org.apache.beam.sdk.coders

Class SetCoder<T>

java.lang.Object

org.apache.beam.sdk.coders.StandardCoder<IterableT>

org.apache.beam.sdk.coders.IterableLikeCoder<T,Set<T>>

org.apache.beam.sdk.coders.SetCoder<T>

Type Parameters:

T - the type of the elements of the set

All Implemented Interfaces:

Serializable, Coder<Set<T>>

public class SetCoder<T>
extends IterableLikeCoder<T,Set<T>>

A SetCoder encodes any Set using the format of IterableLikeCoder. The elements may not be in a deterministic order, depending on the Set implementation.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.beam.sdk.coders.Coder

Coder.Context, Coder.NonDeterministicException

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SetCoder(Coder<T> elemCoder)

Method Summary

Modifier and Type	Method and Description
protected Set<T>	decodeToIterable(List<T> decodedElements) Builds an instance of IterableT, this coder's associated Iterable-like subtype, from a list of decoded elements.
static <T> List<Object>	getInstanceComponents(Set<T> exampleValue) Returns the first element in this set if it is non-empty, otherwise returns null.
static <T> SetCoder<T>	of(Coder<T> elementCoder) Produces a SetCoder with the given elementCoder.
static SetCoder<?>	of(List<Object> components) Dynamically typed constructor for JSON deserialization.
void	verifyDeterministic() Throw Coder.NonDeterministicException if the coding is not deterministic.

Methods inherited from class org.apache.beam.sdk.coders.IterableLikeCoder

decode, encode, getCoderArguments, getElemCoder, getInstanceComponentsHelper, isRegisterByteSizeObserverCheap, registerByteSizeObserver

Methods inherited from class org.apache.beam.sdk.coders.StandardCoder

asCloudObject, consistentWithEquals, equals, getAllowedEncodings, getComponents, getEncodedElementByteSize, getEncodingId, hashCode, structuralValue, toString, verifyDeterministic, verifyDeterministic

Methods inherited from class java.lang.Object

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

Constructor Detail

SetCoder

protected SetCoder(Coder<T> elemCoder)

Method Detail

of

public static <T> SetCoder<T> of(Coder<T> elementCoder)

Produces a SetCoder with the given elementCoder.

of

public static SetCoder<?> of(List<Object> components)

Dynamically typed constructor for JSON deserialization.

verifyDeterministic

public void verifyDeterministic()
                         throws Coder.NonDeterministicException

Throw Coder.NonDeterministicException if the coding is not deterministic.

In order for a Coder to be considered deterministic, the following must be true:

• two values that compare as equal (via Object.equals() or Comparable.compareTo(), if supported) have the same encoding.
• the Coder always produces a canonical encoding, which is the same for an instance of an object even if produced on different computers at different times.

Specified by:

verifyDeterministic in interface Coder<Set<T>>

Overrides:

verifyDeterministic in class IterableLikeCoder<T,Set<T>>

Throws:

NonDeterministicException - always. Sets are not ordered, but they are encoded in the order of an arbitrary iteration.

Coder.NonDeterministicException - if this coder is not deterministic.

getInstanceComponents

public static <T> List<Object> getInstanceComponents(Set<T> exampleValue)

Returns the first element in this set if it is non-empty, otherwise returns null.

decodeToIterable

protected final Set<T> decodeToIterable(List<T> decodedElements)

Builds an instance of IterableT, this coder's associated Iterable-like subtype, from a list of decoded elements.

Specified by:

decodeToIterable in class IterableLikeCoder<T,Set<T>>

Returns:

A new Set built from the elements in the List decoded by IterableLikeCoder.