org.apache.flink.contrib.streaming.state

Class RocksDBValueState<K,N,V>

java.lang.Object

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

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

Type Parameters:

K - The type of the key.

N - The type of the namespace.

V - The type of value that the state state stores.

All Implemented Interfaces:

State, ValueState<V>, InternalKvState<K,N,V>, InternalValueState<K,N,V>

public class RocksDBValueState<K,N,V>
extends AbstractRocksDBState<K,N,V,ValueState<V>>
implements InternalValueState<K,N,V>

ValueState implementation that stores state in RocksDB.

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
RocksDBValueState(org.rocksdb.ColumnFamilyHandle columnFamily, TypeSerializer<N> namespaceSerializer, TypeSerializer<V> valueSerializer, V defaultValue, RocksDBKeyedStateBackend<K> backend) Creates a new RocksDBValueState.

Method Summary

Modifier and Type	Method and Description
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<V>	getValueSerializer() Returns the TypeSerializer for the type of value this state holds.
void	update(V value) Updates the operator state accessible by ValueState.value() to the given value.
V	value() Returns the current value for the state.

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

RocksDBValueState

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

Creates a new RocksDBValueState.

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.

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,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,V>

getValueSerializer

public TypeSerializer<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,V>

value

public V value()

Description copied from interface: ValueState

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.

If you didn't specify a default value when creating the ValueStateDescriptor this will return null when to value was previously set using ValueState.update(Object).

Specified by:

value in interface ValueState<V>

Returns:

The state value corresponding to the current input.

update

public void update(V value)
            throws IOException

Description copied from interface: ValueState

Updates the operator state accessible by ValueState.value() to the given value. The next time ValueState.value() is called (for the same state partition) the returned state will represent the updated value. When a partitioned state is updated with null, the state for the current key will be removed and the default value is returned on the next access.

Specified by:

update in interface ValueState<V>

Parameters:

value - The new value for the state.

Throws:

IOException - Thrown if the system cannot access the state.