Implement C++ line_sender::flush_and_keep_with_flags()

include/questdb/ingress/line_sender.hpp

@@ -1247,6 +1247,42 @@ namespace questdb::ingress
             }
         }
 
+        /**
+         * Send the batch of rows in the buffer to the QuestDB server, and, if the parameter
+         * `transactional` is true, ensure the flush will be transactional.
+         * See docs on the ::line_sender_flush_and_keep_with_flags() function for more details.
+         */
+        bool flush_and_keep_with_flags(const line_sender_buffer& buffer, bool transactional)
+        {
+            try
+            {
+                if (buffer._impl)
+                {
+                    ensure_impl();
+                    line_sender_error::wrapped_call(
+                        ::line_sender_flush_and_keep_with_flags,
+                        _impl,
+                        buffer._impl,
+                        transactional);
+                }
+                else
+                {
+                    line_sender_buffer buffer2{0};
+                    buffer2.may_init();
+                    line_sender_error::wrapped_call(
+                        ::line_sender_flush_and_keep_with_flags,
+                        _impl,
+                        buffer2._impl,
+                        transactional);
+                }
+            }
+            catch (...)
+            {
+                return false;
+            }
+            return true;
+        }
+
         /**
          * Check if an error occurred previously and the sender must be closed.
          * This happens when there was an earlier failure.