org.github.jamm.strategies

Class InstrumentationAndSpecStrategy

java.lang.Object

org.github.jamm.strategies.MemoryLayoutBasedStrategy

org.github.jamm.strategies.InstrumentationAndSpecStrategy

All Implemented Interfaces:

MemoryMeterStrategy

public class InstrumentationAndSpecStrategy
extends MemoryLayoutBasedStrategy

Strategy that use java.lang.instrument.Instrumentation to measure non array object and the Specification approach to measure arrays. This strategy tries to combine the best of both strategies the accuracy and speed of Instrumentation for non array object and the speed of Specification for measuring array objects for which all strategy are accurate. For some reason Instrumentation is slower for arrays before Java 17.

Field Summary

Fields inherited from interface org.github.jamm.MemoryMeterStrategy

MEMORY_LAYOUT

Constructor Summary

Constructors

Constructor and Description
InstrumentationAndSpecStrategy(Instrumentation instrumentation)

Method Summary

Modifier and Type	Method and Description
long	measureInstance(Object object, Class<?> type) Measures the shallow memory used by objects of the specified class.

Methods inherited from class org.github.jamm.strategies.MemoryLayoutBasedStrategy

arrayBaseOffset, computeArraySize, measure, measureArray, measureArray, measureArray, measureArray, measureArray, measureArray, measureArray, measureArray, measureArray, measureArray, measureField, supportComputeArraySize

Methods inherited from class java.lang.Object

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

Constructor Detail

InstrumentationAndSpecStrategy

public InstrumentationAndSpecStrategy(Instrumentation instrumentation)

Method Detail

measureInstance

public long measureInstance(Object object,
                            Class<?> type)

Description copied from class: MemoryLayoutBasedStrategy

Measures the shallow memory used by objects of the specified class.

Specified by:

measureInstance in class MemoryLayoutBasedStrategy

Parameters:

object - the object to measure

type - the object type

Returns:

the shallow memory used by the object