mirror of
https://github.com/kuhyx/utils.git
synced 2026-11-10 20:27:15 +01:00
Krzysztof Rudnicki
02e2e13790
Extracts the three-method remote surface GitHub was reached through into a `RemoteStore` interface, then implements it against Firebase Realtime Database over REST, so apps can move backend with a constructor change. Why REST and not the SDKs: official FlutterFire has no Linux desktop support, and `wake_alarm`'s PC side is a dependency-free systemd job. The RTDB REST endpoints are plain HTTPS and behave identically on Linux, Android and headless. Firebase is a transport, never the datastore -- each app keeps its local log as the source of truth, so offline-first survives. Why RTDB and not Firestore: on the Spark plan RTDB bills only storage and bandwidth with no per-operation quota, so a runaway loop cannot exhaust a daily budget and silently stop syncing mid-day. Two savings make the no-cost tier a guarantee rather than a hope. Measured against the GitHub-backed history this replaces: 4894 of 5542 commits (88.3%) were byte-identical no-ops, and every tick re-downloaded every peer's whole log. Both are now driven by one sha256 revision -- an unchanged log is not re-pushed, and an unchanged peer is not re-fetched. That turns egress from "ticks x log size" (~700 MB/month, and growing with the log) into "edits" (~40 MB/month against a 10 GiB cap). Revisions are one node per device, written only by its owner, rather than one shared map -- a whole-map write would erase every peer's entry, after which those peers would look permanently unchanged and never be fetched again. Per-device keys make that impossible rather than merely avoided. `.` is illegal in an RTDB key and the REST `.json` is a format suffix, so paths get a reversible `~XX` escape (`log.json` -> `log~2Ejson`). Lossy extension-stripping would break `todo`, whose listings return filenames. `MirrorStore` / `MirrorSyncClient` dual-writes during the cutover. Reads consult *both* backends: with primary-only reads a migrated device would never see an un-migrated peer's writes while still mirroring its own back -- silent one-directional convergence with no error raised. Writes are asymmetric on purpose: a primary failure fails the tick, a mirror failure is logged and survived. Auth is Firebase email/password over identitytoolkit REST, with mandatory refresh-token rotation. No service-account key anywhere: it would bypass the security rules and is trivially extractable from an APK. Verified live against a real database, not only mocks: sign-in and refresh, key escaping round-tripping byte-for-byte, an unchanged tick writing nothing, two devices converging, a revoked session throwing rather than returning null, and a log written by the Python client being read by the Dart one. No app is migrated by this commit; every app still runs on GitHub. Dart: 194 tests. Python: 203 tests at 100% branch coverage. No lint suppressions added.
72 lines
2.2 KiB
Dart
72 lines
2.2 KiB
Dart
/// Live cross-language check: reads what the Python client wrote, merges a
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/// Dart-side record, and confirms both survive. The two implementations must
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/// agree byte-for-byte or a phone on Dart would not see a PC on Python.
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library;
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import 'dart:convert';
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import 'dart:io';
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import 'package:crdt_sync/crdt_sync.dart';
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/// Environment-specific values (project, account, database URL) live here,
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/// mode 0600 -- never in source, because this repository is public.
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final _configDir = '${Platform.environment['HOME']}/.config/crdt-sync';
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Log _decode(String t) => (jsonDecode(t) as Map<String, dynamic>)
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.map((k, v) => MapEntry(k, Record.fromJson(v as Map<String, dynamic>)));
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String _encode(Log l) =>
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jsonEncode(l.map((k, v) => MapEntry(k, v.toJson())));
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Future<void> main(List<String> args) async {
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final cfg = jsonDecode(
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File('$_configDir/firebase.json').readAsStringSync(),
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) as Map<String, dynamic>;
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final auth = FirebaseTokenProvider(
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apiKey: cfg['apiKey'] as String,
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store: InMemoryCredentialStore(),
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);
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await auth.signIn(
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email: cfg['email'] as String,
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password: File('$_configDir/password').readAsStringSync(),
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);
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final client = FirebaseRestClient(
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databaseUrl: cfg['databaseUrl'] as String,
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auth: auth,
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);
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final merged = await syncLog(
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client: client,
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deviceId: 'dartdev',
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pathPrefix: '_interop/devices',
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localLog: {
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'dart-rec': Record(
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id: 'dart-rec',
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fields: {
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'value': (
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'written-by-dart',
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Hlc(wallTimeMs: 1000, counter: 0, nodeId: 'node-dart'),
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),
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},
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),
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},
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encode: _encode,
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decode: _decode,
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stateStore: InMemorySyncStateStore(),
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);
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final ok = merged.containsKey('py-rec') && merged.containsKey('dart-rec');
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stdout.writeln('dart sees records: ${merged.keys.toList()}');
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stdout.writeln(
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'python record value: ${merged['py-rec']?.fields['value']?.$1}',
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);
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stdout.writeln('revs: ${await client.getStringMap('_interop/revs')}');
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// Clean up both devices' data.
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for (final d in ['pydev', 'dartdev']) {
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await client.deleteFile('_interop/devices/$d/log.json');
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await client.deleteFile('_interop/revs/$d');
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}
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stdout.writeln(ok ? '\nINTEROP OK' : '\nINTEROP FAILED');
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exit(ok ? 0 : 1);
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}
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