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This artifact provides a single jar that contains all classes required to use remote Jakarta Enterprise Beans and Jakarta Messaging, including all dependencies. It is intended for use by those not using maven, maven users should just import the Jakarta Enterprise Beans and Jakarta Messaging BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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.PlatformDependent;
import io.netty.util.internal.UnstableApi;

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.*;

/**
 * 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 comparator;
    private final Cache resolveCache = new Cache() {
        @Override
        protected boolean shouldReplaceAll(InetSocketAddress entry) {
            return false;
        }

        @Override
        protected boolean equals(InetSocketAddress entry, InetSocketAddress otherEntry) {
            if (PlatformDependent.javaVersion() >= 7) {
                return entry.getHostString().equalsIgnoreCase(otherEntry.getHostString());
            }
            return entry.getHostName().equalsIgnoreCase(otherEntry.getHostName());
        }

        @Override
        protected void sortEntries(String hostname, List entries) {
            if (comparator != null) {
                Collections.sort(entries, 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 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;
    }

    @SuppressWarnings("unchecked")
    @Override
    public DnsServerAddressStream get(String hostname) {
        checkNotNull(hostname, "hostname");

        List 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) {
        checkNotNull(hostname, "hostname");
        checkNotNull(address, "address");
        checkNotNull(loop, "loop");

        if (PlatformDependent.javaVersion() >= 7 && 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) {
        return resolveCache.clear(checkNotNull(hostname, "hostname"));
    }

    @Override
    public String toString() {
        return "DefaultAuthoritativeDnsServerCache(minTtl=" + minTtl + ", maxTtl=" + maxTtl + ", cached nameservers=" +
                resolveCache.size() + ')';
    }
}