/*
 * 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.datastax.driver.core;

import com.datastax.driver.core.exceptions.DriverException;
import com.datastax.driver.core.exceptions.DriverInternalError;
import java.util.concurrent.ExecutionException;

class DriverThrowables {

  static RuntimeException propagateCause(ExecutionException e) {
    Throwable cause = e.getCause();

    if (cause instanceof Error) throw ((Error) cause);

    // We could just rethrow e.getCause(). However, the cause of the ExecutionException has likely
    // been
    // created on the I/O thread receiving the response. Which means that the stacktrace associated
    // with said cause will make no mention of the current thread. This is painful for say, finding
    // out which execute() statement actually raised the exception. So instead, we re-create the
    // exception.
    if (cause instanceof DriverException) throw ((DriverException) cause).copy();
    else throw new DriverInternalError("Unexpected exception thrown", cause);
  }
}
