com.google.cloud.dataflow.sdk.coders

Class ByteStringCoder

java.lang.Object

com.google.cloud.dataflow.sdk.coders.StandardCoder<T>

com.google.cloud.dataflow.sdk.coders.DeterministicStandardCoder<T>

com.google.cloud.dataflow.sdk.coders.AtomicCoder<com.google.protobuf.ByteString>

com.google.cloud.dataflow.sdk.coders.ByteStringCoder

All Implemented Interfaces:

Coder<com.google.protobuf.ByteString>, Serializable

public class ByteStringCoder
extends AtomicCoder<com.google.protobuf.ByteString>

A Coder for ByteString objects based on their encoded Protocol Buffer form.

When this code is used in a nested Coder.Context, the serialized ByteString objects are first delimited by their size.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.cloud.dataflow.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).
com.google.protobuf.ByteString	decode(InputStream inStream, Coder.Context context) Decodes a value of type T from the given input stream in the given context.
void	encode(com.google.protobuf.ByteString 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(com.google.protobuf.ByteString value, Coder.Context context) Returns the size in bytes of the encoded value using this coder.
boolean	isRegisterByteSizeObserverCheap(com.google.protobuf.ByteString value, Coder.Context context) Returns whether Coder.registerByteSizeObserver(T, com.google.cloud.dataflow.sdk.util.common.ElementByteSizeObserver, com.google.cloud.dataflow.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 ByteStringCoder	of()

Methods inherited from class com.google.cloud.dataflow.sdk.coders.AtomicCoder

getCoderArguments, getInstanceComponents

Methods inherited from class com.google.cloud.dataflow.sdk.coders.DeterministicStandardCoder

verifyDeterministic

Methods inherited from class com.google.cloud.dataflow.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 ByteStringCoder of()

encode

public void encode(com.google.protobuf.ByteString value,
                   OutputStream outStream,
                   Coder.Context context)
            throws IOException,
                   CoderException

Description copied from interface: Coder

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

Throws:

IOException - if writing to the OutputStream fails for some reason

CoderException - if the value could not be encoded for some reason

decode

public com.google.protobuf.ByteString decode(InputStream inStream,
                                             Coder.Context context)
                                      throws IOException

Description copied from interface: Coder

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

Throws:

IOException - if reading from the InputStream fails for some reason

CoderException - if the value could not be decoded for some reason

getEncodedElementByteSize

protected long getEncodedElementByteSize(com.google.protobuf.ByteString 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<com.google.protobuf.ByteString>

Throws:

Exception

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.

Returns true; the encoded output of two invocations of ByteStringCoder in the same Coder.Context will be identical if and only if the original ByteString objects are equal according to Object.equals(java.lang.Object).

Specified by:

consistentWithEquals in interface Coder<com.google.protobuf.ByteString>

Overrides:

consistentWithEquals in class StandardCoder<com.google.protobuf.ByteString>

Returns:

false for StandardCoder unless overridden.

isRegisterByteSizeObserverCheap

public boolean isRegisterByteSizeObserverCheap(com.google.protobuf.ByteString value,
                                               Coder.Context context)

Returns whether Coder.registerByteSizeObserver(T, com.google.cloud.dataflow.sdk.util.common.ElementByteSizeObserver, com.google.cloud.dataflow.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.

Returns true. ByteString.size() returns the size of an array and a VarInt.

Specified by:

isRegisterByteSizeObserverCheap in interface Coder<com.google.protobuf.ByteString>

Overrides:

isRegisterByteSizeObserverCheap in class StandardCoder<com.google.protobuf.ByteString>

Returns:

false unless it is overridden. StandardCoder.registerByteSizeObserver(T, com.google.cloud.dataflow.sdk.util.common.ElementByteSizeObserver, com.google.cloud.dataflow.sdk.coders.Coder.Context) invokes StandardCoder.getEncodedElementByteSize(T, com.google.cloud.dataflow.sdk.coders.Coder.Context) which requires re-encoding an element unless it is overridden. This is considered expensive.