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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 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.NetUtil;
import io.netty.util.collection.IntObjectHashMap;
import io.netty.util.collection.IntObjectMap;
import io.netty.util.internal.PlatformDependent;

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.util.HashMap;
import java.util.Map;

final class DnsQueryContextManager {

    /**
     * A map whose key is the DNS server address and value is the map of the DNS query ID and its corresponding
     * {@link DnsQueryContext}.
     */
    final Map> map =
            new HashMap>();

    int add(DnsQueryContext qCtx) {
        final IntObjectMap contexts = getOrCreateContextMap(qCtx.nameServerAddr());

        int id = PlatformDependent.threadLocalRandom().nextInt(65536 - 1) + 1;
        final int maxTries = 65535 << 1;
        int tries = 0;

        synchronized (contexts) {
            for (;;) {
                if (!contexts.containsKey(id)) {
                    contexts.put(id, qCtx);
                    return id;
                }

                id = id + 1 & 0xFFFF;

                if (++tries >= maxTries) {
                    throw new IllegalStateException("query ID space exhausted: " + qCtx.question());
                }
            }
        }
    }

    DnsQueryContext get(InetSocketAddress nameServerAddr, int id) {
        final IntObjectMap contexts = getContextMap(nameServerAddr);
        final DnsQueryContext qCtx;
        if (contexts != null) {
            synchronized (contexts) {
                qCtx = contexts.get(id);
            }
        } else {
            qCtx = null;
        }

        return qCtx;
    }

    DnsQueryContext remove(InetSocketAddress nameServerAddr, int id) {
        final IntObjectMap contexts = getContextMap(nameServerAddr);
        if (contexts == null) {
            return null;
        }

        synchronized (contexts) {
            return  contexts.remove(id);
        }
    }

    private IntObjectMap getContextMap(InetSocketAddress nameServerAddr) {
        synchronized (map) {
            return map.get(nameServerAddr);
        }
    }

    private IntObjectMap getOrCreateContextMap(InetSocketAddress nameServerAddr) {
        synchronized (map) {
            final IntObjectMap contexts = map.get(nameServerAddr);
            if (contexts != null) {
                return contexts;
            }

            final IntObjectMap newContexts = new IntObjectHashMap();
            final InetAddress a = nameServerAddr.getAddress();
            final int port = nameServerAddr.getPort();
            map.put(nameServerAddr, newContexts);

            if (a instanceof Inet4Address) {
                // Also add the mapping for the IPv4-compatible IPv6 address.
                final Inet4Address a4 = (Inet4Address) a;
                if (a4.isLoopbackAddress()) {
                    map.put(new InetSocketAddress(NetUtil.LOCALHOST6, port), newContexts);
                } else {
                    map.put(new InetSocketAddress(toCompactAddress(a4), port), newContexts);
                }
            } else if (a instanceof Inet6Address) {
                // Also add the mapping for the IPv4 address if this IPv6 address is compatible.
                final Inet6Address a6 = (Inet6Address) a;
                if (a6.isLoopbackAddress()) {
                    map.put(new InetSocketAddress(NetUtil.LOCALHOST4, port), newContexts);
                } else if (a6.isIPv4CompatibleAddress()) {
                    map.put(new InetSocketAddress(toIPv4Address(a6), port), newContexts);
                }
            }

            return newContexts;
        }
    }

    private static Inet6Address toCompactAddress(Inet4Address a4) {
        byte[] b4 = a4.getAddress();
        byte[] b6 = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, b4[0], b4[1], b4[2], b4[3] };
        try {
            return (Inet6Address) InetAddress.getByAddress(b6);
        } catch (UnknownHostException e) {
            throw new Error(e);
        }
    }

    private static Inet4Address toIPv4Address(Inet6Address a6) {
        byte[] b6 = a6.getAddress();
        byte[] b4 = { b6[12], b6[13], b6[14], b6[15] };
        try {
            return (Inet4Address) InetAddress.getByAddress(b4);
        } catch (UnknownHostException e) {
            throw new Error(e);
        }
    }
}