org.apache.flink.runtime.state

Class AbstractChannelStateHandle<Info>

java.lang.Object

org.apache.flink.runtime.state.AbstractChannelStateHandle<Info>

Type Parameters:

Info - type of channel info (e.g. InputChannelInfo).

All Implemented Interfaces:

Serializable, StateObject

Direct Known Subclasses:

InputChannelStateHandle, ResultSubpartitionStateHandle

@Internal
public abstract class AbstractChannelStateHandle<Info>
extends Object
implements StateObject

Abstract channel state handle.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractChannelStateHandle.StateContentMetaInfo Describes the underlying content.

Method Summary

Modifier and Type	Method and Description
static Set<StreamStateHandle>	collectUniqueDelegates(Collection<? extends AbstractChannelStateHandle<?>>... collections)
void	discardState() Discards the state referred to and solemnly owned by this handle, to free up resources in the persistent storage.
boolean	equals(Object o)
StreamStateHandle	getDelegate()
Info	getInfo()
List<Long>	getOffsets()
long	getStateSize() Returns the size of the state in bytes.
int	getSubtaskIndex()
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

collectUniqueDelegates

public static Set<StreamStateHandle> collectUniqueDelegates(Collection<? extends AbstractChannelStateHandle<?>>... collections)

discardState

public void discardState()
                  throws Exception

Description copied from interface: StateObject

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

Specified by:

discardState in interface StateObject

Throws:

Exception

getStateSize

public long getStateSize()

Description copied from interface: StateObject

Returns the size of the state in bytes. If the size is not known, this method should return 0.

The values produced by this method are only used for informational purposes and for metrics/monitoring. If this method returns wrong values, the checkpoints and recovery will still behave correctly. However, efficiency may be impacted (wrong space pre-allocation) and functionality that depends on metrics (like monitoring) will be impacted.

Note for implementors: This method should not perform any I/O operations while obtaining the state size (hence it does not declare throwing an IOException). Instead, the state size should be stored in the state object, or should be computable from the state stored in this object. The reason is that this method is called frequently by several parts of the checkpointing and issuing I/O requests from this method accumulates a heavy I/O load on the storage system at higher scale.

Specified by:

getStateSize in interface StateObject

Returns:

Size of the state in bytes.

getOffsets

public List<Long> getOffsets()

getDelegate

public StreamStateHandle getDelegate()

getInfo

public Info getInfo()

getSubtaskIndex

public int getSubtaskIndex()

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