3dtours
64d41f67e9
A folder of RAW took the page down. The catalogue reads four frames at once —
that is what makes a roll land quickly, and for a JPEG it is free — but a RAW is
not read by this page at all: it is handed to libraw-wasm, which opens it inside
a worker of its own, and that worker is built with a quarter of a gigabyte of
linear memory (emscripten's shared memory, 256MB, instantiated per instance) and
the whole frame is copied into it. Four of those at once, on frames of 22.6MB,
is past what a renderer is given before a single tile is drawn, and the page goes
with it — which is the crash this answers.
One open at a time now, whoever asks for it: the gate wraps the read of a RAW and
nothing else, so the frames around the one being opened still have their bytes
read off the disk, their decodes run and their tiles encoded side by side. Only
the open queues. A folder of JPEGs never touches the gate and keeps all four
lanes.
The tile also stops asking the decoder a question the bytes answer. A JPEG — and
the preview a camera writes inside a RAW is one — carries its frame size in its
own header, in the first few hundred bytes the read already holds for the date.
`jpegSize` reads it there, and `tile` is handed the size instead of decoding the
whole frame a second time only to learn which edge is long. `jpegSize` existed
for exactly this and had no caller; it has one now.
Verified:
- library-check.mjs, scan-nav-check.mjs, roll-walk-check.mjs all pass against the
built bundle — the catalogue still reads a roll, a RAW still becomes a tile off
its own preview, a frame still says where it was shot, an interrupted reading
still goes on by itself.
- A stand-in folder answered `showDirectoryPicker`, 48 frames of 22.6MB, resident
memory of the whole browser process tree sampled every 150ms:
- before: 4 frames read at once, peak RSS 1335MB, 565MB before the roll was
picked, 12s, 48 tiles, no error;
- after: 1 frame read at once, peak RSS 1180MB, 32s, 48 tiles, no error.
The 2.6× on the clock is mostly the harness: its `getFile` copies 22.6MB per
frame, so serialising the open serialises that copy too. A real folder pays a
disk read and an open in sequence instead.
- 200 frames of 8.5MB JPEG, same harness: peak 1713MB, 4 at a time, 200 tiles,
no error — the JPEG path is untouched by this commit.
ponytail: reading a RAW could skip LibRaw entirely — the camera's preview is a
plain JPEG and could be cut out of the head of the file this page has already
read. Probed on four samples: RW2 carries a 1920×1280 preview at 54KB, NEF one at
6016×4016 of 1.08MB, but DNG has only 720×480 inside its first 4MB and RAF keeps
almost none, and picking the wrong segment risks a thumbnail for a tile. Not
worth it until a RAW that is neither DNG nor RAF is the common case. The JPEG
path still peaks high (1713MB over 200 frames) and that is `createImageBitmap`
decoding every 5472×3648 frame whole, at four lanes — an app that reads fewer at
once trades time for the same headroom, if a page that large is ever the crash
again.
Co-authored-by: PenguinHarness <noreply@penguin.local>
RecipesCam web — self-contained stack
A Docker-hosted web build of RecipesCam. Everything it needs is in this folder: move it to another machine, run two commands, and the app is up. It does not need the React Native project around it.
cp .env.example .env
docker compose up -d --build
# → http://localhost:8090
What runs where
| Service | Image | Role |
|---|---|---|
frontend |
nginx:1.27-alpine (built by frontend/Dockerfile) |
Static SPA + /api/ reverse proxy |
api |
node:22-slim (built by backend/Dockerfile) |
Accounts + saved recipes, SQLite on ./data |
frontend resolves api through Docker's embedded DNS and proxies /api/* to
it — that is why the API container is named api and why it is not published on
the host. Only ${WEB_PORT:-8090} is exposed.
Photos never leave the browser. The CanvasKit render pipeline (grade, frame, watermarks, JPEG encode) runs in the visitor's tab; the API only stores recipes as JSON.
Layout
docker-compose.yml the stack
.env.example WEB_PORT
data/ SQLite (created on first run, gitignored)
backend/ Fastify + better-sqlite3 API, own Dockerfile
frontend/ Vite + React + CanvasKit SPA, own Dockerfile + nginx.conf
shared/ vendored copies of the app's types + utils (see below)
src/engine/ skiaShim.ts (CanvasKit) + exportEngine.ts (render pipeline)
+ session.ts (localStorage/IndexedDB studio persistence)
Vendored files
frontend/shared/{types/index.ts,utils/*.ts} are byte-identical copies of
src/types/index.ts and ten src/utils/*.ts files from the React Native
project (@shopify/react-native-skia is aliased to src/engine/skiaShim.ts in
vite.config.ts + tsconfig.json, so those files compile unchanged):
cinemaShader colorUtils defaultRecipes exifWrite frameUtils jpegDpi
paramDefs recipeShare skiaImage toneShader.
The landing page needs no CDN: frontend/public/assets/fonts/*.woff2 are the
seven self-hosted faces behind the three font groups the Themes menu offers
(Plus Jakarta Sans / Inter / JetBrains Mono, Fraunces / Be Vietnam Pro /
Courier Prime, Be Vietnam Pro / Space Mono — all SIL OFL, pulled from Google
Fonts, vietnamese + latin + latin-ext subsets), and
frontend/public/assets/samples/s*.jpg are the six placeholder negatives the
film strip, preset tester and QR card show (swap them for real graded stills
whenever we have them). Its one foreign request is the QR image from
api.qrserver.com, which degrades to an empty slot offline.
When the app changes one of them, copy it back in — the renderer is only "parity" for as long as these stay in sync:
cd <repo>/docker/frontend/shared/utils
cp <repo>/src/utils/<name>.ts .
Operations
docker compose logs -f api # API log
docker compose restart api # after backend/src changes (rebuild: --build)
docker compose down # stop; ./data survives
Backup is the ./data folder — that is the whole database.
Checks
curl -s http://localhost:8090/api/health # {"ok":true}
curl -sI http://localhost:8090/ # 200, index.html
Then open the UI, drop a photo in, and confirm the preview shows the picture and
EXPORT downloads a JPEG that opens. The preview going solid black while the
export still reports a plausible size is the one failure mode worth knowing: it
means the CanvasKit GPU surfaces lost their shared GrDirectContext (see
frontend/src/engine/skiaShim.ts), and with no GPU the raster fallback renders
the same pipeline correctly, just slower.