org.apache.hadoop.fs.Abortable Maven / Gradle / Ivy
/**
* 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.fs;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Abort data being written to a stream, so that close() does
* not write the data. It is implemented by output streams in
* some object stores, and passed through {@link FSDataOutputStream}.
*/
@InterfaceAudience.Public
@InterfaceStability.Unstable
public interface Abortable {
/**
* Abort the active operation without the output becoming visible.
*
* This is to provide ability to cancel the write on stream; once
* a stream is aborted, the write MUST NOT become visible.
*
* @throws UnsupportedOperationException if the operation is not supported.
* @return the result.
*/
AbortableResult abort();
/**
* Interface for the result of aborts; allows subclasses to extend
* (IOStatistics etc) or for future enhancements if ever needed.
*/
interface AbortableResult {
/**
* Was the stream already closed/aborted?
* @return true if a close/abort operation had already
* taken place.
*/
boolean alreadyClosed();
/**
* Any exception caught during cleanup operations,
* exceptions whose raising/catching does not change
* the semantics of the abort.
* @return an exception or null.
*/
IOException anyCleanupException();
}
}