org.apache.beam.sdk.coders

Class SetCoder<T>

java.lang.Object

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

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

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

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

Type Parameters:

T - the type of the elements of the set

All Implemented Interfaces:

java.io.Serializable

public class SetCoder<T>
extends IterableLikeCoder<T,java.util.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 class 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 java.util.Set<T>	decodeToIterable(java.util.List<T> decodedElements) Builds an instance of IterableT, this coder's associated Iterable-like subtype, from a list of decoded elements.
TypeDescriptor<java.util.Set<T>>	getEncodedTypeDescriptor() Returns the TypeDescriptor for the type encoded.
static <T> SetCoder<T>	of(Coder<T> elementCoder) Produces a SetCoder with the given elementCoder.
void	verifyDeterministic() Throw Coder.NonDeterministicException if the coding is not deterministic.

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

decode, decodeToIterable, encode, getCoderArguments, getElemCoder, isRegisterByteSizeObserverCheap, registerByteSizeObserver

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

equals, getComponents, hashCode, toString

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

consistentWithEquals, decode, encode, getEncodedElementByteSize, structuralValue, 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.

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.

Overrides:

verifyDeterministic in class IterableLikeCoder<T,java.util.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.

getEncodedTypeDescriptor

public TypeDescriptor<java.util.Set<T>> getEncodedTypeDescriptor()

Description copied from class: Coder

Returns the TypeDescriptor for the type encoded.

Overrides:

getEncodedTypeDescriptor in class Coder<java.util.Set<T>>

decodeToIterable

protected final java.util.Set<T> decodeToIterable(java.util.List<T> decodedElements)

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

Override IterableLikeCoder.decodeToIterable(List, long, InputStream) if you need access to the terminator value and the InputStream.

Specified by:

decodeToIterable in class IterableLikeCoder<T,java.util.Set<T>>

Returns:

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