e8efcd82a8
Motivation: We can just use Objects.requireNonNull(...) as a replacement for ObjectUtil.checkNotNull(....) Modifications: - Use Objects.requireNonNull(...) Result: Less code to maintain.
127 lines
4.4 KiB
Java
127 lines
4.4 KiB
Java
/*
|
|
* Copyright 2018 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.channel.EventLoop;
|
|
import io.netty.util.internal.UnstableApi;
|
|
|
|
import java.net.InetSocketAddress;
|
|
import java.util.Comparator;
|
|
import java.util.List;
|
|
import java.util.concurrent.ConcurrentMap;
|
|
|
|
import static io.netty.util.internal.ObjectUtil.checkPositive;
|
|
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;
|
|
import static java.util.Objects.requireNonNull;
|
|
|
|
/**
|
|
* Default implementation of {@link AuthoritativeDnsServerCache}, backed by a {@link ConcurrentMap}.
|
|
*/
|
|
@UnstableApi
|
|
public class DefaultAuthoritativeDnsServerCache implements AuthoritativeDnsServerCache {
|
|
|
|
private final int minTtl;
|
|
private final int maxTtl;
|
|
private final Comparator<InetSocketAddress> comparator;
|
|
private final Cache<InetSocketAddress> resolveCache = new Cache<InetSocketAddress>() {
|
|
@Override
|
|
protected boolean shouldReplaceAll(InetSocketAddress entry) {
|
|
return false;
|
|
}
|
|
|
|
@Override
|
|
protected boolean equals(InetSocketAddress entry, InetSocketAddress otherEntry) {
|
|
return entry.getHostString().equalsIgnoreCase(otherEntry.getHostString());
|
|
}
|
|
|
|
@Override
|
|
protected void sortEntries(String hostname, List<InetSocketAddress> entries) {
|
|
if (comparator != null) {
|
|
entries.sort(comparator);
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Create a cache that respects the TTL returned by the DNS server.
|
|
*/
|
|
public DefaultAuthoritativeDnsServerCache() {
|
|
this(0, Cache.MAX_SUPPORTED_TTL_SECS, null);
|
|
}
|
|
|
|
/**
|
|
* Create a cache.
|
|
*
|
|
* @param minTtl the minimum TTL
|
|
* @param maxTtl the maximum TTL
|
|
* @param comparator the {@link Comparator} to order the {@link InetSocketAddress} for a hostname or {@code null}
|
|
* if insertion order should be used.
|
|
*/
|
|
public DefaultAuthoritativeDnsServerCache(int minTtl, int maxTtl, Comparator<InetSocketAddress> comparator) {
|
|
this.minTtl = Math.min(Cache.MAX_SUPPORTED_TTL_SECS, checkPositiveOrZero(minTtl, "minTtl"));
|
|
this.maxTtl = Math.min(Cache.MAX_SUPPORTED_TTL_SECS, checkPositive(maxTtl, "maxTtl"));
|
|
if (minTtl > maxTtl) {
|
|
throw new IllegalArgumentException(
|
|
"minTtl: " + minTtl + ", maxTtl: " + maxTtl + " (expected: 0 <= minTtl <= maxTtl)");
|
|
}
|
|
this.comparator = comparator;
|
|
}
|
|
|
|
@Override
|
|
public DnsServerAddressStream get(String hostname) {
|
|
requireNonNull(hostname, "hostname");
|
|
|
|
List<? extends InetSocketAddress> addresses = resolveCache.get(hostname);
|
|
if (addresses == null || addresses.isEmpty()) {
|
|
return null;
|
|
}
|
|
return new SequentialDnsServerAddressStream(addresses, 0);
|
|
}
|
|
|
|
@Override
|
|
public void cache(String hostname, InetSocketAddress address, long originalTtl, EventLoop loop) {
|
|
requireNonNull(hostname, "hostname");
|
|
requireNonNull(address, "address");
|
|
requireNonNull(loop, "loop");
|
|
|
|
if (address.getHostString() == null) {
|
|
// We only cache addresses that have also a host string as we will need it later when trying to replace
|
|
// unresolved entries in the cache.
|
|
return;
|
|
}
|
|
|
|
resolveCache.cache(hostname, address, Math.max(minTtl, (int) Math.min(maxTtl, originalTtl)), loop);
|
|
}
|
|
|
|
@Override
|
|
public void clear() {
|
|
resolveCache.clear();
|
|
}
|
|
|
|
@Override
|
|
public boolean clear(String hostname) {
|
|
requireNonNull(hostname, "hostname");
|
|
|
|
return resolveCache.clear(hostname);
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return "DefaultAuthoritativeDnsServerCache(minTtl=" + minTtl + ", maxTtl=" + maxTtl + ", cached nameservers=" +
|
|
resolveCache.size() + ')';
|
|
}
|
|
}
|