adds Error::Unroutable and maps it to wire code 30. OriginProducer and OriginConsumer now share a dynamic queue for unannounced broadcast requests, and new origin dynamic request types handle polling, acceptance, rejection, and tests.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main moq-net API additions and matches the changeset.
Description check	✅ Passed	The description is directly related to the ported dynamic-fallback API and supporting kio changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch claude/gallant-pasteur-e488d0

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}