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.aliyun.odps;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  
  /**
   * OdpsHooks 类
   * 注册 OdpsHook 类 用于在启动 Instance 前后分别运行插件代码
   *
   * 一个 OdpsHooks 实例针对一个 Instance， 包含了一组实例化的 OdpsHook 对象
   */
  public class OdpsHooks {
  
  
    private static boolean enabled = true;
  
    private static List<Class<? extends OdpsHook>>
        registeredHooks =
        new ArrayList<Class<? extends OdpsHook>>();
  
    private List<OdpsHook> runningHooks = new ArrayList<OdpsHook>();
  
    private static final Object lock = new Object();
  
    /**
     * 新建一个 OdpsHooks 对象
     */
    public OdpsHooks() {
      try {
        synchronized (lock) {
          for (Class<? extends OdpsHook> hookClass : registeredHooks) {
            runningHooks.add(hookClass.newInstance());
          }
        }
      } catch (Exception e) {
        throw new RuntimeException(e.getMessage(), e);
      }
    }
  
    /**
     * 调用 Hook 的 before
     *
     * @param job
     *     调用 hook 的 job
     * @param odps
     *     odps 实例
     * @throws OdpsException
     */
    public void before(Job job, Odps odps) throws OdpsException {
      for (OdpsHook hook : runningHooks) {
        hook.before(job, odps);
      }
    }
  
    /**
     * 调用 Hook 的 ready
     *
     * @param instance
     *     创建的 instance
     * @param odps
     *     odps 实例
     * @throws OdpsException
     */
    public void onInstanceCreated(Instance instance, Odps odps) throws OdpsException {
      for (OdpsHook hook : runningHooks) {
        hook.onInstanceCreated(instance, odps);
      }
    }
  
    /**
     * 调用 Hook 的 after
     *
     * @param instance
     *     创建的 instance
     * @param odps
     *     odps 实例
     * @throws OdpsException
     */
    public void after(Instance instance, Odps odps) throws OdpsException {
      for (OdpsHook hook : runningHooks) {
        hook.after(instance, odps);
      }
    }
  
    /**
     * 注册多个 hook
     *
     * @param hooks
     *     注册的 hook 列表
     */
    public static void registerHooks(Collection<Class<? extends OdpsHook>> hooks) {
      synchronized (lock) {
        registeredHooks.addAll(hooks);
      }
    }
  
    /**
     * 注册一个 hook
     *
     * @param hook
     *     注册的 hook 名字列表
     */
    public static void registerHook(Class<? extends OdpsHook> hook) {
      synchronized (lock) {
        registeredHooks.add(hook);
      }
    }
  
    @Deprecated
    public static List<Class<? extends OdpsHook>> getRegisteredHooks() {
      return registeredHooks;
    }
  
    /**
     * 清空 hooks
     */
    public static void clearRegisteredHooks() {
      synchronized (lock) {
        registeredHooks.clear();
      }
    }
  
    /**
     * 获取 hook 开关
     *
     * @return 是否开启 hook
     */
    public static boolean isEnabled() {
      return enabled;
    }
  
    /**
     * 设置 hook 开关
     *
     * @param enabled
     *     是否开启 hook
     */
    public static void setEnabled(boolean enabled) {
      OdpsHooks.enabled = enabled;
    }
  
  }
  