org.apache.flink.runtime.state

Class CheckpointMetadataOutputStream

java.lang.Object

java.io.OutputStream

org.apache.flink.core.fs.FSDataOutputStream

org.apache.flink.runtime.state.CheckpointMetadataOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

FsCheckpointMetadataOutputStream

public abstract class CheckpointMetadataOutputStream
extends FSDataOutputStream

An output stream for checkpoint metadata.

This stream is similar to the CheckpointStreamFactory.CheckpointStateOutputStream, but for metadata files rather thancdata files.

This stream always creates a file, regardless of the amount of data written.

Constructor Summary

Constructors

Constructor and Description
CheckpointMetadataOutputStream()

Method Summary

Modifier and Type	Method and Description
abstract void	close() This method should close the stream, if has not been closed before.
abstract CompletedCheckpointStorageLocation	closeAndFinalizeCheckpoint() Closes the stream after all metadata was written and finalizes the checkpoint location.

Methods inherited from class org.apache.flink.core.fs.FSDataOutputStream

flush, getPos, sync

Methods inherited from class java.io.OutputStream

write, write, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CheckpointMetadataOutputStream

public CheckpointMetadataOutputStream()

Method Detail

closeAndFinalizeCheckpoint

public abstract CompletedCheckpointStorageLocation closeAndFinalizeCheckpoint()
                                                                       throws IOException

Closes the stream after all metadata was written and finalizes the checkpoint location.

Returns:

An object representing a finalized checkpoint storage location.

Throws:

IOException - Thrown, if the stream cannot be closed or the finalization fails.

close

public abstract void close()
                    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 closeAndFinalizeCheckpoint().

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class FSDataOutputStream

Throws:

IOException - Thrown, if the stream cannot be closed.