uk.ac.ed.epcc.safe.accounting

Class OverlapHandler<T extends UsageRecord>

java.lang.Object

uk.ac.ed.epcc.safe.accounting.OverlapHandler<T>

Type Parameters:

T -

public class OverlapHandler<T extends UsageRecord>
extends java.lang.Object

Class that implements the logic of overlap calculations.

This is needed whenever positive definite properties from a UsageRecord with known start and end dates is mapped onto a TimePeriod for example a table column or a chart data point. These routines only make sense when the record period is significant compared to the target period.

There are two kinds of scaling we need to worry about.

• SUM where the weight is the fraction of the record that overlaps. This is usually correct for Cumulative properties.
• AVG where the weight is the fraction of the period that overlaps. This is usually correct for Point properties such as rates as this gives the contribution to the time average over the period.

We keep this logic in a separate class so it can be used with different UsageProducer implementations.

Author:

spb

Field Summary

Fields

Modifier and Type	Field and Description
static uk.ac.ed.epcc.webapp.Feature	USE_CASE_OVERLAP
static uk.ac.ed.epcc.webapp.Feature	USE_QUERY_MAPPER_FEATURE

Constructor Summary

Constructors

Constructor and Description
OverlapHandler(uk.ac.ed.epcc.webapp.AppContext conn, UsageProducer<T> prod)

Method Summary

Methods

Modifier and Type	Method and Description
static java.lang.Number	getOverlap(ExpressionTarget rec, NumberReductionTarget target, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date p_start, java.util.Date p_end) property proportional to fraction of record that overlaps period
java.util.Map<ExpressionTuple,ReductionMapResult>	getOverlapIndexedReductionMap(java.util.Set<ReductionTarget> property, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date start, java.util.Date end, RecordSelector input_selector)
static double	getOverlappWeight(ExpressionTarget rec, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date p_start, java.util.Date p_end, Reduction op) Get the fraction of this record that overlaps with the specified period.
<R> java.util.Map<R,java.lang.Number>	getOverlapReductionMap(NumberReductionTarget main_target, PropExpression<R> tag, PropertyTag<java.util.Date> start_prop, PropertyTag<java.util.Date> end_prop, java.util.Date start, java.util.Date end, RecordSelector sel) sum the specified quantity matching date range and selector grouped by the other specified property.
java.lang.Number	getOverlapSum(NumberReductionTarget target, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, RecordSelector o_sel, java.util.Date start, java.util.Date end)
double	getOverlapSum(Reduction op, PropExpression<? extends java.lang.Number> type, PropExpression<java.util.Date> start_prop, PropertyTag<java.util.Date> end_prop, RecordSelector sel, java.util.Date start, java.util.Date end) Combine the specified quantity matching the date range and selector.
NumberReductionTarget	makeCaseOverlapReductionTarget(Reduction red, PropExpression<? extends java.lang.Number> type, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date start, java.util.Date end)
static NumberReductionTarget	makeInnerAverageReductionTarget(PropExpression<? extends java.lang.Number> type, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date start, java.util.Date end) Convert a numerical property into the ReductionTarget needed to calculate the overlap contribution to the time-average of records totally within the overlap period.
static DurationPropExpression	makeOverlapExpression(OverlapType overlap_type, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date start, java.util.Date end) Calculate expression for the overlap of a record and a period.
static NumberReductionTarget	makeOverlapReductionTarget(OverlapType overlap_type, Reduction red, PropExpression<? extends java.lang.Number> type, PropertyTag<java.util.Date> start_prop, PropertyTag<java.util.Date> end_prop, java.util.Date start, java.util.Date end)
static boolean	overlaps(ExpressionTarget rec, PropExpression<java.util.Date> start_prop, PropExpression<java.util.Date> end_prop, java.util.Date start, java.util.Date end)

Methods inherited from class java.lang.Object

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

Field Detail

USE_QUERY_MAPPER_FEATURE

public static final uk.ac.ed.epcc.webapp.Feature USE_QUERY_MAPPER_FEATURE

USE_CASE_OVERLAP

public static final uk.ac.ed.epcc.webapp.Feature USE_CASE_OVERLAP

Constructor Detail

OverlapHandler

public OverlapHandler(uk.ac.ed.epcc.webapp.AppContext conn,
              UsageProducer<T> prod)

Method Detail

getOverlapSum

public double getOverlapSum(Reduction op,
                   PropExpression<? extends java.lang.Number> type,
                   PropExpression<java.util.Date> start_prop,
                   PropertyTag<java.util.Date> end_prop,
                   RecordSelector sel,
                   java.util.Date start,
                   java.util.Date end)
                     throws java.lang.Exception

Combine the specified quantity matching the date range and selector. All records that overlap the data range are processed. Records that overlap the ends of the period can have their value rescaled appropriately. Because of the possible re-scaling the result is always returned as a double

Throws:

java.lang.Exception

Parameters:

op - Reduction

type - PropertyTag of property to Sum

start_prop - PropertyTag defining the start of the record

end_prop - ProeprtyTag defining the end of the record

start - Start Date

end - End Date

sel - RecordSelector to select target records

Returns:

sum of quantity

getOverlapSum

public java.lang.Number getOverlapSum(NumberReductionTarget target,
                             PropExpression<java.util.Date> start_prop,
                             PropExpression<java.util.Date> end_prop,
                             RecordSelector o_sel,
                             java.util.Date start,
                             java.util.Date end)
                               throws java.lang.Exception

Throws:

java.lang.Exception

makeInnerAverageReductionTarget

public static NumberReductionTarget makeInnerAverageReductionTarget(PropExpression<? extends java.lang.Number> type,
                                                    PropExpression<java.util.Date> start_prop,
                                                    PropExpression<java.util.Date> end_prop,
                                                    java.util.Date start,
                                                    java.util.Date end)
                                                             throws IllegalReductionException,
                                                                    PropertyCastException

Convert a numerical property into the ReductionTarget needed to calculate the overlap contribution to the time-average of records totally within the overlap period.

Throws:

IllegalReductionException

PropertyCastException

Parameters:

type -

start_prop -

end_prop -

start -

end -

Returns:

NumberReductionTarget

makeOverlapExpression

public static DurationPropExpression makeOverlapExpression(OverlapType overlap_type,
                                           PropExpression<java.util.Date> start_prop,
                                           PropExpression<java.util.Date> end_prop,
                                           java.util.Date start,
                                           java.util.Date end)
                                                    throws IllegalReductionException,
                                                           PropertyCastException

Calculate expression for the overlap of a record and a period.

Throws:

IllegalReductionException

PropertyCastException

Parameters:

overlap_type -

start_prop -

end_prop -

start -

end -

Returns:

NumberReductionTarget

makeOverlapReductionTarget

public static NumberReductionTarget makeOverlapReductionTarget(OverlapType overlap_type,
                                               Reduction red,
                                               PropExpression<? extends java.lang.Number> type,
                                               PropertyTag<java.util.Date> start_prop,
                                               PropertyTag<java.util.Date> end_prop,
                                               java.util.Date start,
                                               java.util.Date end)
                                                        throws IllegalReductionException,
                                                               PropertyCastException

Throws:

IllegalReductionException

PropertyCastException

makeCaseOverlapReductionTarget

public NumberReductionTarget makeCaseOverlapReductionTarget(Reduction red,
                                                   PropExpression<? extends java.lang.Number> type,
                                                   PropExpression<java.util.Date> start_prop,
                                                   PropExpression<java.util.Date> end_prop,
                                                   java.util.Date start,
                                                   java.util.Date end)
                                                     throws IllegalReductionException,
                                                            PropertyCastException

Throws:

IllegalReductionException

PropertyCastException

getOverlapReductionMap

public <R> java.util.Map<R,java.lang.Number> getOverlapReductionMap(NumberReductionTarget main_target,
                                                           PropExpression<R> tag,
                                                           PropertyTag<java.util.Date> start_prop,
                                                           PropertyTag<java.util.Date> end_prop,
                                                           java.util.Date start,
                                                           java.util.Date end,
                                                           RecordSelector sel)
                                                         throws java.lang.Exception

sum the specified quantity matching date range and selector grouped by the other specified property. All records that overlap the data range are processed. Records that overlap the ends of the period can have their value rescaled appropriately.

Throws:

java.lang.Exception

uk.ac.ed.epcc.webapp.jdbc.exception.DataException

Type Parameters:

R -

Parameters:

main_target -

tag -

start_prop -

end_prop -

start -

end -

sel -

Returns:

Map

getOverlapIndexedReductionMap

public java.util.Map<ExpressionTuple,ReductionMapResult> getOverlapIndexedReductionMap(java.util.Set<ReductionTarget> property,
                                                                              PropExpression<java.util.Date> start_prop,
                                                                              PropExpression<java.util.Date> end_prop,
                                                                              java.util.Date start,
                                                                              java.util.Date end,
                                                                              RecordSelector input_selector)
                                                                                throws java.lang.Exception

Throws:

java.lang.Exception

getOverlap

public static java.lang.Number getOverlap(ExpressionTarget rec,
                          NumberReductionTarget target,
                          PropExpression<java.util.Date> start_prop,
                          PropExpression<java.util.Date> end_prop,
                          java.util.Date p_start,
                          java.util.Date p_end)
                                   throws InvalidPropertyException

property proportional to fraction of record that overlaps period

Throws:

InvalidPropertyException

Parameters:

rec -

target -

start_prop -

end_prop -

p_start - period start i

p_end - period end

Returns:

weighted value of property

overlaps

public static boolean overlaps(ExpressionTarget rec,
               PropExpression<java.util.Date> start_prop,
               PropExpression<java.util.Date> end_prop,
               java.util.Date start,
               java.util.Date end)

getOverlappWeight

public static double getOverlappWeight(ExpressionTarget rec,
                       PropExpression<java.util.Date> start_prop,
                       PropExpression<java.util.Date> end_prop,
                       java.util.Date p_start,
                       java.util.Date p_end,
                       Reduction op)

Get the fraction of this record that overlaps with the specified period. The algorithm used depends on the requested operation. For SUM we weight by the fraction of the record that overlaps. For AVG we weight by the fraction of the period (a time average).

Parameters:

rec -

start_prop - PropertyTag for record start

end_prop - PropertyTag for record end

p_start - Period start

p_end - Period end

op - Reduction operation

Returns:

double fraction