io.netty.resolver.dns.DnsCache Maven / Gradle / Ivy
/*
* Copyright 2016 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.handler.codec.dns.DnsRecord;
import java.net.InetAddress;
import java.util.List;
/**
* A cache for DNS resolution entries.
*/
public interface DnsCache {
/**
* Clears all the resolved addresses cached by this resolver.
*
* @see #clear(String)
*/
void clear();
/**
* Clears the resolved addresses of the specified host name from the cache of this resolver.
*
* @return {@code true} if and only if there was an entry for the specified host name in the cache and
* it has been removed by this method
*/
boolean clear(String hostname);
/**
* Return the cached entries for the given hostname.
* @param hostname the hostname
* @param additionals the additional records
* @return the cached entries
*/
List get(String hostname, DnsRecord[] additionals);
/**
* Create a new {@link DnsCacheEntry} and cache a resolved address for a given hostname.
* @param hostname the hostname
* @param additionals the additional records
* @param address the resolved address
* @param originalTtl the TLL as returned by the DNS server
* @param loop the {@link EventLoop} used to register the TTL timeout
* @return The {@link DnsCacheEntry} corresponding to this cache entry.
*/
DnsCacheEntry cache(String hostname, DnsRecord[] additionals, InetAddress address, long originalTtl,
EventLoop loop);
/**
* Cache the resolution failure for a given hostname.
* Be aware this won't be called with timeout / cancel / transport exceptions.
*
* @param hostname the hostname
* @param additionals the additional records
* @param cause the resolution failure
* @param loop the {@link EventLoop} used to register the TTL timeout
* @return The {@link DnsCacheEntry} corresponding to this cache entry, or {@code null} if this cache doesn't
* support caching failed responses.
*/
DnsCacheEntry cache(String hostname, DnsRecord[] additionals, Throwable cause, EventLoop loop);
}