_len -= sent;
if( (_seq - 1) == __startId || _io_in.available() >= 1024 ) {
while( _io_in.available() > 0 ) {
ackId = readResponseOk();
if( __startId > ackId || ackId > _seq - 1 ) {
throw new SftpException(SSH_FX_FAILURE, "Invalid ack ID: "+ackId);
}
__ackCount++;
}
}
}