org.apache.beam.sdk.coders

Class VoidCoder

java.lang.Object

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

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

org.apache.beam.sdk.coders.AtomicCoder<Void>

org.apache.beam.sdk.coders.VoidCoder

All Implemented Interfaces:

Serializable, Coder<Void>

public class VoidCoder
extends AtomicCoder<Void>

A Coder for Void. Uses zero bytes per Void.

See Also:

Serialized Form

Nested Class Summary

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

Coder.Context, Coder.NonDeterministicException

Method Summary

Modifier and Type	Method and Description
boolean	consistentWithEquals() Returns true if this Coder is injective with respect to Object.equals(java.lang.Object).
Void	decode(InputStream inStream, Coder.Context context) Decodes a value of type T from the given input stream in the given context.
void	encode(Void value, OutputStream outStream, Coder.Context context) Encodes the given value of type T onto the given output stream in the given context.
protected long	getEncodedElementByteSize(Void value, Coder.Context context) Returns the size in bytes of the encoded value using this coder.
boolean	isRegisterByteSizeObserverCheap(Void value, Coder.Context context) Returns whether Coder.registerByteSizeObserver(T, org.apache.beam.sdk.util.common.ElementByteSizeObserver, org.apache.beam.sdk.coders.Coder.Context) cheap enough to call for every element, that is, if this Coder can calculate the byte size of the element to be coded in roughly constant time (or lazily).
static VoidCoder	of()

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

getCoderArguments, getInstanceComponents

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

verifyDeterministic

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

asCloudObject, equals, getAllowedEncodings, getComponents, getEncodingId, hashCode, registerByteSizeObserver, structuralValue, toString, verifyDeterministic, verifyDeterministic

Methods inherited from class java.lang.Object

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

Method Detail

of

public static VoidCoder of()

encode

public void encode(Void value,
                   OutputStream outStream,
                   Coder.Context context)

Description copied from interface: Coder

Encodes the given value of type T onto the given output stream in the given context.

decode

public Void decode(InputStream inStream,
                   Coder.Context context)

Description copied from interface: Coder

Decodes a value of type T from the given input stream in the given context. Returns the decoded value.

consistentWithEquals

public boolean consistentWithEquals()

Returns true if this Coder is injective with respect to Object.equals(java.lang.Object).

Whenever the encoded bytes of two values are equal, then the original values are equal according to Objects.equals(). Note that this is well-defined for null.

This condition is most notably false for arrays. More generally, this condition is false whenever equals() compares object identity, rather than performing a semantic/structural comparison.

Specified by:

consistentWithEquals in interface Coder<Void>

Overrides:

consistentWithEquals in class StandardCoder<Void>

Returns:

true. VoidCoder is (vacuously) injective.

isRegisterByteSizeObserverCheap

public boolean isRegisterByteSizeObserverCheap(Void value,
                                               Coder.Context context)

Returns whether Coder.registerByteSizeObserver(T, org.apache.beam.sdk.util.common.ElementByteSizeObserver, org.apache.beam.sdk.coders.Coder.Context) cheap enough to call for every element, that is, if this Coder can calculate the byte size of the element to be coded in roughly constant time (or lazily).

Not intended to be called by user code, but instead by PipelineRunner implementations.

Specified by:

isRegisterByteSizeObserverCheap in interface Coder<Void>

Overrides:

isRegisterByteSizeObserverCheap in class StandardCoder<Void>

Returns:

true. getEncodedElementByteSize(java.lang.Void, org.apache.beam.sdk.coders.Coder.Context) runs in constant time.

getEncodedElementByteSize

protected long getEncodedElementByteSize(Void value,
                                         Coder.Context context)
                                  throws Exception

Description copied from class: StandardCoder

Returns the size in bytes of the encoded value using this coder.

Overrides:

getEncodedElementByteSize in class StandardCoder<Void>

Throws:

Exception