content: /**
   * 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 com.alibaba.wasp.master;
  
  import com.alibaba.wasp.EntityGroupInfo;
  import com.alibaba.wasp.ServerName;
  import com.alibaba.wasp.zookeeper.ZooKeeperWatcher;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.zookeeper.AsyncCallback.StringCallback;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.ZooKeeper;
  import org.apache.zookeeper.data.Stat;
  
  import java.util.Map;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * Callback handler for creating unassigned offline znodes used during bulk
   * assign, async setting entityGroup to offline.
   */
  public class OfflineCallback implements StringCallback {
    private final Log LOG = LogFactory.getLog(OfflineCallback.class);
    private final ExistCallback callBack;
    private final ZooKeeperWatcher zkw;
    private final ServerName destination;
    private final AtomicInteger counter;
  
    OfflineCallback(final ZooKeeperWatcher zkw, final ServerName destination,
        final AtomicInteger counter,
        final Map<String, Integer> offlineNodesVersions) {
      this.callBack = new ExistCallback(destination, counter,
          offlineNodesVersions);
      this.destination = destination;
      this.counter = counter;
      this.zkw = zkw;
    }
  
    @Override
    public void processResult(int rc, String path, Object ctx, String name) {
      if (rc == KeeperException.Code.NODEEXISTS.intValue()) {
        LOG.warn("Node for " + path + " already exists");
      } else if (rc != 0) {
        // This is result code. If non-zero, need to resubmit.
        LOG.warn("rc != 0 for " + path + " -- retryable connectionloss -- "
            + "FIX see http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A2");
        this.counter.addAndGet(1);
        return;
      }
  
      if (LOG.isDebugEnabled()) {
        LOG.debug("rs=" + ctx + ", server=" + destination);
      }
      // Async exists to set a watcher so we'll get triggered when
      // unassigned node changes.
      ZooKeeper zk = this.zkw.getRecoverableZooKeeper().getZooKeeper();
      zk.exists(path, this.zkw, callBack, ctx);
    }
  
    /**
     * Callback handler for the exists call that sets watcher on unassigned
     * znodes. Used during bulk assign on startup.
     */
    static class ExistCallback implements StatCallback {
      private final Log LOG = LogFactory.getLog(ExistCallback.class);
      private final Map<String, Integer> offlineNodesVersions;
      private final AtomicInteger counter;
      private ServerName destination;
  
      ExistCallback(final ServerName destination, final AtomicInteger counter,
          final Map<String, Integer> offlineNodesVersions) {
        this.offlineNodesVersions = offlineNodesVersions;
        this.destination = destination;
        this.counter = counter;
      }
  
      @Override
      public void processResult(int rc, String path, Object ctx, Stat stat) {
        if (rc != 0) {
          // This is result code. If non-zero, need to resubmit.
          LOG.warn("rc != 0 for " + path + " -- retryable connectionloss -- "
              + "FIX see http://wiki.apache.org/hadoop/ZooKeeper/FAQ#A2");
          this.counter.addAndGet(1);
          return;
        }
  
        if (LOG.isDebugEnabled()) {
          LOG.debug("rs=" + ctx + ", server=" + destination);
        }
        EntityGroupInfo entityGroup = ((EntityGroupState) ctx).getEntityGroup();
        offlineNodesVersions.put(entityGroup.getEncodedName(),
            Integer.valueOf(stat.getVersion()));
        this.counter.addAndGet(1);
      }
    }
  
  }
  