Krzysztof kuhy Rudnicki
da0b54d886
The largest consumer moves last on purpose: diet_guard was 71% of all sync traffic, and both its surfaces (the PC timer and the phone app) share one prefix, so they move together. Firebase becomes the primary backend when it is set up, with GitHub kept as a mirror so a device that has not moved yet still converges. An unconfigured device keeps syncing exactly as before, which is also the rollback. Revision tracking is new here. The PC hand-rolled its own pull-merge-push instead of calling sync_log, so it had none: every tick re-downloaded every peer's whole food log -- hundreds of KB, 96 times a day -- and re-pushed its own regardless of change. It now reads one small revision map first, skips any peer whose hash is unchanged, and suppresses a no-op push. Every sub-sync (log, budget, food bank, manual bank) takes the client as a parameter, so one swap covers all four. The app could not have reached Firebase at all: nothing called saveAccount(), so loadAccount() always returned null and openFirebase() always returned null. Settings now has a Firebase section that stores the account in the OS keystore and signs in immediately, so a typo surfaces on the screen where it can be fixed rather than as a silently failed background sync hours later. The email and password never touch the repo -- it is public. Platform reaches now degrade instead of failing: an unavailable keystore or application-support directory costs one tick of extra traffic, where before it would have taken sync down entirely. Caught by `on Object` rather than `on Exception`, because an uninitialised binding raises an Error. Verified end to end against the real database, not just in tests: a live PC sync merged 57 days / 339 entries and put 221 KB of food log plus 97 food-bank records into Firebase; a second unchanged tick issued zero pushes; and the Dart client signed in and read back all 339 meals and 97 foods, then completed a push / publish-revision / suppress-no-op round trip under a throwaway prefix. diet_guard: 618 tests at 100% branch coverage. diet_guard_app: 477 tests. Two assertions moved from 4 pushes to 5 -- the extra one is this device's revision, published after the log so a peer can never cache "seen rev X" against a log it never received. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01SJ9sxEw3ymzXNjL7SHNpJc |
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| .. | ||
| .agents/skills | ||
| android | ||
| assets/icon | ||
| bin | ||
| desktop | ||
| lib | ||
| test | ||
| web | ||
| .gitignore | ||
| .metadata | ||
| analysis_options.yaml | ||
| install_arch.sh | ||
| pubspec.lock | ||
| pubspec.yaml | ||
| README.md | ||
| run.sh | ||
| skills-lock.json | ||
diet_guard_app
Companion app for diet_guard: log meals on the phone, and on the Linux
desktop, sharing one food log through GitHub-backed sync.
Two targets, and only two
| Target | What it is |
|---|---|
| Android | a normal Flutter app (flutter build apk) |
| Linux desktop | the Flutter web build, served by a local wrapper and shown in a Chrome --app window |
There is no linux/ directory. Flutter's GTK embedder manages ~20fps at
3840x2160 -- measured on a stock flutter create counter app, so it is the
toolkit rather than this code -- where the same Dart rendered by Chrome
sustains ~144fps (~/todo/docs/desktop-performance-findings.md). Running
flutter create --platforms linux here would silently restore the slow path.
Commands
flutter test # the app's suite
flutter analyze
bash run.sh # build the web bundle and launch the desktop app
bash install_arch.sh # build + install the pacman package and .desktop entry
flutter build apk --release # the phone build
adb install -r build/app/outputs/flutter-apk/app-release.apk
Never adb uninstall or pm clear this package: both wipe the on-device log.
The desktop wrapper
bin/diet_guard_desktop.dart is the other half of the desktop app, because a
browser cannot touch the filesystem. It:
- serves the built web assets from
build/web(or/opt/diet-guard-app/webonce packaged); - keeps an on-disk copy of every document and photo under
~/.local/share/diet-guard-desktop/, which is what makes a wiped Chrome profile recoverable -- for photos it is the only copy, since they never sync; - holds the GitHub token (
~/.config/diet_guard_app/sync_token, falling back to the PC gate's~/.config/diet_guard/sync_token) and proxiesapi.github.complus the device flow, whose endpoints send no CORS headers and so cannot be called from a page at all.
The port (8732) and the Chrome --user-data-dir must stay fixed.
IndexedDB is keyed by origin and lives inside that profile, so changing either
looks to the app like a device with no history.
Platform seams
dart:io does not fail a web compile; it becomes a stub that throws at
runtime, so the symptom of a missed seam is a blank white window rather than a
build error. Every platform edge is a conditional export -- document_store*,
blob_store*, background_tasks*, notification_backend*, token_vault*,
github_client_factory*, attached_image*. Branch on kIsWeb before any
Platform.is…, which itself throws on web.
What the desktop genuinely loses, by design rather than omission:
- Background reminders. A browser runs nothing once its window is closed,
so the due-slot check runs in-page every 5 minutes while the window is open.
On the PC the real backstop is
diet-guard-gate.timer, which locks the screen. - Camera capture. The browser picker is a file input.
- Photo sharing between devices -- unchanged:
imagePathwas always stripped before push.
Sync identity
Three devices push under diet-guard-sync/devices/: pc (the Python gate),
phone, and desktop. Each must keep its own id -- two devices sharing one
would overwrite each other's pushed log on every tick.