Combine.BinaryCombineLongFn (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Class Combine.BinaryCombineLongFn

    • Constructor Detail

      • BinaryCombineLongFn

        public BinaryCombineLongFn()
    • Method Detail

      • apply

        public abstract long apply(long left,
                                   long right)
        Applies the binary operation to the two operands, returning the result.
      • identity

        public abstract long identity()
        Returns the identity element of this operation, i.e. an element e such that apply(e, x) == apply(x, e) == x for all values of x.
      • addInput

        public long[] addInput(long[] accumulator,
                               Long input)
        Description copied from class: Combine.CombineFn
        Adds the given input value to the given accumulator, returning the new accumulator value.

        For efficiency, the input accumulator may be modified and returned.

        Specified by:
        addInput in class Combine.CombineFn<Long,long[],Long>
      • mergeAccumulators

        public long[] mergeAccumulators(Iterable<long[]> accumulators)
        Description copied from class: Combine.CombineFn
        Returns an accumulator representing the accumulation of all the input values accumulated in the merging accumulators.

        May modify any of the argument accumulators. May return a fresh accumulator, or may return one of the (modified) argument accumulators.

        Specified by:
        mergeAccumulators in class Combine.CombineFn<Long,long[],Long>
      • extractOutput

        public Long extractOutput(long[] accumulator)
        Description copied from class: Combine.CombineFn
        Returns the output value that is the result of combining all the input values represented by the given accumulator.
        Specified by:
        extractOutput in class Combine.CombineFn<Long,long[],Long>
      • getAccumulatorCoder

        public Coder<long[]> getAccumulatorCoder(CoderRegistry registry,
                                                 Coder<Long> inputCoder)
        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<Long,long[],Long>
      • getCounter

        public<Long> getCounter(String name)
      • populateDisplayData

        public void populateDisplayData(DisplayData.Builder builder)
        Register display data for the given transform or component.

        populateDisplayData(DisplayData.Builder) is invoked by Pipeline runners to collect display data via DisplayData.from(HasDisplayData). Implementations may call super.populateDisplayData(builder) in order to register display data in the current namespace, but should otherwise use subcomponent.populateDisplayData(builder) to use the namespace of the subcomponent.

        By default, does not register any display data. Implementors may override this method to provide their own display data.

        Specified by:
        populateDisplayData in interface HasDisplayData
        builder - The builder to populate with display data.
        See Also: