/*
* JBoss, Home of Professional Open Source.
* Copyright 2011, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.controller;
import static org.jboss.as.controller.ControllerLogger.MGMT_OP_LOGGER;
import static org.jboss.as.controller.ControllerMessages.MESSAGES;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.NAME;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.VALUE;
import java.util.HashMap;
import java.util.Map;
import org.jboss.as.controller.descriptions.ModelDescriptionConstants;
import org.jboss.as.controller.operations.validation.ParameterValidator;
import org.jboss.as.controller.operations.validation.ParametersValidator;
import org.jboss.as.controller.operations.validation.StringLengthValidator;
import org.jboss.as.controller.registry.ManagementResourceRegistration;
import org.jboss.dmr.ModelNode;
/**
* Abstract handler for the write aspect of a
* {@link ManagementResourceRegistration#registerReadWriteAttribute(AttributeDefinition, OperationStepHandler, OperationStepHandler) read-write attribute}.
*
* @param <T> the type of an object that, if stored by the
* {@link AbstractWriteAttributeHandler#applyUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, HandbackHolder)}
* implementation, will be passed to
* {@link AbstractWriteAttributeHandler#revertUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, Object)}.
*
* @author Brian Stansberry (c) 2011 Red Hat Inc.
*/
public abstract class AbstractWriteAttributeHandler<T> implements OperationStepHandler {
private final ParametersValidator nameValidator = new ParametersValidator();
private final ParameterValidator unresolvedValueValidator;
private final ParameterValidator resolvedValueValidator;
private final Map<String, AttributeDefinition> attributeDefinitions;
protected AbstractWriteAttributeHandler() {
this(null, null);
}
protected AbstractWriteAttributeHandler(final ParameterValidator validator) {
this(validator, validator);
}
protected AbstractWriteAttributeHandler(final AttributeDefinition... definitions) {
assert definitions != null : MESSAGES.nullVar("definitions").getLocalizedMessage();
attributeDefinitions = new HashMap<String, AttributeDefinition>();
for (AttributeDefinition def : definitions) {
attributeDefinitions.put(def.getName(), def);
}
this.unresolvedValueValidator = null;
this.resolvedValueValidator = null;
}
protected AbstractWriteAttributeHandler(final ParameterValidator unresolvedValidator, final ParameterValidator resolvedValidator) {
this.nameValidator.registerValidator(NAME, new StringLengthValidator(1));
this.unresolvedValueValidator = unresolvedValidator;
this.resolvedValueValidator = resolvedValidator;
this.attributeDefinitions = null;
}
@Override
public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {
nameValidator.validate(operation);
final String attributeName = operation.require(NAME).asString();
// Don't require VALUE. Let the validator decide if it's bothered by an undefined value
final ModelNode newValue = operation.hasDefined(VALUE) ? operation.get(VALUE) : new ModelNode();
validateUnresolvedValue(attributeName, newValue);
final ModelNode submodel = context.readResourceForUpdate(PathAddress.EMPTY_ADDRESS).getModel();
final ModelNode currentValue = submodel.get(attributeName).clone();
final AttributeDefinition attributeDefinition = getAttributeDefinition(attributeName);
if (attributeDefinition != null) {
final ModelNode syntheticOp = new ModelNode();
syntheticOp.get(attributeName).set(newValue);
attributeDefinition.validateAndSet(syntheticOp, submodel);
} else {
submodel.get(attributeName).set(newValue);
}
if (requiresRuntime(context)) {
context.addStep(new OperationStepHandler() {
@Override
public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {
ModelNode resolvedValue = attributeDefinition != null ? attributeDefinition.resolveModelAttribute(context, submodel) : newValue.resolve();
validateResolvedValue(attributeName, newValue);
HandbackHolder<T> handback = new HandbackHolder<T>();
boolean restartRequired = applyUpdateToRuntime(context, operation, attributeName, resolvedValue, currentValue, handback);
if (restartRequired) {
context.reloadRequired();
}
if (context.completeStep() != OperationContext.ResultAction.KEEP) {
ModelNode valueToRestore = currentValue.resolve();
try {
revertUpdateToRuntime(context, operation, attributeName, valueToRestore, resolvedValue, handback.handback);
} catch (Exception e) {
MGMT_OP_LOGGER.errorRevertingOperation(e, getClass().getSimpleName(),
operation.require(ModelDescriptionConstants.OP).asString(),
PathAddress.pathAddress(operation.get(ModelDescriptionConstants.OP_ADDR)));
}
if (restartRequired) {
context.revertReloadRequired();
}
}
}
}, OperationContext.Stage.RUNTIME);
}
context.completeStep();
}
/**
* Hook to allow subclasses to make runtime changes to effect the attribute value change.
*
* @param context the context of the operation
* @param operation the operation
* @param attributeName the name of the attribute being modified
* @param resolvedValue the new value for the attribute, after {@link ModelNode#resolve()} has been called on it
* @param currentValue the existing value for the attribute
* @param handbackHolder holder for an arbitrary object to pass to
* {@link #revertUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, Object)} if
* the operation needs to be rolled back
*
* @return {@code true} if the server requires restart to effect the attribute
* value change; {@code false} if not
*/
protected abstract boolean applyUpdateToRuntime(OperationContext context, ModelNode operation, String attributeName,
ModelNode resolvedValue, ModelNode currentValue, HandbackHolder<T> handbackHolder)
throws OperationFailedException;
/**
* Hook to allow subclasses to revert runtime changes made in
* {@link #applyUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, HandbackHolder)}.
*
* @param context the context of the operation
* @param operation the operation
* @param attributeName the name of the attribute being modified
* @param valueToRestore the previous value for the attribute, before this operation was executed
* @param valueToRevert the new value for the attribute that should be reverted
* @param handback an object, if any, passed in to the {@code handbackHolder} by the {@code applyUpdateToRuntime}
* implementation
*/
protected abstract void revertUpdateToRuntime(OperationContext context, ModelNode operation, String attributeName,
ModelNode valueToRestore, ModelNode valueToRevert, T handback)
throws OperationFailedException;
/**
* If an unresolved value validator was passed to the constructor, uses it to validate the value.
* Subclasses can alter this behavior.
*
* @param attributeName the name of the attribute being updated
* @param unresolvedValue the unresolved value
*/
protected void validateUnresolvedValue(final String attributeName, final ModelNode unresolvedValue) throws OperationFailedException {
if (unresolvedValueValidator != null) {
unresolvedValueValidator.validateParameter(VALUE, unresolvedValue);
}
}
/**
* If a resolved value validator was passed to the constructor, uses it to validate the value.
* Subclasses can alter this behavior.
*
* @param attributeName the name of the attribute being updated
* @param resolvedValue the resolved value
*/
protected void validateResolvedValue(final String attributeName, final ModelNode resolvedValue) throws OperationFailedException {
if (resolvedValueValidator != null) {
resolvedValueValidator.validateResolvedParameter(VALUE, resolvedValue);
}
}
/**
* Gets whether a {@link OperationContext.Stage#RUNTIME} handler should be added.
*
* @param context operation context
* @return {@code true} if a runtime stage handler should be added; {@code false} otherwise.
*/
protected boolean requiresRuntime(OperationContext context) {
return context.isNormalServer() && !context.isBooting();
}
protected AttributeDefinition getAttributeDefinition(final String attributeName) {
return attributeDefinitions == null ? null : attributeDefinitions.get(attributeName);
}
/**
* Holder subclasses can use to pass an object between
* {@link AbstractWriteAttributeHandler#applyUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, HandbackHolder)}
* and {@link AbstractWriteAttributeHandler#revertUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, Object)}.
* Typically that object would encapsulate some state useful in reverting the runtime update.
*
* @param <T> the type of the object being passed
*/
public static class HandbackHolder<T> {
private T handback;
/**
* Store an object for use in
* {@link AbstractWriteAttributeHandler#revertUpdateToRuntime(OperationContext, ModelNode, String, ModelNode, ModelNode, Object)}.
*
* @param handback the object
*/
public void setHandback(final T handback) {
this.handback = handback;
}
}
}