AccumulatorTaskTKey, TValue Class

Base class for tasks that accumulate values associated with a specific key.

Inheritance Hierarchy

SystemObject
  Ookii.Jumbo.JetConfigurable
    Ookii.Jumbo.JetPushTaskPairTKey, TValue, PairTKey, TValue
      Ookii.Jumbo.Jet.TasksAccumulatorTaskTKey, TValue
        Ookii.Jumbo.Jet.TasksSumTaskTKey

Namespace: Ookii.Jumbo.Jet.Tasks
Assembly: Ookii.Jumbo.Jet (in Ookii.Jumbo.Jet.dll) Version: 0.3.0+dc1307f20e065bb638e0b73a34cd216f57e486f1

Syntax

C++

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public abstract class AccumulatorTask<TKey, TValue> : PushTask<Pair<TKey, TValue>, Pair<TKey, TValue>>
where TKey : Object, IComparable<TKey>

Public MustInherit Class AccumulatorTask(Of TKey As {Object, IComparable(Of TKey)}, TValue)
	Inherits PushTask(Of Pair(Of TKey, TValue), Pair(Of TKey, TValue))

generic<typename TKey, typename TValue>
where TKey : Object, IComparable<TKey>
public ref class AccumulatorTask abstract : public PushTask<Pair<TKey, TValue>^, Pair<TKey, TValue>^>

[<AbstractClassAttribute>]
type AccumulatorTask<'TKey, 'TValue when 'TKey : Object and IComparable<'TKey>> = 
    class
        inherit PushTask<Pair<'TKey, 'TValue>, Pair<'TKey, 'TValue>>
    end

Type Parameters

TKey: The type of the keys.
TValue: The type of the values.

The AccumulatorTaskTKey, TValue type exposes the following members.

Constructors

	Name	Description
	AccumulatorTaskTKey, TValue	Initializes a new instance of the AccumulatorTaskTKey, TValue class.

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Properties

	Name	Description
	DfsConfiguration	Gets or sets the configuration used to access the Distributed File System. (Inherited from Configurable)
	JetConfiguration	Gets or sets the configuration used to access the Jet servers. (Inherited from Configurable)
	TaskContext	Gets or sets the configuration for the task attempt. (Inherited from Configurable)

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Methods

	Name	Description
	Accumulate	When implemented in a derived class, accumulates the values of the records.
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object)
	Finish	Method called after the last record was processed. (Overrides PushTaskTInput, TOutputFinish(RecordWriterTOutput))
	GetHashCode	Serves as the default hash function. (Inherited from Object)
	GetType	Gets the Type of the current instance. (Inherited from Object)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object)
	NotifyConfigurationChanged	Indicates the configuration has been changed. ApplyConfiguration(Object, DfsConfiguration, JetConfiguration, TaskContext) calls this method after setting the configuration. (Overrides ConfigurableNotifyConfigurationChanged)
	ProcessRecord	Method called for each record in the task's input. (Overrides PushTaskTInput, TOutputProcessRecord(TInput, RecordWriterTOutput))
	Run	Runs the task. (Inherited from PushTaskTInput, TOutput)
	ToString	Returns a string that represents the current object. (Inherited from Object)

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Remarks

It is safe to reuse the same PairTKey, TValue in every call to ProcessRecord(PairTKey, TValue, RecordWriterPairTKey, TValue) if the key and value are either value types or implement ICloneable. Therefore, if you specify the AllowRecordReuseAttribute on a class deriving from this class, the key and value must either be value types or implement ICloneable.

You can specify a custom key comparer using the AccumulatorTaskKeyComparerSettingKey key in the stage settings. Note that it is recommended to also use that has the comparer type for the HashPartitionerT in that case.

Reference

Ookii.Jumbo.Jet.Tasks Namespace