oss请求处理

backend/internal/assets/assets.go

@@ -126,6 +126,9 @@ type BlobStore interface {
 	Read(context.Context, string) (Blob, error)
 	Delete(context.Context, string) error
 }
+type BlobURLSigner interface {
+	SignReadURL(string, time.Duration) (string, error)
+}
 type RemoteFetcher interface {
 	Fetch(context.Context, string) (Blob, error)
 }
@@ -364,6 +367,52 @@ func (s *Service) Download(ctx context.Context, scope Scope, id string) (Blob, e
 	return s.remote.Fetch(ctx, a.URL)
 }
 
+// SignedDownloadURL returns a short-lived direct URL only when the configured
+// blob store supports it. Callers can otherwise fall back to Download without
+// exposing storage credentials or assuming that every backend is OSS.
+func (s *Service) SignedDownloadURL(ctx context.Context, scope Scope, id string, ttl time.Duration) (string, bool, error) {
+	a, err := s.Get(ctx, scope, id)
+	if err != nil {
+		return "", false, err
+	}
+	return s.signedDownloadURL(a, ttl)
+}
+
+func (s *Service) signedDownloadURL(a Asset, ttl time.Duration) (string, bool, error) {
+	if a.StoragePath == "" || s.blobs == nil {
+		return "", false, nil
+	}
+	signer, ok := s.blobs.(BlobURLSigner)
+	if !ok {
+		return "", false, nil
+	}
+	signed, err := signer.SignReadURL(a.StoragePath, ttl)
+	if err != nil {
+		return "", false, err
+	}
+	return signed, true, nil
+}
+
+// ResolveProviderAssetURL implements the jobs package's narrow resolver seam
+// without importing jobs. The stable source URL is used only to replace the
+// matching value in a transient provider request; the signed URL is never
+// persisted in the asset catalog or job payload.
+func (s *Service) ResolveProviderAssetURL(ctx context.Context, ownerID, id string, ttl time.Duration) (string, string, error) {
+	scope := PlatformScope(ownerID)
+	a, err := s.Get(ctx, scope, id)
+	if err != nil {
+		return "", "", err
+	}
+	signed, ok, err := s.signedDownloadURL(a, ttl)
+	if err != nil {
+		return "", "", err
+	}
+	if ok {
+		return a.URL, signed, nil
+	}
+	return a.URL, a.URL, nil
+}
+
 // DownloadPath serves a stored object only after its metadata has been found
 // in the requesting owner's catalog. Catalogs that support HTTP file serving
 // implement the optional storage-path lookup without widening other callers.