org.omegat.util

Class MemoryUtils

java.lang.Object

org.omegat.util.MemoryUtils

public final class MemoryUtils
extends java.lang.Object

Utils for calculate used memory. Calculation of object size is not perfect. It doesn't support multiple links to one object instance(object shares), memory alignments.

Field Summary

Fields

Modifier and Type	Field and Description
protected static boolean	IS64 JVM architecture.
protected static int	SZ_OBJFOOT Object footprint - 16 for 64bit, 8 for 32 bit.
protected static int	SZ_OBJLINK Link to object - 8 for 64bit, 4 for 32bit.

Method Summary

Modifier and Type	Method and Description
static long	calcObjectSize(java.lang.Object obj) Calculate memory usage for object.
static long	getMemoryAllocated() Get memory allocated by jvm.
static long	getMemoryLimit() Get maximum memory which can be allocated by jvm.
static long	getMemoryUsed() Get memory which used by jvm.
protected static long	getSimpleTypeSize(java.lang.Class<?> oc) Calculate memory usage for simple types.

Methods inherited from class java.lang.Object

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

Field Detail

IS64

protected static final boolean IS64

JVM architecture.

SZ_OBJFOOT

protected static final int SZ_OBJFOOT

Object footprint - 16 for 64bit, 8 for 32 bit.

SZ_OBJLINK

protected static final int SZ_OBJLINK

Link to object - 8 for 64bit, 4 for 32bit.

Method Detail

getMemoryUsed

public static long getMemoryUsed()

Get memory which used by jvm.

Returns:

memory size

getMemoryAllocated

public static long getMemoryAllocated()

Get memory allocated by jvm.

Returns:

memory size

getMemoryLimit

public static long getMemoryLimit()

Get maximum memory which can be allocated by jvm.

Returns:

memory size

calcObjectSize

public static long calcObjectSize(java.lang.Object obj)

Calculate memory usage for object.

Parameters:

obj - object

Returns:

memory size, or -1 if size is unknown

Throws:

java.lang.Exception

getSimpleTypeSize

protected static long getSimpleTypeSize(java.lang.Class<?> oc)

Calculate memory usage for simple types.

Parameters:

oc - simple type class

Returns:

memory size