Class ClassCopyProvider<T>

java.lang.Object

net.imglib2.loops.ClassCopyProvider<T>

public class ClassCopyProvider<T>
extends Object

Helper to create multiple copies of a class.

The copies of the class have individual copies of the byte code. The JIT compiler optimizes the class copies individually, which can increase performance.

Field Summary

Fields

Modifier and Type	Field	Description
private final ClassCopier<T>	copier
private final Map<Object, Class<? extends T>>	map
private final Class<?>[]	signature

Constructor Summary

Constructors

Constructor	Description
ClassCopyProvider(Class<? extends T> clazz, Class<T> interfaceOfClazz, Class<?>... constructorSignature)	Create a ClassCopyProvider to make copy a a given class.

Method Summary

Modifier and Type	Method	Description
private static Class<?>[]	assumeConstructorSignature(Class<?> clazz)
private Class<? extends T>	classForKey(Object key)
private static boolean	hasDefaultConstructor(Class<?> clazz)
boolean	matches(Object... parameters)	Returns true if the given list of objects, matches the constructor signature provided to ClassCopyProvider(Class, Class, Class[]).
T	newInstanceForKey(Object key, Object... parameters)	Returns an instance of a copy of the original class, that has been provided to the constructor.

Methods inherited from class Object

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

Field Details

map

private final Map<Object, Class<? extends T>> map

copier

private final ClassCopier<T> copier

signature

private final Class<?>[] signature

Constructor Details

ClassCopyProvider

public ClassCopyProvider(Class<? extends T> clazz,
 Class<T> interfaceOfClazz,
 Class<?>... constructorSignature)

Create a ClassCopyProvider to make copy a a given class.

Parameters:

clazz - Class to be copied.

interfaceOfClazz - Interface that's implemented by the clazz. A class copies can only be used through this interface.

constructorSignature - Constructor signature to be used when creating a new instance with newInstanceForKey(Object, Object...)

Method Details

assumeConstructorSignature

private static Class<?>[] assumeConstructorSignature(Class<?> clazz)

hasDefaultConstructor

private static boolean hasDefaultConstructor(Class<?> clazz)

classForKey

private Class<? extends T> classForKey(Object key)

matches

public boolean matches(Object... parameters)

Returns true if the given list of objects, matches the constructor signature provided to ClassCopyProvider(Class, Class, Class[]).

newInstanceForKey

public T newInstanceForKey(Object key,
 Object... parameters)

Returns an instance of a copy of the original class, that has been provided to the constructor.

Note: The returned object isn't an instance of the original class. Class.isInstance(Object) and "instanceof" will return false. And ClassCastException might occur if this is ignored.

The returned instance has a copy of the byte code of the original class. This byte code is independently optimised by the JIT compiler. The JIT compiler will optimise the byte code, if it's only used in a specific use case. If used wisely a performance increase is the consequence.

Parameters:

key - Instances created with the same key, share their byte code.

parameters - Parameters that are passed to the constructor.