interleave metric and nonblock IO

[raghavm243512]

Changes:

allow validation and metrics to run on successful conversations even if other conversations need rerun. These will be saved and used at the final pass once all retries are done or success is for all records

Much smaller changes:
Release semaphore before doing expensive writes for audio

Don't block main thread with IO. Files reads are large enough where this will help somewhat, Probably not a lot though.

[JosephMarinier]

Since we except Exception inside _run_and_pipeline(), we don't expect _run_and_pipeline() to raise anything. Can you make that intentional by removing return_exceptions=True?

Also, it's a tiny detail, but since we're here, we don't need to instantiate a list; we can simply use a generator (in parentheses).

Suggested change

	*[_run_and_pipeline(output_id_to_record[oid], oid) for oid in pending_output_ids],
	return_exceptions=True,
	*(_run_and_pipeline(output_id_to_record[oid], oid) for oid in pending_output_ids)

[JosephMarinier]

Again, that shouldn't happen, so I think we can clean that up. Also, if that even happened, this wouldn't add the sample to either finished_ids or not_finished_ids, and it would disappear, which seems a bit broken. Does that make sense?

[JosephMarinier]

Detail: I think a single if not self._audio_buffer would be clearer than repeating 3 times.

Suggested change

	if not self._audio_buffer and self.user_audio_buffer and self.assistant_audio_buffer:
	diff_bytes = abs(len(self.user_audio_buffer) - len(self.assistant_audio_buffer))
	diff_ms = diff_bytes / (2 * self._audio_sample_rate) * 1000
	if diff_ms > 500:
	logger.warning(
	f"Audio buffer length mismatch: user={len(self.user_audio_buffer)} "
	f"assistant={len(self.assistant_audio_buffer)} "
	f"diff={diff_ms:.0f}ms — mixed recording may be temporally skewed"
	)
	from eva.assistant.audio_bridge import pcm16_mix # lazy: avoids circular import at module load
	self._audio_buffer = bytearray(pcm16_mix(bytes(self.user_audio_buffer), bytes(self.assistant_audio_buffer)))
	elif not self._audio_buffer and self.user_audio_buffer:
	self._audio_buffer = bytearray(self.user_audio_buffer)
	elif not self._audio_buffer and self.assistant_audio_buffer:
	self._audio_buffer = bytearray(self.assistant_audio_buffer)
	if not self._audio_buffer:
	if self.user_audio_buffer and self.assistant_audio_buffer:
	diff_bytes = abs(len(self.user_audio_buffer) - len(self.assistant_audio_buffer))
	diff_ms = diff_bytes / (2 * self._audio_sample_rate) * 1000
	if diff_ms > 500:
	logger.warning(
	f"Audio buffer length mismatch: user={len(self.user_audio_buffer)} "
	f"assistant={len(self.assistant_audio_buffer)} "
	f"diff={diff_ms:.0f}ms — mixed recording may be temporally skewed"
	)
	from eva.assistant.audio_bridge import pcm16_mix # lazy: avoids circular import at module load
	self._audio_buffer = bytearray(
	pcm16_mix(bytes(self.user_audio_buffer), bytes(self.assistant_audio_buffer))
	)
	elif self.user_audio_buffer:
	self._audio_buffer = bytearray(self.user_audio_buffer)
	elif self.assistant_audio_buffer:
	self._audio_buffer = bytearray(self.assistant_audio_buffer)

[JosephMarinier]

Suggested change

	if isinstance(self.pipeline_config, SpeechToSpeechConfig):
	self.audit_log.save_transcript_jsonl(transcript_path)
	elif not transcript_path.exists():
	if isinstance(self.pipeline_config, SpeechToSpeechConfig) or not transcript_path.exists():

[JosephMarinier]

Duplicating most of super().save_outputs(), instead of calling it, worries me about them going out of sync. Have you considered refactoring so that you can keep calling super().save_outputs()?

[JosephMarinier]

Now that we call _run_and_save_record() from two places outside of running.py, should we remove the "private" underscore prefix?

[JosephMarinier]

Since we're now mutating metrics_runner.record_ids, I think we need to be extra careful with the ordering of the steps. Would adding a comment like that make sense?

Suggested change

	# The final run() skips already-computed records and only does summary aggregation.
	# The final run() skips already-computed records and only does summary aggregation.
	# IMPORTANT: Must await all background tasks BEFORE mutating metrics_runner.record_ids
	# below — running tasks read record_ids to filter which records to process.