/*
* Copyright (C) 2012 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.errai.ioc.support.bus.rebind;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.jboss.errai.bus.client.ErraiBus;
import org.jboss.errai.bus.client.api.ClientMessageBus;
import org.jboss.errai.bus.client.api.base.MessageBuilder;
import org.jboss.errai.bus.client.api.messaging.Message;
import org.jboss.errai.bus.client.api.messaging.MessageCallback;
import org.jboss.errai.bus.server.annotations.Remote;
import org.jboss.errai.bus.server.annotations.ShadowService;
import org.jboss.errai.codegen.Parameter;
import org.jboss.errai.codegen.Statement;
import org.jboss.errai.codegen.builder.AnonymousClassStructureBuilder;
import org.jboss.errai.codegen.builder.BlockBuilder;
import org.jboss.errai.codegen.builder.ElseBlockBuilder;
import org.jboss.errai.codegen.builder.impl.ObjectBuilder;
import org.jboss.errai.codegen.builder.impl.StatementBuilder;
import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.MetaClassFactory;
import org.jboss.errai.codegen.meta.MetaMethod;
import org.jboss.errai.codegen.util.EmptyStatement;
import org.jboss.errai.codegen.util.If;
import org.jboss.errai.codegen.util.ProxyUtil;
import org.jboss.errai.codegen.util.Refs;
import org.jboss.errai.codegen.util.Stmt;
import org.jboss.errai.ioc.client.api.CodeDecorator;
import org.jboss.errai.ioc.rebind.ioc.extension.IOCDecoratorExtension;
import org.jboss.errai.ioc.rebind.ioc.injector.api.Decorable;
import org.jboss.errai.ioc.rebind.ioc.injector.api.FactoryController;
import org.jboss.errai.ioc.support.bus.client.ServiceNotReady;
import org.jboss.errai.ioc.support.bus.client.ShadowServiceHelper;
/**
* Generates logic to register client-side shadow services for Errai's message
* bus. Shadow services are used when:
* <ul>
* <li>Remote communication is turned off
* <li>Errai's message bus is not in connected state
* <li>A remote endpoint for the service doesn't exist
* </ul>
*
* @author Mike Brock
* @author Christian Sadilek <csadilek@redhat.com>
*/
@CodeDecorator
public class ShadowServiceDecorator extends IOCDecoratorExtension<ShadowService> {
public ShadowServiceDecorator(final Class<ShadowService> decoratesWith) {
super(decoratesWith);
}
@Override
public void generateDecorator(final Decorable decorable, final FactoryController controller) {
final ShadowService shadowService = (ShadowService) decorable.getAnnotation();
String serviceName = null;
Statement subscribeShadowStatement = null;
final Class<?> javaClass = decorable.getType().asClass();
for (final Class<?> intf : javaClass.getInterfaces()) {
if (intf.isAnnotationPresent(Remote.class)) {
serviceName = intf.getName() + ":RPC";
final AnonymousClassStructureBuilder builder = generateMethodDelegates(intf, decorable, controller);
subscribeShadowStatement = Stmt.castTo(ClientMessageBus.class, Stmt.invokeStatic(ErraiBus.class, "get"))
.invoke("subscribeShadow", serviceName, builder.finish());
}
if (serviceName == null) {
if (shadowService.value().equals("")) {
serviceName = decorable.getName();
}
else {
serviceName = shadowService.value();
}
subscribeShadowStatement = Stmt.castTo(ClientMessageBus.class, Stmt.invokeStatic(ErraiBus.class, "get"))
.invoke("subscribeShadow", serviceName, controller.contextGetInstanceStmt());
}
controller.addFactoryInitializationStatements(Collections.singletonList(subscribeShadowStatement));
}
}
private AnonymousClassStructureBuilder generateMethodDelegates(final Class<?> intf, final Decorable decorable, final FactoryController controller) {
final BlockBuilder<AnonymousClassStructureBuilder> builder = ObjectBuilder.newInstanceOf(MessageCallback.class)
.extend().publicOverridesMethod("callback", Parameter.of(Message.class, "message"))
.append(Stmt.declareVariable("commandType", String.class,
Stmt.loadVariable("message").invoke("getCommandType")))
.append(Stmt.declareVariable("methodParms", List.class,
Stmt.loadVariable("message").invoke("get", List.class, Stmt.loadLiteral("MethodParms"))));
final MetaClass mc = MetaClassFactory.get(intf);
for (final MetaMethod method : mc.getMethods()) {
if (ProxyUtil.isMethodInInterface(mc, method) && ProxyUtil.shouldProxyMethod(method)) {
final MetaClass[] parameterTypes = Arrays.stream(method.getParameters()).map(p -> p.getType()).toArray(MetaClass[]::new);
final Statement[] objects = new Statement[parameterTypes.length];
final BlockBuilder<ElseBlockBuilder> blockBuilder = If
.cond(Stmt.loadLiteral(ProxyUtil.createCallSignature(method)).invoke("equals",
Stmt.loadVariable("commandType")));
blockBuilder.append(Stmt.declareFinalVariable("instance", intf, controller.contextGetInstanceStmt()));
for (int i = 0; i < parameterTypes.length; i++) {
final MetaClass parameterType = parameterTypes[i];
objects[i] = Stmt.castTo(parameterType, Stmt.loadVariable("methodParms").invoke("get", i));
}
final boolean hasReturnType = !method.getReturnType().isVoid();
final Statement methodInvocation = Stmt.nestedCall(Stmt.loadVariable("instance")).invoke(method.getName(), (Object[]) objects);
final Statement invocation = (hasReturnType) ? Stmt.declareFinalVariable("ret", method.getReturnType(), methodInvocation) : methodInvocation;
final Statement maybeDestroy = (decorable.isEnclosingTypeDependent()) ? Stmt.loadVariable("context").invoke("destroyInstance", Refs.get("instance"))
: EmptyStatement.INSTANCE;
final Statement sendResponse = (hasReturnType) ? Stmt.invokeStatic(MessageBuilder.class, "createConversation", Stmt.loadVariable("message"))
.invoke("subjectProvided").invoke("with", "MethodReply", Refs.get("ret"))
.invoke("noErrorHandling").invoke("sendNowWith", Stmt.invokeStatic(ErraiBus.class, "get"))
: EmptyStatement.INSTANCE;
final ObjectBuilder runnable = Stmt
.newObject(Runnable.class)
.extend()
.publicOverridesMethod("run")
.append(Stmt.try_()
.append(invocation)
.append(maybeDestroy)
.append(sendResponse)
.finish()
.catch_(RuntimeException.class, "ex")
.append(Stmt.throw_("ex"))
.finish()
.catch_(Throwable.class, "t")
.append(Stmt.throw_(RuntimeException.class, Stmt.loadVariable("t")))
.finish())
.finish().finish();
final StatementBuilder runnableDecl = Stmt.declareFinalVariable("invocation", Runnable.class, runnable);
blockBuilder.append(runnableDecl);
blockBuilder.append(Stmt.try_()
.append(Stmt.loadVariable("invocation").invoke("run"))
.finish()
.catch_(ServiceNotReady.class, "ex")
.append(Stmt.invokeStatic(ShadowServiceHelper.class, "deferred", Stmt.loadVariable("invocation"))).finish());
builder.append(blockBuilder.finish());
}
}
return builder.finish();
}
}