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16 package io.netty.handler.codec.dns;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.channel.AddressedEnvelope;
20 import io.netty.channel.ChannelHandler;
21 import io.netty.channel.ChannelHandlerContext;
22 import io.netty.channel.socket.DatagramPacket;
23 import io.netty.handler.codec.MessageToMessageEncoder;
24 import io.netty.util.internal.UnstableApi;
25
26 import java.net.InetSocketAddress;
27 import java.util.List;
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32
33 @UnstableApi
34 @ChannelHandler.Sharable
35 public class DatagramDnsQueryEncoder extends MessageToMessageEncoder<AddressedEnvelope<DnsQuery, InetSocketAddress>> {
36
37 private final DnsQueryEncoder encoder;
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41
42 public DatagramDnsQueryEncoder() {
43 this(DnsRecordEncoder.DEFAULT);
44 }
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49 public DatagramDnsQueryEncoder(DnsRecordEncoder recordEncoder) {
50 this.encoder = new DnsQueryEncoder(recordEncoder);
51 }
52
53 @Override
54 protected void encode(
55 ChannelHandlerContext ctx,
56 AddressedEnvelope<DnsQuery, InetSocketAddress> in, List<Object> out) throws Exception {
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58 final InetSocketAddress recipient = in.recipient();
59 final DnsQuery query = in.content();
60 final ByteBuf buf = allocateBuffer(ctx, in);
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62 boolean success = false;
63 try {
64 encoder.encode(query, buf);
65 success = true;
66 } finally {
67 if (!success) {
68 buf.release();
69 }
70 }
71
72 out.add(new DatagramPacket(buf, recipient, null));
73 }
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78
79 protected ByteBuf allocateBuffer(
80 ChannelHandlerContext ctx,
81 @SuppressWarnings("unused") AddressedEnvelope<DnsQuery, InetSocketAddress> msg) throws Exception {
82 return ctx.alloc().ioBuffer(1024);
83 }
84 }