docs: protected void payloadWritten(int payloadSize)
    {
        if (tc.isEntryEnabled()) Tr.entry(tc, "payloadWritten", new Object[] {this, new Integer(payloadSize)});
        
        // Track the unwritten payload decrease directly. We take no account for this classes header
        // values in this figure. The total payload remains unchanged since we are not removing the
        // corrisponding payload, just writing it to the underlying recovery log.
        _unwrittenDataSize -= payloadSize;
        
        // When writing existing payload, if the resulting unwritten data size has gone back down to 
        // zero then there will be no further need to account for the unwritten data header.
        // When we pass on this payload adjustment we must account for the header size.
        if (_unwrittenDataSize == 0)
        {
            _recUnit.payloadWritten(payloadSize + HEADER_SIZE);    
        }
        else
        {
            _recUnit.payloadWritten(payloadSize);   
        }
        
        if (tc.isDebugEnabled()) Tr.debug(tc, "unwrittenDataSize = " + _unwrittenDataSize + " totalDataSize = " + _totalDataSize);
        if (tc.isEntryEnabled()) Tr.exit(tc, "payloadWritten");
    }