add knowhere error message

Former-commit-id: 2c20ca16ad79f359ecfcf858211f40a289f90376

cpp/src/core/include/knowhere/common/exception.h

@@ -26,6 +26,9 @@ class KnowhereException : public std::exception {
 };
 
 
+#define KNOHWERE_ERROR_MSG(MSG)\
+printf("%s", KnowhereException(MSG, __PRETTY_FUNCTION__, __FILE__, __LINE__).what())
+
 #define KNOWHERE_THROW_MSG(MSG)\
 do {\
     throw KnowhereException(MSG, __PRETTY_FUNCTION__, __FILE__, __LINE__);\

cpp/src/core/src/knowhere/index/vector_index/ivf.cpp

@@ -350,12 +350,16 @@ void BasicIndex::LoadImpl(const BinarySet &index_binary) {
 }
 
 void BasicIndex::SealImpl() {
+// TODO(linxj): enable
 //#ifdef ZILLIZ_FAISS
     faiss::Index *index = index_.get();
     auto idx = dynamic_cast<faiss::IndexIVF *>(index);
     if (idx != nullptr) {
         idx->to_readonly();
     }
+    else {
+        KNOHWERE_ERROR_MSG("Seal failed");
+    }
 //#endif
 }