001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.ipc;
019
020import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
021
022import org.apache.hbase.thirdparty.io.netty.channel.Channel;
023import org.apache.hbase.thirdparty.io.netty.channel.EventLoopGroup;
024
025import java.util.HashMap;
026import java.util.Map;
027
028import org.apache.commons.lang3.StringUtils;
029import org.apache.hadoop.conf.Configuration;
030import org.apache.yetus.audience.InterfaceAudience;
031import org.apache.hadoop.hbase.util.Pair;
032
033/**
034 * Helper class for passing config to {@link NettyRpcClient}.
035 * <p>
036 * As hadoop Configuration can not pass an Object directly, we need to find a way to pass the
037 * EventLoopGroup to {@code AsyncRpcClient} if we want to use a single {@code EventLoopGroup} for
038 * the whole process.
039 * @since 2.0.0
040 */
041@InterfaceAudience.Public
042public class NettyRpcClientConfigHelper {
043
044  public static final String EVENT_LOOP_CONFIG = "hbase.rpc.client.event-loop.config";
045
046  private static final String CONFIG_NAME = "global-event-loop";
047
048  private static final Map<String, Pair<EventLoopGroup, Class<? extends Channel>>>
049    EVENT_LOOP_CONFIG_MAP = new HashMap<>();
050
051  /**
052   * Set the EventLoopGroup and channel class for {@code AsyncRpcClient}.
053   */
054  public static void setEventLoopConfig(Configuration conf, EventLoopGroup group,
055      Class<? extends Channel> channelClass) {
056    Preconditions.checkNotNull(group, "group is null");
057    Preconditions.checkNotNull(channelClass, "channel class is null");
058    conf.set(EVENT_LOOP_CONFIG, CONFIG_NAME);
059    EVENT_LOOP_CONFIG_MAP.put(CONFIG_NAME,
060      Pair.<EventLoopGroup, Class<? extends Channel>> newPair(group, channelClass));
061  }
062
063  /**
064   * The {@code AsyncRpcClient} will create its own {@code NioEventLoopGroup}.
065   */
066  public static void createEventLoopPerClient(Configuration conf) {
067    conf.set(EVENT_LOOP_CONFIG, "");
068    EVENT_LOOP_CONFIG_MAP.clear();
069  }
070
071  static Pair<EventLoopGroup, Class<? extends Channel>> getEventLoopConfig(Configuration conf) {
072    String name = conf.get(EVENT_LOOP_CONFIG);
073    if (name == null) {
074      return DefaultNettyEventLoopConfig.GROUP_AND_CHANNEL_CLASS;
075    }
076    if (StringUtils.isBlank(name)) {
077      return null;
078    }
079    return EVENT_LOOP_CONFIG_MAP.get(name);
080  }
081
082}