Package org.apache.flink.runtime.state.filesystem

Class FileStateHandle

java.lang.Object

org.apache.flink.runtime.state.filesystem.FileStateHandle

All Implemented Interfaces:

Serializable, StateObject, StreamStateHandle

Direct Known Subclasses:

RelativeFileStateHandle

public class FileStateHandle
extends Object
implements StreamStateHandle

StreamStateHandle for state that was written to a file stream. The written data is identified by the file path. The state can be read again by calling openInputStream().

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.runtime.state.StateObject

StateObject.StateObjectLocation, StateObject.StateObjectSizeStatsCollector

Constructor Summary

Constructors

Constructor	Description
FileStateHandle(Path filePath, long stateSize)	Creates a new file state for the given file path.

Method Summary

Modifier and Type	Method	Description
Optional<byte[]>	asBytesIfInMemory()
void	collectSizeStats(StateObject.StateObjectSizeStatsCollector collector)	Collects statistics about state size and location from the state object.
void	discardState()	Discard the state by deleting the file that stores the state.
boolean	equals(Object o)
Path	getFilePath()	Gets the path where this handle's state is stored.
long	getStateSize()	Returns the file size in bytes.
PhysicalStateHandleID	getStreamStateHandleID()
int	hashCode()
Optional<Path>	maybeGetPath()
FSDataInputStream	openInputStream()	Returns an FSDataInputStream that can be used to read back the data that was previously written to the stream.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FileStateHandle

public FileStateHandle(Path filePath,
                       long stateSize)

Creates a new file state for the given file path.

Parameters:

filePath - The path to the file that stores the state.

Method Detail

maybeGetPath

public Optional<Path> maybeGetPath()

Specified by:

maybeGetPath in interface StreamStateHandle

Returns:

Path to an underlying file represented by this StreamStateHandle or Optional.empty() if there is no such file.

getFilePath

public Path getFilePath()

Gets the path where this handle's state is stored.

Returns:

The path where this handle's state is stored.

openInputStream

public FSDataInputStream openInputStream()
                                  throws IOException

Description copied from interface: StreamStateHandle

Returns an FSDataInputStream that can be used to read back the data that was previously written to the stream.

Specified by:

openInputStream in interface StreamStateHandle

Throws:

IOException

asBytesIfInMemory

public Optional<byte[]> asBytesIfInMemory()

Specified by:

asBytesIfInMemory in interface StreamStateHandle

Returns:

Content of this handle as bytes array if it is already in memory.

getStreamStateHandleID

public PhysicalStateHandleID getStreamStateHandleID()

Specified by:

getStreamStateHandleID in interface StreamStateHandle

Returns:

a unique identifier of this handle.

discardState

public void discardState()
                  throws Exception

Discard the state by deleting the file that stores the state. If the parent directory of the state is empty after deleting the state file, it is also deleted.

Specified by:

discardState in interface StateObject

Throws:

Exception - Thrown, if the file deletion (not the directory deletion) fails.

getStateSize

public long getStateSize()

Returns the file size in bytes.

Specified by:

getStateSize in interface StateObject

Returns:

The file size in bytes.

collectSizeStats

public void collectSizeStats(StateObject.StateObjectSizeStatsCollector collector)

Description copied from interface: StateObject

Collects statistics about state size and location from the state object.

Specified by:

collectSizeStats in interface StateObject

Parameters:

collector - the statistics collector.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object