org.apache.flink.api.common.typeutils

Class CompositeSerializer<T>

java.lang.Object

org.apache.flink.api.common.typeutils.TypeSerializer<T>

org.apache.flink.api.common.typeutils.CompositeSerializer<T>

Type Parameters:

T - type of custom serialized value

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

TtlStateFactory.TtlSerializer, ValueWithTs.Serializer

public abstract class CompositeSerializer<T>
extends TypeSerializer<T>

Base class for composite serializers.

This class serializes a composite type using array of its field serializers. Fields are indexed the same way as their serializers.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	CompositeSerializer.PrecomputedParameters This class holds composite serializer parameters which can be precomputed in advanced for better performance.

Field Summary

Fields

Modifier and Type	Field and Description
protected TypeSerializer<Object>[]	fieldSerializers Serializers for fields which constitute T.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CompositeSerializer(boolean immutableTargetType, TypeSerializer<?>... fieldSerializers) Can be used for user facing constructor.
protected	CompositeSerializer(CompositeSerializer.PrecomputedParameters precomputed, TypeSerializer<?>... fieldSerializers) Can be used in createSerializerInstance for internal operations.

Method Summary

Modifier and Type	Method and Description
void	copy(DataInputView source, DataOutputView target) Copies exactly one record from the source input view to the target output view.
T	copy(T from) Creates a deep copy of the given element in a new element.
T	copy(T from, T reuse) Creates a copy from the given element.
T	createInstance() Creates a new instance of the data type.
abstract T	createInstance(Object... values) Create new instance from its fields.
protected abstract CompositeSerializer<T>	createSerializerInstance(CompositeSerializer.PrecomputedParameters precomputed, TypeSerializer<?>... originalSerializers) Factory for concrete serializer.
T	deserialize(DataInputView source) De-serializes a record from the given source input view.
T	deserialize(T reuse, DataInputView source) De-serializes a record from the given source input view into the given reuse record instance if mutable.
CompositeSerializer<T>	duplicate() Creates a deep copy of this serializer if it is necessary, i.e. if it is stateful.
boolean	equals(Object obj)
protected abstract Object	getField(T value, int index) Get field of existing instance.
int	getLength() Gets the length of the data type, if it is a fix length data type.
int	hashCode()
boolean	isImmutableType() Gets whether the type is an immutable type.
void	serialize(T record, DataOutputView target) Serializes the given record to the given target output view.
protected abstract void	setField(T value, int index, Object fieldValue) Modify field of existing instance.

Methods inherited from class org.apache.flink.api.common.typeutils.TypeSerializer

snapshotConfiguration

Methods inherited from class java.lang.Object

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

Field Detail

fieldSerializers

protected final TypeSerializer<Object>[] fieldSerializers

Serializers for fields which constitute T.

Constructor Detail

CompositeSerializer

protected CompositeSerializer(boolean immutableTargetType,
                              TypeSerializer<?>... fieldSerializers)

Can be used for user facing constructor.

CompositeSerializer

protected CompositeSerializer(CompositeSerializer.PrecomputedParameters precomputed,
                              TypeSerializer<?>... fieldSerializers)

Can be used in createSerializerInstance for internal operations.

Method Detail

createInstance

public abstract T createInstance(@Nonnull
                                 Object... values)

Create new instance from its fields.

setField

protected abstract void setField(@Nonnull
                                 T value,
                                 int index,
                                 Object fieldValue)

Modify field of existing instance. Supported only by mutable types.

getField

protected abstract Object getField(@Nonnull
                                   T value,
                                   int index)

Get field of existing instance.

createSerializerInstance

protected abstract CompositeSerializer<T> createSerializerInstance(CompositeSerializer.PrecomputedParameters precomputed,
                                                                   TypeSerializer<?>... originalSerializers)

Factory for concrete serializer.

duplicate

public CompositeSerializer<T> duplicate()

Description copied from class: TypeSerializer

Creates a deep copy of this serializer if it is necessary, i.e. if it is stateful. This can return itself if the serializer is not stateful.

We need this because Serializers might be used in several threads. Stateless serializers are inherently thread-safe while stateful serializers might not be thread-safe.

Specified by:

duplicate in class TypeSerializer<T>

isImmutableType

public boolean isImmutableType()

Description copied from class: TypeSerializer

Gets whether the type is an immutable type.

Specified by:

isImmutableType in class TypeSerializer<T>

Returns:

True, if the type is immutable.

createInstance

public T createInstance()

Description copied from class: TypeSerializer

Creates a new instance of the data type.

Specified by:

createInstance in class TypeSerializer<T>

Returns:

A new instance of the data type.

copy

public T copy(T from)

Description copied from class: TypeSerializer

Creates a deep copy of the given element in a new element.

Specified by:

copy in class TypeSerializer<T>

Parameters:

from - The element reuse be copied.

Returns:

A deep copy of the element.

copy

public T copy(T from,
              T reuse)

Description copied from class: TypeSerializer

Creates a copy from the given element. The method makes an attempt to store the copy in the given reuse element, if the type is mutable. This is, however, not guaranteed.

Specified by:

copy in class TypeSerializer<T>

Parameters:

from - The element to be copied.

reuse - The element to be reused. May or may not be used.

Returns:

A deep copy of the element.

getLength

public int getLength()

Description copied from class: TypeSerializer

Gets the length of the data type, if it is a fix length data type.

Specified by:

getLength in class TypeSerializer<T>

Returns:

The length of the data type, or -1 for variable length data types.

serialize

public void serialize(T record,
                      DataOutputView target)
               throws IOException

Description copied from class: TypeSerializer

Serializes the given record to the given target output view.

Specified by:

serialize in class TypeSerializer<T>

Parameters:

record - The record to serialize.

target - The output view to write the serialized data to.

Throws:

IOException - Thrown, if the serialization encountered an I/O related error. Typically raised by the output view, which may have an underlying I/O channel to which it delegates.

deserialize

public T deserialize(DataInputView source)
              throws IOException

Description copied from class: TypeSerializer

De-serializes a record from the given source input view.

Specified by:

deserialize in class TypeSerializer<T>

Parameters:

source - The input view from which to read the data.

Returns:

The deserialized element.

Throws:

IOException - Thrown, if the de-serialization encountered an I/O related error. Typically raised by the input view, which may have an underlying I/O channel from which it reads.

deserialize

public T deserialize(T reuse,
                     DataInputView source)
              throws IOException

Description copied from class: TypeSerializer

De-serializes a record from the given source input view into the given reuse record instance if mutable.

Specified by:

deserialize in class TypeSerializer<T>

Parameters:

reuse - The record instance into which to de-serialize the data.

source - The input view from which to read the data.

Returns:

The deserialized element.

Throws:

IOException - Thrown, if the de-serialization encountered an I/O related error. Typically raised by the input view, which may have an underlying I/O channel from which it reads.

copy

public void copy(DataInputView source,
                 DataOutputView target)
          throws IOException

Description copied from class: TypeSerializer

Copies exactly one record from the source input view to the target output view. Whether this operation works on binary data or partially de-serializes the record to determine its length (such as for records of variable length) is up to the implementer. Binary copies are typically faster. A copy of a record containing two integer numbers (8 bytes total) is most efficiently implemented as target.write(source, 8);.

Specified by:

copy in class TypeSerializer<T>

Parameters:

source - The input view from which to read the record.

target - The target output view to which to write the record.

Throws:

IOException - Thrown if any of the two views raises an exception.

hashCode

public int hashCode()

Specified by:

hashCode in class TypeSerializer<T>

equals

public boolean equals(Object obj)

Specified by:

equals in class TypeSerializer<T>