The trait's default implementation of transcribe_sync_with_abort fell
through to plain transcribe_sync, silently dropping the abort flag for
any backend that did not explicitly override it. That re-introduced the
5725836 wedge for SpeechModelAdapter (Parakeet today, any future
cloud STT or transformer adapter tomorrow): the live session's
drain_inference timeout would set the flag, the backend would ignore
it, the orphan inference thread would keep the engine Mutex held, and
the next start/stop would deadlock on it.
Removing the default impl makes the method required, so any backend
that does not implement it fails to compile. Compile-time enforcement
of cancellation completeness.
SpeechModelAdapter now implements the method explicitly with a
pre-decode short-circuit: if the abort flag is already set before we
dispatch into transcribe-rs (which owns the Parakeet decoder behind an
opaque call that has no cancellation hook), return an error
immediately. The in-flight decode itself is still uncancellable, but
that is documented with a SAFETY comment and bounded by the live
session's drain timeout dropping the receiver — the orphan exits the
instant it tries to send.
Regression tests:
- transcriber::tests::transcribe_sync_with_abort_is_required_and_flag_is_observed —
fake backend records the abort flag at dispatch time; proves the
trait method is required (file would not compile without it) and the
flag is actually piped through.
- local_engine::tests::speech_model_adapter_short_circuits_when_abort_set_pre_dispatch —
SpeechModelAdapter must NOT call the underlying decoder when the
abort flag was set before dispatch.
- local_engine::tests::speech_model_adapter_dispatches_decoder_when_abort_clear —
companion: clear flag must still dispatch (we did not kill
transcription entirely).
cargo test -p lumotia-transcription --lib: 64 passed, 0 failed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Three findings chain: thread::spawn discarded the JoinHandle and gave
no cancellation route into the whisper backend; drain_inference busy-
polled with no timeout; stop_live_transcription_session held the
lifecycle AsyncMutex across the await of a non-cancellable
spawn_blocking handle. Together: a single wedged inference (ggml
deadlock, GPU stall) bricked every future start/stop until app restart.
Fix: each inference task carries an Arc<AtomicBool> abort_flag; the
flag is wired into whisper-rs::FullParams::set_abort_callback_safe so
the spawned blocking thread checks it and exits cleanly. drain_inference
is bounded by a deadline (3 x chunk_duration, min 2s); on expiry the
flag is set, the receiver is dropped, and a typed Error::InferenceTimeout
status is surfaced. Drop for InferenceTask asserts the abort flag so
any '?'-propagation or panic unwind closes the cancellation route
without relying on the explicit drain path. stop_live_transcription_session
restructured so the lifecycle guard is dropped BEFORE the JoinHandle
is awaited; start_live_transcription_session releases the guard
explicitly after installing the RunningLiveSession.
Unit test added: dropping_inference_task_sets_abort_flag covers the
Race-A regression directly. A real Race-B drain-timeout test would
require a wedged whisper-rs, which is hard to fixture; that path is
covered by the SAFETY comment and cargo build + manual smoke.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Replace all instances of the legacy product names "Kon" and "Corbie" with
"Magnotia" across user-facing copy, code identifiers, package names, bundle
ids, file paths, and documentation. Preserves the unrelated "konsole" (KDE
terminal) reference and the parent CORBEL company name.
- Renames 10 Rust crates (kon-* → magnotia-*) and the tauri binary
- Updates package.json, tauri.conf.json (productName + identifier)
- Renames CSS classes (kon-rh-* → magnotia-rh-*) and animations
- Renames brand and roadmap docs
- Regenerates Cargo.lock and package-lock.json
Verified: svelte-check passes; pure-rust crates compile under new names.
New crates/transcription/src/transcriber.rs defines a Transcriber
trait (Send supertrait for spawn_blocking travel) with
TranscriberCapabilities (sample_rate, channels, supports_initial_prompt).
TranscriberCapabilities.sample_rate is load-bearing for the upcoming
progressive WAV writer (#19).
Concrete impls:
- SpeechModelAdapter wraps Box<dyn transcribe_rs::SpeechModel + Send>
for Parakeet (and any future transcribe-rs-backed engine).
- WhisperRsBackend moves its transcribe_sync body into the impl,
widening the signature from &self to &mut self so per-call
WhisperState can be created cleanly through the trait object.
LocalEngine now holds Box<dyn Transcriber + Send>; dispatch in
transcribe_sync collapses from a match to a direct call. Adds
LocalEngine::capabilities() for the WAV-writer.
Cargo feature flag "whisper" (default on) makes whisper-rs, num_cpus,
and the whole whisper_rs_backend module optional. cargo check
--no-default-features -p kon-transcription now builds without pulling
whisper-rs-sys — the escape hatch brief item #6 / #13 called for on
Windows / non-AVX2 / cloud-only builds. load_whisper is cfg-gated
behind the same feature.
src-tauri/src/commands/models.rs load_model_from_disk returns
Box<dyn Transcriber + Send> instead of SpeechBackend; caller chain
(ensure_model_loaded, prewarm_default_model) is unchanged.
transcriber_trait_is_object_safe test lands alongside the trait as a
compile-time witness against future Self-returning / generic-method
additions.
