Package com.cupoftea.table

Class GroupAccumulators.DoubleSumAccumulator

java.lang.Object

com.cupoftea.table.GroupAccumulators.DoubleSumAccumulator

All Implemented Interfaces:

GroupAccumulator

Enclosing class:

GroupAccumulators

public static class GroupAccumulators.DoubleSumAccumulator
extends Object
implements GroupAccumulator

Constructor Summary

Constructors

Constructor	Description
DoubleSumAccumulator(int numGroups, DoubleColumnVector vec, String outputName)

Method Summary

Modifier and Type	Method	Description
void	accumulate(int groupId, int row)	Accumulates row row from the source vector into group groupId.
ColumnVector	finish(int numGroups)	Finishes accumulation and returns the typed output ColumnVector of size numGroups.
void	merge(GroupAccumulator other)	Merges another accumulator of the same type into this accumulator.

Methods inherited from class java.lang.Object

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

Constructor Details

DoubleSumAccumulator

public DoubleSumAccumulator(int numGroups,
 DoubleColumnVector vec,
 String outputName)

Method Details

accumulate

public void accumulate(int groupId,
 int row)

Description copied from interface: GroupAccumulator

Accumulates row row from the source vector into group groupId.

Specified by:

accumulate in interface GroupAccumulator

Parameters:

groupId - the 0-based group ID

row - the row index in the source vector

merge

public void merge(GroupAccumulator other)

Description copied from interface: GroupAccumulator

Merges another accumulator of the same type into this accumulator. Used for parallel chunk reduction.

Specified by:

merge in interface GroupAccumulator

Parameters:

other - the other accumulator to merge

finish

public ColumnVector finish(int numGroups)

Description copied from interface: GroupAccumulator

Finishes accumulation and returns the typed output ColumnVector of size numGroups.

Specified by:

finish in interface GroupAccumulator

Parameters:

numGroups - total number of groups

Returns:

the populated output vector