net.bytebuddy.implementation.Implementation Maven / Gradle / Ivy
package net.bytebuddy.implementation;
import net.bytebuddy.ClassFileVersion;
import net.bytebuddy.description.field.FieldDescription;
import net.bytebuddy.description.method.MethodDescription;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.dynamic.scaffold.BridgeMethodResolver;
import net.bytebuddy.dynamic.scaffold.InstrumentedType;
import net.bytebuddy.dynamic.scaffold.MethodLookupEngine;
import net.bytebuddy.dynamic.scaffold.TypeWriter;
import net.bytebuddy.implementation.attribute.MethodAttributeAppender;
import net.bytebuddy.implementation.auxiliary.AuxiliaryType;
import net.bytebuddy.implementation.bytecode.ByteCodeAppender;
import net.bytebuddy.implementation.bytecode.StackManipulation;
import net.bytebuddy.implementation.bytecode.member.FieldAccess;
import net.bytebuddy.implementation.bytecode.member.MethodInvocation;
import net.bytebuddy.implementation.bytecode.member.MethodReturn;
import net.bytebuddy.implementation.bytecode.member.MethodVariableAccess;
import net.bytebuddy.utility.RandomString;
import net.bytebuddy.jar.asm.ClassVisitor;
import net.bytebuddy.jar.asm.MethodVisitor;
import net.bytebuddy.jar.asm.Opcodes;
import java.util.*;
/**
* An implementation is responsible for implementing methods of a dynamically created type as byte code. An
* implementation is applied in two stages:
*
* - The implementation is able to prepare an instrumented type by adding fields and/or helper methods that are
* required for the methods implemented by this implementation. Furthermore,
* {@link LoadedTypeInitializer}s and byte code for the type initializer can be registered for the instrumented
* type.
* - Any implementation is required to supply a byte code appender that is responsible for providing the byte code
* to the instrumented methods that were delegated to this implementation. This byte code appender is also
* be responsible for providing implementations for the methods added in step 1.
*
*
* An implementation should provide meaningful implementations of both {@link java.lang.Object#equals(Object)}
* and {@link Object#hashCode()} if it wants to avoid to be used twice within the creation of a dynamic type. For two
* equal implementations only one will be applied on the creation of a dynamic type.
*/
public interface Implementation {
/**
* During the preparation phase of an implementation, implementations are eligible to adding fields or methods
* to the currently instrumented type. All methods that are added by this implementation are required to be
* implemented by the {@link net.bytebuddy.implementation.bytecode.ByteCodeAppender} that is emitted
* on the call to
* {@link Implementation#appender(Implementation.Target)}
* call. On this method call, loaded type initializers can also be added to the instrumented type.
*
* @param instrumentedType The instrumented type that is the basis of the ongoing instrumentation.
* @return The instrumented type with any applied changes, if any.
*/
InstrumentedType prepare(InstrumentedType instrumentedType);
/**
* Creates a byte code appender that determines the implementation of the instrumented type's methods.
*
* @param implementationTarget The target of the current implementation.
* @return A byte code appender for implementing methods delegated to this implementation. This byte code appender
* is also responsible for handling methods that were added by this implementation on the call to
* {@link Implementation#prepare(InstrumentedType)}.
*/
ByteCodeAppender appender(Target implementationTarget);
/**
* Represents an type-specific method invocation on the current instrumented type which is not legal from outside
* the type such as a super method or default method invocation. Legal instances of special method invocations must
* be equal to one another if they represent the same invocation target.
*/
interface SpecialMethodInvocation extends StackManipulation {
/**
* Returns the method that represents this special method invocation. This method can be different even for
* equal special method invocations, dependant on the method that was used to request such an invocation by the
* means of a {@link Implementation.Target}.
*
* @return The method description that describes this instances invocation target.
*/
MethodDescription getMethodDescription();
/**
* Returns the target type the represented method is invoked on.
*
* @return The type the represented method is invoked on.
*/
TypeDescription getTypeDescription();
/**
* A canonical implementation of an illegal {@link Implementation.SpecialMethodInvocation}.
*/
enum Illegal implements SpecialMethodInvocation {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public boolean isValid() {
return false;
}
@Override
public Size apply(MethodVisitor methodVisitor, Context implementationContext) {
throw new IllegalStateException("Cannot implement an undefined method");
}
@Override
public MethodDescription getMethodDescription() {
throw new IllegalStateException("An illegal special method invocation must not be applied");
}
@Override
public TypeDescription getTypeDescription() {
throw new IllegalStateException("An illegal special method invocation must not be applied");
}
@Override
public String toString() {
return "Implementation.SpecialMethodInvocation.Illegal." + name();
}
}
/**
* A canonical implementation of a {@link Implementation.SpecialMethodInvocation}.
*/
class Simple implements SpecialMethodInvocation {
/**
* The method description that is represented by this legal special method invocation.
*/
private final MethodDescription methodDescription;
/**
* The type description that is represented by this legal special method invocation.
*/
private final TypeDescription typeDescription;
/**
* A stack manipulation representing the method's invocation on the type description.
*/
private final StackManipulation stackManipulation;
/**
* Creates a new legal special method invocation.
*
* @param methodDescription The method that represents the special method invocation.
* @param typeDescription The type on which the method should be invoked on by an {@code INVOKESPECIAL}
* invocation.
* @param stackManipulation The stack manipulation that represents this special method invocation.
*/
protected Simple(MethodDescription methodDescription,
TypeDescription typeDescription,
StackManipulation stackManipulation) {
this.methodDescription = methodDescription;
this.typeDescription = typeDescription;
this.stackManipulation = stackManipulation;
}
/**
* Creates a special method invocation for a given invocation target.
*
* @param methodDescription The method that represents the special method invocation.
* @param typeDescription The type on which the method should be invoked on by an {@code INVOKESPECIAL}
* invocation.
* @return A special method invocation representing a legal invocation if the method can be invoked
* specially on the target type or an illegal invocation if this is not possible.
*/
public static SpecialMethodInvocation of(MethodDescription methodDescription,
TypeDescription typeDescription) {
StackManipulation stackManipulation = MethodInvocation.invoke(methodDescription).special(typeDescription);
return stackManipulation.isValid() && !methodDescription.isAbstract()
? new Simple(methodDescription, typeDescription, stackManipulation)
: SpecialMethodInvocation.Illegal.INSTANCE;
}
@Override
public MethodDescription getMethodDescription() {
return methodDescription;
}
@Override
public TypeDescription getTypeDescription() {
return typeDescription;
}
@Override
public boolean isValid() {
return stackManipulation.isValid();
}
@Override
public Size apply(MethodVisitor methodVisitor, Context implementationContext) {
return stackManipulation.apply(methodVisitor, implementationContext);
}
@Override
public boolean equals(Object other) {
if (this == other) return true;
if (!(other instanceof SpecialMethodInvocation)) return false;
SpecialMethodInvocation specialMethodInvocation = (SpecialMethodInvocation) other;
return isValid() == specialMethodInvocation.isValid()
&& typeDescription.equals(specialMethodInvocation.getTypeDescription())
&& methodDescription.getInternalName().equals(specialMethodInvocation.getMethodDescription().getInternalName())
&& methodDescription.getParameters().asTypeList().equals(specialMethodInvocation.getMethodDescription().getParameters().asTypeList())
&& methodDescription.getReturnType().equals(specialMethodInvocation.getMethodDescription().getReturnType());
}
@Override
public int hashCode() {
int result = methodDescription.getInternalName().hashCode();
result = 31 * result + methodDescription.getParameters().asTypeList().hashCode();
result = 31 * result + methodDescription.getReturnType().hashCode();
result = 31 * result + typeDescription.hashCode();
return result;
}
@Override
public String toString() {
return "Instrumentation.SpecialMethodInvocation.Simple{" +
"typeDescription=" + typeDescription +
", methodDescription=" + methodDescription +
'}';
}
}
}
/**
* The target of an implementation. Implementation targets must be immutable and can be queried without altering
* the implementation result. An implementation target provides information on the type that is to be created
* where it is the implementation's responsibility to cache expensive computations, especially such computations
* that require reflective look-up.
*/
interface Target {
/**
* Returns a description of the instrumented type.
*
* @return A description of the instrumented type.
*/
TypeDescription getTypeDescription();
/**
* Identifies the origin type of an implementation. The origin type describes the type that is subject to
* any form of enhancement. If a subclass of a given type is generated, the base type of this subclass
* describes the origin type. If a given type is redefined or rebased, the origin type is described by the
* instrumented type itself.
*
* @return The origin type of this implementation.
*/
TypeDescription getOriginType();
/**
* Creates a special method invocation for invoking the super method of the given method.
*
* @param methodDescription The method that is to be invoked specially.
* @param methodLookup The lookup for this method which mainly serves to avoid bridge method invocation.
* @return The corresponding special method invocation which might be illegal if the requested invocation is
* not legal.
*/
SpecialMethodInvocation invokeSuper(MethodDescription methodDescription, MethodLookup methodLookup);
/**
* Creates a special method invocation for invoking a default method.
*
* @param targetType The interface on which the default method is to be invoked.
* @param uniqueMethodSignature The unique method signature as defined by
* {@link MethodDescription#getUniqueSignature()}
* of the method that is to be invoked.
* @return The corresponding special method invocation which might be illegal if the requested invocation is
* not legal.
*/
SpecialMethodInvocation invokeDefault(TypeDescription targetType, String uniqueMethodSignature);
/**
* A strategy for looking up a method.
*/
interface MethodLookup {
/**
* Resolves the target method that is actually invoked.
*
* @param methodDescription The method that is to be invoked specially.
* @param invokableMethods A map of all invokable methods on the instrumented type.
* @param bridgeMethodResolver The bridge method resolver for this type.
* @return The target method that is actually invoked.
*/
MethodDescription resolve(MethodDescription methodDescription,
Map invokableMethods,
BridgeMethodResolver bridgeMethodResolver);
/**
* Default implementations of a {@link Implementation.Target.MethodLookup}.
*/
enum Default implements MethodLookup {
/**
* An exact method lookup which directly invokes the given method.
*/
EXACT {
@Override
public MethodDescription resolve(MethodDescription methodDescription,
Map invokableMethods,
BridgeMethodResolver bridgeMethodResolver) {
return methodDescription;
}
},
/**
* Looks up a most specific method by a method signature. All bridge methods are resolved by this
* lookup.
*/
MOST_SPECIFIC {
@Override
public MethodDescription resolve(MethodDescription methodDescription,
Map invokableMethods,
BridgeMethodResolver bridgeMethodResolver) {
return bridgeMethodResolver.resolve(invokableMethods.get(methodDescription.getUniqueSignature()));
}
};
@Override
public String toString() {
return "Implementation.Target.MethodLookup.Default." + name();
}
}
}
/**
* A factory for creating an {@link Implementation.Target}.
*/
interface Factory {
/**
* Creates a new implementation target.
*
* @param finding The analyzed instrumented type.
* @param instrumentedMethods A list of all methods that are to be instrumented.
* @return A suitable implementation target.
*/
Target make(MethodLookupEngine.Finding finding, List instrumentedMethods);
}
/**
* An abstract base implementation for an {@link Implementation.Target}.
*/
abstract class AbstractBase implements Target {
/**
* The type that is subject to instrumentation.
*/
protected final TypeDescription typeDescription;
/**
* A map of invokable methods by their unique signature.
*/
protected final Map invokableMethods;
/**
* A map of default methods by their unique signature.
*/
protected final Map> defaultMethods;
/**
* A bridge method resolver for the given instrumented type.
*/
protected final BridgeMethodResolver bridgeMethodResolver;
/**
* Creates a new implementation target.
*
* @param finding A finding of a {@link MethodLookupEngine}
* for the instrumented type.
* @param bridgeMethodResolverFactory A factory for creating a
* {@link net.bytebuddy.dynamic.scaffold.BridgeMethodResolver}.
*/
protected AbstractBase(MethodLookupEngine.Finding finding,
BridgeMethodResolver.Factory bridgeMethodResolverFactory) {
bridgeMethodResolver = bridgeMethodResolverFactory.make(finding.getInvokableMethods());
typeDescription = finding.getTypeDescription();
invokableMethods = new HashMap(finding.getInvokableMethods().size());
for (MethodDescription methodDescription : finding.getInvokableMethods()) {
invokableMethods.put(methodDescription.getUniqueSignature(), methodDescription);
}
defaultMethods = new HashMap>(finding.getInvokableDefaultMethods().size());
for (Map.Entry> entry : finding.getInvokableDefaultMethods().entrySet()) {
Map defaultMethods = new HashMap(entry.getValue().size());
for (MethodDescription methodDescription : entry.getValue()) {
defaultMethods.put(methodDescription.getUniqueSignature(), methodDescription);
}
this.defaultMethods.put(entry.getKey(), defaultMethods);
}
}
@Override
public TypeDescription getTypeDescription() {
return typeDescription;
}
@Override
public Implementation.SpecialMethodInvocation invokeSuper(MethodDescription methodDescription,
MethodLookup methodLookup) {
return invokeSuper(methodLookup.resolve(methodDescription, invokableMethods, bridgeMethodResolver));
}
/**
* Invokes the fully resolved method to be invoked by a super method call.
*
* @param methodDescription The method that is to be invoked specially.
* @return A special method invocation for calling the super method.
*/
protected abstract Implementation.SpecialMethodInvocation invokeSuper(MethodDescription methodDescription);
@Override
public Implementation.SpecialMethodInvocation invokeDefault(TypeDescription targetType,
String uniqueMethodSignature) {
Map defaultMethods = this.defaultMethods.get(targetType);
if (defaultMethods != null) {
MethodDescription defaultMethod = defaultMethods.get(uniqueMethodSignature);
if (defaultMethod != null) {
return SpecialMethodInvocation.Simple.of(defaultMethod, targetType);
}
}
return Implementation.SpecialMethodInvocation.Illegal.INSTANCE;
}
@Override
public boolean equals(Object other) {
if (this == other) return true;
if (other == null || getClass() != other.getClass()) return false;
AbstractBase that = (AbstractBase) other;
return bridgeMethodResolver.equals(that.bridgeMethodResolver)
&& defaultMethods.equals(that.defaultMethods)
&& typeDescription.equals(that.typeDescription);
}
@Override
public int hashCode() {
int result = typeDescription.hashCode();
result = 31 * result + defaultMethods.hashCode();
result = 31 * result + bridgeMethodResolver.hashCode();
return result;
}
}
}
/**
* The context for an implementation application. An implementation context represents a mutable data structure
* where any registration is irrevocable. Calling methods on an implementation context should be considered equally
* sensitive as calling a {@link net.bytebuddy.jar.asm.MethodVisitor}. As such, an implementation context and a
* {@link net.bytebuddy.jar.asm.MethodVisitor} are complementary for creating an new Java type.
*/
interface Context {
/**
* Registers an auxiliary type as required for the current implementation. Registering a type will cause the
* creation of this type even if this type is not effectively used for the current implementation.
*
* @param auxiliaryType The auxiliary type that is required for the current implementation.
* @return A description of the registered auxiliary type.
*/
TypeDescription register(AuxiliaryType auxiliaryType);
/**
* Caches a single value by storing it in form of a {@code private}, {@code final} and {@code static} field.
* By caching values, expensive instance creations can be avoided and object identity can be preserved.
* The field is initiated in a generated class's static initializer.
*
* @param fieldValue A stack manipulation for creating the value that is to be cached in a {@code static} field.
* After executing the stack manipulation, exactly one value must be put onto the operand
* stack which is assignable to the given {@code fieldType}.
* @param fieldType The type of the field for storing the cached value. This field's type determines the value
* that is put onto the operand stack by this method's returned stack manipulation.
* @return A description of a field that was defined on the instrumented type which contains the given value.
*/
FieldDescription cache(StackManipulation fieldValue, TypeDescription fieldType);
/**
* Represents an extractable view of an {@link Implementation.Context} which
* allows the retrieval of any registered auxiliary type.
*/
interface ExtractableView extends Context {
/**
* A default modifier for a field that serves as a cache.
*/
int FIELD_CACHE_MODIFIER = Opcodes.ACC_SYNTHETIC | Opcodes.ACC_FINAL | Opcodes.ACC_STATIC;
/**
* Returns any {@link net.bytebuddy.implementation.auxiliary.AuxiliaryType} that was registered
* with this {@link Implementation.Context}.
*
* @return A list of all manifested registered auxiliary types.
*/
List getRegisteredAuxiliaryTypes();
/**
* Writes any information that was registered with an {@link Implementation.Context}
* to the provided class visitor. This contains any fields for value caching, any accessor method and it
* writes the type initializer. The type initializer must therefore never be written manually.
*
* @param classVisitor The class visitor to which the extractable view is to be written.
* @param methodPool A method pool which is queried for any user code to add to the type initializer.
* @param injectedCode Potential code that is to be injected into the type initializer.
*/
void drain(ClassVisitor classVisitor, TypeWriter.MethodPool methodPool, InjectedCode injectedCode);
/**
* When draining an implementation context, a type initializer might be written to the created class
* file. If any code must be explicitly invoked from within the type initializer, this can be achieved
* by providing a code injection by this instance. The injected code is added after the class is set up but
* before any user code is run from within the type initializer.
*/
interface InjectedCode {
/**
* Returns a byte code appender for appending the injected code.
*
* @return A byte code appender for appending the injected code.
*/
ByteCodeAppender getByteCodeAppender();
/**
* Checks if there is actually code defined to be injected.
*
* @return {@code true} if code is to be injected.
*/
boolean isDefined();
/**
* A canonical implementation of non-applicable injected code.
*/
enum None implements InjectedCode {
/**
* The singleton instance.
*/
INSTANCE;
@Override
public ByteCodeAppender getByteCodeAppender() {
throw new IllegalStateException();
}
@Override
public boolean isDefined() {
return false;
}
@Override
public String toString() {
return "Implementation.Context.ExtractableView.InjectedCode.None." + name();
}
}
}
}
/**
* A default implementation of an {@link Implementation.Context.ExtractableView}
* which serves as its own {@link net.bytebuddy.implementation.auxiliary.AuxiliaryType.MethodAccessorFactory}.
*/
class Default implements Implementation.Context.ExtractableView, AuxiliaryType.MethodAccessorFactory {
/**
* The name suffix to be appended to an accessor method.
*/
public static final String ACCESSOR_METHOD_SUFFIX = "accessor";
/**
* The name prefix to be prepended to a field storing a cached value.
*/
public static final String FIELD_CACHE_PREFIX = "cachedValue";
/**
* Indicates that a field should be defined without a default value.
*/
private static final Object NO_DEFAULT_VALUE = null;
/**
* The instrumented type that this instance represents.
*/
private final TypeDescription instrumentedType;
/**
* The type initializer of the created instrumented type.
*/
private final InstrumentedType.TypeInitializer typeInitializer;
/**
* The class file version that the instrumented type is written in.
*/
private final ClassFileVersion classFileVersion;
/**
* The naming strategy for naming auxiliary types that are registered.
*/
private final AuxiliaryType.NamingStrategy auxiliaryTypeNamingStrategy;
/**
* A mapping of special method invocations to their accessor methods that each invoke their mapped invocation.
*/
private final Map registeredAccessorMethods;
/**
* The registered getters.
*/
private final Map registeredGetters;
/**
* The registered setters.
*/
private final Map registeredSetters;
/**
* A map of accessor methods to a method pool entry that represents their implementation.
*/
private final Map accessorMethodEntries;
/**
* A map of registered auxiliary types to their dynamic type representation.
*/
private final Map auxiliaryTypes;
/**
* A map of already registered field caches to their field representation.
*/
private final Map registeredFieldCacheEntries;
/**
* An instance for supporting the creation of random values.
*/
private final RandomString randomString;
/**
* Signals if this type extension delegate is still capable of registering field cache entries. Such entries
* must be explicitly initialized in the instrumented type's type initializer such that no entries can be
* registered after the type initializer was written.
*/
private boolean canRegisterFieldCache;
/**
* Creates a new implementation context.
*
* @param instrumentedType The description of the type that is currently subject of creation.
* @param auxiliaryTypeNamingStrategy The naming strategy for naming an auxiliary type.
* @param typeInitializer The type initializer of the created instrumented type.
* @param classFileVersion The class file version of the created class.
*/
public Default(TypeDescription instrumentedType,
AuxiliaryType.NamingStrategy auxiliaryTypeNamingStrategy,
InstrumentedType.TypeInitializer typeInitializer,
ClassFileVersion classFileVersion) {
this.instrumentedType = instrumentedType;
this.auxiliaryTypeNamingStrategy = auxiliaryTypeNamingStrategy;
this.typeInitializer = typeInitializer;
this.classFileVersion = classFileVersion;
registeredAccessorMethods = new HashMap();
registeredGetters = new HashMap();
registeredSetters = new HashMap();
accessorMethodEntries = new HashMap();
auxiliaryTypes = new HashMap();
registeredFieldCacheEntries = new HashMap();
randomString = new RandomString();
canRegisterFieldCache = true;
}
@Override
public MethodDescription registerAccessorFor(Implementation.SpecialMethodInvocation specialMethodInvocation) {
MethodDescription accessorMethod = registeredAccessorMethods.get(specialMethodInvocation);
if (accessorMethod == null) {
String name = String.format("%s$%s$%s", specialMethodInvocation.getMethodDescription().getInternalName(),
ACCESSOR_METHOD_SUFFIX,
randomString.nextString());
accessorMethod = new MethodDescription.Latent(name,
instrumentedType,
specialMethodInvocation.getMethodDescription().getReturnType(),
specialMethodInvocation.getMethodDescription().getParameters().asTypeList(),
resolveModifier(specialMethodInvocation.getMethodDescription().isStatic()),
specialMethodInvocation.getMethodDescription().getExceptionTypes());
registerAccessor(specialMethodInvocation, accessorMethod);
}
return accessorMethod;
}
/**
* Resolves the modifier for an accessor method.
*
* @param isStatic {@code true} if the accessor method is supposed to be static.
* @return The modifier for the method.
*/
private int resolveModifier(boolean isStatic) {
return ACCESSOR_METHOD_MODIFIER | (isStatic ? Opcodes.ACC_STATIC : 0);
}
/**
* Registers a new accessor method.
*
* @param specialMethodInvocation The special method invocation that the accessor method should invoke.
* @param accessorMethod The accessor method for this invocation.
*/
private void registerAccessor(Implementation.SpecialMethodInvocation specialMethodInvocation, MethodDescription accessorMethod) {
registeredAccessorMethods.put(specialMethodInvocation, accessorMethod);
accessorMethodEntries.put(accessorMethod, new AccessorMethodDelegation(specialMethodInvocation));
}
@Override
public MethodDescription registerGetterFor(FieldDescription fieldDescription) {
MethodDescription accessorMethod = registeredGetters.get(fieldDescription);
if (accessorMethod == null) {
String name = String.format("%s$%s$%s", fieldDescription.getName(),
ACCESSOR_METHOD_SUFFIX,
randomString.nextString());
accessorMethod = new MethodDescription.Latent(name,
instrumentedType,
fieldDescription.getFieldType(),
Collections.emptyList(),
resolveModifier(fieldDescription.isStatic()),
Collections.emptyList());
registerGetter(fieldDescription, accessorMethod);
}
return accessorMethod;
}
/**
* Registers a new getter method.
*
* @param fieldDescription The field to read.
* @param accessorMethod The accessor method for this field.
*/
private void registerGetter(FieldDescription fieldDescription, MethodDescription accessorMethod) {
registeredGetters.put(fieldDescription, accessorMethod);
accessorMethodEntries.put(accessorMethod, new FieldGetter(fieldDescription));
}
@Override
public MethodDescription registerSetterFor(FieldDescription fieldDescription) {
MethodDescription accessorMethod = registeredSetters.get(fieldDescription);
if (accessorMethod == null) {
String name = String.format("%s$%s$%s", fieldDescription.getName(),
ACCESSOR_METHOD_SUFFIX,
randomString.nextString());
accessorMethod = new MethodDescription.Latent(name,
instrumentedType,
TypeDescription.VOID,
Collections.singletonList(fieldDescription.getFieldType()),
resolveModifier(fieldDescription.isStatic()),
Collections.emptyList());
registerSetter(fieldDescription, accessorMethod);
}
return accessorMethod;
}
/**
* Registers a new setter method.
*
* @param fieldDescription The field to write to.
* @param accessorMethod The accessor method for this field.
*/
private void registerSetter(FieldDescription fieldDescription, MethodDescription accessorMethod) {
registeredSetters.put(fieldDescription, accessorMethod);
accessorMethodEntries.put(accessorMethod, new FieldSetter(fieldDescription));
}
@Override
public TypeDescription register(AuxiliaryType auxiliaryType) {
DynamicType dynamicType = auxiliaryTypes.get(auxiliaryType);
if (dynamicType == null) {
dynamicType = auxiliaryType.make(auxiliaryTypeNamingStrategy.name(auxiliaryType, instrumentedType),
classFileVersion,
this);
auxiliaryTypes.put(auxiliaryType, dynamicType);
}
return dynamicType.getTypeDescription();
}
@Override
public List getRegisteredAuxiliaryTypes() {
return new ArrayList(auxiliaryTypes.values());
}
@Override
public FieldDescription cache(StackManipulation fieldValue, TypeDescription fieldType) {
FieldCacheEntry fieldCacheEntry = new FieldCacheEntry(fieldValue, fieldType);
FieldDescription fieldCache = registeredFieldCacheEntries.get(fieldCacheEntry);
if (fieldCache != null) {
return fieldCache;
}
validateFieldCacheAccessibility();
fieldCache = new FieldDescription.Latent(String.format("%s$%s", FIELD_CACHE_PREFIX, randomString.nextString()),
instrumentedType,
fieldType,
FIELD_CACHE_MODIFIER);
registeredFieldCacheEntries.put(fieldCacheEntry, fieldCache);
return fieldCache;
}
/**
* Validates that the field cache is still accessible. Once the type initializer of a class is written, no
* additional field caches can be defined. See
* {@link Implementation.Context.Default#canRegisterFieldCache} for a more
* detailed explanation of this validation.
*/
private void validateFieldCacheAccessibility() {
if (!canRegisterFieldCache) {
throw new IllegalStateException("A field cache cannot be registered during or after the creation of a " +
"type initializer - instead, the field cache should be registered in the method that requires " +
"the cached value");
}
}
@Override
public void drain(ClassVisitor classVisitor, TypeWriter.MethodPool methodPool, InjectedCode injectedCode) {
canRegisterFieldCache = false;
InstrumentedType.TypeInitializer typeInitializer = this.typeInitializer;
for (Map.Entry entry : registeredFieldCacheEntries.entrySet()) {
classVisitor.visitField(entry.getValue().getModifiers(),
entry.getValue().getInternalName(),
entry.getValue().getDescriptor(),
entry.getValue().getGenericSignature(),
NO_DEFAULT_VALUE).visitEnd();
typeInitializer = typeInitializer.expandWith(new ByteCodeAppender.Simple(entry.getKey().storeIn(entry.getValue())));
}
if (injectedCode.isDefined()) {
typeInitializer = typeInitializer.expandWith(injectedCode.getByteCodeAppender());
}
MethodDescription typeInitializerMethod = MethodDescription.Latent.typeInitializerOf(instrumentedType);
TypeWriter.MethodPool.Entry initializerEntry = methodPool.target(typeInitializerMethod);
if (initializerEntry.getSort().isImplemented() && typeInitializer.isDefined()) {
initializerEntry = initializerEntry.prepend(typeInitializer);
} else if (typeInitializer.isDefined()) {
initializerEntry = new TypeWriter.MethodPool.Entry.ForImplementation(typeInitializer.withReturn(), MethodAttributeAppender.NoOp.INSTANCE);
}
initializerEntry.apply(classVisitor, this, typeInitializerMethod);
for (Map.Entry entry : accessorMethodEntries.entrySet()) {
entry.getValue().apply(classVisitor, this, entry.getKey());
}
}
@Override
public String toString() {
return "Implementation.Context.Default{" +
"instrumentedType=" + instrumentedType +
", typeInitializer=" + typeInitializer +
", classFileVersion=" + classFileVersion +
", auxiliaryTypeNamingStrategy=" + auxiliaryTypeNamingStrategy +
", registeredAccessorMethods=" + registeredAccessorMethods +
", registeredGetters=" + registeredGetters +
", registeredSetters=" + registeredSetters +
", accessorMethodEntries=" + accessorMethodEntries +
", auxiliaryTypes=" + auxiliaryTypes +
", registeredFieldCacheEntries=" + registeredFieldCacheEntries +
", randomString=" + randomString +
", canRegisterFieldCache=" + canRegisterFieldCache +
'}';
}
/**
* A field cache entry for uniquely identifying a cached field. A cached field is described by the stack
* manipulation that loads the field's value onto the operand stack and the type of the field.
*/
protected static class FieldCacheEntry implements StackManipulation {
/**
* The field value that is represented by this field cache entry.
*/
private final StackManipulation fieldValue;
/**
* The field type that is represented by this field cache entry.
*/
private final TypeDescription fieldType;
/**
* Creates a new field cache entry.
*
* @param fieldValue The field value that is represented by this field cache entry.
* @param fieldType The field type that is represented by this field cache entry.
*/
protected FieldCacheEntry(StackManipulation fieldValue, TypeDescription fieldType) {
this.fieldValue = fieldValue;
this.fieldType = fieldType;
}
/**
* Returns a stack manipulation where the represented value is stored in the given field.
*
* @param fieldDescription A static field in which the value is to be stored.
* @return A stack manipulation that represents this storage.
*/
public StackManipulation storeIn(FieldDescription fieldDescription) {
return new Compound(this, FieldAccess.forField(fieldDescription).putter());
}
/**
* Returns the field type that is represented by this field cache entry.
*
* @return The field type that is represented by this field cache entry.
*/
public TypeDescription getFieldType() {
return fieldType;
}
@Override
public boolean isValid() {
return fieldValue.isValid();
}
@Override
public Size apply(MethodVisitor methodVisitor, Context implementationContext) {
return fieldValue.apply(methodVisitor, implementationContext);
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& fieldType.equals(((FieldCacheEntry) other).fieldType)
&& fieldValue.equals(((FieldCacheEntry) other).fieldValue);
}
@Override
public int hashCode() {
return 31 * fieldValue.hashCode() + fieldType.hashCode();
}
@Override
public String toString() {
return "Implementation.Context.Default.FieldCacheEntry{" +
"fieldValue=" + fieldValue +
", fieldType=" + fieldType +
'}';
}
}
/**
* An abstract method pool entry that delegates the implementation of a method to itself.
*/
protected abstract static class AbstractDelegationEntry extends TypeWriter.MethodPool.Entry.AbstractDefiningEntry implements ByteCodeAppender {
@Override
public Sort getSort() {
return Sort.IMPLEMENT;
}
@Override
public void applyHead(MethodVisitor methodVisitor, MethodDescription methodDescription) {
/* do nothing */
}
@Override
public void applyBody(MethodVisitor methodVisitor, Context implementationContext, MethodDescription methodDescription) {
methodVisitor.visitCode();
Size size = apply(methodVisitor, implementationContext, methodDescription);
methodVisitor.visitMaxs(size.getOperandStackSize(), size.getLocalVariableSize());
}
@Override
public TypeWriter.MethodPool.Entry prepend(ByteCodeAppender byteCodeAppender) {
throw new UnsupportedOperationException("Cannot prepend code to a delegator");
}
}
/**
* An implementation of a {@link net.bytebuddy.dynamic.scaffold.TypeWriter.MethodPool.Entry} for implementing
* an accessor method.
*/
protected static class AccessorMethodDelegation extends AbstractDelegationEntry {
/**
* The stack manipulation that represents the requested special method invocation.
*/
private final StackManipulation accessorMethodInvocation;
/**
* Creates a new accessor method delegation.
*
* @param accessorMethodInvocation The stack manipulation that represents the requested special method
* invocation.
*/
protected AccessorMethodDelegation(StackManipulation accessorMethodInvocation) {
this.accessorMethodInvocation = accessorMethodInvocation;
}
@Override
public Size apply(MethodVisitor methodVisitor,
Implementation.Context implementationContext,
MethodDescription instrumentedMethod) {
StackManipulation.Size stackSize = new StackManipulation.Compound(
MethodVariableAccess.loadThisReferenceAndArguments(instrumentedMethod),
accessorMethodInvocation,
MethodReturn.returning(instrumentedMethod.getReturnType())
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& accessorMethodInvocation.equals(((AccessorMethodDelegation) other).accessorMethodInvocation);
}
@Override
public int hashCode() {
return accessorMethodInvocation.hashCode();
}
@Override
public String toString() {
return "Implementation.Context.Default.AccessorMethodDelegation{accessorMethodInvocation=" + accessorMethodInvocation + '}';
}
}
/**
* An implementation for a field getter.
*/
protected static class FieldGetter extends AbstractDelegationEntry {
/**
* The field to read from.
*/
private final FieldDescription fieldDescription;
/**
* Creates a new field getter implementation.
*
* @param fieldDescription The field to read.
*/
protected FieldGetter(FieldDescription fieldDescription) {
this.fieldDescription = fieldDescription;
}
@Override
public Size apply(MethodVisitor methodVisitor, Context implementationContext, MethodDescription instrumentedMethod) {
StackManipulation.Size stackSize = new StackManipulation.Compound(
fieldDescription.isStatic()
? StackManipulation.LegalTrivial.INSTANCE
: MethodVariableAccess.REFERENCE.loadOffset(0),
FieldAccess.forField(fieldDescription).getter(),
MethodReturn.returning(fieldDescription.getFieldType())
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& fieldDescription.equals(((FieldGetter) other).fieldDescription);
}
@Override
public int hashCode() {
return fieldDescription.hashCode();
}
@Override
public String toString() {
return "Implementation.Context.Default.FieldGetter{" +
"fieldDescription=" + fieldDescription +
'}';
}
}
/**
* An implementation for a field setter.
*/
protected static class FieldSetter extends AbstractDelegationEntry {
/**
* The field to write to.
*/
private final FieldDescription fieldDescription;
/**
* Creates a new field setter.
*
* @param fieldDescription The field to write to.
*/
protected FieldSetter(FieldDescription fieldDescription) {
this.fieldDescription = fieldDescription;
}
@Override
public Size apply(MethodVisitor methodVisitor, Context implementationContext, MethodDescription instrumentedMethod) {
StackManipulation.Size stackSize = new StackManipulation.Compound(
MethodVariableAccess.loadThisReferenceAndArguments(instrumentedMethod),
FieldAccess.forField(fieldDescription).putter(),
MethodReturn.VOID
).apply(methodVisitor, implementationContext);
return new Size(stackSize.getMaximalSize(), instrumentedMethod.getStackSize());
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& fieldDescription.equals(((FieldSetter) other).fieldDescription);
}
@Override
public int hashCode() {
return fieldDescription.hashCode();
}
@Override
public String toString() {
return "Implementation.Context.Default.FieldSetter{" +
"fieldDescription=" + fieldDescription +
'}';
}
}
}
}
/**
* A compound implementation that allows to combine several implementations.
*
* Note that the combination of two implementation might break the contract for implementing
* {@link java.lang.Object#equals(Object)} and {@link Object#hashCode()} as described for
* {@link Implementation}.
*
* @see Implementation
*/
class Compound implements Implementation {
/**
* All implementation that are represented by this compound implementation.
*/
private final Implementation[] implementation;
/**
* Creates a new immutable compound implementation.
*
* @param implementation The implementations to combine in their order.
*/
public Compound(Implementation... implementation) {
this.implementation = implementation;
}
@Override
public InstrumentedType prepare(InstrumentedType instrumentedType) {
for (Implementation implementation : this.implementation) {
instrumentedType = implementation.prepare(instrumentedType);
}
return instrumentedType;
}
@Override
public ByteCodeAppender appender(Target implementationTarget) {
ByteCodeAppender[] byteCodeAppender = new ByteCodeAppender[implementation.length];
int index = 0;
for (Implementation implementation : this.implementation) {
byteCodeAppender[index++] = implementation.appender(implementationTarget);
}
return new ByteCodeAppender.Compound(byteCodeAppender);
}
@Override
public boolean equals(Object o) {
return this == o || !(o == null || getClass() != o.getClass())
&& Arrays.equals(implementation, ((Compound) o).implementation);
}
@Override
public int hashCode() {
return Arrays.hashCode(implementation);
}
@Override
public String toString() {
return "Implementation.Compound{implementation=" + Arrays.toString(implementation) + '}';
}
}
/**
* A simple implementation that does not register any members with the instrumented type.
*/
class Simple implements Implementation {
/**
* The byte code appender to emmit.
*/
private final ByteCodeAppender byteCodeAppender;
/**
* Creates a new simple implementation for the given byte code appenders.
*
* @param byteCodeAppender The byte code appenders to apply in their order of application.
*/
public Simple(ByteCodeAppender... byteCodeAppender) {
this.byteCodeAppender = new ByteCodeAppender.Compound(byteCodeAppender);
}
/**
* Creates a new simple instrumentation for the given stack manipulations which are summarized in a
* byte code appender that defines any requested method by these manipulations.
*
* @param stackManipulation The stack manipulation to apply in their order of application.
*/
public Simple(StackManipulation... stackManipulation) {
byteCodeAppender = new ByteCodeAppender.Simple(stackManipulation);
}
@Override
public InstrumentedType prepare(InstrumentedType instrumentedType) {
return instrumentedType;
}
@Override
public ByteCodeAppender appender(Target implementationTarget) {
return byteCodeAppender;
}
@Override
public boolean equals(Object other) {
return this == other || !(other == null || getClass() != other.getClass())
&& byteCodeAppender.equals(((Simple) other).byteCodeAppender);
}
@Override
public int hashCode() {
return byteCodeAppender.hashCode();
}
@Override
public String toString() {
return "Implementation.Simple{byteCodeAppender=" + byteCodeAppender + '}';
}
}
}
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