Examples with DNSQuestion javax.jmdns.impl.DNSQuestion used on opensource projects

Example 1 with DNSQuestion

use of javax.jmdns.impl.DNSQuestion in project JAirPort by froks.

the class Responder method start.

/*
     * (non-Javadoc)
     * @see javax.jmdns.impl.tasks.DNSTask#start(java.util.Timer)
     */
@Override
public void start(Timer timer) {
    // According to draft-cheshire-dnsext-multicastdns.txt chapter "7 Responding":
    // We respond immediately if we know for sure, that we are the only one who can respond to the query.
    // In all other cases, we respond within 20-120 ms.
    //
    // According to draft-cheshire-dnsext-multicastdns.txt chapter "6.2 Multi-Packet Known Answer Suppression":
    // We respond after 20-120 ms if the query is truncated.
    boolean iAmTheOnlyOne = true;
    for (DNSQuestion question : _in.getQuestions()) {
        if (logger.isLoggable(Level.FINEST)) {
            logger.finest(this.getName() + "start() question=" + question);
        }
        iAmTheOnlyOne = question.iAmTheOnlyOne(this.getDns());
        if (!iAmTheOnlyOne) {
            break;
        }
    }
    int delay = (iAmTheOnlyOne && !_in.isTruncated()) ? 0 : DNSConstants.RESPONSE_MIN_WAIT_INTERVAL + JmDNSImpl.getRandom().nextInt(DNSConstants.RESPONSE_MAX_WAIT_INTERVAL - DNSConstants.RESPONSE_MIN_WAIT_INTERVAL + 1) - _in.elapseSinceArrival();
    if (delay < 0) {
        delay = 0;
    }
    if (logger.isLoggable(Level.FINEST)) {
        logger.finest(this.getName() + "start() Responder chosen delay=" + delay);
    }
    if (!this.getDns().isCanceling() && !this.getDns().isCanceled()) {
        timer.schedule(this, delay);
    }
}

Example 2 with DNSQuestion

use of javax.jmdns.impl.DNSQuestion in project JAirPort by froks.

the class Responder method run.

@Override
public void run() {
    this.getDns().respondToQuery(_in);
    // We use these sets to prevent duplicate records
    Set<DNSQuestion> questions = new HashSet<DNSQuestion>();
    Set<DNSRecord> answers = new HashSet<DNSRecord>();
    if (this.getDns().isAnnounced()) {
        try {
            // Answer questions
            for (DNSQuestion question : _in.getQuestions()) {
                if (logger.isLoggable(Level.FINER)) {
                    logger.finer(this.getName() + "run() JmDNS responding to: " + question);
                }
                // for unicast responses the question must be included
                if (_unicast) {
                    // out.addQuestion(q);
                    questions.add(question);
                }
                question.addAnswers(this.getDns(), answers);
            }
            // remove known answers, if the ttl is at least half of the correct value. (See Draft Cheshire chapter 7.1.).
            long now = System.currentTimeMillis();
            for (DNSRecord knownAnswer : _in.getAnswers()) {
                if (knownAnswer.isStale(now)) {
                    answers.remove(knownAnswer);
                    if (logger.isLoggable(Level.FINER)) {
                        logger.finer(this.getName() + "JmDNS Responder Known Answer Removed");
                    }
                }
            }
            // respond if we have answers
            if (!answers.isEmpty()) {
                if (logger.isLoggable(Level.FINER)) {
                    logger.finer(this.getName() + "run() JmDNS responding");
                }
                DNSOutgoing out = new DNSOutgoing(DNSConstants.FLAGS_QR_RESPONSE | DNSConstants.FLAGS_AA, !_unicast, _in.getSenderUDPPayload());
                out.setId(_in.getId());
                for (DNSQuestion question : questions) {
                    if (question != null) {
                        out = this.addQuestion(out, question);
                    }
                }
                for (DNSRecord answer : answers) {
                    if (answer != null) {
                        out = this.addAnswer(out, _in, answer);
                    }
                }
                if (!out.isEmpty())
                    this.getDns().send(out);
            }
        // this.cancel();
        } catch (Throwable e) {
            logger.log(Level.WARNING, this.getName() + "run() exception ", e);
            this.getDns().close();
        }
    }
}