Enha (onnx): unload model if noop for 30s

rag/embedder.go

@@ -308,6 +308,19 @@ func (e *ONNXEmbedder) getModelPath() string {
 	return e.modelPath
 }
 
+func (e *ONNXEmbedder) Destroy() error {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	if e.session != nil {
+		if err := e.session.Destroy(); err != nil {
+			return fmt.Errorf("failed to destroy ONNX session: %w", err)
+		}
+		e.session = nil
+		e.logger.Info("ONNX session destroyed, VRAM freed")
+	}
+	return nil
+}
+
 func (e *ONNXEmbedder) Embed(text string) ([]float32, error) {
 	if err := e.ensureInitialized(); err != nil {
 		return nil, err

rag/rag.go

@@ -12,6 +12,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/neurosnap/sentences/english"
 )
@@ -32,6 +33,8 @@ type RAG struct {
 	storage     *VectorStorage
 	mu          sync.Mutex
 	fallbackMsg string
+	idleTimer   *time.Timer
+	idleTimeout time.Duration
 }
 
 func New(l *slog.Logger, s storage.FullRepo, cfg *config.Config) (*RAG, error) {
@@ -58,6 +61,7 @@ func New(l *slog.Logger, s storage.FullRepo, cfg *config.Config) (*RAG, error) {
 		embedder:    embedder,
 		storage:     NewVectorStorage(l, s),
 		fallbackMsg: fallbackMsg,
+		idleTimeout: 30 * time.Second,
 	}
 
 	// Note: Vector tables are created via database migrations, not at runtime
@@ -187,6 +191,7 @@ func (r *RAG) LoadRAG(fpath string) error {
 		}
 	}
 	r.logger.Debug("finished writing vectors", "batches", batchCount)
+	r.resetIdleTimer()
 	select {
 	case LongJobStatusCh <- FinishedRAGStatus:
 	default:
@@ -196,10 +201,12 @@ func (r *RAG) LoadRAG(fpath string) error {
 }
 
 func (r *RAG) LineToVector(line string) ([]float32, error) {
+	r.resetIdleTimer()
 	return r.embedder.Embed(line)
 }
 
 func (r *RAG) SearchEmb(emb *models.EmbeddingResp) ([]models.VectorRow, error) {
+	r.resetIdleTimer()
 	return r.storage.SearchClosest(emb.Embedding)
 }
 
@@ -208,6 +215,7 @@ func (r *RAG) ListLoaded() ([]string, error) {
 }
 
 func (r *RAG) RemoveFile(filename string) error {
+	r.resetIdleTimer()
 	return r.storage.RemoveEmbByFileName(filename)
 }
 
@@ -471,3 +479,38 @@ func Init(c *config.Config, l *slog.Logger, s storage.FullRepo) error {
 func GetInstance() *RAG {
 	return ragInstance
 }
+
+func (r *RAG) resetIdleTimer() {
+	if r.idleTimer != nil {
+		r.idleTimer.Stop()
+	}
+	r.idleTimer = time.AfterFunc(r.idleTimeout, func() {
+		r.freeONNXMemory()
+	})
+}
+
+func (r *RAG) freeONNXMemory() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if onnx, ok := r.embedder.(*ONNXEmbedder); ok {
+		if err := onnx.Destroy(); err != nil {
+			r.logger.Error("failed to free ONNX memory", "error", err)
+		} else {
+			r.logger.Info("freed ONNX VRAM after idle timeout")
+		}
+	}
+}
+
+func (r *RAG) Destroy() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.idleTimer != nil {
+		r.idleTimer.Stop()
+		r.idleTimer = nil
+	}
+	if onnx, ok := r.embedder.(*ONNXEmbedder); ok {
+		if err := onnx.Destroy(); err != nil {
+			r.logger.Error("failed to destroy ONNX embedder", "error", err)
+		}
+	}
+}