org.apache.flink.runtime.state

Class FileStateHandle

java.lang.Object

org.apache.flink.runtime.state.ByteStreamStateHandle

org.apache.flink.runtime.state.FileStateHandle

All Implemented Interfaces:

Serializable, StateHandle<Serializable>

public class FileStateHandle
extends ByteStreamStateHandle

Statehandle that writes the checkpointed state to a random file in the provided checkpoint directory. Any Flink supported File system can be used but it is advised to use a filesystem that is persistent in case of node failures, such as HDFS or Tachyon.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
FileStateHandle(Serializable state, String folder)

Method Summary

Modifier and Type	Method and Description
static StateHandleProvider<Serializable>	createProvider(String checkpointDir) Creates a StateHandleProvider for creating FileStateHandles for a given checkpoint directory.
void	discardState() Discards the state referred to by this handle, to free up resources in the persistent storage.
protected InputStream	getInputStream() The state will be read from the stream returned by this method.
protected OutputStream	getOutputStream() The state will be written to the stream returned by this method.

Methods inherited from class org.apache.flink.runtime.state.ByteStreamStateHandle

getState, stateFetched

Methods inherited from class java.lang.Object

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

Constructor Detail

FileStateHandle

public FileStateHandle(Serializable state,
                       String folder)

Method Detail

getOutputStream

protected OutputStream getOutputStream()
                                throws IOException,
                                       URISyntaxException

Description copied from class: ByteStreamStateHandle

The state will be written to the stream returned by this method.

Specified by:

getOutputStream in class ByteStreamStateHandle

Throws:

IOException

URISyntaxException

getInputStream

protected InputStream getInputStream()
                              throws IOException,
                                     URISyntaxException

Description copied from class: ByteStreamStateHandle

The state will be read from the stream returned by this method.

Specified by:

getInputStream in class ByteStreamStateHandle

Throws:

IOException

URISyntaxException

discardState

public void discardState()
                  throws Exception

Description copied from interface: StateHandle

Discards the state referred to by this handle, to free up resources in the persistent storage. This method is called when the handle will not be used any more.

Throws:

Exception

createProvider

public static StateHandleProvider<Serializable> createProvider(String checkpointDir)

Creates a StateHandleProvider for creating FileStateHandles for a given checkpoint directory.