public boolean flush() {
        final long flushWhere = getFlushedPosition();
        final AbstractFile abstractFile = findFileByOffset(flushWhere, flushWhere == 0);
        if (abstractFile != null) {
            final int flushOffset = abstractFile.flush();
            setFlushedPosition(abstractFile.getFileFromOffset() + flushOffset);
            return getFlushedPosition() != flushWhere;
        }
        return false;
    }
Flush from flushPosition
@return true if flush success
jraft-extension/java-log-storage-impl/src/main/java/com/alipay/sofa/jraft/storage/file/FileManager.java