Combine.SimpleCombineFn (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Warning: Dataflow SDK 1.x for Java is unsupported as of October 16, 2018. After August 12, 2020, you can use unsupported SDKs temporarily while you upgrade your pipelines. For more information, see Using an unsupported SDK.

For information on migrating from the 1.x SDK, see Migrating from Dataflow SDK 1.x for Java.

Note: If you are using Cloud Dataflow SDK version 2.x, see the Apache Beam API reference documentation.

com.google.cloud.dataflow.sdk.transforms

Class Combine.SimpleCombineFn<V>

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.Combine.CombineFn<V,List<V>,V>
  • • com.google.cloud.dataflow.sdk.transforms.Combine.IterableCombineFn<V>
    • • com.google.cloud.dataflow.sdk.transforms.Combine.SimpleCombineFn<V>

• All Implemented Interfaces:

  CombineFnBase.GlobalCombineFn<V,List<V>,V>, HasDisplayData, Serializable

  Enclosing class:

  Combine

  ---

  Deprecated.
  
  

  @Deprecated
  public static class Combine.SimpleCombineFn<V>
  extends Combine.IterableCombineFn<V>

  Converts a SerializableFunction from Iterable<V>s to Vs into a simple Combine.CombineFn over Vs.

  @deprecated Use Combine.IterableCombineFn or the more space efficient Combine.BinaryCombineFn instead (which avoids buffering values).

  See Also:

  Serialized Form

• • Constructor Summary

    Constructors 

    Modifier	Constructor and Description
    protected	SimpleCombineFn(SerializableFunction<Iterable<V>,V> combiner) Deprecated.

  • Method Summary

    All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 

    Modifier and Type	Method and Description
    TypeVariable<?>	getAccumTVariable() Returns the TypeVariable of AccumT.
    Coder<AccumT>	getAccumulatorCoder(CoderRegistry registry, Coder<InputT> inputCoder) Returns the Coder to use for accumulator AccumT values, or null if it is not able to be inferred.
    Coder<OutputT>	getDefaultOutputCoder(CoderRegistry registry, Coder<InputT> inputCoder) Returns the Coder to use by default for output OutputT values, or null if it is not able to be inferred.
    String	getIncompatibleGlobalWindowErrorMessage() Returns the error message for not supported default values in Combine.globally().
    TypeVariable<?>	getInputTVariable() Returns the TypeVariable of InputT.
    TypeVariable<?>	getOutputTVariable() Returns the TypeVariable of OutputT.
    static <V> Combine.SimpleCombineFn<V>	of(SerializableFunction<Iterable<V>,V> combiner) Deprecated.

    • Methods inherited from class com.google.cloud.dataflow.sdk.transforms.Combine.IterableCombineFn

      addInput, compact, createAccumulator, extractOutput, mergeAccumulators, of, populateDisplayData

    • Methods inherited from class com.google.cloud.dataflow.sdk.transforms.Combine.CombineFn

      apply, asKeyedFn, defaultValue, getOutputType

    • Methods inherited from class java.lang.Object

      clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• • Constructor Detail

    • SimpleCombineFn

      protected SimpleCombineFn(SerializableFunction<Iterable<V>,V> combiner)

      Deprecated. 

  • Method Detail

    • of

      @Deprecated
      public static <V> Combine.SimpleCombineFn<V> of(SerializableFunction<Iterable<V>,V> combiner)

      Deprecated. 
      Returns a CombineFn that uses the given SerializableFunction to combine values.

    • getAccumulatorCoder

      public Coder<AccumT> getAccumulatorCoder(CoderRegistry registry,
                                               Coder<InputT> inputCoder)
                                        throws CannotProvideCoderException

      Description copied from interface: CombineFnBase.GlobalCombineFn
      Returns the Coder to use for accumulator AccumT values, or null if it is not able to be inferred.

      By default, uses the knowledge of the Coder being used for InputT values and the enclosing Pipeline's CoderRegistry to try to infer the Coder for AccumT values.

      This is the Coder used to send data through a communication-intensive shuffle step, so a compact and efficient representation may have significant performance benefits.

      Specified by:

      getAccumulatorCoder in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>

      Throws:

      CannotProvideCoderException

    • getDefaultOutputCoder

      public Coder<OutputT> getDefaultOutputCoder(CoderRegistry registry,
                                                  Coder<InputT> inputCoder)
                                           throws CannotProvideCoderException

      Description copied from interface: CombineFnBase.GlobalCombineFn
      Returns the Coder to use by default for output OutputT values, or null if it is not able to be inferred.

      By default, uses the knowledge of the Coder being used for input InputT values and the enclosing Pipeline's CoderRegistry to try to infer the Coder for OutputT values.

      Specified by:

      getDefaultOutputCoder in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>

      Throws:

      CannotProvideCoderException

    • getIncompatibleGlobalWindowErrorMessage

      public String getIncompatibleGlobalWindowErrorMessage()

      Description copied from interface: CombineFnBase.GlobalCombineFn
      Returns the error message for not supported default values in Combine.globally().

      Specified by:

      getIncompatibleGlobalWindowErrorMessage in interface CombineFnBase.GlobalCombineFn<InputT,AccumT,OutputT>

    • getInputTVariable

      public TypeVariable<?> getInputTVariable()

      Returns the TypeVariable of InputT.

    • getAccumTVariable

      public TypeVariable<?> getAccumTVariable()

      Returns the TypeVariable of AccumT.

    • getOutputTVariable

      public TypeVariable<?> getOutputTVariable()

      Returns the TypeVariable of OutputT.