org.ehcache.sizeof.impl
Class AgentSizeOf

java.lang.Object
  org.ehcache.sizeof.SizeOf
      org.ehcache.sizeof.impl.AgentSizeOf

public class AgentSizeOf
extends SizeOf

SizeOf implementation that relies on a Java agent to be loaded to do the measurement It will try to load the agent through the JDK6 Attach API if available All it's constructor do throw UnsupportedOperationException if the agent isn't present or couldn't be loaded dynamically Inspired by Dr. Heinz Kabutz's Java Specialist Newsletter Issue #142

Author:

Chris Dennis, Alex Snaps

Field Summary

static String

BYPASS_LOADING System property name to bypass attaching to the VM and loading of Java agent to measure Object sizes.

Constructor Summary

AgentSizeOf()
Builds a new SizeOf that will not filter fields and will cache reflected fields

AgentSizeOf(SizeOfFilter filter)
Builds a new SizeOf that will filter fields according to the provided filter and will cache reflected fields

AgentSizeOf(SizeOfFilter filter, boolean caching, boolean bypassFlyweight)
Builds a new SizeOf that will filter fields according to the provided filter

Method Summary

long	sizeOf(Object obj) Calculates the size in memory (heap) of the instance passed in, not navigating the down graph

Methods inherited from class org.ehcache.sizeof.SizeOf

deepSizeOf, deepSizeOf, newInstance, newInstance

Methods inherited from class java.lang.Object

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

Field Detail

BYPASS_LOADING

public static final String BYPASS_LOADING

System property name to bypass attaching to the VM and loading of Java agent to measure Object sizes.

See Also:

Constant Field Values

Constructor Detail

AgentSizeOf

public AgentSizeOf()
            throws UnsupportedOperationException

Builds a new SizeOf that will not filter fields and will cache reflected fields

Throws:

UnsupportedOperationException - If agent couldn't be loaded or isn't present

See Also:

AgentSizeOf(SizeOfFilter, boolean, boolean)

AgentSizeOf

public AgentSizeOf(SizeOfFilter filter)
            throws UnsupportedOperationException

Builds a new SizeOf that will filter fields according to the provided filter and will cache reflected fields

Parameters:

filter - The filter to apply

Throws:

UnsupportedOperationException - If agent couldn't be loaded or isn't present

See Also:

AgentSizeOf(SizeOfFilter, boolean, boolean), SizeOfFilter

AgentSizeOf

public AgentSizeOf(SizeOfFilter filter,
                   boolean caching,
                   boolean bypassFlyweight)
            throws UnsupportedOperationException

Builds a new SizeOf that will filter fields according to the provided filter

Parameters:

filter - The filter to apply

caching - whether to cache reflected fields

bypassFlyweight - whether "Flyweight Objects" are to be ignored

Throws:

UnsupportedOperationException - If agent couldn't be loaded or isn't present

See Also:

SizeOfFilter

Method Detail

sizeOf

public long sizeOf(Object obj)

Description copied from class: SizeOf

Calculates the size in memory (heap) of the instance passed in, not navigating the down graph

Specified by:

sizeOf in class SizeOf

Parameters:

obj - the object to measure the size of

Returns:

the object size in memory in bytes