Adding socket resolver helper that will load the appropriate SocketChannel

http-clients/netty-nio-client/src/main/java/software/amazon/awssdk/http/nio/netty/NettyNioAsyncHttpClient.java

@@ -16,25 +16,21 @@
 package software.amazon.awssdk.http.nio.netty;
 
 import static io.netty.handler.ssl.SslContext.defaultClientProvider;
+import static software.amazon.awssdk.http.nio.netty.internal.utils.SocketChannelResolver.resolveSocketChannelClass;
 import static software.amazon.awssdk.utils.FunctionalUtils.invokeSafely;
 
 import io.netty.bootstrap.Bootstrap;
-import io.netty.channel.Channel;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
-import io.netty.channel.epoll.EpollEventLoopGroup;
-import io.netty.channel.epoll.EpollSocketChannel;
 import io.netty.channel.pool.ChannelHealthChecker;
 import io.netty.channel.pool.ChannelPool;
 import io.netty.channel.pool.ChannelPoolMap;
 import io.netty.channel.pool.FixedChannelPool;
-import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
 import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
 import java.net.URI;
 import java.util.Optional;
-import software.amazon.awssdk.annotations.ReviewBeforeRelease;
 import software.amazon.awssdk.annotations.SdkInternalApi;
 import software.amazon.awssdk.http.SdkHttpConfigurationOption;
 import software.amazon.awssdk.http.SdkHttpRequest;
@@ -44,7 +40,6 @@
 import software.amazon.awssdk.http.async.SdkHttpRequestProvider;
 import software.amazon.awssdk.http.async.SdkHttpResponseHandler;
 import software.amazon.awssdk.http.nio.netty.internal.ChannelPipelineInitializer;
-import software.amazon.awssdk.http.nio.netty.internal.DelegatingEventLoopGroup;
 import software.amazon.awssdk.http.nio.netty.internal.NettyConfiguration;
 import software.amazon.awssdk.http.nio.netty.internal.NonManagedEventLoopGroup;
 import software.amazon.awssdk.http.nio.netty.internal.RequestAdapter;
@@ -78,7 +73,7 @@ protected ChannelPool newPool(URI key) {
                 Bootstrap bootstrap =
                         new Bootstrap()
                                 .group(group)
-                                .channel(resolveSocketChannelClass())
+                                .channel(resolveSocketChannelClass(group))
                                 .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, configuration.connectionTimeout())
                                 .option(ChannelOption.TCP_NODELAY, true)
                                 .remoteAddress(key.getHost(), key.getPort());
@@ -117,20 +112,6 @@ public void close() {
         group.shutdownGracefully();
     }
 
-    /**
-     * Depending on the EventLoopGroup used we may need to use a different socket channel.
-     */
-    @ReviewBeforeRelease("Perhaps we should make the customer provide both event loop group" +
-                         "and channel in some kind of wrapper class to avoid having to do this.")
-    private Class<? extends Channel> resolveSocketChannelClass() {
-        EventLoopGroup unwrapped = group;
-        // Keep unwrapping until it's not a DelegatingEventLoopGroup
-        while (unwrapped instanceof DelegatingEventLoopGroup) {
-            unwrapped = ((DelegatingEventLoopGroup) unwrapped).getDelegate();
-        }
-        return unwrapped instanceof EpollEventLoopGroup ? EpollSocketChannel.class : NioSocketChannel.class;
-    }
-
     private static URI poolKey(SdkHttpRequest sdkRequest) {
         return invokeSafely(() -> new URI(sdkRequest.protocol(), null, sdkRequest.host(),
                                           sdkRequest.port(), null, null, null));

http-clients/netty-nio-client/src/main/java/software/amazon/awssdk/http/nio/netty/internal/utils/SocketChannelResolver.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2010-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ * or in the "license" file accompanying this file. This file 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 software.amazon.awssdk.http.nio.netty.internal.utils;
+
+import static software.amazon.awssdk.utils.FunctionalUtils.invokeSafely;
+
+import io.netty.channel.Channel;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import io.netty.channel.epoll.EpollSocketChannel;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import java.util.HashMap;
+import java.util.Map;
+import software.amazon.awssdk.http.nio.netty.internal.DelegatingEventLoopGroup;
+
+public final class SocketChannelResolver {
+
+    private static final Map<String, String> KNOWN_EL_GROUPS = new HashMap<>();
+
+    static {
+        KNOWN_EL_GROUPS.put("io.netty.channel.kqueue.KQueueEventLoopGroup", "io.netty.channel.kqueue.KQueueSocketChannel");
+        KNOWN_EL_GROUPS.put("io.netty.channel.oio.OioEventLoopGroup", "io.netty.channel.socket.oio.OioSocketChannel");
+    }
+
+    private SocketChannelResolver() {
+    }
+
+    /**
+     * Attempts to determine the {@link Channel} class that corresponds to the given
+     * event loop group.
+     *
+     * @param eventLoopGroup the event loop group to determine the {@link Channel} for
+     * @return A {@link Channel} class for the given event loop group.
+     */
+    public static Class<? extends Channel> resolveSocketChannelClass(EventLoopGroup eventLoopGroup) {
+        if (eventLoopGroup instanceof DelegatingEventLoopGroup) {
+            return resolveSocketChannelClass(((DelegatingEventLoopGroup) eventLoopGroup).getDelegate());
+        }
+        if (eventLoopGroup instanceof NioEventLoopGroup) {
+            return NioSocketChannel.class;
+        }
+        if (eventLoopGroup instanceof EpollEventLoopGroup) {
+            return EpollSocketChannel.class;
+        }
+        String socketFqcn = KNOWN_EL_GROUPS.get(eventLoopGroup.getClass().getName());
+        if (socketFqcn == null) {
+            throw new IllegalArgumentException("Unknown event loop group : " + eventLoopGroup.getClass());
+        }
+        return invokeSafely(() -> (Class<? extends Channel>) Class.forName(socketFqcn));
+    }
+}

http-clients/netty-nio-client/src/test/java/software/amazon/awssdk/http/nio/netty/internal/utils/SocketChannelResolverTest.java

@@ -0,0 +1,39 @@
+package software.amazon.awssdk.http.nio.netty.internal.utils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assume.assumeTrue;
+import static software.amazon.awssdk.http.nio.netty.internal.utils.SocketChannelResolver.resolveSocketChannelClass;
+
+import io.netty.channel.epoll.Epoll;
+import io.netty.channel.epoll.EpollEventLoopGroup;
+import io.netty.channel.epoll.EpollSocketChannel;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.oio.OioEventLoopGroup;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.channel.socket.oio.OioSocketChannel;
+import org.junit.Test;
+import software.amazon.awssdk.http.nio.netty.internal.DelegatingEventLoopGroup;
+
+public class SocketChannelResolverTest {
+
+    @Test
+    public void canDetectForStandardNioEventLoopGroup() {
+        assertThat(resolveSocketChannelClass(new NioEventLoopGroup())).isEqualTo(NioSocketChannel.class);
+    }
+
+    @Test
+    public void canDetectEpollEventLoopGroup() {
+        assumeTrue(Epoll.isAvailable());
+        assertThat(resolveSocketChannelClass(new EpollEventLoopGroup())).isEqualTo(EpollSocketChannel.class);
+    }
+
+    @Test
+    public void worksWithDelegateEventLoopGroups() {
+        assertThat(resolveSocketChannelClass(new DelegatingEventLoopGroup(new NioEventLoopGroup()) {})).isEqualTo(NioSocketChannel.class);
+    }
+
+    @Test
+    public void worksWithOioEventLoopGroup() {
+        assertThat(resolveSocketChannelClass(new OioEventLoopGroup())).isEqualTo(OioSocketChannel.class);
+    }
+}