/*
* 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.descriptions.ModelDescriptionConstants.NAME;
import static org.jboss.as.controller.descriptions.ModelDescriptionConstants.VALUE;
import static org.jboss.as.controller.logging.ControllerLogger.MGMT_OP_LOGGER;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import org.jboss.as.controller.descriptions.ModelDescriptionConstants;
import org.jboss.as.controller.operations.validation.ParametersValidator;
import org.jboss.as.controller.registry.AttributeAccess;
import org.jboss.as.controller.registry.Resource;
import org.jboss.dmr.ModelNode;
import org.wildfly.common.Assert;
/**
* Abstract handler for the write aspect of a
* {@link org.jboss.as.controller.registry.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 Map<String, AttributeDefinition> attributeDefinitions;
protected AbstractWriteAttributeHandler(final AttributeDefinition... definitions) {
Assert.assertNotNull(definitions);
attributeDefinitions = new HashMap<String, AttributeDefinition>();
for (AttributeDefinition def : definitions) {
attributeDefinitions.put(def.getName(), def);
}
}
protected AbstractWriteAttributeHandler(final Collection<AttributeDefinition> definitions) {
this(definitions.toArray(new AttributeDefinition[definitions.size()]));
}
@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
ModelNode newValue = operation.hasDefined(VALUE) ? operation.get(VALUE) : new ModelNode();
final Resource resource = context.readResourceForUpdate(PathAddress.EMPTY_ADDRESS);
final ModelNode submodel = resource.getModel();
final ModelNode currentValue = submodel.get(attributeName).clone();
final AttributeDefinition attributeDefinition = getAttributeDefinition(attributeName);
final ModelNode defaultValue;
if (attributeDefinition != null) {
defaultValue = attributeDefinition.getDefaultValue();
final ModelNode syntheticOp = new ModelNode();
syntheticOp.get(attributeName).set(newValue);
attributeDefinition.validateAndSet(syntheticOp, submodel);
newValue = submodel.get(attributeName);
recordCapabilitiesAndRequirements(context, attributeDefinition, newValue, currentValue);
} else {
defaultValue = null;
submodel.get(attributeName).set(newValue);
}
finishModelStage(context, operation, attributeName, newValue, currentValue, resource);
if (requiresRuntime(context)) {
final ModelNode updatedValue = newValue;
context.addStep(operation, new OperationStepHandler() {
@Override
public void execute(OperationContext context, ModelNode operation) throws OperationFailedException {
final ModelNode resolvedValue = attributeDefinition != null ? attributeDefinition.resolveModelAttribute(context, submodel) : updatedValue.resolve();
final HandbackHolder<T> handback = new HandbackHolder<T>();
final boolean reloadRequired = applyUpdateToRuntime(context, operation, attributeName, resolvedValue, currentValue, handback);
if (reloadRequired) {
if (attributeDefinition != null && attributeDefinition.getFlags().contains(AttributeAccess.Flag.RESTART_JVM)){
context.restartRequired();
}else{
context.reloadRequired();
}
}
context.completeStep(new OperationContext.RollbackHandler() {
@Override
public void handleRollback(OperationContext context, ModelNode operation) {
ModelNode valueToRestore = currentValue.resolve();
if (valueToRestore.isDefined() == false && defaultValue != null) {
valueToRestore = defaultValue;
}
try {
revertUpdateToRuntime(context, operation, attributeName, valueToRestore, resolvedValue, handback.handback);
} catch (Exception e) {
MGMT_OP_LOGGER.errorRevertingOperation(e, getClass().getSimpleName(),
operation.require(ModelDescriptionConstants.OP).asString(),
context.getCurrentAddress());
}
if (reloadRequired) {
if (attributeDefinition != null && attributeDefinition.getFlags().contains(AttributeAccess.Flag.RESTART_JVM)) {
context.revertRestartRequired();
} else {
context.revertReloadRequired();
}
}
}
});
}
}, OperationContext.Stage.RUNTIME);
}
}
/**
* 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 reload 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;
/**
* Record any new requirements for other {@link org.jboss.as.controller.capability.RuntimeCapability capabilities}
* that now exist as a result of this operation, or remove any existing requirements that no longer exist.
*
* @param context the context. Will not be {@code null}
* @param attributeDefinition the definition of the attribute being modified. Will not be {@code null}
* @param newValue the new value of the attribute
* @param oldValue the previous value of the attribute
*/
protected void recordCapabilitiesAndRequirements(OperationContext context, AttributeDefinition attributeDefinition,
ModelNode newValue, ModelNode oldValue) {
attributeDefinition.removeCapabilityRequirements(context, oldValue);
attributeDefinition.addCapabilityRequirements(context, newValue);
}
/**
* Hook to allow subclasses to do any final {@link OperationContext.Stage#MODEL} processing following the
* application of the new attribute value. This default implementation calls
* {@link #validateUpdatedModel(OperationContext, Resource)}.
* <p>
* <strong>NOTE:</strong> Implementations must not call
* {@link OperationContext#completeStep(OperationContext.ResultHandler)} or any of its variants. The method that
* calls this one handles step completion.
* </p>
*
*
* @param context the operation context
* @param operation the operation
* @param attributeName the name of the attribute being modified
* @param newValue the new value for the attribute
* @param oldValue the previous value for the attribute
* @param model the updated model resource
* @throws OperationFailedException
*/
protected void finishModelStage(final OperationContext context, final ModelNode operation, String attributeName,
ModelNode newValue, ModelNode oldValue, final Resource model) throws OperationFailedException {
validateUpdatedModel(context, model);
}
/**
* Hook to allow subclasses to validate the model following the application of the new attribute value.
* This default implementation does nothing.
*
* @param context the operation context
* @param model the updated model resource
* @throws OperationFailedException
*/
protected void validateUpdatedModel(final OperationContext context, final Resource model) throws OperationFailedException {
// default impl does nothing
}
/**
* Gets whether a {@link OperationContext.Stage#RUNTIME} handler should be added. This default implementation
* returns true if the process is a {@link OperationContext#isNormalServer() normal server} and the process
* is not {@link OperationContext#isBooting() booting}. The rationale for the latter check is if the process is
* booting, the resource being modified will have been added as a previous step in the same context, and
* the Stage.RUNTIME handling for that add will see a model the reflects the changes made by this handler and
* will apply them to the runtime.
*
* @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.isDefaultRequiresRuntime() && !context.isBooting();
}
/**
* Gets the {@link AttributeDefinition} provided to the constructor (if present) whose
* {@link AttributeDefinition#getName() name} matches the given {@code attributeName}.
*
* @param attributeName the attribute name
* @return the attribute definition, or {@code null} if no matching definition is found
*/
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 data 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;
}
}
}