/*
    * 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.thrift;
  
  import org.apache.hadoop.hbase.CallQueueTooBigException;
  import org.apache.hadoop.hbase.Cell;
  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.UnknownScannerException;
  import org.apache.hadoop.hbase.client.Get;
  import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
  import org.apache.hadoop.hbase.coprocessor.ObserverContext;
  import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
  import org.apache.hadoop.hbase.exceptions.FailedSanityCheckException;
  import org.apache.hadoop.hbase.exceptions.OutOfOrderScannerNextException;
  import org.apache.hadoop.hbase.exceptions.RegionMovedException;
  import org.apache.hadoop.hbase.exceptions.ScannerResetException;
  import org.apache.hadoop.hbase.metrics.ExceptionTrackingSource;
  import org.apache.hadoop.hbase.util.Bytes;
  
  import java.io.IOException;
  import java.util.List;
  
  /**
   * Simple test coprocessor for injecting exceptions on Get requests.
   */
  public class ErrorThrowingGetObserver extends BaseRegionObserver {
    public static final String SHOULD_ERROR_ATTRIBUTE = "error";
  
    @Override
    public void preGetOp(ObserverContext<RegionCoprocessorEnvironment> e,
                         Get get, List<Cell> results) throws IOException {
      byte[] errorType = get.getAttribute(SHOULD_ERROR_ATTRIBUTE);
      if (errorType != null) {
        ErrorType type = ErrorType.valueOf(Bytes.toString(errorType));
        switch (type) {
          case CALL_QUEUE_TOO_BIG:
            throw new CallQueueTooBigException("Failing for test");
          case MULTI_ACTION_RESULT_TOO_LARGE:
            throw new MultiActionResultTooLarge("Failing for test");
          case FAILED_SANITY_CHECK:
            throw new FailedSanityCheckException("Failing for test");
          case NOT_SERVING_REGION:
            throw new NotServingRegionException("Failing for test");
          case REGION_MOVED:
            throw new RegionMovedException(
                e.getEnvironment().getRegionServerServices().getServerName(), 1);
          case SCANNER_RESET:
            throw new ScannerResetException("Failing for test");
          case UNKNOWN_SCANNER:
            throw new UnknownScannerException("Failing for test");
          case REGION_TOO_BUSY:
            throw new RegionTooBusyException("Failing for test");
          case OUT_OF_ORDER_SCANNER_NEXT:
            throw new OutOfOrderScannerNextException("Failing for test");
          default:
            throw new DoNotRetryIOException("Failing for test");
        }
      }
      super.preGetOp(e, get, results);
    }
  
    public enum ErrorType {
      CALL_QUEUE_TOO_BIG(ExceptionTrackingSource.EXCEPTIONS_CALL_QUEUE_TOO_BIG),
      MULTI_ACTION_RESULT_TOO_LARGE(ExceptionTrackingSource.EXCEPTIONS_MULTI_TOO_LARGE_NAME),
      FAILED_SANITY_CHECK(ExceptionTrackingSource.EXCEPTIONS_SANITY_NAME),
      NOT_SERVING_REGION(ExceptionTrackingSource.EXCEPTIONS_NSRE_NAME),
      REGION_MOVED(ExceptionTrackingSource.EXCEPTIONS_MOVED_NAME),
      SCANNER_RESET(ExceptionTrackingSource.EXCEPTIONS_SCANNER_RESET_NAME),
      UNKNOWN_SCANNER(ExceptionTrackingSource.EXCEPTIONS_UNKNOWN_NAME),
      REGION_TOO_BUSY(ExceptionTrackingSource.EXCEPTIONS_BUSY_NAME),
      OUT_OF_ORDER_SCANNER_NEXT(ExceptionTrackingSource.EXCEPTIONS_OOO_NAME);
  
      private final String metricName;
  
      ErrorType(String metricName) {
        this.metricName = metricName;
      }
  
      public String getMetricName() {
        return metricName;
     }
   }
 }