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 org.apache.cassandra.exceptions;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.junit.Test;
  
  import org.apache.cassandra.io.util.DataInputBuffer;
  import org.apache.cassandra.io.util.DataOutputBuffer;
  import org.apache.cassandra.net.MessagingService;
  
  import static com.google.common.base.Throwables.getStackTraceAsString;
  import static org.apache.cassandra.exceptions.ExceptionSerializer.getMessageWithOriginatingHost;
  import static org.apache.cassandra.exceptions.ExceptionSerializer.nullableRemoteExceptionSerializer;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNull;
  
  public class RemoteExceptionTest
  {
      @Test
      public void testRoundtrip() throws Exception
      {
          testRoundtrip(null);
          Throwable root = new Throwable();
          testRoundtrip(root);
          Throwable suppressed = new Throwable();
          Throwable causedByRoot = new Throwable(root);
          testRoundtrip(causedByRoot);
          causedByRoot.addSuppressed(root);
          testRoundtrip(causedByRoot);
          root.addSuppressed(causedByRoot);
          testRoundtrip(root);
          root.addSuppressed(suppressed);
          testRoundtrip(root);
      }
  
      public void testRoundtrip(Throwable original) throws Exception
      {
          Throwable normalizedOriginal = normalizeThrowable(original);
  
          DataOutputBuffer dob = new DataOutputBuffer();
          nullableRemoteExceptionSerializer.serialize(original, dob, MessagingService.current_version);
          assertEquals(nullableRemoteExceptionSerializer.serializedSize(original, MessagingService.current_version), dob.toByteArray().length);
          DataInputBuffer dib = new DataInputBuffer(dob.toByteArray());
          Throwable test = nullableRemoteExceptionSerializer.deserialize(dib, MessagingService.current_version);
          if (original == null)
          {
              assertNull(test);
          }
          else
          {
              String originalString = getStackTraceAsString(normalizedOriginal);
              String testString = getStackTraceAsString(test);
              assertEquals(originalString, testString);
          }
      }
  
      public static Throwable normalizeThrowable(Throwable t) throws Exception
      {
          return normalizeThrowable(t, true, new HashMap<>());
      }
  
      private static Throwable normalizeThrowable(Throwable t, boolean isFirstException, Map<Throwable, Throwable> alreadyNormalized) throws Exception
      {
          if (t == null)
              return null;
  
          if (alreadyNormalized.containsKey(t))
              return alreadyNormalized.get(t);
  
          // Classloader, module name, and module version are difficult to get right because STE doesn't
          // expose enough parameters to serialize the formatting correctly so settle for something close, but not exact
          // Alternatives look fragile across different JVM versions and yield only moderate additional debugability
          // when using class loaders and modules
          StackTraceElement[] originalStack = t.getStackTrace();
          StackTraceElement[] normalizedStack = new StackTraceElement[originalStack.length];
          for (int i = 0; i < originalStack.length; i++)
          {
              StackTraceElement originalSTE = originalStack[i];
              normalizedStack[i] = new StackTraceElement(originalSTE.getClassName(), originalSTE.getMethodName(), originalSTE.getFileName(), originalSTE.getLineNumber());
          }
  
          Throwable normalized;
          if (t.getCause() == null)
              normalized = t.getClass().getConstructor(String.class).newInstance(getMessageWithOriginatingHost(t, isFirstException));
          else
              normalized = t.getClass().getConstructor(String.class, Throwable.class).newInstance(getMessageWithOriginatingHost(t, isFirstException), normalizeThrowable(t.getCause(), false, alreadyNormalized));
          alreadyNormalized.put(t, normalized);
          normalized.setStackTrace(normalizedStack);
          for (Throwable suppressed : t.getSuppressed())
              normalized.addSuppressed(normalizeThrowable(suppressed, false, alreadyNormalized));
          return normalized;
      }
  }