org.apache.beam.sdk.extensions.protobuf

Class ByteStringCoder

java.lang.Object

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

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

org.apache.beam.sdk.coders.AtomicCoder<com.google.protobuf.ByteString>

org.apache.beam.sdk.extensions.protobuf.ByteStringCoder

All Implemented Interfaces:

java.io.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 class 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).
com.google.protobuf.ByteString	decode(java.io.InputStream inStream) Decodes a value of type T from the given input stream in the given context.
com.google.protobuf.ByteString	decode(java.io.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, java.io.OutputStream outStream) Encodes the given value of type T onto the given output stream.
void	encode(com.google.protobuf.ByteString value, java.io.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) Returns the size in bytes of the encoded value using this coder.
TypeDescriptor<com.google.protobuf.ByteString>	getEncodedTypeDescriptor() Returns the TypeDescriptor for the type encoded.
boolean	isRegisterByteSizeObserverCheap(com.google.protobuf.ByteString value) Returns whether Coder.registerByteSizeObserver(T, org.apache.beam.sdk.util.common.ElementByteSizeObserver) 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()
void	verifyDeterministic() Throw Coder.NonDeterministicException if the coding is not deterministic.

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

equals, getCoderArguments, getComponents, hashCode

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

toString

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

registerByteSizeObserver, structuralValue, 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,
                   java.io.OutputStream outStream)
            throws java.io.IOException,
                   CoderException

Description copied from class: Coder

Encodes the given value of type T onto the given output stream. Multiple elements can be encoded next to each other on the output stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.

Specified by:

encode in class Coder<com.google.protobuf.ByteString>

Throws:

java.io.IOException - if writing to the OutputStream fails for some reason

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

encode

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

Description copied from class: Coder

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

Overrides:

encode in class Coder<com.google.protobuf.ByteString>

Throws:

java.io.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(java.io.InputStream inStream)
                                      throws java.io.IOException

Description copied from class: Coder

Decodes a value of type T from the given input stream in the given context. Returns the decoded value. Multiple elements can be encoded next to each other on the input stream, each coder should encode information to know how many bytes to read when decoding. A common approach is to prefix the encoding with the element's encoded length.

Specified by:

decode in class Coder<com.google.protobuf.ByteString>

Throws:

java.io.IOException - if reading from the InputStream fails for some reason

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

decode

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

Description copied from class: Coder

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

Overrides:

decode in class Coder<com.google.protobuf.ByteString>

Throws:

java.io.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)
                                  throws java.lang.Exception

Description copied from class: Coder

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

Overrides:

getEncodedElementByteSize in class Coder<com.google.protobuf.ByteString>

Throws:

java.lang.Exception

verifyDeterministic

public void verifyDeterministic()

Description copied from class: AtomicCoder

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.

.

Unless overridden, does not throw. An AtomicCoder is presumed to be deterministic

Overrides:

verifyDeterministic in class AtomicCoder<com.google.protobuf.ByteString>

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.

By default, returns false.

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).

Overrides:

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

isRegisterByteSizeObserverCheap

public boolean isRegisterByteSizeObserverCheap(com.google.protobuf.ByteString value)

Returns whether Coder.registerByteSizeObserver(T, org.apache.beam.sdk.util.common.ElementByteSizeObserver) 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.

By default, returns false. The default Coder.registerByteSizeObserver(T, org.apache.beam.sdk.util.common.ElementByteSizeObserver) implementation invokes Coder.getEncodedElementByteSize(T) which requires re-encoding an element unless it is overridden. This is considered expensive.

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

Overrides:

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

getEncodedTypeDescriptor

public TypeDescriptor<com.google.protobuf.ByteString> getEncodedTypeDescriptor()

Description copied from class: Coder

Returns the TypeDescriptor for the type encoded.

Overrides:

getEncodedTypeDescriptor in class Coder<com.google.protobuf.ByteString>