public interface GroupAssertion<C> extends Assertion<C>
Assertion
used with the Every
pipe Operator.
Implementers should also extend BaseOperation
.
Aggregator
Modifier and Type | Method and Description |
---|---|
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.
|
supportsPlannerLevel
cleanup, flush, getFieldDeclaration, getNumArgs, isSafe, prepare
void start(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall)
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.
flowProcess
- of type FlowProcessassertionCall
- of type GroupAssertionCallvoid aggregate(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall)
TupleEntry
value in the current grouping.flowProcess
- of type FlowProcessassertionCall
- of type GroupAssertionCallvoid doAssert(FlowProcess flowProcess, GroupAssertionCall<C> assertionCall)
flowProcess
- of type FlowProcessassertionCall
- of type GroupAssertionCallCopyright © 2007-2017 Cascading Maintainers. All Rights Reserved.