Class CachedReturnPlugin

java.lang.Object

net.bytebuddy.build.Plugin.ForElementMatcher

net.bytebuddy.build.CachedReturnPlugin

All Implemented Interfaces:

Closeable, AutoCloseable, Plugin, Plugin.Factory, ElementMatcher<TypeDescription>

@Enhance
public class CachedReturnPlugin
extends Plugin.ForElementMatcher
implements Plugin.Factory

A plugin that caches the return value of a method in a synthetic field. The caching mechanism is not thread-safe but can be used in a concurrent setup if the cached value is frozen, i.e. only defines final fields. In this context, it is possible that the method is executed multiple times by different threads but at the same time, this approach avoids a volatile field declaration. For methods with a primitive return type, the type's default value is used to indicate that a method was not yet invoked. For methods that return a reference type, null is used as an indicator. If a method returns such a value, this mechanism will not work. This plugin does not need to be closed.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static enum	CachedReturnPlugin.AdviceResolver	A resolver for Advice that caches a method's return type.
protected static @interface	CachedReturnPlugin.CacheField	Indicates the field that stores the cached value.
protected static class	CachedReturnPlugin.CacheFieldOffsetMapping	An offset mapping for the cached field.
static @interface	CachedReturnPlugin.Enhance	Indicates methods that should be cached, i.e.

Nested classes/interfaces inherited from interface ElementMatcher

ElementMatcher.Junction<S>

Nested classes/interfaces inherited from interface Plugin

Plugin.Engine, Plugin.Factory, Plugin.ForElementMatcher, Plugin.NoOp, Plugin.WithInitialization, Plugin.WithPreprocessor

Nested classes/interfaces inherited from interface Plugin.Factory

Plugin.Factory.Simple, Plugin.Factory.UsingReflection

Field Summary

Fields

Modifier and Type	Field	Description
private static final MethodDescription.InDefinedShape	ENHANCE_VALUE	A description of the CachedReturnPlugin.Enhance.value() method.
private final boolean	ignoreExistingFields	true if existing fields should be ignored if the field name was explicitly given.
private static final String	NAME_INFIX	An infix between a field and the random suffix if no field name is chosen.
private final RandomString	randomString	A random string to use for avoid field name collisions.

Constructor Summary

Constructors

Constructor	Description
CachedReturnPlugin()	Creates a plugin for caching method return values.
CachedReturnPlugin(boolean ignoreExistingFields)	Creates a plugin for caching method return values.

Method Summary

Modifier and Type	Method	Description
DynamicType.Builder<?>	apply(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassFileLocator classFileLocator)	Applies this plugin.
void	close()
Plugin	make()	Returns a plugin that can be used for a transformation and which is subsequently closed.

Methods inherited from class Plugin.ForElementMatcher

matches

Methods inherited from class Object

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

Field Details

NAME_INFIX

private static final String NAME_INFIX

An infix between a field and the random suffix if no field name is chosen.

See Also:

• Constant Field Values

ENHANCE_VALUE

private static final MethodDescription.InDefinedShape ENHANCE_VALUE

A description of the CachedReturnPlugin.Enhance.value() method.

ignoreExistingFields

private final boolean ignoreExistingFields

true if existing fields should be ignored if the field name was explicitly given.

randomString

@ValueHandling(IGNORE)
private final RandomString randomString

A random string to use for avoid field name collisions.

Constructor Details

CachedReturnPlugin

public CachedReturnPlugin()

Creates a plugin for caching method return values. If a field name exists before applying this plugin, an exception is raised.

CachedReturnPlugin

public CachedReturnPlugin(boolean ignoreExistingFields)

Creates a plugin for caching method return values.

Parameters:

ignoreExistingFields - true if existing fields should be ignored if the field name was explicitly given.

Method Details

make

public Plugin make()

Returns a plugin that can be used for a transformation and which is subsequently closed.

Specified by:

make in interface Plugin.Factory

Returns:

The plugin to use for type transformations.

apply

public DynamicType.Builder<?> apply(DynamicType.Builder<?> builder,
 TypeDescription typeDescription,
 ClassFileLocator classFileLocator)

Applies this plugin.

Specified by:

apply in interface Plugin

Parameters:

builder - The builder to use as a basis for the applied transformation.

typeDescription - The type being transformed.

classFileLocator - A class file locator that can locate other types in the scope of the project.

Returns:

The supplied builder with additional transformations registered.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable