@Override
                    public void run() {
                        try {
                            final StringBuilder strBuffer = new StringBuilder(512);
                            flush(strBuffer);
                        } catch (Throwable e) {
                            logger.error("[Data Store] Error during flush", e);
                        } finally {
                            if (isTimeTrigger) {
                                msgStoreStatsHolder.addCacheTimeoutFlush();
                            }
                        }
                    }
Append message and trigger flush operation.

@param needAdd           whether to add a message
@param isTimeTrigger     whether is timer trigger
@param partitionId       the partitionId for reading messages
@param keyCode           the filter item hash code
@param receivedTime      the received time of message
@param indexEntry        the stored index entry
@param dataLength        the stored data entry length
@param dataEntry         the stored data entry
@param appendResult      the append result

@return                  the append result
@throws IOException      the exception during processing
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/broker/msgstore/MessageStore.java