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Diffstat (limited to 'sca-java-1.x/tags/java-M1-final/java/sca/core/src/main/java/org/apache/tuscany/core/context/scope/RequestScopeContext.java')
| -rw-r--r-- | sca-java-1.x/tags/java-M1-final/java/sca/core/src/main/java/org/apache/tuscany/core/context/scope/RequestScopeContext.java | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/java-M1-final/java/sca/core/src/main/java/org/apache/tuscany/core/context/scope/RequestScopeContext.java b/sca-java-1.x/tags/java-M1-final/java/sca/core/src/main/java/org/apache/tuscany/core/context/scope/RequestScopeContext.java new file mode 100644 index 0000000000..67ce176af5 --- /dev/null +++ b/sca-java-1.x/tags/java-M1-final/java/sca/core/src/main/java/org/apache/tuscany/core/context/scope/RequestScopeContext.java @@ -0,0 +1,228 @@ +/** + * + * Copyright 2005 The Apache Software Foundation or its licensors, as applicable. + * + * 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.apache.tuscany.core.context.scope; + +import org.apache.tuscany.core.builder.ContextFactory; +import org.apache.tuscany.core.context.Context; +import org.apache.tuscany.core.context.CoreRuntimeException; +import org.apache.tuscany.core.context.EventContext; +import org.apache.tuscany.core.context.AtomicContext; +import org.apache.tuscany.core.context.TargetException; +import org.apache.tuscany.core.context.Lifecycle; +import org.apache.tuscany.core.context.event.InstanceCreated; +import org.apache.tuscany.core.context.event.Event; +import org.apache.tuscany.core.context.event.RequestEnd; +import org.apache.tuscany.core.context.event.RequestStart; + +import java.util.ArrayList; +import java.util.List; +import java.util.Map; +import java.util.ListIterator; +import java.util.concurrent.ConcurrentHashMap; + +/** + * An implementation of a request-scoped component container. This scope contexts eagerly starts contexts when + * a {@link org.apache.tuscany.core.context.event.RequestStart} event is received. If a contained context has an implementation marked to eagerly initialized, + * the an instance will be created at that time as well. Contained contexts are shutdown when a {@link org.apache.tuscany.core.context.event.RequestEnd} + * event is received in reverse order to which their implementation instances were created. + * + * @version $Rev$ $Date$ + */ +public class RequestScopeContext extends AbstractScopeContext { + + // A collection of service component contexts keyed by thread. Note this could have been implemented with a ThreadLocal but + // using a Map allows finer-grained concurrency. + private Map<Object, Map<String, Context>> contexts; + + // stores ordered lists of contexts to shutdown for each thread. + private Map<Object, List<Context>> destroyQueues; + + public RequestScopeContext(EventContext eventContext) { + super(eventContext); + setName("Request Scope"); + } + + public void onEvent(Event event){ + if (event instanceof RequestStart){ + getContexts(); // eager load + }else if (event instanceof RequestEnd){ + checkInit(); + getEventContext().clearIdentifiers(); // clean up current context for pooled threads + shutdownContexts(); + cleanupRequestContexts(); + }else if (event instanceof InstanceCreated){ + checkInit(); + assert(event.getSource() instanceof Context): "Context must be passed on created event"; + Context context = (Context)event.getSource(); + List<Context> collection = destroyQueues.get(Thread.currentThread()); + collection.add(context); + } + } + + public synchronized void start() { + if (lifecycleState != UNINITIALIZED) { + throw new IllegalStateException("Scope must be in UNINITIALIZED state [" + lifecycleState + "]"); + } + contexts = new ConcurrentHashMap<Object, Map<String, Context>>(); + destroyQueues = new ConcurrentHashMap<Object, List<Context>>(); + lifecycleState = RUNNING; + } + + public synchronized void stop() { + if (lifecycleState != RUNNING) { + throw new IllegalStateException("Scope in wrong state [" + lifecycleState + "]"); + } + contexts = null; + destroyQueues = null; + lifecycleState = STOPPED; + } + + public boolean isCacheable() { + return true; + } + + public void registerFactory(ContextFactory<Context> configuration) { + contextFactories.put(configuration.getName(), configuration); + } + + public Context getContext(String ctxName) { + checkInit(); + Map<String, Context> contexts = getContexts(); + Context ctx = contexts.get(ctxName); + if (ctx == null){ + // check to see if the configuration was added after the request was started + ContextFactory<Context> configuration = contextFactories.get(ctxName); + if (configuration != null) { + ctx = configuration.createContext(); + //ctx.addListener(this); + ctx.start(); + contexts.put(ctx.getName(), ctx); + } + } + return ctx; + } + + public Context getContextByKey(String ctxName, Object key) { + checkInit(); + if (key == null) { + return null; + } + Map<String, Context> components = contexts.get(key); + if (components == null) { + return null; + } + return components.get(ctxName); + } + + public void removeContext(String ctxName) { + removeContextByKey(ctxName, Thread.currentThread()); + } + + public void removeContextByKey(String ctxName, Object key) { + checkInit(); + if (key == null || ctxName == null) { + return; + } + Map components = contexts.get(key); + if (components == null) { + return; + } + components.remove(ctxName); + } + + + + private void cleanupRequestContexts() { + // TODO uninitialize all request-scoped components + contexts.remove(Thread.currentThread()); + destroyQueues.remove(Thread.currentThread()); + } + + /** + * Initializes ServiceComponentContexts for the current request. + * <p> + * TODO This eagerly creates all component contexts, even if the component is never accessed during the request. This method + * should be profiled to determine if lazy initialization is more performant + * <p> + * TODO Eager initialization is not performed for request-scoped components + */ + + private Map<String, Context> getContexts() throws CoreRuntimeException { + Map<String, Context> requestContexts = this.contexts.get(Thread.currentThread()); + if (requestContexts == null) { + requestContexts = new ConcurrentHashMap<String, Context>(); + List<Context> shutdownQueue = new ArrayList<Context>(); + for (ContextFactory<Context> config : contextFactories.values()) { + Context context = config.createContext(); + context.start(); + requestContexts.put(context.getName(), context); + } + // initialize eager components. Note this cannot be done when we initially create each context since a component may + // contain a forward reference to a component which has not been instantiated + for (Context context : requestContexts.values()) { + if (context instanceof AtomicContext) { + AtomicContext atomic = (AtomicContext) context; + if (atomic.isEagerInit()) { + atomic.init(); // Notify the instance + synchronized(shutdownQueue){ + shutdownQueue.add(context); + } + } + } + context.addListener(this); + } + contexts.put(Thread.currentThread(), requestContexts); + destroyQueues.put(Thread.currentThread(), shutdownQueue); + } + return requestContexts; + } + + private void shutdownContexts() { + List<Context> destroyQueue = destroyQueues.remove(Thread.currentThread()); + if (destroyQueue == null || destroyQueue.size() == 0) { + return; + } + synchronized(destroyQueue){ + // shutdown destroyable instances in reverse instantiation order + ListIterator<Context> iter = destroyQueue.listIterator(destroyQueue.size()); + while(iter.hasPrevious()){ + Lifecycle context = iter.previous(); + if (context.getLifecycleState() == RUNNING) { + try { + if (context instanceof AtomicContext){ + ((AtomicContext)context).destroy(); + } + } catch (TargetException e) { + // TODO send a monitoring event + } + } + } + } + // shutdown contexts + Map<String,Context> currentContexts = contexts.remove(Thread.currentThread()); + if (currentContexts == null){ + return; + } + for (Lifecycle context: currentContexts.values()){ + if (context.getLifecycleState() == RUNNING) { + context.stop(); + } + } + + } + +}
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