DefaultAuthoritativeDnsServerCache.java — netty Source File

Source Code

/*
 * 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:
 *
 *   https://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 java.net.InetSocketAddress;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.ConcurrentMap;

import static io.netty.util.internal.ObjectUtil.checkNotNull;
import static io.netty.util.internal.ObjectUtil.checkPositive;
import static io.netty.util.internal.ObjectUtil.checkPositiveOrZero;

/**
 * Default implementation of {@link AuthoritativeDnsServerCache}, backed by a {@link ConcurrentMap}.
 */
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) {
                Collections.sort(entries, comparator);
            }
        }
    };

    /**
     * Create a cache that respects the TTL returned by the DNS server.
     */
    public DefaultAuthoritativeDnsServerCache() {
// ... (75 more lines)