/*
    *
    * 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 org.apache.hadoop.hbase.exceptions;
  
  import org.apache.hadoop.hbase.CallQueueTooBigException;
  import org.apache.hadoop.hbase.MultiActionResultTooLarge;
  import org.apache.hadoop.hbase.NotServingRegionException;
  import org.apache.hadoop.hbase.RegionTooBusyException;
  import org.apache.hadoop.hbase.RetryImmediatelyException;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.quotas.ThrottlingException;
  import org.apache.hadoop.ipc.RemoteException;
  
  @InterfaceAudience.Private
  @InterfaceStability.Evolving
  public final class ClientExceptionsUtil {
  
    private ClientExceptionsUtil() {}
  
    public static boolean isMetaClearingException(Throwable cur) {
      cur = findException(cur);
  
      if (cur == null) {
        return true;
      }
      return !isSpecialException(cur) || (cur instanceof RegionMovedException)
          || cur instanceof NotServingRegionException;
    }
  
    public static boolean isSpecialException(Throwable cur) {
      return (cur instanceof RegionMovedException || cur instanceof RegionOpeningException
          || cur instanceof RegionTooBusyException || cur instanceof ThrottlingException
          || cur instanceof MultiActionResultTooLarge || cur instanceof RetryImmediatelyException
          || cur instanceof CallQueueTooBigException || cur instanceof NotServingRegionException);
    }
  
  
    /**
     * Look for an exception we know in the remote exception:
     * - hadoop.ipc wrapped exceptions
     * - nested exceptions
     *
     * Looks for: RegionMovedException / RegionOpeningException / RegionTooBusyException /
     *            ThrottlingException
     * @return null if we didn't find the exception, the exception otherwise.
     */
    public static Throwable findException(Object exception) {
      if (exception == null || !(exception instanceof Throwable)) {
        return null;
      }
      Throwable cur = (Throwable) exception;
      while (cur != null) {
        if (isSpecialException(cur)) {
          return cur;
        }
        if (cur instanceof RemoteException) {
          RemoteException re = (RemoteException) cur;
          cur = re.unwrapRemoteException(
              RegionOpeningException.class, RegionMovedException.class,
              RegionTooBusyException.class);
          if (cur == null) {
            cur = re.unwrapRemoteException();
          }
          // unwrapRemoteException can return the exception given as a parameter when it cannot
          //  unwrap it. In this case, there is no need to look further
          // noinspection ObjectEquality
          if (cur == re) {
            return cur;
          }
        } else if (cur.getCause() != null) {
          cur = cur.getCause();
        } else {
          return cur;
        }
      }
  
      return null;
    }
  }