Method triggerAsyncCompression

internal/llmloop/compression.go:291–331

triggerAsyncCompression kicks off a background compression job for the conversation owning st. A no-op when a job is already pending — the check-and-set happens under st.mu so concurrent callers cannot replace (and thereby leak) an in-flight job.

(ctx context.Context, st *compressionState, messages []llm.Message, filePath string)

// check-and-set happens under st.mu so concurrent callers cannot replace
// (and thereby leak) an in-flight job.
func (r *Runner) triggerAsyncCompression(ctx context.Context, st *compressionState, messages []llm.Message, filePath string) {
	st.mu.Lock()
	if st.pendingJob != nil {
		st.mu.Unlock()
		return
	}
	msgSnapshot := copyMessages(messages)
	asyncCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 5*time.Minute)
	job := &compressionJob{done: make(chan struct{}), cancel: cancel, snapshotLen: len(messages)}
	st.pendingJob = job
	st.mu.Unlock()

	// Registered before the goroutine starts so WaitBackground can never miss
	// a job that was launched but has not run yet.
	r.bg.Add(1)
	go func() {
		defer r.bg.Done()
		defer cancel()
		rebuilt, err := r.runCompression(asyncCtx, msgSnapshot, filePath)

		st.mu.Lock()
		defer st.mu.Unlock()

		if st.pendingJob != job {
			return // cancelled or superseded
		}
		if err != nil {
			// Still the owner, so this is a genuine failure rather than a
			// deliberate cancel (cancelPendingCompression cancels and clears
			// pendingJob under the lock, so cancelled jobs fail the ownership
			// check above and die silently). Abandon the job rather than
			// applying a truncated/unmodified snapshot over live messages.
			fmt.Fprintf(stdout.Writer(), "[ocr] Memory compression failed: %v\n", err)
			st.pendingJob = nil
			close(job.done)
			return
		}
		job.rebuilt = rebuilt
		close(job.done)
	}()
}

// tryApplyPendingCompression checks whether a background compression has
// completed and swaps the rebuilt messages into place. Returns true if