org.apache.flink.contrib.streaming.state

Class RocksDBListState<K,N,V>

java.lang.Object

org.apache.flink.contrib.streaming.state.AbstractRocksDBState<K,N,List<V>,ListState<V>>

org.apache.flink.contrib.streaming.state.RocksDBListState<K,N,V>

Type Parameters:

K - The type of the key.

N - The type of the namespace.

V - The type of the values in the list state.

All Implemented Interfaces:

AppendingState<V,Iterable<V>>, ListState<V>, MergingState<V,Iterable<V>>, State, InternalAppendingState<K,N,V,List<V>,Iterable<V>>, InternalKvState<K,N,List<V>>, InternalListState<K,N,V>, InternalMergingState<K,N,V,List<V>,Iterable<V>>

public class RocksDBListState<K,N,V>
extends AbstractRocksDBState<K,N,List<V>,ListState<V>>
implements InternalListState<K,N,V>

ListState implementation that stores state in RocksDB.

RocksDBStateBackend must ensure that we set the StringAppendOperator on the column family that we use for our state since we use the merge() call.

Field Summary

Fields inherited from class org.apache.flink.contrib.streaming.state.AbstractRocksDBState

backend, columnFamily, defaultValue, keySerializationDataOutputView, keySerializationStream, writeOptions

Constructor Summary

Constructors

Constructor and Description
RocksDBListState(org.rocksdb.ColumnFamilyHandle columnFamily, TypeSerializer<N> namespaceSerializer, TypeSerializer<List<V>> valueSerializer, List<V> defaultValue, TypeSerializer<V> elementSerializer, RocksDBKeyedStateBackend<K> backend) Creates a new RocksDBListState.

Method Summary

Modifier and Type	Method and Description
void	add(V value) Updates the operator state accessible by AppendingState.get() by adding the given value to the list of values.
void	addAll(List<V> values) Updates the operator state accessible by AppendingState.get() by adding the given values to existing list of values.
Iterable<V>	get() Returns the current value for the state.
TypeSerializer<K>	getKeySerializer() Returns the TypeSerializer for the type of key this state is associated to.
TypeSerializer<N>	getNamespaceSerializer() Returns the TypeSerializer for the type of namespace this state is associated to.
TypeSerializer<List<V>>	getValueSerializer() Returns the TypeSerializer for the type of value this state holds.
void	mergeNamespaces(N target, Collection<N> sources) Merges the state of the current key for the given source namespaces into the state of the target namespace.
void	update(List<V> values) Updates the operator state accessible by AppendingState.get() by updating existing values to to the given list of values.

Methods inherited from class org.apache.flink.contrib.streaming.state.AbstractRocksDBState

clear, getDefaultValue, getSerializedValue, setCurrentNamespace, writeCurrentKeyWithGroupAndNamespace, writeKeyWithGroupAndNamespace, writeKeyWithGroupAndNamespace

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.runtime.state.internal.InternalKvState

getSerializedValue, setCurrentNamespace

Methods inherited from interface org.apache.flink.api.common.state.State

clear

Constructor Detail

RocksDBListState

public RocksDBListState(org.rocksdb.ColumnFamilyHandle columnFamily,
                        TypeSerializer<N> namespaceSerializer,
                        TypeSerializer<List<V>> valueSerializer,
                        List<V> defaultValue,
                        TypeSerializer<V> elementSerializer,
                        RocksDBKeyedStateBackend<K> backend)

Creates a new RocksDBListState.

Parameters:

columnFamily - The RocksDB column family that this state is associated to.

namespaceSerializer - The serializer for the namespace.

valueSerializer - The serializer for the state.

defaultValue - The default value for the state.

elementSerializer - The serializer for elements of the list state.

backend - The backend for which this state is bind to.

Method Detail

getKeySerializer

public TypeSerializer<K> getKeySerializer()

Description copied from interface: InternalKvState

Returns the TypeSerializer for the type of key this state is associated to.

Specified by:

getKeySerializer in interface InternalKvState<K,N,List<V>>

getNamespaceSerializer

public TypeSerializer<N> getNamespaceSerializer()

Description copied from interface: InternalKvState

Returns the TypeSerializer for the type of namespace this state is associated to.

Specified by:

getNamespaceSerializer in interface InternalKvState<K,N,List<V>>

getValueSerializer

public TypeSerializer<List<V>> getValueSerializer()

Description copied from interface: InternalKvState

Returns the TypeSerializer for the type of value this state holds.

Specified by:

getValueSerializer in interface InternalKvState<K,N,List<V>>

get

public Iterable<V> get()

Description copied from interface: AppendingState

Returns the current value for the state. When the state is not partitioned the returned value is the same for all inputs in a given operator instance. If state partitioning is applied, the value returned depends on the current operator input, as the operator maintains an independent state for each partition.

NOTE TO IMPLEMENTERS: if the state is empty, then this method should return null.

Specified by:

get in interface AppendingState<V,Iterable<V>>

Returns:

The operator state value corresponding to the current input or null if the state is empty.

add

public void add(V value)
         throws IOException

Description copied from interface: AppendingState

Updates the operator state accessible by AppendingState.get() by adding the given value to the list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list.

If null is passed in, the state value will remain unchanged.

Specified by:

add in interface AppendingState<V,Iterable<V>>

Parameters:

value - The new value for the state.

Throws:

IOException

mergeNamespaces

public void mergeNamespaces(N target,
                            Collection<N> sources)
                     throws Exception

Description copied from interface: InternalMergingState

Merges the state of the current key for the given source namespaces into the state of the target namespace.

Specified by:

mergeNamespaces in interface InternalMergingState<K,N,V,List<V>,Iterable<V>>

Parameters:

target - The target namespace where the merged state should be stored.

sources - The source namespaces whose state should be merged.

Throws:

Exception - The method may forward exception thrown internally (by I/O or functions).

update

public void update(List<V> values)
            throws Exception

Description copied from interface: InternalListState

Updates the operator state accessible by AppendingState.get() by updating existing values to to the given list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list. If `null` or an empty list is passed in, the state value will be null

Specified by:

update in interface ListState<V>

Specified by:

update in interface InternalListState<K,N,V>

Parameters:

values - The new values for the state.

Throws:

Exception - The method may forward exception thrown internally (by I/O or functions).

addAll

public void addAll(List<V> values)
            throws Exception

Description copied from interface: InternalListState

Updates the operator state accessible by AppendingState.get() by adding the given values to existing list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list. If `null` or an empty list is passed in, the state value remains unchanged

Specified by:

addAll in interface ListState<V>

Specified by:

addAll in interface InternalListState<K,N,V>

Parameters:

values - The new values to be added to the state.

Throws:

Exception - The method may forward exception thrown internally (by I/O or functions).