ioff += maxChunkSize;
                        }

                        if ( dfd == null || !dfd.isValid() ) {
                            // don't reopen the file for every round if it's not necessary, keep the lock
                            dfd = openCopyTargetFile(dest, src.getAttributes(), !write);
                        }

        work   = (leftt ^ right) & 0xaaaaaaaa;
        leftt ^= work;
        right ^= work;
        leftt  = (leftt << 1) | ((leftt >>> 31) & 1);

        for ( round = 0; round < 8; ++round )  {
            work   = (right << 28) | (right >>> 4);
            work  ^= keys[keysi++];
            fval   = SP7[ work         & 0x0000003f ];
            fval  |= SP5[(work >>>  8) & 0x0000003f ];