1 /*
2 * Copyright 2017 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.channel.unix;
17
18 import io.netty.buffer.ByteBuf;
19
20 import java.net.InetAddress;
21 import java.net.InetSocketAddress;
22 import java.net.UnknownHostException;
23
24 import static io.netty.channel.unix.Limits.IOV_MAX;
25
26 public final class UnixChannelUtil {
27
28 private UnixChannelUtil() {
29 }
30
31 /**
32 * Checks if the specified buffer has memory address or is composed of n(n <= IOV_MAX) NIO direct buffers.
33 * (We check this because otherwise we need to make it a new direct buffer.)
34 */
35 public static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf) {
36 return isBufferCopyNeededForWrite(byteBuf, IOV_MAX);
37 }
38
39 static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf, int iovMax) {
40 return !byteBuf.hasMemoryAddress() && (!byteBuf.isDirect() || byteBuf.nioBufferCount() > iovMax);
41 }
42
43 public static InetSocketAddress computeRemoteAddr(InetSocketAddress remoteAddr, InetSocketAddress osRemoteAddr) {
44 if (osRemoteAddr != null) {
45 try {
46 // Only try to construct a new InetSocketAddress if we using java >= 7 as getHostString() does not
47 // exists in earlier releases and so the retrieval of the hostname could block the EventLoop if a
48 // reverse lookup would be needed.
49 return new InetSocketAddress(InetAddress.getByAddress(remoteAddr.getHostString(),
50 osRemoteAddr.getAddress().getAddress()),
51 osRemoteAddr.getPort());
52 } catch (UnknownHostException ignore) {
53 // Should never happen but fallback to osRemoteAddr anyway.
54 }
55 return osRemoteAddr;
56 }
57 return remoteAddr;
58 }
59 }