@Internal public class CombineToGroupCombineWrapper<IN,OUT,F extends CombineFunction<IN,IN> & GroupReduceFunction<IN,OUT>> extends Object implements GroupCombineFunction<IN,IN>, GroupReduceFunction<IN,OUT>
GroupReduceFunctioninterfaces and makes it look like a function that implements
GroupReduceFunctionto the runtime.
|Constructor and Description|
|Modifier and Type||Method and Description|
The combine method, called (potentially multiple timed) with subgroups of elements.
The reduce method.
public CombineToGroupCombineWrapper(F wrappedFunction)
public void combine(Iterable<IN> values, Collector<IN> out) throws Exception
values- The elements to be combined.
out- The collector to use to return values from the function.
Exception- The function may throw Exceptions, which will cause the program to cancel, and may trigger the recovery logic.
public void reduce(Iterable<IN> values, Collector<OUT> out) throws Exception
values- All records that belong to the given input key.
out- The collector to hand results to.
Exception- This method may throw exceptions. Throwing an exception will cause the operation to fail and may trigger recovery.
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