719d1dbad1
Related: #4065 Motivation: DnsNameResolver was using a special Iterable/Iterator implementation that yields an infinite stream of DNS server addresses. However, this seems to cause confusion. Modifications: - Make DnsServerAddresses an abstract class with an abstract stream() method that returns DnsServerAddressStream - Add DnsServerAddressStream that yields DNS server address infinitely - Remove DnsServerResolver(Group) constructors that accept only a single server address, which wasn't very useful in practice - Extract the DnsServerAddresses implementations to top level - DnsServerAddresses.defaultAddresses() now returns DnsServerAddresses. - Add DnsServerAddresses.defaultAddressList() instead Result: Less confusion and more explicitness
65 lines
1.8 KiB
Java
65 lines
1.8 KiB
Java
/*
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* Copyright 2015 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.resolver.dns;
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import io.netty.util.internal.ThreadLocalRandom;
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import java.net.InetSocketAddress;
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import java.util.Random;
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final class ShuffledDnsServerAddressStream implements DnsServerAddressStream {
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private final InetSocketAddress[] addresses;
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private int i;
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ShuffledDnsServerAddressStream(InetSocketAddress[] addresses) {
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this.addresses = addresses.clone();
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shuffle();
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}
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private void shuffle() {
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final InetSocketAddress[] addresses = this.addresses;
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final Random r = ThreadLocalRandom.current();
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for (int i = addresses.length - 1; i >= 0; i --) {
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InetSocketAddress tmp = addresses[i];
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int j = r.nextInt(i + 1);
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addresses[i] = addresses[j];
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addresses[j] = tmp;
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}
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}
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@Override
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public InetSocketAddress next() {
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int i = this.i;
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InetSocketAddress next = addresses[i];
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if (++ i < addresses.length) {
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this.i = i;
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} else {
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this.i = 0;
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shuffle();
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}
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return next;
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}
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@Override
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public String toString() {
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return SequentialDnsServerAddressStream.toString("shuffled", i, addresses);
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}
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}
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