cascading.operation
Interface GroupAssertion<C>

All Superinterfaces:

Assertion<C>, Operation<C>

All Known Implementing Classes:

AssertGroupBase, AssertGroupSizeEquals, AssertGroupSizeLessThan, AssertGroupSizeMoreThan

public interface GroupAssertion<C>
extends Assertion<C>

Class GroupAssertion is a kind of Assertion used with the Every pipe Operator.

Implementors should also extend BaseOperation.

See Also:

Aggregator

Field Summary

Fields inherited from interface cascading.operation.Operation

ANY

Method Summary

void	aggregate(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall) Method aggregate is called for each TupleEntry value in the current grouping.
void	doAssert(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall) Method doAssert performs the assertion.
void	start(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall) Method start initializes the aggregation procedure and is called for every unique grouping.

Methods inherited from interface cascading.operation.Operation

cleanup, getFieldDeclaration, getNumArgs, prepare

Method Detail

start

void start(FlowProcess flowProcess,
           GroupAssertionCall<C> assertionCall)

Method start initializes the aggregation procedure and is called for every unique grouping.

The AggregatorCall context should be initialized here if necessary.

The first time this method is called for a given 'process', the AggregatorCall context will be null. This method should set a new instance of the user defined context object. When the AggregatorCall context is not null, it is up to the developer to create a new instance, or 'recycle' the given instance. If recycled, it must be re-initialized to remove any previous state/values.

For example, if a Map is used to hold the intermediate data for each subsequent aggregate(cascading.flow.FlowProcess, GroupAssertionCall) call, new HashMap() should be set on the AggregatorCall instance when OperationCall.getContext() is null. On the next grouping, start() will be called again, but this time with the old Map instance. In this case, map.clear() should be invoked before returning.

Parameters:

flowProcess - of type FlowProcess

assertionCall - of type GroupAssertionCall

aggregate

void aggregate(FlowProcess flowProcess,
               GroupAssertionCall<C> assertionCall)

Method aggregate is called for each TupleEntry value in the current grouping.

Parameters:

flowProcess - of type FlowProcess

assertionCall - of type GroupAssertionCall

doAssert

void doAssert(FlowProcess flowProcess,
              GroupAssertionCall<C> assertionCall)

Method doAssert performs the assertion.

Parameters:

flowProcess - of type FlowProcess

assertionCall - of type GroupAssertionCall