DnsQueryContextManager.java — netty Source File

Source Code

/*
 * 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:
 *
 *   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.util.NetUtil;
import io.netty.util.collection.IntObjectHashMap;
import io.netty.util.collection.IntObjectMap;

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}.
     */
    private final Map<InetSocketAddress, DnsQueryContextMap> map =
            new HashMap<InetSocketAddress, DnsQueryContextMap>();

    /**
     * Add {@link DnsQueryContext} to the context manager and return the ID that should be used for the query.
     * This method will return {@code -1} if an ID could not be generated and the context was not stored.
     *
     * @param nameServerAddr    The {@link InetSocketAddress} of the nameserver to query.
     * @param qCtx              The {@link {@link DnsQueryContext} to store.
     * @return                  the ID that should be used or {@code -1} if none could be generated.
     */
    int add(InetSocketAddress nameServerAddr, DnsQueryContext qCtx) {
        assert !nameServerAddr.isUnresolved();
        final DnsQueryContextMap contexts = getOrCreateContextMap(nameServerAddr);
        return contexts.add(qCtx);
    }

    /**
     * Return the {@link DnsQueryContext} for the given {@link InetSocketAddress} and id or {@code null} if
     * none could be found.
     *
     * @param nameServerAddr    The {@link InetSocketAddress} of the nameserver.
     * @param id                The id that identifies the {@link DnsQueryContext} and was used for the query.
     * @return                  The context or {@code null} if none could be found.
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