package org.apache.helix;
   
   /*
    * 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.
   */
  
  import java.util.List;
  
  import org.I0Itec.zkclient.DataUpdater;
  import org.I0Itec.zkclient.IZkChildListener;
  import org.I0Itec.zkclient.IZkDataListener;
  import org.apache.zookeeper.CreateMode;
  import org.apache.zookeeper.data.Stat;
  
  public interface BaseDataAccessor<T>
  {
    /**
     * This will always attempt to create the znode, if it exists it will return false. Will
     * create parents if they do not exist. For performance reasons, it may try to create
     * child first and only if it fails it will try to create parent
     * 
     * @param path
     * @param record
     * @return
     */
    boolean create(String path, T record, int options);
  
    /**
     * This will always attempt to set the data on existing node. If the znode does not
     * exist it will create it.
     * 
     * @param path
     * @param record
     * @param options Set the type of ZNode see the valid values in {@link AccessOption}
     * @return
     */
    boolean set(String path, T record, int options);
  
    /**
     * This will attempt to merge with existing data by calling znrecord.merge and if it
     * does not exist it will create it znode
     * 
     * @param path
     * @param record
     * @param options Set the type of ZNode see the valid values in {@link AccessOption}
     * @return
     */
    boolean update(String path, DataUpdater<T> updater, int options);
  
    /**
     * This will remove znode and all it's child nodes if any
     * 
     * @param path
     * @param options Set the type of ZNode see the valid values in {@link AccessOption}
     * @return
     */
    boolean remove(String path, int options);
  
    /**
     * Use it when creating children under a parent node. This will use async api for better
     * performance. If the child already exists it will return false.
     * 
     * @param parentPath
     * @param record
     * @param options Set the type of ZNode see the valid values in {@link AccessOption}
     * @return
     */
    boolean[] createChildren(List<String> paths, List<T> records, int options);
  
    /**
     * can set multiple children under a parent node. This will use async api for better
     * performance. If this child does not exist it will create it.
     * 
     * @param parentPath
     * @param record
     * @param options Set the type of ZNode see the valid values in {@link AccessOption}
     */
    boolean[] setChildren(List<String> paths, List<T> records, int options);
  
    /**
     * Can update multiple nodes using async api for better performance. If a child does not
     * exist it will create it.
     * 
     * @param parentPath
    * @param record
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   boolean[] updateChildren(List<String> paths, List<DataUpdater<T>> updaters, int options);
 
   /**
    * remove multiple paths using async api. will remove any child nodes if any
    * 
    * @param paths
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   boolean[] remove(List<String> paths, int options);
 
   /**
    * Get the {@link T} corresponding to the path
    * 
    * @param path
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   T get(String path, Stat stat, int options);
 
   /**
    * Get List of {@link T} corresponding to the paths using async api
    * 
    * @param paths
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   List<T> get(List<String> paths, List<Stat> stats, int options);
 
   /**
    * Get the children under a parent path using async api
    * 
    * @param path
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   List<T> getChildren(String parentPath, List<Stat> stats, int options);
 
   /**
    * Returns the child names given a parent path
    * 
    * @param type
    * @param keys
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   List<String> getChildNames(String parentPath, int options);
 
   /**
    * checks if the path exists in zk
    * 
    * @param path
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   boolean exists(String path, int options);
 
   /**
    * checks if the all the paths exists
    * 
    * @param paths
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   boolean[] exists(List<String> paths, int options);
 
   /**
    * Get the stats of all the paths
    * 
    * @param paths
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   Stat[] getStats(List<String> paths, int options);
 
   /**
    * Get the stats of all the paths
    * 
    * @param paths
    * @param options Set the type of ZNode see the valid values in {@link AccessOption}
    * @return
    */
   Stat getStat(String path, int options);
 
   /**
    * Subscribe data listener to path
    * 
    * @param path
    * @param listener
    * @return
    */
   void subscribeDataChanges(String path, IZkDataListener listener);
 
   /**
    * Unsubscribe data listener to path
    * 
    * @param path
    * @param listener
    */
   void unsubscribeDataChanges(String path, IZkDataListener listener);
 
   /**
    * Subscribe child listener to path
    * 
    * @param path
    * @param listener
    * @return
    */
   List<String> subscribeChildChanges(String path, IZkChildListener listener);
 
   /**
    * Unsubscribe child listener to path
    * 
    * @param path
    * @param listener
    */
   void unsubscribeChildChanges(String path, IZkChildListener listener);
 
   /**
    * reset the cache if any, when session expiry happens
    */
   void reset();
 }