straw/rust
Kayos dd151e322d vc=66: hybrid feed backfill — RSS-fast + streamInfo-complete
Cobb asked for views + durations back in the subs feed without
giving up the 5-10× RSS speedup vc=56 bought. Hybrid path:

1. Rust wrapper — new enrich_feed_item(video_url) ->
   EnrichedFeedMetadata { view_count, duration_seconds }. Thin
   wrapper around stream_info that discards the heavy play-URL
   payload. Future opt: parse watch-page HTML JSON state directly
   to skip JS deobf entirely. ~150 lines of pluck logic, punted.

2. EnrichmentStore — new SharedPreferences-lite store keyed by
   videoId, value Enrichment(viewCount, durationSeconds,
   fetchedAt). Bound to Settings.cacheTtl for staleness. Hard cap
   5000 entries with oldest-eviction.

3. SubscriptionFeedViewModel — after the RSS refresh paints,
   enrichVisibleItems() fans out enrichFeedItem for the first 30
   items (skipping any already enriched fresh). Bounded at 8 wide
   so we don't hammer YT; each call ~500ms full streamInfo so
   30 items in ~2s. Runs on StrawApp.globalScope so a
   refresh-cancel doesn't kill the in-flight enrichment.
   mergeFromCache overlays the enrichment via .withEnrichment()
   so RSS rows pick up viewCount + durationSeconds the moment
   they land. The Enrichment store's StateFlow.value is read on
   every merge call; the enrichment-complete handler triggers a
   _ui.update that re-merges.

Net behavior: feed paints instantly from RSS (no view/duration),
~2s later the visible top-N populate with full metadata. Cached
forever (or until TTL/cap). Subsequent opens read straight from
EnrichmentStore.

StrawApp.onCreate inits the new store alongside the existing
SP-backed ones.
2026-05-26 13:40:26 -07:00
..
strawcore vc=66: hybrid feed backfill — RSS-fast + streamInfo-complete 2026-05-26 13:40:26 -07:00
Cargo.toml v0.1.0-V (vc=9): U-3 — streamInfo via rustypipe drives VideoDetail+Player 2026-05-24 08:52:43 -07:00
README.md v0.1.0-U (vc=8): Phase U-1 + U-2 — Rust core + rustypipe search 2026-05-24 08:36:50 -07:00

rust/ — strawcore: Rust YouTube core for Straw

Phase U- of the Straw build. Goal: replace the Java NewPipeExtractor dependency with a Rust core (rustypipe + tokio + reqwest), exposed to the Kotlin/Compose UI via UniFFI. Compose UI stays in Kotlin — only the YouTube/Innertube fetching layer moves to Rust.

Phases

Phase What
U-1 Toolchain + UniFFI smoke test (hello_from_rust) round-tripping through JNA. No real APIs yet.
U-2 rustypipe search. SearchViewModel calls the Rust core.
U-3 rustypipe streamInfo + streams. VideoDetailViewModel + PlayerViewModel use it.
U-4 rustypipe channel + tabs. ChannelViewModel + SubscriptionFeedViewModel.
U-5 Rip NewPipeExtractor Java dep. Measure APK + cold-fetch latency before/after.
U-6 (stretch) SponsorBlock + RYD HTTP through reqwest + tokio in the same lib.

Build chain

crafting-table
├── rustup stable (target add: aarch64-linux-android, armv7-linux-androideabi,
│                  x86_64-linux-android, i686-linux-android)
├── cargo-ndk      (cross-compile helper)
├── android-sdk    (ANDROID_HOME, sdkmanager, build-tools, platforms)
└── android-ndk    (ANDROID_NDK_HOME, r27c LTS at /caches/android-sdk/ndk/...)

Gradle (strawApp/build.gradle.kts)
├── cargoBuild         Exec task → cargo ndk -t <abi>... -o jniLibs/ build --release
├── uniffiBindgen      Exec task → cargo run --bin uniffi-bindgen ... --library libstrawcore.so
└── source-set wiring  generated Kotlin lands in strawApp/src/main/java/uniffi/strawcore/

Runtime (StrawApp.onCreate)
├── System.loadLibrary("strawcore")
└── uniffi.strawcore.initLogging()

Why UniFFI (and not raw JNI / JNA bindings)

  • Hand-written JNI: tedious, error-prone, every type change is two files (Kotlin + Rust) that must stay in sync.
  • Raw JNA: better, but you still hand-write the Kotlin side and worry about string ownership.
  • UniFFI: write Rust, annotate with #[uniffi::export], get a Kotlin shim generated. Strings, structs, enums, Result types, async functions all cross the boundary transparently. The runtime is JNA under the hood.

When in doubt

  • cargo check -p strawcore --target aarch64-linux-android — fast iteration.
  • cargo run --bin uniffi-bindgen -- generate ... — regenerate Kotlin bindings.
  • adb logcat -s strawcore — Rust log::info!() lands here.
  • aapt dump badging strawApp/build/outputs/apk/debug/strawApp-debug.apk — inspect what ABIs/native-libs the APK carries.