content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed 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 com.alibaba.nacos.core.distributed.raft;
  
  import com.alibaba.nacos.common.model.RestResult;
  import com.alibaba.nacos.common.notify.NotifyCenter;
  import com.alibaba.nacos.common.notify.listener.Subscriber;
  import com.alibaba.nacos.common.notify.Event;
  import com.alibaba.nacos.common.utils.MapUtil;
  import com.alibaba.nacos.common.utils.ThreadUtils;
  import com.alibaba.nacos.consistency.ProtocolMetaData;
  import com.alibaba.nacos.consistency.SerializeFactory;
  import com.alibaba.nacos.consistency.Serializer;
  import com.alibaba.nacos.consistency.cp.CPProtocol;
  import com.alibaba.nacos.consistency.cp.RequestProcessor4CP;
  import com.alibaba.nacos.consistency.cp.MetadataKey;
  import com.alibaba.nacos.consistency.entity.ReadRequest;
  import com.alibaba.nacos.consistency.entity.Response;
  import com.alibaba.nacos.consistency.entity.WriteRequest;
  import com.alibaba.nacos.core.cluster.Member;
  import com.alibaba.nacos.core.cluster.ServerMemberManager;
  import com.alibaba.nacos.core.distributed.AbstractConsistencyProtocol;
  import com.alibaba.nacos.core.distributed.raft.exception.NoSuchRaftGroupException;
  import com.alibaba.nacos.core.utils.Loggers;
  import com.alipay.sofa.jraft.Node;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  /**
   * A concrete implementation of CP protocol: JRaft.
   *
   * <pre>
   *                                           ┌──────────────────────┐
   *            ┌──────────────────────┐       │                      ▼
   *            │   ProtocolManager    │       │        ┌───────────────────────────┐
   *            └──────────────────────┘       │        │for p in [LogProcessor4CP] │
   *                        │                  │        └───────────────────────────┘
   *                        ▼                  │                      │
   *      ┌──────────────────────────────────┐ │                      ▼
   *      │    discovery LogProcessor4CP     │ │             ┌─────────────────┐
   *      └──────────────────────────────────┘ │             │  get p.group()  │
   *                        │                  │             └─────────────────┘
   *                        ▼                  │                      │
   *                 ┌─────────────┐           │                      │
   *                 │ RaftConfig  │           │                      ▼
   *                 └─────────────┘           │      ┌──────────────────────────────┐
   *                        │                  │      │  create raft group service   │
   *                        ▼                  │      └──────────────────────────────┘
   *              ┌──────────────────┐         │
   *              │  JRaftProtocol   │         │
   *              └──────────────────┘         │
   *                        │                  │
   *                     init()                │
   *                        │                  │
   *                        ▼                  │
   *               ┌─────────────────┐         │
   *               │   JRaftServer   │         │
   *               └─────────────────┘         │
   *                        │                  │
   *                        │                  │
   *                        ▼                  │
   *             ┌────────────────────┐        │
   *             │JRaftServer.start() │        │
   *             └────────────────────┘        │
   *                        │                  │
   *                        └──────────────────┘
   * </pre>
   *
   * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
   */
  @SuppressWarnings("all")
  public class JRaftProtocol extends AbstractConsistencyProtocol<RaftConfig, RequestProcessor4CP>
          implements CPProtocol<RaftConfig, RequestProcessor4CP> {
      
      private final AtomicBoolean initialized = new AtomicBoolean(false);
      
      private final AtomicBoolean shutdowned = new AtomicBoolean(false);
      
      private final Serializer serializer = SerializeFactory.getDefault();
      
      private RaftConfig raftConfig;
      
      private JRaftServer raftServer;
      
      private JRaftMaintainService jRaftMaintainService;
      
      private ServerMemberManager memberManager;
      
      public JRaftProtocol(ServerMemberManager memberManager) throws Exception {
          this.memberManager = memberManager;
          this.raftServer = new JRaftServer();
          this.jRaftMaintainService = new JRaftMaintainService(raftServer);
      }
      
      @Override
      public void init(RaftConfig config) {
          if (initialized.compareAndSet(false, true)) {
              this.raftConfig = config;
              NotifyCenter.registerToSharePublisher(RaftEvent.class);
              this.raftServer.init(this.raftConfig);
              this.raftServer.start();
              
              // There is only one consumer to ensure that the internal consumption
              // is sequential and there is no concurrent competition
              NotifyCenter.registerSubscriber(new Subscriber<RaftEvent>() {
                  @Override
                  public void onEvent(RaftEvent event) {
                      Loggers.RAFT.info("This Raft event changes : {}", event);
                      final String groupId = event.getGroupId();
                      Map<String, Map<String, Object>> value = new HashMap<>();
                      Map<String, Object> properties = new HashMap<>();
                      final String leader = event.getLeader();
                      final Long term = event.getTerm();
                      final List<String> raftClusterInfo = event.getRaftClusterInfo();
                      final String errMsg = event.getErrMsg();
                      
                      // Leader information needs to be selectively updated. If it is valid data,
                      // the information in the protocol metadata is updated.
                      MapUtil.putIfValNoEmpty(properties, MetadataKey.LEADER_META_DATA, leader);
                      MapUtil.putIfValNoNull(properties, MetadataKey.TERM_META_DATA, term);
                      MapUtil.putIfValNoEmpty(properties, MetadataKey.RAFT_GROUP_MEMBER, raftClusterInfo);
                      MapUtil.putIfValNoEmpty(properties, MetadataKey.ERR_MSG, errMsg);
                      
                      value.put(groupId, properties);
                      metaData.load(value);
                      
                      // The metadata information is injected into the metadata information of the node
                      injectProtocolMetaData(metaData);
                  }
                  
                  @Override
                  public Class<? extends Event> subscribeType() {
                      return RaftEvent.class;
                  }
                  
              });
          }
      }
      
      @Override
      public void addRequestProcessors(Collection<RequestProcessor4CP> processors) {
          raftServer.createMultiRaftGroup(processors);
      }
      
      @Override
      public Response getData(ReadRequest request) throws Exception {
          CompletableFuture<Response> future = aGetData(request);
          return future.get(5_000L, TimeUnit.MILLISECONDS);
      }
      
      @Override
      public CompletableFuture<Response> aGetData(ReadRequest request) {
          return raftServer.get(request);
      }
      
      @Override
      public Response write(WriteRequest request) throws Exception {
          CompletableFuture<Response> future = writeAsync(request);
          // Here you wait for 10 seconds, as long as possible, for the request to complete
          return future.get(10_000L, TimeUnit.MILLISECONDS);
      }
      
      @Override
      public CompletableFuture<Response> writeAsync(WriteRequest request) {
          return raftServer.commit(request.getGroup(), request, new CompletableFuture<>());
      }
      
      @Override
      public void memberChange(Set<String> addresses) {
          for (int i = 0; i < 5; i++) {
              if (this.raftServer.peerChange(jRaftMaintainService, addresses)) {
                  return;
              }
              ThreadUtils.sleep(100L);
          }
          Loggers.RAFT.warn("peer removal failed");
      }
      
      @Override
      public void shutdown() {
          if (initialized.get() && shutdowned.compareAndSet(false, true)) {
              Loggers.RAFT.info("shutdown jraft server");
              raftServer.shutdown();
          }
      }
      
      @Override
      public RestResult<String> execute(Map<String, String> args) {
          return jRaftMaintainService.execute(args);
      }
      
      private void injectProtocolMetaData(ProtocolMetaData metaData) {
          Member member = memberManager.getSelf();
          member.setExtendVal("raftMetaData", metaData);
          memberManager.update(member);
      }
      
      @Override
      public boolean isLeader(String group) {
          Node node = raftServer.findNodeByGroup(group);
          if (node == null) {
              throw new NoSuchRaftGroupException(group);
          }
          return node.isLeader();
      }
      
      @Override
      public boolean isReady() {
          return raftServer.isReady();
      }
  }
  