/*
    *
    * 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.
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  package org.apache.hadoop.hbase.replication;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.Abortable;
  import org.apache.hadoop.hbase.zookeeper.ZKUtil;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.data.Stat;
  
  @InterfaceAudience.Private
  public class ReplicationQueuesClientZKImpl extends ReplicationStateZKBase implements
      ReplicationQueuesClient {
  
    public ReplicationQueuesClientZKImpl(final ZooKeeperWatcher zk, Configuration conf,
        Abortable abortable) {
      super(zk, conf, abortable);
    }
  
    @Override
    public void init() throws ReplicationException {
      try {
        if (ZKUtil.checkExists(this.zookeeper, this.queuesZNode) < 0) {
          ZKUtil.createWithParents(this.zookeeper, this.queuesZNode);
        }
      } catch (KeeperException e) {
        throw new ReplicationException("Internal error while initializing a queues client", e);
      }
    }
  
    @Override
    public List<String> getListOfReplicators() throws KeeperException {
      return super.getListOfReplicatorsZK();
    }
  
    @Override
    public List<String> getLogsInQueue(String serverName, String queueId) throws KeeperException {
      String znode = ZKUtil.joinZNode(this.queuesZNode, serverName);
      znode = ZKUtil.joinZNode(znode, queueId);
      List<String> result = null;
      try {
        result = ZKUtil.listChildrenNoWatch(this.zookeeper, znode);
      } catch (KeeperException e) {
        this.abortable.abort("Failed to get list of wals for queueId=" + queueId
            + " and serverName=" + serverName, e);
        throw e;
      }
      return result;
    }
  
    @Override
    public List<String> getAllQueues(String serverName) throws KeeperException {
      String znode = ZKUtil.joinZNode(this.queuesZNode, serverName);
      List<String> result = null;
      try {
        result = ZKUtil.listChildrenNoWatch(this.zookeeper, znode);
      } catch (KeeperException e) {
        this.abortable.abort("Failed to get list of queues for serverName=" + serverName, e);
        throw e;
      }
      return result;
    }
  
    @Override public int getQueuesZNodeCversion() throws KeeperException {
      try {
        Stat stat = new Stat();
        ZKUtil.getDataNoWatch(this.zookeeper, this.queuesZNode, stat);
        return stat.getCversion();
      } catch (KeeperException e) {
        this.abortable.abort("Failed to get stat of replication rs node", e);
        throw e;
      }
    }
  
    @Override public Map<String, Integer> getReplicatorsZNodeCversion()
      throws KeeperException {
      List<String> rss = super.getListOfReplicatorsZK();
     Map<String, Integer> rsToCversion = new HashMap<>();
     for (String rs : rss) {
       Stat stat = new Stat();
       ZKUtil.getDataNoWatch(this.zookeeper, ZKUtil.joinZNode(this.queuesZNode, rs), stat);
       rsToCversion.put(rs, stat.getCversion());
     }
     return rsToCversion;
   }
 
   @Override
   public int getHFileRefsNodeChangeVersion() throws KeeperException {
     Stat stat = new Stat();
     try {
       ZKUtil.getDataNoWatch(this.zookeeper, this.hfileRefsZNode, stat);
     } catch (KeeperException e) {
       this.abortable.abort("Failed to get stat of replication hfile references node.", e);
       throw e;
     }
     return stat.getCversion();
   }
 
   @Override
   public List<String> getAllPeersFromHFileRefsQueue() throws KeeperException {
     List<String> result = null;
     try {
       result = ZKUtil.listChildrenNoWatch(this.zookeeper, this.hfileRefsZNode);
     } catch (KeeperException e) {
       this.abortable.abort("Failed to get list of all peers in hfile references node.", e);
       throw e;
     }
     return result;
   }
 
   @Override
   public List<String> getReplicableHFiles(String peerId) throws KeeperException {
     String znode = ZKUtil.joinZNode(this.hfileRefsZNode, peerId);
     List<String> result = null;
     try {
       result = ZKUtil.listChildrenNoWatch(this.zookeeper, znode);
     } catch (KeeperException e) {
       this.abortable.abort("Failed to get list of hfile references for peerId=" + peerId, e);
       throw e;
     }
     return result;
   }
 }