MemoryLayoutBasedStrategy (Java Agent for Memory Measurements 0.4.0 API)

java.lang.Object
- org.github.jamm.strategies.MemoryLayoutBasedStrategy

All Implemented Interfaces:

MemoryMeterStrategy

Direct Known Subclasses:

InstrumentationAndSpecStrategy, UnsafeStrategy
```
public abstract class MemoryLayoutBasedStrategy
extends Object
implements MemoryMeterStrategy
```
Base class for strategies that need access to the MemoryLayoutSpecification for computing object size.

Field Summary
- Fields inherited from interface org.github.jamm.MemoryMeterStrategy
  MEMORY_LAYOUT

Constructor Summary

Constructors
Constructor and Description

MemoryLayoutBasedStrategy()

Constructors
Constructor and Description
`MemoryLayoutBasedStrategy()`

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`protected int`	`arrayBaseOffset()` Returns the array base offset.
`long`	`computeArraySize(int length, int elementSize)` Computes the size of an array from its length and elementSize.
`long`	`measure(Object object)` Measures the shallow memory used by the specified object.
`long`	`measureArray(boolean[] array)` Measures the shallow memory used by the specified boolean array.
`long`	`measureArray(byte[] array)` Measures the shallow memory used by the specified byte array.
`long`	`measureArray(char[] array)` Measures the shallow memory used by the specified char array.
`long`	`measureArray(double[] array)` Measures the shallow memory used by the specified double array.
`long`	`measureArray(float[] array)` Measures the shallow memory used by the specified float array.
`long`	`measureArray(int[] array)` Measures the shallow memory used by the specified int array.
`long`	`measureArray(long[] array)` Measures the shallow memory used by the specified long array.
`long`	`measureArray(Object[] array)` Measures the shallow memory used by the specified array.
`long`	`measureArray(Object instance, Class<?> type)` Measure the shallow memory used by the specified array.
`long`	`measureArray(short[] array)` Measures the shallow memory used by the specified short array.
`protected int`	`measureField(Class<?> type)` Returns the size of a field of the specified type.
`protected abstract long`	`measureInstance(Object instance, Class<?> type)` Measures the shallow memory used by objects of the specified class.
`boolean`	`supportComputeArraySize()` Checks if this instance supports the `computeArraySize` operation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MemoryLayoutBasedStrategy
```
public MemoryLayoutBasedStrategy()
```
- Method Detail
  - measure
```
public final long measure(Object object)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified object.
    
    Specified by:
    
    measure in interface MemoryMeterStrategy
    
    Parameters:
    
    object - the object to measure
    
    Returns:
    
    the shallow memory usage of the specified object
  - measureArray
```
public long measureArray(Object[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the array to measure
    
    Returns:
    
    the shallow memory used by the specified array.
  - measureArray
```
public long measureArray(byte[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified byte array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the array to measure
    
    Returns:
    
    the shallow memory used by the specified byte array.
  - measureArray
```
public long measureArray(boolean[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified boolean array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the boolean array to measure
    
    Returns:
    
    the shallow memory used by the specified boolean array.
  - measureArray
```
public long measureArray(short[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified short array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the short array to measure
    
    Returns:
    
    the shallow memory used by the specified short array.
  - measureArray
```
public long measureArray(char[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified char array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the char array to measure
    
    Returns:
    
    the shallow memory used by the specified char array.
  - measureArray
```
public long measureArray(int[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified int array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the int array to measure
    
    Returns:
    
    the shallow memory used by the specified int array.
  - measureArray
```
public long measureArray(float[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified float array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the float array to measure
    
    Returns:
    
    the shallow memory used by the specified float array.
  - measureArray
```
public long measureArray(long[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified long array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the long array to measure
    
    Returns:
    
    the shallow memory used by the specified long array.
  - measureArray
```
public long measureArray(double[] array)
```
    Description copied from interface: MemoryMeterStrategy
    
    Measures the shallow memory used by the specified double array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    array - the long array to measure
    
    Returns:
    
    the shallow memory used by the specified double array.
  - measureInstance
```
protected abstract long measureInstance(Object instance,
                                        Class<?> type)
```
    Measures the shallow memory used by objects of the specified class.
    
    Parameters:
    
    instance - the object to measure
    
    type - the object type
    
    Returns:
    
    the shallow memory used by the object
  - measureArray
```
public final long measureArray(Object instance,
                               Class<?> type)
```
    Measure the shallow memory used by the specified array.
    
    Specified by:
    
    measureArray in interface MemoryMeterStrategy
    
    Parameters:
    
    instance - the array instance
    
    type - the array type
    
    Returns:
    
    the shallow memory used by the specified array
  - supportComputeArraySize
```
public boolean supportComputeArraySize()
```
    Description copied from interface: MemoryMeterStrategy
    
    Checks if this instance supports the computeArraySize operation.
    
    Specified by:
    
    supportComputeArraySize in interface MemoryMeterStrategy
    
    Returns:
    
    true if this instance support the computeArraySize operation, false otherwise.
  - arrayBaseOffset
```
protected int arrayBaseOffset()
```
    Returns the array base offset.
    Array base is aligned based on heap word. It is not visible by default as compressed references are used and the header size is 16 but becomes visible when they are disabled.
    
    Returns:
    
    the array base offset.
  - computeArraySize
```
public long computeArraySize(int length,
                             int elementSize)
```
    Computes the size of an array from its length and elementSize.
    
    Specified by:
    
    computeArraySize in interface MemoryMeterStrategy
    
    Parameters:
    
    length - the array length
    
    elementSize - the size of the array elements
    
    Returns:
    
    the size of the array
  - measureField
```
protected final int measureField(Class<?> type)
```
    Returns the size of a field of the specified type.
    
    Parameters:
    
    type - the field type
    
    Returns:
    
    The memory size of a field of a class of the provided type; for Objects this is the size of the reference only

Class MemoryLayoutBasedStrategy

Field Summary

Fields inherited from interface org.github.jamm.MemoryMeterStrategy

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MemoryLayoutBasedStrategy

Method Detail

measure

measureArray

measureArray

measureArray

measureArray

measureArray

measureArray

measureArray

measureArray

measureArray

measureInstance

measureArray

supportComputeArraySize

arrayBaseOffset

computeArraySize

measureField