M2: thumbnail engine — turbojpeg DCT-shrink decode, worker pool, disk cache
- images.rs: libjpeg-turbo 1/2..1/8 shrink decode (48MP @1/8 ~2.3MB peak),
all 8 EXIF orientations, imageops::resize final fit, PNG via image crate,
q85 re-encode for the disk cache
- thumb.rs: dispatcher + N=cores/2 workers (2..8), cache
thumbs/{sha1(path|mtime|size|target)}.jpg (target in key: list 64px and
grid 500px coexist), atomic rename, generation-based cancellation,
per-worker sqlite set_thumb, 256-job cadence logs
- lib.rs: AppState OnceLock, 10Hz drain timer (leaked !Send Timer),
scroll prefetch (50-row margin), do_prefetch gating for scan batches
- main.slint/db.rs: rows carry images; list_entries + set_thumb
- build.sh: NDK CMake toolchain env for turbojpeg-sys (ANDROID_JAR vs
ANDROID_PLATFORM conflict), nasm on PATH, ADB_SERIAL, debug-aarch64
- HANDOFF: M2 done + acceptance data; HEIC deferred (0 HEIC on device);
transient first-launch black screen parked as §10.7 (unreproducible)
Verified: 12 unit tests + 5k engine test; Pixel 9 Pro 8577 photos —
cold scan ~5s streaming, warm relaunch instant, thumbnails in every row,
~100% cache hits on relaunch; release aarch64 APK 9.8 MB.
Greg Pomerantz
572409b702