org.openjdk.jmc.flightrecorder.rules.jdk.combine

Class SpanToolkit

java.lang.Object

org.openjdk.jmc.flightrecorder.rules.jdk.combine.SpanToolkit

public class SpanToolkit
extends Object

Toolkit for calculating combined span values. Creates spans which consist of at least a start time, an end time and a value. Spans are then combined together (see Combinable and Combiner) to form the largest time span where the combined value is still deemed to be over some threshold. Threshold can be either a defined limit or a calculated density.

Currently, it's up to the caller of this toolkit to call the methods with a subset of items that have only one item iterable, which means that events should not overlap in time.

Constructor Summary

Constructors

Constructor and Description
SpanToolkit()

Method Summary

Modifier and Type	Method and Description
static SpanSquare	getMaxCountCluster(IItemCollection items, IAttribute<IQuantity> countAttribute, IAttribute<IQuantity> timestampAttribute) Calculates the largest count cluster.
static SpanSquare	getMaxDurationCluster(IItemCollection items) Calculates the largest duration cluster.
static SpanLimit	getMaxSpanLimit(IItemCollection items, IAttribute<IQuantity> valueAttribute, IAttribute<IQuantity> endTimeAttribute, double limit) Calculates the longest span where the combined value still is above the limit.

Methods inherited from class java.lang.Object

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

Constructor Detail

SpanToolkit

public SpanToolkit()

Method Detail

getMaxCountCluster

public static SpanSquare getMaxCountCluster(IItemCollection items,
                                            IAttribute<IQuantity> countAttribute,
                                            IAttribute<IQuantity> timestampAttribute)

Calculates the largest count cluster.

Parameters:

items - the item collection

countAttribute - the attribute to get count value from, is assumed to be an accumulative value, for example exception statistics

timestampAttribute - the attribute to get a time stamp from

Returns:

The maximum count span

getMaxDurationCluster

public static SpanSquare getMaxDurationCluster(IItemCollection items)

Calculates the largest duration cluster.

Parameters:

items - the item collection

Returns:

The maximum duration span

getMaxSpanLimit

public static SpanLimit getMaxSpanLimit(IItemCollection items,
                                        IAttribute<IQuantity> valueAttribute,
                                        IAttribute<IQuantity> endTimeAttribute,
                                        double limit)

Calculates the longest span where the combined value still is above the limit.

Parameters:

items - the item collection

valueAttribute - the value attribute

endTimeAttribute - the end time attribute

limit - the min limit

Returns:

a span