package net.bytebuddy.agent.builder;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.Instrumentation;
/**
* A class file transformer that can reset its transformation.
*/
public interface ResettableClassFileTransformer extends ClassFileTransformer {
/**
* <p>
* Deregisters this class file transformer and redefines any transformed class to its state without this
* class file transformer applied, if the supplied redefinition strategy is enabled. If it is not enabled,
* only the {@link net.bytebuddy.agent.builder.AgentBuilder.InstallationListener} is informed about the
* resetting without undoing any code changes.
* </p>
* <p>
* <b>Note</b>: A reset class file transformer should not be reinstalled. Instead, the {@link AgentBuilder}
* which built the transformer should be asked to install a new transformer.
* </p>
* <p>
* <b>Important</b>: Most JVMs do not support changes of a class's structure after a class was already
* loaded. Therefore, it is typically required that this class file transformer was built while enabling
* {@link AgentBuilder#disableClassFormatChanges()}.
* </p>
*
* @param instrumentation The instrumentation instance from which to deregister the transformer.
* @param redefinitionStrategy The redefinition to apply.
* @return {@code true} if a reset was applied and this transformer was not previously removed.
*/
boolean reset(Instrumentation instrumentation, AgentBuilder.RedefinitionStrategy redefinitionStrategy);
/**
* <p>
* Deregisters this class file transformer and redefines any transformed class to its state without this
* class file transformer applied, if the supplied redefinition strategy is enabled. If it is not enabled,
* only the {@link net.bytebuddy.agent.builder.AgentBuilder.InstallationListener} is informed about the
* resetting without undoing any code changes.
* </p>
* <p>
* <b>Note</b>: A reset class file transformer should not be reinstalled. Instead, the {@link AgentBuilder}
* which built the transformer should be asked to install a new transformer.
* </p>
* <p>
* <b>Important</b>: Most JVMs do not support changes of a class's structure after a class was already
* loaded. Therefore, it is typically required that this class file transformer was built while enabling
* {@link AgentBuilder#disableClassFormatChanges()}.
* </p>
*
* @param instrumentation The instrumentation instance from which to deregister the transformer.
* @param redefinitionStrategy The redefinition to apply.
* @param redefinitionBatchAllocator The batch allocator to use.
* @return {@code true} if a reset was applied and this transformer was not previously removed.
*/
boolean reset(Instrumentation instrumentation,
AgentBuilder.RedefinitionStrategy redefinitionStrategy,
AgentBuilder.RedefinitionStrategy.BatchAllocator redefinitionBatchAllocator);
/**
* <p>
* Deregisters this class file transformer and redefines any transformed class to its state without this
* class file transformer applied, if the supplied redefinition strategy is enabled. If it is not enabled,
* only the {@link net.bytebuddy.agent.builder.AgentBuilder.InstallationListener} is informed about the
* resetting without undoing any code changes.
* </p>
* <p>
* <b>Note</b>: A reset class file transformer should not be reinstalled. Instead, the {@link AgentBuilder}
* which built the transformer should be asked to install a new transformer.
* </p>
* <p>
* <b>Important</b>: Most JVMs do not support changes of a class's structure after a class was already
* loaded. Therefore, it is typically required that this class file transformer was built while enabling
* {@link AgentBuilder#disableClassFormatChanges()}.
* </p>
*
* @param instrumentation The instrumentation instance from which to deregister the transformer.
* @param redefinitionStrategy The redefinition to apply.
* @param redefinitionBatchAllocator The batch allocator to use.
* @param redefinitionListener The redefinition listener to apply.
* @return {@code true} if a reset was applied and this transformer was not previously removed.
*/
boolean reset(Instrumentation instrumentation,
AgentBuilder.RedefinitionStrategy redefinitionStrategy,
AgentBuilder.RedefinitionStrategy.BatchAllocator redefinitionBatchAllocator,
AgentBuilder.RedefinitionStrategy.Listener redefinitionListener);
/**
* An abstract base implementation of a {@link ResettableClassFileTransformer}.
*/
abstract class AbstractBase implements ResettableClassFileTransformer {
@Override
public boolean reset(Instrumentation instrumentation, AgentBuilder.RedefinitionStrategy redefinitionStrategy) {
return reset(instrumentation,
redefinitionStrategy,
AgentBuilder.RedefinitionStrategy.BatchAllocator.ForTotal.INSTANCE);
}
@Override
public boolean reset(Instrumentation instrumentation,
AgentBuilder.RedefinitionStrategy redefinitionStrategy,
AgentBuilder.RedefinitionStrategy.BatchAllocator redefinitionBatchAllocator) {
return reset(instrumentation,
redefinitionStrategy,
redefinitionBatchAllocator,
AgentBuilder.RedefinitionStrategy.Listener.NoOp.INSTANCE);
}
}
}