65 lines
1.8 KiB
Java
65 lines
1.8 KiB
Java
|
/*
|
||
|
* 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;
|
||
|
|
||
|
import io.netty.util.internal.ThreadLocalRandom;
|
||
|
|
||
|
import java.net.InetSocketAddress;
|
||
|
import java.util.Random;
|
||
|
|
||
|
final class ShuffledDnsServerAddressStream implements DnsServerAddressStream {
|
||
|
|
||
|
private final InetSocketAddress[] addresses;
|
||
|
private int i;
|
||
|
|
||
|
ShuffledDnsServerAddressStream(InetSocketAddress[] addresses) {
|
||
|
this.addresses = addresses.clone();
|
||
|
|
||
|
shuffle();
|
||
|
}
|
||
|
|
||
|
private void shuffle() {
|
||
|
final InetSocketAddress[] addresses = this.addresses;
|
||
|
final Random r = ThreadLocalRandom.current();
|
||
|
|
||
|
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;
|
||
|
}
|
||
|
|
||
|
@Override
|
||
|
public String toString() {
|
||
|
return SequentialDnsServerAddressStream.toString("shuffled", i, addresses);
|
||
|
}
|
||
|
}
|