org.apache.flink.runtime.state.CheckpointMetadataOutputStream 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.flink.runtime.state;
import org.apache.flink.core.fs.FSDataOutputStream;
import java.io.IOException;
/**
* An output stream for checkpoint metadata.
*
* This stream is similar to the {@link CheckpointStreamFactory.CheckpointStateOutputStream},
* but for metadata files rather thancdata files.
*
*
This stream always creates a file, regardless of the amount of data written.
*/
public abstract class CheckpointMetadataOutputStream extends FSDataOutputStream {
/**
* Closes the stream after all metadata was written and finalizes the checkpoint location.
*
* @return An object representing a finalized checkpoint storage location.
*
* @throws IOException Thrown, if the stream cannot be closed or the finalization fails.
*/
public abstract CompletedCheckpointStorageLocation closeAndFinalizeCheckpoint() throws IOException;
/**
* This method should close the stream, if has not been closed before.
* If this method actually closes the stream, it should delete/release the
* resource behind the stream, such as the file that the stream writes to.
*
*
The above implies that this method is intended to be the "unsuccessful close",
* such as when cancelling the stream writing, or when an exception occurs.
* Closing the stream for the successful case must go through {@link #closeAndFinalizeCheckpoint()}.
*
* @throws IOException Thrown, if the stream cannot be closed.
*/
@Override
public abstract void close() throws IOException;
}