2015-08-19 04:51:15 +02:00
|
|
|
/*
|
|
|
|
* Copyright 2015 The Netty Project
|
|
|
|
*
|
|
|
|
* The Netty Project licenses this file to you under the Apache License,
|
|
|
|
* version 2.0 (the "License"); you may not use this file except in compliance
|
|
|
|
* with the License. You may obtain a copy of the License at:
|
|
|
|
*
|
|
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
*
|
|
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
|
|
* License for the specific language governing permissions and limitations
|
|
|
|
* under the License.
|
|
|
|
*/
|
|
|
|
|
|
|
|
package io.netty.resolver.dns;
|
|
|
|
|
2017-02-15 08:12:40 +01:00
|
|
|
import io.netty.util.internal.PlatformDependent;
|
2015-08-19 04:51:15 +02:00
|
|
|
|
|
|
|
import java.net.InetSocketAddress;
|
|
|
|
import java.util.Random;
|
|
|
|
|
|
|
|
final class ShuffledDnsServerAddressStream implements DnsServerAddressStream {
|
|
|
|
|
|
|
|
private final InetSocketAddress[] addresses;
|
|
|
|
private int i;
|
|
|
|
|
2017-07-03 23:46:36 +02:00
|
|
|
/**
|
|
|
|
* Create a new instance.
|
|
|
|
* @param addresses The addresses are not cloned. It is assumed the caller has cloned this array or otherwise will
|
|
|
|
* not modify the contents.
|
|
|
|
*/
|
2015-08-19 04:51:15 +02:00
|
|
|
ShuffledDnsServerAddressStream(InetSocketAddress[] addresses) {
|
2017-07-03 23:46:36 +02:00
|
|
|
this.addresses = addresses;
|
2015-08-19 04:51:15 +02:00
|
|
|
|
|
|
|
shuffle();
|
|
|
|
}
|
|
|
|
|
2017-07-03 23:46:36 +02:00
|
|
|
private ShuffledDnsServerAddressStream(InetSocketAddress[] addresses, int startIdx) {
|
|
|
|
this.addresses = addresses;
|
|
|
|
i = startIdx;
|
|
|
|
}
|
|
|
|
|
2015-08-19 04:51:15 +02:00
|
|
|
private void shuffle() {
|
|
|
|
final InetSocketAddress[] addresses = this.addresses;
|
2017-02-15 08:12:40 +01:00
|
|
|
final Random r = PlatformDependent.threadLocalRandom();
|
2015-08-19 04:51:15 +02:00
|
|
|
|
|
|
|
for (int i = addresses.length - 1; i >= 0; i --) {
|
|
|
|
InetSocketAddress tmp = addresses[i];
|
|
|
|
int j = r.nextInt(i + 1);
|
|
|
|
addresses[i] = addresses[j];
|
|
|
|
addresses[j] = tmp;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
@Override
|
|
|
|
public InetSocketAddress next() {
|
|
|
|
int i = this.i;
|
|
|
|
InetSocketAddress next = addresses[i];
|
|
|
|
if (++ i < addresses.length) {
|
|
|
|
this.i = i;
|
|
|
|
} else {
|
|
|
|
this.i = 0;
|
|
|
|
shuffle();
|
|
|
|
}
|
|
|
|
return next;
|
|
|
|
}
|
|
|
|
|
2017-07-03 23:46:36 +02:00
|
|
|
@Override
|
|
|
|
public int size() {
|
|
|
|
return addresses.length;
|
|
|
|
}
|
|
|
|
|
|
|
|
@Override
|
|
|
|
public ShuffledDnsServerAddressStream duplicate() {
|
|
|
|
return new ShuffledDnsServerAddressStream(addresses, i);
|
|
|
|
}
|
|
|
|
|
2015-08-19 04:51:15 +02:00
|
|
|
@Override
|
|
|
|
public String toString() {
|
|
|
|
return SequentialDnsServerAddressStream.toString("shuffled", i, addresses);
|
|
|
|
}
|
|
|
|
}
|