uk.ac.ed.epcc.safe.accounting

Interface ReductionProducer<UR extends ExpressionTarget>

All Known Subinterfaces:

AllocationManager<K,T>, ChargedAllocationManager<K,T>, UsageProducer<UR>

All Known Implementing Classes:

AccountingClassificationFactory, AggregateUsageRecordFactory, AllocationFactory, ChargedAllocationFactory, ConfigUsageManager, ConfigUsageRecordFactory, DailyAggregateUsageRecordFactory, DefaultUsageProducer, HourlyAggregateUsageRecordFactory, ParseUsageRecordFactory, PropertyTargetHistoryFactory, PropertyTargetLinkHistoryFactory, ReductionHandler, SequenceAllocationFactory, UsageManager, UsageRecordFactory, UsageRecordUsageManager

public interface ReductionProducer<UR extends ExpressionTarget>

Method Summary

Methods

Modifier and Type	Method and Description
java.util.Map<ExpressionTuple,ReductionMapResult>	getIndexedReductionMap(java.util.Set<ReductionTarget> property, RecordSelector selector) General reduction operation.
<T> T	getReduction(ReductionTarget<T> target, RecordSelector sel) Perform a reduction over a set of records
<I> java.util.Map<I,java.lang.Number>	getReductionMap(PropExpression<I> index, ReductionTarget<java.lang.Number> property, RecordSelector selector) sum the specified numerical quantity over all records that match the selector grouped by the other specified property

Method Detail

getReduction

<T> T getReduction(ReductionTarget<T> target,
                 RecordSelector sel)
               throws java.lang.Exception

Perform a reduction over a set of records

Throws:

java.lang.Exception

Parameters:

target - ReductionTarget specifying reduction to perform

sel - RecordSelector to select target records

Returns:

result of reduction

getIndexedReductionMap

java.util.Map<ExpressionTuple,ReductionMapResult> getIndexedReductionMap(java.util.Set<ReductionTarget> property,
                                                                       RecordSelector selector)
                                                                         throws java.lang.Exception

General reduction operation. The reduction is specified by a set of ReductionTarget objects. This method generates Maps from the requested ReductionTarget to the result of the corresponding reduction. If the list of ReductionTargets contains any IndexReduction objects then multiple results will be returned so these results are themselves returned as a Map indexed by PropertyTuple objects representing the Index values. If there are no IndexValues an empty PropertyTuple will be used. A non-index target that does not resolve may be ignored or return the default value for the ReductionTarget. This is so target set compatible with composite UsageProducers can contain targets only relevant to some of its parts without suppressing all output from the tables that don't support the property. This does run the risk that spurious index-tuples might be generated from tables that support none of the non-index targets. In that case the producer has to be tuned.

Throws:

java.lang.Exception

Parameters:

property -

selector -

Returns:

Map

getReductionMap

<I> java.util.Map<I,java.lang.Number> getReductionMap(PropExpression<I> index,
                                                    ReductionTarget<java.lang.Number> property,
                                                    RecordSelector selector)
                                                  throws java.lang.Exception

sum the specified numerical quantity over all records that match the selector grouped by the other specified property

Throws:

java.lang.Exception

Type Parameters:

I -

Parameters:

index -

property -

selector -

Returns:

Map