Every request went through the module-level requests.get/put/post/delete
helpers, so each one paid a fresh DNS+TCP+TLS handshake. Measured today
against the real backends that is 95ms/req to api.github.com and 52ms to
Realtime Database -- on a 27-request diet-guard tick, most of the wall clock.
Each transport module now binds a pooling requests.Session to the name
`requests`. A Session is a drop-in for those helpers, so all 9 call sites and
all 16 tests that patch `<module>.requests.<verb>` are untouched; the real
module stays available as `_requests` for the RequestException/Response
references. Sessions are per-module rather than shared because the tests use
sequence-consuming side_effect lists, where one module could otherwise eat
another's queued response.
Transient failures now retry, restricted to GET: a PUT here carries a
Contents-API sha, and replaying one whose response was merely lost would
write against a stale precondition on a remote the phone also reads.
Also thread timeout_seconds through firebase_client_for, which accepted none,
so a caller's tighter budget silently reached the GitHub backend only.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCucBhUkHBBHHbsY7bSdGV
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.
