Package org.apache.flink.runtime.state

Class KeyedStateCheckpointOutputStream

java.lang.Object

java.io.OutputStream

org.apache.flink.runtime.state.NonClosingCheckpointOutputStream<KeyGroupsStateHandle>

org.apache.flink.runtime.state.KeyedStateCheckpointOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

@PublicEvolving
public final class KeyedStateCheckpointOutputStream
extends NonClosingCheckpointOutputStream<KeyGroupsStateHandle>

Checkpoint output stream that allows to write raw keyed state in a partitioned way, split into key-groups.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NO_CURRENT_KEY_GROUP
static final long	NO_OFFSET_SET

Fields inherited from class org.apache.flink.runtime.state.NonClosingCheckpointOutputStream

delegate

Constructor Summary

Constructors

Constructor	Description
KeyedStateCheckpointOutputStream(CheckpointStateOutputStream delegate, KeyGroupRange keyGroupRange)

Method Summary

Modifier and Type	Method	Description
void	close()
int	getCurrentKeyGroup()	Returns the key group that is currently being written.
KeyGroupsList	getKeyGroupList()	Returns a list of all key-groups which can be written to this stream.
boolean	isKeyGroupAlreadyFinished(int keyGroupId)	Returns true if the key group is already completely written and immutable.
boolean	isKeyGroupAlreadyStarted(int keyGroupId)	Returns true, if the key group with the given id was already started.
void	startNewKeyGroup(int keyGroupId)	User code can call this method to signal that it begins to write a new key group with the given key group id.

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

acquireLease, flush, write, write, write

Methods inherited from class java.io.OutputStream

nullOutputStream

Methods inherited from class java.lang.Object

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

Field Details

NO_OFFSET_SET

public static final long NO_OFFSET_SET

See Also:

• Constant Field Values

NO_CURRENT_KEY_GROUP

public static final int NO_CURRENT_KEY_GROUP

See Also:

• Constant Field Values

Constructor Details

KeyedStateCheckpointOutputStream

public KeyedStateCheckpointOutputStream(CheckpointStateOutputStream delegate,
 KeyGroupRange keyGroupRange)

Method Details

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class NonClosingCheckpointOutputStream<KeyGroupsStateHandle>

Throws:

IOException

getKeyGroupList

public KeyGroupsList getKeyGroupList()

Returns a list of all key-groups which can be written to this stream.

startNewKeyGroup

public void startNewKeyGroup(int keyGroupId)
                      throws IOException

User code can call this method to signal that it begins to write a new key group with the given key group id. This id must be within the KeyGroupsList provided by the stream. Each key-group can only be started once and is considered final/immutable as soon as this method is called again.

Throws:

IOException

isKeyGroupAlreadyStarted

public boolean isKeyGroupAlreadyStarted(int keyGroupId)

Returns true, if the key group with the given id was already started. The key group might not yet be finished, if it's id is equal to the return value of getCurrentKeyGroup().

isKeyGroupAlreadyFinished

public boolean isKeyGroupAlreadyFinished(int keyGroupId)

Returns true if the key group is already completely written and immutable. It was started and since then another key group has been started.

getCurrentKeyGroup

public int getCurrentKeyGroup()

Returns the key group that is currently being written. The key group was started but not yet finished, i.e. data can still be added. If no key group was started, this returns NO_CURRENT_KEY_GROUP.