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 and Inner Type Summary

Modifier and Type	Class and Description
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.
public static @interface	CachedReturnPlugin.Enhance Indicates methods that should be cached, i.e. where the return value is stored in a synthetic field.

Field Summary

Modifier and Type	Field and Description
private static final String	ADVICE_INFIX The infix symbol for advice classes.
private final Map<TypeDescription, TypeDescription>	adviceByType A map of advice types mapped by their argument type.
private final ClassFileLocator	classFileLocator The class file locator to use.
private static final MethodDescription.InDefinedShape	ENHANCE_VALUE A description of the `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.

Access	Constructor and Description
public	CachedReturnPlugin() Creates a plugin for caching method return values.
public	CachedReturnPlugin(boolean `true` if existing fields should be ignored if the field name was explicitly given. ignoreExistingFields) Creates a plugin for caching method return values.

Method Summary

Modifier and Type	Method and Description
public DynamicType.Builder<?>	apply(DynamicType.Builder<?> The builder to use as a basis for the applied transformation. builder, TypeDescription The type being transformed. typeDescription, ClassFileLocator A class file locator that can locate other types in the scope of the project. classFileLocator) Implements net.bytebuddy.build.Plugin.apply. Applies this plugin.
public void	close() Implements java.io.Closeable.close. Closes this stream and releases any system resources associated with it.
public Plugin	make() Implements net.bytebuddy.build.Plugin.Factory.make. Returns a plugin that can be used for a transformation and which is subsequently closed.

Inherited from net.bytebuddy.build.Plugin.ForElementMatcher:: matches

Field Detail

ADVICE_INFIX	back to summary
private static final String ADVICE_INFIX The infix symbol for advice classes.

adviceByType	back to summary
private final Map<TypeDescription, TypeDescription> adviceByType A map of advice types mapped by their argument type. All advice types are precompiled using Java 6 to allow for releasing Byte Buddy with a Java 5 byte code level where compiled classes do not contain stack map frames. Byte Buddy filters stack map frames when applying advice in newer version but it cannot add stack map frames without explicit frame computation which is expensive which is why precompilation was used. To avoid loading Java classes in incompatible versions, all advice types are resolved using a type pool. Annotations @ValueHandling:IGNORE

adviceByType

back to summary

private final Map<TypeDescription, TypeDescription> adviceByType

A map of advice types mapped by their argument type. All advice types are precompiled using Java 6 to allow for releasing Byte Buddy with a Java 5 byte code level where compiled classes do not contain stack map frames. Byte Buddy filters stack map frames when applying advice in newer version but it cannot add stack map frames without explicit frame computation which is expensive which is why precompilation was used. To avoid loading Java classes in incompatible versions, all advice types are resolved using a type pool.

Annotations

@ValueHandling:IGNORE

classFileLocator	back to summary
private final ClassFileLocator classFileLocator The class file locator to use.

ENHANCE_VALUE	back to summary
private static final MethodDescription.InDefinedShape ENHANCE_VALUE A description of the `Enhance#value()` method.

ignoreExistingFields	back to summary
private final boolean ignoreExistingFields `true` if existing fields should be ignored if the field name was explicitly given.

NAME_INFIX	back to summary
private static final String NAME_INFIX An infix between a field and the random suffix if no field name is chosen.

randomString	back to summary
private final RandomString randomString A random string to use for avoid field name collisions. Annotations @ValueHandling:IGNORE

Constructor Detail

CachedReturnPlugin	back to summary
public CachedReturnPlugin() Creates a plugin for caching method return values. If a field name exists before applying this plugin, an exception is raised.

CachedReturnPlugin back to summary

CachedReturnPlugin	back to summary
public CachedReturnPlugin(boolean ignoreExistingFields) Creates a plugin for caching method return values. Parameters ignoreExistingFields:boolean `true` if existing fields should be ignored if the field name was explicitly given.

public CachedReturnPlugin(boolean ignoreExistingFields)

Creates a plugin for caching method return values.

Parameters

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

Method Detail

apply	back to summary
public DynamicType.Builder<?> apply(DynamicType.Builder<?> builder, TypeDescription typeDescription, ClassFileLocator classFileLocator) Implements net.bytebuddy.build.Plugin.apply. Doc from net.bytebuddy.build.Plugin.apply. Applies this plugin. Parameters builder:DynamicType.Builder<?> The builder to use as a basis for the applied transformation. typeDescription:TypeDescription The type being transformed. classFileLocator:ClassFileLocator A class file locator that can locate other types in the scope of the project. Returns:DynamicType.Builder<?> The supplied builder with additional transformations registered. Annotations @SuppressFBWarnings:NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE justification:Annotation presence is required by matcher.

apply

back to summary

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

Implements net.bytebuddy.build.Plugin.apply.

Doc from net.bytebuddy.build.Plugin.apply.

Applies this plugin.

Parameters

builder:DynamicType.Builder<?>: The builder to use as a basis for the applied transformation.
typeDescription:TypeDescription: The type being transformed.
classFileLocator:ClassFileLocator: A class file locator that can locate other types in the scope of the project.

Returns:DynamicType.Builder<?>

The supplied builder with additional transformations registered.

Annotations

@SuppressFBWarnings:NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE
justification:Annotation presence is required by matcher.

close back to summary

close	back to summary
public void close() Implements java.io.Closeable.close. Doc from java.io.Closeable.close. Closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect. As noted in `AutoCloseable#close()`, cases where the close may fail require careful attention. It is strongly advised to relinquish the underlying resources and to internally mark the `Closeable` as closed, prior to throwing the `IOException`.

public void close()

Implements java.io.Closeable.close.

Doc from java.io.Closeable.close.

Closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect.

As noted in AutoCloseable#close(), cases where the close may fail require careful attention. It is strongly advised to relinquish the underlying resources and to internally mark the Closeable as closed, prior to throwing the IOException.

make	back to summary
public Plugin make() Implements net.bytebuddy.build.Plugin.Factory.make. Doc from net.bytebuddy.build.Plugin.Factory.make. Returns a plugin that can be used for a transformation and which is subsequently closed. Returns:Plugin The plugin to use for type transformations.

make

back to summary

public Plugin make()

Implements net.bytebuddy.build.Plugin.Factory.make.

Doc from net.bytebuddy.build.Plugin.Factory.make.

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

Returns:Plugin: The plugin to use for type transformations.

net.bytebuddy.build back to summary

protected @Interface CachedReturnPlugin.CacheField

Annotations

extends Annotation

@Target:PARAMETER
@Retention:RUNTIME

Indicates the field that stores the cached value.

Method Summary

Inherited from java.lang.annotation.Annotation:: annotationType equals hashCode toString

net.bytebuddy.build back to summary

protected Class CachedReturnPlugin.CacheFieldOffsetMapping

Class Inheritance

extends Object
implements OffsetMapping

java.lang.Object
net.bytebuddy.build.CachedReturnPlugin.CacheFieldOffsetMapping

All Implemented Interfaces

net.bytebuddy.asm.Advice.OffsetMapping

Annotations

@Enhance

An offset mapping for the cached field.

Field Summary

Modifier and Type	Field and Description
private final String	name The field's name.

Constructor Summary

Access	Constructor and Description
protected	CacheFieldOffsetMapping(String The field's name. name) Creates an offset mapping for the cached field.

Method Summary

Modifier and Type	Method and Description
public Advice.OffsetMapping.Target	resolve(TypeDescription The instrumented type. instrumentedType, MethodDescription The instrumented method for which the mapping is to be resolved. instrumentedMethod, Assigner The assigner to use. assigner, Advice.ArgumentHandler The argument handler to use for resolving offsets of the local variable array of the instrumented method. argumentHandler, Advice.OffsetMapping.Sort The sort of the advice method being resolved. sort) Implements net.bytebuddy.asm.Advice.OffsetMapping.resolve. Resolves an offset mapping to a given target offset.

Modifier and Type

Method and Description

public Advice.OffsetMapping.Target

resolve(TypeDescription

The instrumented type.

instrumentedType, MethodDescription

The instrumented method for which the mapping is to be resolved.

instrumentedMethod, Assigner

The assigner to use.

assigner, Advice.ArgumentHandler

The argument handler to use for resolving offsets of the local variable array of the instrumented method.

argumentHandler, Advice.OffsetMapping.Sort

The sort of the advice method being resolved.

sort)

Implements net.bytebuddy.asm.Advice.OffsetMapping.resolve.

Resolves an offset mapping to a given target offset.

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

Field Detail

name	back to summary
private final String name The field's name.

Constructor Detail

CacheFieldOffsetMapping	back to summary
protected CacheFieldOffsetMapping(String name) Creates an offset mapping for the cached field. Parameters name:String The field's name.

CacheFieldOffsetMapping

back to summary

protected CacheFieldOffsetMapping(String name)

Creates an offset mapping for the cached field.

Parameters

name:String: The field's name.

Method Detail

resolve	back to summary
public Advice.OffsetMapping.Target resolve(TypeDescription instrumentedType, MethodDescription instrumentedMethod, Assigner assigner, Advice.ArgumentHandler argumentHandler, Advice.OffsetMapping.Sort sort) Implements net.bytebuddy.asm.Advice.OffsetMapping.resolve. Doc from net.bytebuddy.asm.Advice.OffsetMapping.resolve. Resolves an offset mapping to a given target offset. Parameters instrumentedType:TypeDescription The instrumented type. instrumentedMethod:MethodDescription The instrumented method for which the mapping is to be resolved. assigner:Assigner The assigner to use. argumentHandler:Advice.ArgumentHandler The argument handler to use for resolving offsets of the local variable array of the instrumented method. sort:Advice.OffsetMapping.Sort The sort of the advice method being resolved. Returns:Advice.OffsetMapping.Target A suitable target mapping.

resolve

back to summary

public Advice.OffsetMapping.Target resolve(TypeDescription instrumentedType, MethodDescription instrumentedMethod, Assigner assigner, Advice.ArgumentHandler argumentHandler, Advice.OffsetMapping.Sort sort)

Implements net.bytebuddy.asm.Advice.OffsetMapping.resolve.

Doc from net.bytebuddy.asm.Advice.OffsetMapping.resolve.

Resolves an offset mapping to a given target offset.

Parameters

instrumentedType:TypeDescription: The instrumented type.
instrumentedMethod:MethodDescription: The instrumented method for which the mapping is to be resolved.
assigner:Assigner: The assigner to use.
argumentHandler:Advice.ArgumentHandler: The argument handler to use for resolving offsets of the local variable array of the instrumented method.
sort:Advice.OffsetMapping.Sort: The sort of the advice method being resolved.

Returns:Advice.OffsetMapping.Target

A suitable target mapping.

net.bytebuddy.build back to summary

public @Interface CachedReturnPlugin.Enhance

Annotations

extends Annotation

@Documented
@Target:METHOD
@Retention:RUNTIME

Indicates methods that should be cached, i.e. where the return value is stored in a synthetic field. For this to be possible, the returned value should not be altered and the instance must be thread-safe if the value might be used from multiple threads.

Method Summary

Modifier and Type	Method and Description
public String	Returns: The fields name or an empty string if the name should be generated randomly. value() The fields name or an empty string if the name should be generated randomly.

Inherited from java.lang.annotation.Annotation:: annotationType equals hashCode toString

Method Detail

value	back to summary
public String value() The fields name or an empty string if the name should be generated randomly. Returns:String The fields name or an empty string if the name should be generated randomly.

value

back to summary

public String value()

The fields name or an empty string if the name should be generated randomly.

Returns:String: The fields name or an empty string if the name should be generated randomly.

public Class CachedReturnPlugin

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

protected @Interface CachedReturnPlugin.CacheField

Method Summary

protected Class CachedReturnPlugin.CacheFieldOffsetMapping

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public @Interface CachedReturnPlugin.Enhance

Method Summary

Method Detail