Add getQueryOutputSpan

Author: auxten

src/Client/ClientBase.h

@@ -104,6 +104,13 @@ class ClientBase
         // std::vector<char> vec(buf.begin(), buf.end());
         return query_result_memory;
     }
+
+    std::span<char> getQueryOutputSpan()
+    {
+        auto size = query_result_buf->count();
+        return std::span<char>(query_result_memory->begin(), size);
+    }
+
     size_t getProcessedRows() const { return processed_rows; }
     size_t getProcessedBytes() const { return processed_bytes; }
     double getElapsedTime() const { return progress_indication.elapsedSeconds(); }