com.metamx.common.guava.ResourceClosingSequence Maven / Gradle / Ivy

/*
 * Copyright 2011 - 2015 Metamarkets Group Inc.
 *
 * Licensed 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.metamx.common.guava;

import java.io.Closeable;

/**
 */
public class ResourceClosingSequence implements Sequence
{
  private final Sequence baseSequence;
  private final Closeable closeable;

  public ResourceClosingSequence(Sequence baseSequence, Closeable closeable)
  {
    this.baseSequence = baseSequence;
    this.closeable = closeable;
  }

  @Override
  public  OutType accumulate(OutType initValue, Accumulator accumulator)
  {
    try {
      return baseSequence.accumulate(initValue, accumulator);
    }
    finally {
      CloseQuietly.close(closeable);
    }
  }

  @Override
  public  Yielder toYielder(
      OutType initValue, YieldingAccumulator accumulator
  )
  {
    final Yielder baseYielder;
    try {
      baseYielder = baseSequence.toYielder(initValue, accumulator);
    }
    catch (RuntimeException e) {
      CloseQuietly.close(closeable);
      throw e;
    }

    return new ResourceClosingYielder<>(baseYielder, closeable);
  }
}