org.apache.flink.queryablestate.client.state.serialization

Class KvStateSerializer

java.lang.Object

org.apache.flink.queryablestate.client.state.serialization.KvStateSerializer

public final class KvStateSerializer
extends Object

Serialization and deserialization the different state types and namespaces.

Constructor Summary

Constructors

Constructor and Description
KvStateSerializer()

Method Summary

Modifier and Type	Method and Description
static <K,N> Tuple2<K,N>	deserializeKeyAndNamespace(byte[] serializedKeyAndNamespace, TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer) Deserializes the key and namespace into a Tuple2.
static <T> List<T>	deserializeList(byte[] serializedValue, TypeSerializer<T> serializer) Deserializes all values with the given serializer.
static <UK,UV> Map<UK,UV>	deserializeMap(byte[] serializedValue, TypeSerializer<UK> keySerializer, TypeSerializer<UV> valueSerializer) Deserializes all kv pairs with the given serializer.
static <T> T	deserializeValue(byte[] serializedValue, TypeSerializer<T> serializer) Deserializes the value with the given serializer.
static <K,N> byte[]	serializeKeyAndNamespace(K key, TypeSerializer<K> keySerializer, N namespace, TypeSerializer<N> namespaceSerializer) Serializes the key and namespace into a ByteBuffer.
static <UK,UV> byte[]	serializeMap(Iterable<Map.Entry<UK,UV>> entries, TypeSerializer<UK> keySerializer, TypeSerializer<UV> valueSerializer) Serializes all values of the Iterable with the given serializer.
static <T> byte[]	serializeValue(T value, TypeSerializer<T> serializer) Serializes the value with the given serializer.

Methods inherited from class java.lang.Object

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

Constructor Detail

KvStateSerializer

public KvStateSerializer()

Method Detail

serializeKeyAndNamespace

public static <K,N> byte[] serializeKeyAndNamespace(K key,
                                                    TypeSerializer<K> keySerializer,
                                                    N namespace,
                                                    TypeSerializer<N> namespaceSerializer)
                                             throws IOException

Serializes the key and namespace into a ByteBuffer.

The serialized format matches the RocksDB state backend key format, i.e. the key and namespace don't have to be deserialized for RocksDB lookups.

Type Parameters:

K - Key type

N - Namespace type

Parameters:

key - Key to serialize

keySerializer - Serializer for the key

namespace - Namespace to serialize

namespaceSerializer - Serializer for the namespace

Returns:

Buffer holding the serialized key and namespace

Throws:

IOException - Serialization errors are forwarded

deserializeKeyAndNamespace

public static <K,N> Tuple2<K,N> deserializeKeyAndNamespace(byte[] serializedKeyAndNamespace,
                                                           TypeSerializer<K> keySerializer,
                                                           TypeSerializer<N> namespaceSerializer)
                                                    throws IOException

Deserializes the key and namespace into a Tuple2.

Type Parameters:

K - Key type

N - Namespace

Parameters:

serializedKeyAndNamespace - Serialized key and namespace

keySerializer - Serializer for the key

namespaceSerializer - Serializer for the namespace

Returns:

Tuple2 holding deserialized key and namespace

Throws:

IOException - if the deserialization fails for any reason

serializeValue

public static <T> byte[] serializeValue(T value,
                                        TypeSerializer<T> serializer)
                                 throws IOException

Serializes the value with the given serializer.

Type Parameters:

T - Type of the value

Parameters:

value - Value of type T to serialize

serializer - Serializer for T

Returns:

Serialized value or null if value null

Throws:

IOException - On failure during serialization

deserializeValue

public static <T> T deserializeValue(byte[] serializedValue,
                                     TypeSerializer<T> serializer)
                              throws IOException

Deserializes the value with the given serializer.

Type Parameters:

T - Type of the value

Parameters:

serializedValue - Serialized value of type T

serializer - Serializer for T

Returns:

Deserialized value or null if the serialized value is null

Throws:

IOException - On failure during deserialization

deserializeList

public static <T> List<T> deserializeList(byte[] serializedValue,
                                          TypeSerializer<T> serializer)
                                   throws IOException

Deserializes all values with the given serializer.

Type Parameters:

T - Type of the value

Parameters:

serializedValue - Serialized value of type List<T>

serializer - Serializer for T

Returns:

Deserialized list or null if the serialized value is null

Throws:

IOException - On failure during deserialization

serializeMap

public static <UK,UV> byte[] serializeMap(Iterable<Map.Entry<UK,UV>> entries,
                                          TypeSerializer<UK> keySerializer,
                                          TypeSerializer<UV> valueSerializer)
                                   throws IOException

Serializes all values of the Iterable with the given serializer.

Type Parameters:

UK - Type of the keys

UV - Type of the values

Parameters:

entries - Key-value pairs to serialize

keySerializer - Serializer for UK

valueSerializer - Serializer for UV

Returns:

Serialized values or null if values null or empty

Throws:

IOException - On failure during serialization

deserializeMap

public static <UK,UV> Map<UK,UV> deserializeMap(byte[] serializedValue,
                                                TypeSerializer<UK> keySerializer,
                                                TypeSerializer<UV> valueSerializer)
                                         throws IOException

Deserializes all kv pairs with the given serializer.

Type Parameters:

UK - Type of the key

UV - Type of the value.

Parameters:

serializedValue - Serialized value of type Map<UK, UV>

keySerializer - Serializer for UK

valueSerializer - Serializer for UV

Returns:

Deserialized map or null if the serialized value is null

Throws:

IOException - On failure during deserialization