Modifier and Type	Class and Description
private static class	RamUsageEstimator.ClassCache Cached information about a given class.
private static class	RamUsageEstimator.DummyOneFieldObject
private static class	RamUsageEstimator.DummyTwoLongObject
public static enum	RamUsageEstimator.JvmFeature JVM diagnostic features.

Field Summary

Modifier and Type	Field and Description
public static final String	JVM_INFO_STRING JVM info string for debugging and reports.
public static final int	NUM_BYTES_ARRAY_HEADER Number of bytes to represent an array header (no content, but with alignments).
public static final int	NUM_BYTES_BOOLEAN
public static final int	NUM_BYTES_BYTE
public static final int	NUM_BYTES_CHAR
public static final int	NUM_BYTES_DOUBLE
public static final int	NUM_BYTES_FLOAT
public static final int	NUM_BYTES_INT
public static final int	NUM_BYTES_LONG
public static final int	NUM_BYTES_OBJECT_ALIGNMENT A constant specifying the object alignment boundary inside the JVM.
public static final int	NUM_BYTES_OBJECT_HEADER Number of bytes to represent an object header (no fields, no alignments).
public static final int	NUM_BYTES_OBJECT_REF Number of bytes this jvm uses to represent an object reference.
public static final int	NUM_BYTES_SHORT
private static final Method	objectFieldOffsetMethod A handle to `sun.misc.Unsafe#fieldOffset(Field)`.
public static final long	ONE_GB One gigabyte bytes.
public static final long	ONE_KB One kilobyte bytes.
public static final long	ONE_MB One megabyte bytes.
private static final Map<Class<?>, Integer>	primitiveSizes Sizes of primitive classes.
private static final EnumSet<RamUsageEstimator.JvmFeature>	supportedFeatures All the supported "internal" JVM features detected at clinit.
private static final Object	theUnsafe A handle to `sun.misc.Unsafe`.

Constructor Summary

Access	Constructor and Description
private	RamUsageEstimator() No instantiation.

Method Summary

Modifier and Type	Method and Description
private static long	adjustForField(long sizeSoFar, final Field f) This method returns the maximum representation size of an object.
public static long	alignObjectSize(long size) Aligns an object size to be the next multiple of `NUM_BYTES_OBJECT_ALIGNMENT`.
private static RamUsageEstimator.ClassCache	createCacheEntry(final Class<?> clazz) Create a cached information about shallow size and reference fields for a given class.
public static EnumSet<RamUsageEstimator.JvmFeature>	getSupportedFeatures() Return the set of supported JVM features that improve the estimation.
public static EnumSet<RamUsageEstimator.JvmFeature>	getUnsupportedFeatures() Return the set of unsupported JVM features that improve the estimation.
public static String	humanReadableUnits(long bytes) Returns `size` in human-readable units (GB, MB, KB or bytes).
public static String	humanReadableUnits(long bytes, DecimalFormat df) Returns `size` in human-readable units (GB, MB, KB or bytes).
public static String	humanSizeOf(Object object) Return a human-readable size of a given object.
public static boolean	isSupportedJVM() Returns true, if the current JVM is fully supported by `RamUsageEstimator`.
private static long	measureSizeOf(ArrayList<Object> Root objects. stack) Non-recursive version of object descend.
public static long	shallowSizeOf(Object obj) Estimates a "shallow" memory usage of the given object.
public static long	shallowSizeOfAll(Object... objects) Same as `shallowSizeOf(Object)` but sums up all the arguments.
public static long	shallowSizeOfAll(Iterable<Object> objects) Same as `shallowSizeOf(Object)` but sums up all the arguments.
private static long	shallowSizeOfArray(Object array) Return shallow size of any `array`.
public static long	shallowSizeOfInstance(Class<?> clazz) Returns the shallow instance size in bytes an instance of the given class would occupy.
public static long	sizeOf(byte[] arr) Returns the size in bytes of the byte[] object.
public static long	sizeOf(boolean[] arr) Returns the size in bytes of the boolean[] object.
public static long	sizeOf(char[] arr) Returns the size in bytes of the char[] object.
public static long	sizeOf(short[] arr) Returns the size in bytes of the short[] object.
public static long	sizeOf(int[] arr) Returns the size in bytes of the int[] object.
public static long	sizeOf(float[] arr) Returns the size in bytes of the float[] object.
public static long	sizeOf(long[] arr) Returns the size in bytes of the long[] object.
public static long	sizeOf(double[] arr) Returns the size in bytes of the double[] object.
public static long	sizeOf(Object obj) Estimates the RAM usage by the given object.
public static long	sizeOfAll(Object... objects) Same as `sizeOf(Object)` but sums up all the arguments.
public static long	sizeOfAll(Iterable<Object> objects) Same as `sizeOf(Object)` but sums up all the arguments.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

JVM_INFO_STRING	back to summary
public static final String JVM_INFO_STRING JVM info string for debugging and reports.

NUM_BYTES_ARRAY_HEADER	back to summary
public static final int NUM_BYTES_ARRAY_HEADER Number of bytes to represent an array header (no content, but with alignments).

NUM_BYTES_BOOLEAN	back to summary
public static final int NUM_BYTES_BOOLEAN

NUM_BYTES_BYTE	back to summary
public static final int NUM_BYTES_BYTE

NUM_BYTES_CHAR	back to summary
public static final int NUM_BYTES_CHAR

NUM_BYTES_DOUBLE	back to summary
public static final int NUM_BYTES_DOUBLE

NUM_BYTES_FLOAT	back to summary
public static final int NUM_BYTES_FLOAT

NUM_BYTES_INT	back to summary
public static final int NUM_BYTES_INT

NUM_BYTES_LONG	back to summary
public static final int NUM_BYTES_LONG

NUM_BYTES_OBJECT_ALIGNMENT	back to summary
public static final int NUM_BYTES_OBJECT_ALIGNMENT A constant specifying the object alignment boundary inside the JVM. Objects will always take a full multiple of this constant, possibly wasting some space.

NUM_BYTES_OBJECT_HEADER	back to summary
public static final int NUM_BYTES_OBJECT_HEADER Number of bytes to represent an object header (no fields, no alignments).

NUM_BYTES_OBJECT_REF	back to summary
public static final int NUM_BYTES_OBJECT_REF Number of bytes this jvm uses to represent an object reference.

NUM_BYTES_SHORT	back to summary
public static final int NUM_BYTES_SHORT

objectFieldOffsetMethod	back to summary
private static final Method objectFieldOffsetMethod A handle to `sun.misc.Unsafe#fieldOffset(Field)`.

ONE_GB	back to summary
public static final long ONE_GB One gigabyte bytes.

ONE_KB	back to summary
public static final long ONE_KB One kilobyte bytes.

ONE_MB	back to summary
public static final long ONE_MB One megabyte bytes.

primitiveSizes	back to summary
private static final Map<Class<?>, Integer> primitiveSizes Sizes of primitive classes.

supportedFeatures	back to summary
private static final EnumSet<RamUsageEstimator.JvmFeature> supportedFeatures All the supported "internal" JVM features detected at clinit.

theUnsafe	back to summary
private static final Object theUnsafe A handle to `sun.misc.Unsafe`.

Constructor Detail

RamUsageEstimator	back to summary
private RamUsageEstimator() No instantiation.

Method Detail

adjustForField back to summary

adjustForField	back to summary
private static long adjustForField(long sizeSoFar, final Field f) This method returns the maximum representation size of an object. `sizeSoFar` is the object's size measured so far. `f` is the field being probed. The returned offset will be the maximum of whatever was measured so far and `f` field's offset and representation size (unaligned).

private static long adjustForField(long sizeSoFar, final Field f)

This method returns the maximum representation size of an object. sizeSoFar is the object's size measured so far. f is the field being probed.

The returned offset will be the maximum of whatever was measured so far and f field's offset and representation size (unaligned).

alignObjectSize	back to summary
public static long alignObjectSize(long size) Aligns an object size to be the next multiple of `NUM_BYTES_OBJECT_ALIGNMENT`.

createCacheEntry	back to summary
private static RamUsageEstimator.ClassCache createCacheEntry(final Class<?> clazz) Create a cached information about shallow size and reference fields for a given class.

getSupportedFeatures	back to summary
public static EnumSet<RamUsageEstimator.JvmFeature> getSupportedFeatures() Return the set of supported JVM features that improve the estimation.

getUnsupportedFeatures	back to summary
public static EnumSet<RamUsageEstimator.JvmFeature> getUnsupportedFeatures() Return the set of unsupported JVM features that improve the estimation.

humanReadableUnits	back to summary
public static String humanReadableUnits(long bytes) Returns `size` in human-readable units (GB, MB, KB or bytes).

humanReadableUnits	back to summary
public static String humanReadableUnits(long bytes, DecimalFormat df) Returns `size` in human-readable units (GB, MB, KB or bytes).

humanSizeOf back to summary

humanSizeOf	back to summary
public static String humanSizeOf(Object object) Return a human-readable size of a given object. See Also `sizeOf(Object)`, `humanReadableUnits(long)`

public static String humanSizeOf(Object object)

Return a human-readable size of a given object.

See Also: sizeOf(Object), humanReadableUnits(long)

isSupportedJVM	back to summary
public static boolean isSupportedJVM() Returns true, if the current JVM is fully supported by `RamUsageEstimator`. If this method returns `false` you are maybe using a 3rd party Java VM that is not supporting Oracle/Sun private APIs. The memory estimates can be imprecise then (no way of detecting compressed references, alignments, etc.). Lucene still tries to use sensible defaults.

measureSizeOf	back to summary
private static long measureSizeOf(ArrayList<Object> stack) Non-recursive version of object descend. This consumes more memory than recursive in-depth traversal but prevents stack overflows on long chains of objects or complex graphs (a max. recursion depth on my machine was ~5000 objects linked in a chain so not too much). Parameters stack:ArrayList<Object> Root objects.

measureSizeOf

back to summary

private static long measureSizeOf(ArrayList<Object> stack)

Non-recursive version of object descend. This consumes more memory than recursive in-depth traversal but prevents stack overflows on long chains of objects or complex graphs (a max. recursion depth on my machine was ~5000 objects linked in a chain so not too much).

Parameters

stack:ArrayList<Object>: Root objects.

shallowSizeOf	back to summary
public static long shallowSizeOf(Object obj) Estimates a "shallow" memory usage of the given object. For arrays, this will be the memory taken by array storage (no subreferences will be followed). For objects, this will be the memory taken by the fields. JVM object alignments are also applied.

shallowSizeOfAll	back to summary
public static long shallowSizeOfAll(Object... objects) Same as `shallowSizeOf(Object)` but sums up all the arguments. Not an overload to prevent accidental parameter conflicts with `shallowSizeOf(Object)`.

shallowSizeOfAll	back to summary
public static long shallowSizeOfAll(Iterable<Object> objects) Same as `shallowSizeOf(Object)` but sums up all the arguments. Duplicate objects are not resolved and will be counted twice. Not an overload to prevent accidental parameter conflicts with `shallowSizeOf(Object)`.

shallowSizeOfArray	back to summary
private static long shallowSizeOfArray(Object array) Return shallow size of any `array`.

shallowSizeOfInstance back to summary

shallowSizeOfInstance	back to summary
public static long shallowSizeOfInstance(Class<?> clazz) Returns the shallow instance size in bytes an instance of the given class would occupy. This works with all conventional classes and primitive types, but not with arrays (the size then depends on the number of elements and varies from object to object). Exceptions IllegalArgumentException: if `clazz` is an array class. See Also `shallowSizeOf(Object)`

public static long shallowSizeOfInstance(Class<?> clazz)

Returns the shallow instance size in bytes an instance of the given class would occupy. This works with all conventional classes and primitive types, but not with arrays (the size then depends on the number of elements and varies from object to object).

Exceptions

IllegalArgumentException:: if clazz is an array class.

See Also

shallowSizeOf(Object)

sizeOf	back to summary
public static long sizeOf(byte[] arr) Returns the size in bytes of the byte[] object.

sizeOf	back to summary
public static long sizeOf(boolean[] arr) Returns the size in bytes of the boolean[] object.

sizeOf	back to summary
public static long sizeOf(char[] arr) Returns the size in bytes of the char[] object.

sizeOf	back to summary
public static long sizeOf(short[] arr) Returns the size in bytes of the short[] object.

sizeOf	back to summary
public static long sizeOf(int[] arr) Returns the size in bytes of the int[] object.

sizeOf	back to summary
public static long sizeOf(float[] arr) Returns the size in bytes of the float[] object.

sizeOf	back to summary
public static long sizeOf(long[] arr) Returns the size in bytes of the long[] object.

sizeOf	back to summary
public static long sizeOf(double[] arr) Returns the size in bytes of the double[] object.

sizeOf	back to summary
public static long sizeOf(Object obj) Estimates the RAM usage by the given object. It will walk the object tree and sum up all referenced objects. Resource Usage: This method internally uses a set of every object seen during traversals so it does allocate memory (it isn't side-effect free). After the method exits, this memory should be GCed.

sizeOf

back to summary

public static long sizeOf(Object obj)

Estimates the RAM usage by the given object. It will walk the object tree and sum up all referenced objects.

Resource Usage: This method internally uses a set of every object seen during traversals so it does allocate memory (it isn't side-effect free). After the method exits, this memory should be GCed.

sizeOfAll	back to summary
public static long sizeOfAll(Object... objects) Same as `sizeOf(Object)` but sums up all the arguments. Not an overload to prevent accidental parameter conflicts with `sizeOf(Object)`.

sizeOfAll	back to summary
public static long sizeOfAll(Iterable<Object> objects) Same as `sizeOf(Object)` but sums up all the arguments. Not an overload to prevent accidental parameter conflicts with `sizeOf(Object)`.

com.carrotsearch.sizeof back to summary

private final Class RamUsageEstimator.ClassCache

Class Inheritance

extends Object

java.lang.Object
com.carrotsearch.sizeof.RamUsageEstimator.ClassCache

Cached information about a given class.

Field Summary

Modifier and Type	Field and Description
public final long	alignedShallowInstanceSize
public final Field[]	referenceFields

Constructor Summary

Access	Constructor and Description
public	ClassCache(long alignedShallowInstanceSize, Field[] referenceFields)

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

alignedShallowInstanceSize	back to summary
public final long alignedShallowInstanceSize

referenceFields	back to summary
public final Field[] referenceFields

Constructor Detail

ClassCache	back to summary
public ClassCache(long alignedShallowInstanceSize, Field[] referenceFields)

com.carrotsearch.sizeof back to summary

private final Class RamUsageEstimator.DummyOneFieldObject

Class Inheritance

extends Object

java.lang.Object
com.carrotsearch.sizeof.RamUsageEstimator.DummyOneFieldObject

Annotations

@SuppressWarnings:unused

Field Summary

Modifier and Type	Field and Description
public byte	base

Constructor Summary

Access	Constructor and Description
private	DummyOneFieldObject()

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

base	back to summary
public byte base

Constructor Detail

DummyOneFieldObject	back to summary
private DummyOneFieldObject()

com.carrotsearch.sizeof back to summary

private final Class RamUsageEstimator.DummyTwoLongObject

Class Inheritance

extends Object

java.lang.Object
com.carrotsearch.sizeof.RamUsageEstimator.DummyTwoLongObject

Annotations

@SuppressWarnings:unused

Field Summary

Modifier and Type	Field and Description
public long	dummy1
public long	dummy2

Constructor Summary

Access	Constructor and Description
private	DummyTwoLongObject()

Method Summary

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

dummy1	back to summary
public long dummy1

dummy2	back to summary
public long dummy2

Constructor Detail

DummyTwoLongObject	back to summary
private DummyTwoLongObject()

com.carrotsearch.sizeof back to summary

public final Enum RamUsageEstimator.JvmFeature

Class Inheritance

extends Enum<RamUsageEstimator.JvmFeature>

java.lang.Object
java.lang.Enum
com.carrotsearch.sizeof.RamUsageEstimator.JvmFeature

JVM diagnostic features.

Field Summary

Modifier and Type	Field and Description
public static final RamUsageEstimator.JvmFeature	ARRAY_HEADER_SIZE
public final String	description
public static final RamUsageEstimator.JvmFeature	FIELD_OFFSETS
public static final RamUsageEstimator.JvmFeature	OBJECT_ALIGNMENT
public static final RamUsageEstimator.JvmFeature	OBJECT_REFERENCE_SIZE

Constructor Summary

Access	Constructor and Description
private	JvmFeature(String description)

Method Summary

Modifier and Type	Method and Description
public String	toString() Overrides java.lang.Enum.toString. Returns the name of this enum constant, as contained in the declaration.
public static RamUsageEstimator.JvmFeature	valueOf(String name)
public static RamUsageEstimator.JvmFeature[]	values()

Inherited from java.lang.Enum:: clone compareTo describeConstable equals finalize getDeclaringClass hashCode name ordinal valueOf

Field Detail

ARRAY_HEADER_SIZE	back to summary
public static final RamUsageEstimator.JvmFeature ARRAY_HEADER_SIZE

description	back to summary
public final String description

FIELD_OFFSETS	back to summary
public static final RamUsageEstimator.JvmFeature FIELD_OFFSETS

OBJECT_ALIGNMENT	back to summary
public static final RamUsageEstimator.JvmFeature OBJECT_ALIGNMENT

OBJECT_REFERENCE_SIZE	back to summary
public static final RamUsageEstimator.JvmFeature OBJECT_REFERENCE_SIZE

Constructor Detail

JvmFeature	back to summary
private JvmFeature(String description)

Method Detail

toString

back to summary

public String toString()

Overrides java.lang.Enum.toString.

Doc from java.lang.Enum.toString.

Returns the name of this enum constant, as contained in the declaration. This method may be overridden, though it typically isn't necessary or desirable. An enum class should override this method when a more "programmer-friendly" string form exists.

Returns:String

the name of this enum constant

Annotations

@Override

valueOf	back to summary
public static RamUsageEstimator.JvmFeature valueOf(String name)

values	back to summary
public static RamUsageEstimator.JvmFeature[] values()

public final Class RamUsageEstimator

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class RamUsageEstimator.ClassCache

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

private final Class RamUsageEstimator.DummyOneFieldObject

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

private final Class RamUsageEstimator.DummyTwoLongObject

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

public final Enum RamUsageEstimator.JvmFeature

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail