Add files via upload

internal/multiagent/eino_checkpoint.go

@@ -0,0 +1,68 @@
+package multiagent
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// fileCheckPointStore implements adk.CheckPointStore with one file per checkpoint id.
+type fileCheckPointStore struct {
+	dir string
+}
+
+func newFileCheckPointStore(baseDir string) (*fileCheckPointStore, error) {
+	if strings.TrimSpace(baseDir) == "" {
+		return nil, fmt.Errorf("checkpoint base dir empty")
+	}
+	abs, err := filepath.Abs(baseDir)
+	if err != nil {
+		return nil, err
+	}
+	if err := os.MkdirAll(abs, 0o755); err != nil {
+		return nil, err
+	}
+	return &fileCheckPointStore{dir: abs}, nil
+}
+
+func (s *fileCheckPointStore) path(id string) (string, error) {
+	id = strings.TrimSpace(id)
+	if id == "" {
+		return "", fmt.Errorf("checkpoint id empty")
+	}
+	if strings.ContainsAny(id, `/\`) {
+		return "", fmt.Errorf("invalid checkpoint id")
+	}
+	return filepath.Join(s.dir, id+".ckpt"), nil
+}
+
+func (s *fileCheckPointStore) Get(ctx context.Context, checkPointID string) ([]byte, bool, error) {
+	_ = ctx
+	p, err := s.path(checkPointID)
+	if err != nil {
+		return nil, false, err
+	}
+	b, err := os.ReadFile(p)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil, false, nil
+		}
+		return nil, false, err
+	}
+	return b, true, nil
+}
+
+func (s *fileCheckPointStore) Set(ctx context.Context, checkPointID string, checkPoint []byte) error {
+	_ = ctx
+	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)
+}