Add files via upload

internal/workflow/checkpoint_store.go

@@ -0,0 +1,69 @@
+package workflow
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+// fileCheckPointStore persists Eino workflow checkpoints on disk (per run id).
+type fileCheckPointStore struct {
+	dir string
+	mu  sync.RWMutex
+}
+
+func newFileCheckPointStore(dir string) (*fileCheckPointStore, error) {
+	dir = strings.TrimSpace(dir)
+	if dir == "" {
+		dir = filepath.Join("data", "workflow-checkpoints")
+	}
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, fmt.Errorf("create workflow checkpoint dir: %w", err)
+	}
+	return &fileCheckPointStore{dir: dir}, nil
+}
+
+func (s *fileCheckPointStore) path(id string) (string, error) {
+	id = strings.TrimSpace(id)
+	if id == "" {
+		return "", fmt.Errorf("checkpoint id is empty")
+	}
+	if strings.Contains(id, "..") || strings.ContainsAny(id, `/\`) {
+		return "", fmt.Errorf("invalid checkpoint id")
+	}
+	return filepath.Join(s.dir, id+".ckpt"), nil
+}
+
+func (s *fileCheckPointStore) Get(_ context.Context, checkPointID string) ([]byte, bool, error) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	p, err := s.path(checkPointID)
+	if err != nil {
+		return nil, false, err
+	}
+	data, err := os.ReadFile(p)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, false, nil
+		}
+		return nil, false, err
+	}
+	return data, true, nil
+}
+
+func (s *fileCheckPointStore) Set(_ context.Context, checkPointID string, checkPoint []byte) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	p, err := s.path(checkPointID)
+	if err != nil {
+		return err
+	}
+	tmp := p + ".tmp"
+	if err := os.WriteFile(tmp, checkPoint, 0o600); err != nil {
+		return err
+	}
+	return os.Rename(tmp, p)
+}