Package org.apache.flink.runtime.state

Class AbstractMergedChannelStateHandle<Info,ChannelHandle extends AbstractChannelStateHandle<Info>>

java.lang.Object

org.apache.flink.runtime.state.AbstractMergedChannelStateHandle<Info,ChannelHandle>

All Implemented Interfaces:

Serializable, StateObject

Direct Known Subclasses:

MergedInputChannelStateHandle, MergedResultSubpartitionStateHandle

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

See Also:

Serialized Form

Nested Class Summary

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

StateObject.StateObjectLocation, StateObject.StateObjectSizeStatsCollector

Field Summary

Fields

Modifier and Type	Field	Description
protected StreamStateHandle	delegate
protected byte[]	serializedChannelOffsets
protected long	size
protected int	subtaskIndex	The original subtask index before rescaling recovery.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractMergedChannelStateHandle(int subtaskIndex, StreamStateHandle delegate, long size, byte[] serializedChannelOffsets)
protected	AbstractMergedChannelStateHandle(Collection<ChannelHandle> handles)

Method Summary

Modifier and Type	Method	Description
protected abstract ChannelHandle	createUnmergedHandle(int subtaskIndex, StreamStateHandle delegate, Info info, long stateSize, List<Long> offsets)
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()
List<Info>	getInfos()
byte[]	getSerializedChannelOffsets()
long	getStateSize()	Returns the size of the state in bytes.
int	getSubtaskIndex()
protected Collection<ChannelHandle>	getUnmergedHandles()
int	hashCode()
protected abstract Info	readInfo(DataInputStream dis)
String	toString()
protected abstract void	writeInfo(Info info, DataOutputStream dos)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.state.StateObject

collectSizeStats

Field Detail

subtaskIndex

protected final int subtaskIndex

The original subtask index before rescaling recovery.

delegate

protected final StreamStateHandle delegate

size

protected final long size

serializedChannelOffsets

protected final byte[] serializedChannelOffsets

Constructor Detail

AbstractMergedChannelStateHandle

protected AbstractMergedChannelStateHandle(int subtaskIndex,
                                           StreamStateHandle delegate,
                                           long size,
                                           byte[] serializedChannelOffsets)

AbstractMergedChannelStateHandle

protected AbstractMergedChannelStateHandle(Collection<ChannelHandle> handles)

Method Detail

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 anymore.

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.

getSubtaskIndex

public int getSubtaskIndex()

getDelegate

public StreamStateHandle getDelegate()

getSerializedChannelOffsets

public byte[] getSerializedChannelOffsets()

getInfos

public List<Info> getInfos()

writeInfo

protected abstract void writeInfo(Info info,
                                  DataOutputStream dos)
                           throws IOException

Throws:

IOException

readInfo

protected abstract Info readInfo(DataInputStream dis)
                          throws IOException

Throws:

IOException

createUnmergedHandle

protected abstract ChannelHandle createUnmergedHandle(int subtaskIndex,
                                                      StreamStateHandle delegate,
                                                      Info info,
                                                      long stateSize,
                                                      List<Long> offsets)

getUnmergedHandles

protected Collection<ChannelHandle> getUnmergedHandles()

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