| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF 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 org.apache.hadoop.hdfs.tools.offlineImageViewer; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import io.netty.bootstrap.ServerBootstrap; |
| import io.netty.channel.Channel; |
| import io.netty.channel.ChannelInitializer; |
| import io.netty.channel.ChannelPipeline; |
| import io.netty.channel.EventLoopGroup; |
| import io.netty.channel.group.ChannelGroup; |
| import io.netty.channel.group.DefaultChannelGroup; |
| import io.netty.channel.nio.NioEventLoopGroup; |
| import io.netty.channel.socket.SocketChannel; |
| import io.netty.channel.socket.nio.NioServerSocketChannel; |
| import io.netty.handler.codec.http.HttpRequestDecoder; |
| import io.netty.handler.codec.http.HttpResponseEncoder; |
| import io.netty.handler.codec.string.StringEncoder; |
| import io.netty.util.concurrent.GlobalEventExecutor; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.net.InetSocketAddress; |
| |
| /** |
| * WebImageViewer loads a fsimage and exposes read-only WebHDFS API for its |
| * namespace. |
| */ |
| public class WebImageViewer implements Closeable { |
| public static final Log LOG = LogFactory.getLog(WebImageViewer.class); |
| |
| private Channel channel; |
| private InetSocketAddress address; |
| |
| private final ServerBootstrap bootstrap; |
| private final EventLoopGroup bossGroup; |
| private final EventLoopGroup workerGroup; |
| private final ChannelGroup allChannels; |
| |
| public WebImageViewer(InetSocketAddress address) { |
| this.address = address; |
| this.bossGroup = new NioEventLoopGroup(); |
| this.workerGroup = new NioEventLoopGroup(); |
| this.allChannels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE); |
| this.bootstrap = new ServerBootstrap() |
| .group(bossGroup, workerGroup) |
| .channel(NioServerSocketChannel.class); |
| } |
| |
| /** |
| * Start WebImageViewer and wait until the thread is interrupted. |
| * @param fsimage the fsimage to load. |
| * @throws IOException if failed to load the fsimage. |
| */ |
| public void start(String fsimage) throws IOException { |
| try { |
| initServer(fsimage); |
| channel.closeFuture().await(); |
| } catch (InterruptedException e) { |
| LOG.info("Interrupted. Stopping the WebImageViewer."); |
| close(); |
| } |
| } |
| |
| /** |
| * Start WebImageViewer. |
| * @param fsimage the fsimage to load. |
| * @throws IOException if fail to load the fsimage. |
| */ |
| @VisibleForTesting |
| public void initServer(String fsimage) |
| throws IOException, InterruptedException { |
| final FSImageLoader loader = FSImageLoader.load(fsimage); |
| |
| bootstrap.childHandler(new ChannelInitializer<SocketChannel>() { |
| @Override |
| protected void initChannel(SocketChannel ch) throws Exception { |
| ChannelPipeline p = ch.pipeline(); |
| p.addLast(new HttpRequestDecoder(), |
| new StringEncoder(), |
| new HttpResponseEncoder(), |
| new FSImageHandler(loader, allChannels)); |
| } |
| }); |
| |
| channel = bootstrap.bind(address).sync().channel(); |
| allChannels.add(channel); |
| |
| address = (InetSocketAddress) channel.localAddress(); |
| LOG.info("WebImageViewer started. Listening on " + address.toString() + ". Press Ctrl+C to stop the viewer."); |
| } |
| |
| /** |
| * Get the listening port. |
| * @return the port WebImageViewer is listening on |
| */ |
| @VisibleForTesting |
| public int getPort() { |
| return address.getPort(); |
| } |
| |
| @Override |
| public void close() { |
| allChannels.close().awaitUninterruptibly(); |
| bossGroup.shutdownGracefully(); |
| workerGroup.shutdownGracefully(); |
| } |
| } |