@@ -47,88 +47,43 @@ public class DNSHelper {
Bundle bundle = new Bundle();
try {
String qname = "_xmpp-client._tcp." + host;
- Log.d(Config.LOGTAG,
- "using dns server: " + dnsServer.getHostAddress()
- + " to look up " + host);
- DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN,
- dnsServer.getHostAddress());
-
- // How should we handle priorities and weight?
- // Wikipedia has a nice article about priorities vs. weights:
- // https://en.wikipedia.org/wiki/SRV_record#Provisioning_for_high_service_availability
-
- // we bucket the SRV records based on priority, pick per priority
- // a random order respecting the weight, and dump that priority by
- // priority
+ Log.d(Config.LOGTAG, "using dns server: " + dnsServer.getHostAddress() + " to look up " + host);
+ DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServer.getHostAddress());
TreeMap<Integer, ArrayList<SRV>> priorities = new TreeMap<>();
TreeMap<String, ArrayList<String>> ips4 = new TreeMap<>();
TreeMap<String, ArrayList<String>> ips6 = new TreeMap<>();
- for (Record[] rrset : new Record[][] { message.getAnswers(),
- message.getAdditionalResourceRecords() }) {
+ for (Record[] rrset : new Record[][] { message.getAnswers(), message.getAdditionalResourceRecords() }) {
for (Record rr : rrset) {
Data d = rr.getPayload();
- if (d instanceof SRV
- && NameUtil.idnEquals(qname, rr.getName())) {
+ if (d instanceof SRV && NameUtil.idnEquals(qname, rr.getName())) {
SRV srv = (SRV) d;
if (!priorities.containsKey(srv.getPriority())) {
- priorities.put(srv.getPriority(),
- new ArrayList<SRV>(2));
+ priorities.put(srv.getPriority(),new ArrayList<SRV>());
}
priorities.get(srv.getPriority()).add(srv);
}
if (d instanceof A) {
- A arecord = (A) d;
+ A a = (A) d;
if (!ips4.containsKey(rr.getName())) {
- ips4.put(rr.getName(), new ArrayList<String>(3));
+ ips4.put(rr.getName(), new ArrayList<String>());
}
- ips4.get(rr.getName()).add(arecord.toString());
+ ips4.get(rr.getName()).add(a.toString());
}
if (d instanceof AAAA) {
AAAA aaaa = (AAAA) d;
if (!ips6.containsKey(rr.getName())) {
- ips6.put(rr.getName(), new ArrayList<String>(3));
+ ips6.put(rr.getName(), new ArrayList<String>());
}
ips6.get(rr.getName()).add("[" + aaaa.toString() + "]");
}
}
}
- Random rnd = new Random();
- ArrayList<SRV> result = new ArrayList<>(
- priorities.size() * 2 + 1);
+ ArrayList<SRV> result = new ArrayList<>();
for (ArrayList<SRV> s : priorities.values()) {
-
- // trivial case
- if (s.size() <= 1) {
- result.addAll(s);
- continue;
- }
-
- long totalweight = 0l;
- for (SRV srv : s) {
- totalweight += srv.getWeight();
- }
-
- while (totalweight > 0l && s.size() > 0) {
- long p = (rnd.nextLong() & 0x7fffffffffffffffl)
- % totalweight;
- int i = 0;
- while (p > 0) {
- p -= s.get(i++).getPriority();
- }
- if (i>0) i--;
- // remove is expensive, but we have only a few entries
- // anyway
- SRV srv = s.remove(i);
- totalweight -= srv.getWeight();
- result.add(srv);
- }
-
- Collections.shuffle(s, rnd);
result.addAll(s);
-
}
ArrayList<Bundle> values = new ArrayList<>();