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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 2019 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.handler.codec.dns;

import io.netty.buffer.ByteBuf;

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

final class DnsQueryEncoder {

    private final DnsRecordEncoder recordEncoder;

    /**
     * Creates a new encoder with the specified {@code recordEncoder}.
     */
    DnsQueryEncoder(DnsRecordEncoder recordEncoder) {
        this.recordEncoder = checkNotNull(recordEncoder, "recordEncoder");
    }

    /**
     * Encodes the given {@link DnsQuery} into a {@link ByteBuf}.
     */
    void encode(DnsQuery query, ByteBuf out) throws Exception {
        encodeHeader(query, out);
        encodeQuestions(query, out);
        encodeRecords(query, DnsSection.ADDITIONAL, out);
    }

    /**
     * Encodes the header that is always 12 bytes long.
     *
     * @param query the query header being encoded
     * @param buf   the buffer the encoded data should be written to
     */
    private static void encodeHeader(DnsQuery query, ByteBuf buf) {
        buf.writeShort(query.id());
        int flags = 0;
        flags |= (query.opCode().byteValue() & 0xFF) << 14;
        if (query.isRecursionDesired()) {
            flags |= 1 << 8;
        }
        buf.writeShort(flags);
        buf.writeShort(query.count(DnsSection.QUESTION));
        buf.writeShort(0); // answerCount
        buf.writeShort(0); // authorityResourceCount
        buf.writeShort(query.count(DnsSection.ADDITIONAL));
    }

    private void encodeQuestions(DnsQuery query, ByteBuf buf) throws Exception {
        final int count = query.count(DnsSection.QUESTION);
        for (int i = 0; i < count; i++) {
            recordEncoder.encodeQuestion((DnsQuestion) query.recordAt(DnsSection.QUESTION, i), buf);
        }
    }

    private void encodeRecords(DnsQuery query, DnsSection section, ByteBuf buf) throws Exception {
        final int count = query.count(section);
        for (int i = 0; i < count; i++) {
            recordEncoder.encodeRecord(query.recordAt(section, i), buf);
        }
    }
}