/*
    *
    * 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 java.io.EOFException;
  import java.io.IOException;
  import java.io.SyncFailedException;
  import java.lang.reflect.UndeclaredThrowableException;
  import java.net.ConnectException;
  import java.net.SocketTimeoutException;
  import java.nio.channels.ClosedChannelException;
  import java.util.concurrent.TimeoutException;
  
  import org.apache.hadoop.hbase.CallDroppedException;
  import org.apache.hadoop.hbase.CallQueueTooBigException;
  import org.apache.hadoop.hbase.DoNotRetryIOException;
  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.ipc.CallTimeoutException;
  import org.apache.hadoop.hbase.ipc.FailedServerException;
  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 CallDroppedException
          || cur instanceof NotServingRegionException || cur instanceof RequestTooBigException);
    }
  
  
    /**
     * 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();
  
          // 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;
          }
  
          // When we receive RemoteException which wraps IOException which has a cause as
         // RemoteException we can get into infinite loop here; so if the cause of the exception
         // is RemoteException, we shouldn't look further.
       } else if (cur.getCause() != null && !(cur.getCause() instanceof RemoteException)) {
         cur = cur.getCause();
       } else {
         return cur;
       }
     }
 
     return null;
   }
 
   /**
    * Checks if the exception is CallQueueTooBig exception (maybe wrapped
    * into some RemoteException).
    * @param t exception to check
    * @return true if it's a CQTBE, false otherwise
    */
   public static boolean isCallQueueTooBigException(Throwable t) {
     t = findException(t);
     return (t instanceof CallQueueTooBigException);
   }
 
   /**
    * Checks if the exception is CallDroppedException (maybe wrapped
    * into some RemoteException).
    * @param t exception to check
    * @return true if it's a CQTBE, false otherwise
    */
   public static boolean isCallDroppedException(Throwable t) {
     t = findException(t);
     return (t instanceof CallDroppedException);
   }
 
   /**
    * Check if the exception is something that indicates that we cannot
    * contact/communicate with the server.
    *
    * @param e exception to check
    * @return true when exception indicates that the client wasn't able to make contact with server
    */
   public static boolean isConnectionException(Throwable e) {
     if (e == null) {
       return false;
     }
     // This list covers most connectivity exceptions but not all.
     // For example, in SocketOutputStream a plain IOException is thrown
     // at times when the channel is closed.
     return (e instanceof SocketTimeoutException || e instanceof ConnectException
       || e instanceof ClosedChannelException || e instanceof SyncFailedException
       || e instanceof EOFException || e instanceof TimeoutException
       || e instanceof CallTimeoutException || e instanceof ConnectionClosingException
       || e instanceof FailedServerException);
   }
 
   /**
    * Translates exception for preemptive fast fail checks.
    * @param t exception to check
    * @return translated exception
    * @throws IOException
    */
   public static Throwable translatePFFE(Throwable t) throws IOException {
     if (t instanceof NoSuchMethodError) {
       // We probably can't recover from this exception by retrying.
       throw (NoSuchMethodError) t;
     }
 
     if (t instanceof NullPointerException) {
       // The same here. This is probably a bug.
       throw (NullPointerException) t;
     }
 
     if (t instanceof UndeclaredThrowableException) {
       t = t.getCause();
     }
     if (t instanceof RemoteException) {
       t = ((RemoteException) t).unwrapRemoteException();
     }
     if (t instanceof DoNotRetryIOException) {
       throw (DoNotRetryIOException) t;
     }
     if (t instanceof Error) {
       throw (Error) t;
     }
     return t;
   }
 }