diff options
author | Daniel Gultsch <daniel@gultsch.de> | 2015-06-04 02:48:07 +0200 |
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committer | Daniel Gultsch <daniel@gultsch.de> | 2015-06-04 02:48:07 +0200 |
commit | 8f07e4c441778e476119f25cc8cac833e0937508 (patch) | |
tree | a4addad2ed03d11460ec07a28209ad2864568928 /src/main | |
parent | 6b794eca2cfc8d1edf4f73c740a3e1b4e966da27 (diff) |
streamlined dns helper by ignoring weight
Diffstat (limited to 'src/main')
-rw-r--r-- | src/main/java/eu/siacs/conversations/utils/DNSHelper.java | 65 |
1 files changed, 10 insertions, 55 deletions
diff --git a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java index e91005a1..7a51c1ce 100644 --- a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java +++ b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java @@ -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<>(); |