]> git.argeo.org Git - gpl/argeo-slc.git/blobdiff - runtime/org.argeo.slc.core/src/main/java/org/argeo/slc/core/execution/ExecutionScope.java
Deal with destruction callbacks
[gpl/argeo-slc.git] / runtime / org.argeo.slc.core / src / main / java / org / argeo / slc / core / execution / ExecutionScope.java
index a24046a99869a443f4fb024de4a5aff5875599e3..42fc59522e4cb16e7def6765913e45a6bfe5d8e4 100644 (file)
+/*
+ * Copyright (C) 2007-2012 Mathieu Baudier
+ *
+ * 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.argeo.slc.core.execution;
 
-import java.util.HashMap;
-import java.util.Map;
-
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.argeo.slc.SlcException;
+import org.argeo.slc.UnsupportedException;
 import org.argeo.slc.execution.ExecutionContext;
+import org.argeo.slc.execution.ExecutionFlow;
+import org.argeo.slc.execution.ExecutionSpec;
+import org.argeo.slc.execution.ExecutionStack;
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.config.Scope;
 
+/**
+ * When Spring beans are instantiated with this scope, the same instance is
+ * reused across an execution.
+ */
 public class ExecutionScope implements Scope {
        private final static Log log = LogFactory.getLog(ExecutionScope.class);
 
-       private final ThreadLocal<ExecutionContext> executionContext = new ThreadLocal<ExecutionContext>();
+       private final ThreadLocal<ExecutionStack> executionStack = new ThreadLocal<ExecutionStack>();
+       public final ThreadLocal<String> executionStackBeanName = new ThreadLocal<String>();
 
-       public final ThreadLocal<String> executionContextBeanName = new ThreadLocal<String>();
+       private final ThreadLocal<ExecutionContext> executionContext = new ThreadLocal<ExecutionContext>();
+       private final ThreadLocal<String> executionContextBeanName = new ThreadLocal<String>();
 
        public Object get(String name, ObjectFactory objectFactory) {
-
                if (log.isTraceEnabled())
-                       log.trace("Getting scoped bean " + name);
+                       log.debug("Get execution scoped bean " + name);
+
+               // shortcuts
+               if (executionStackBeanName.get() != null
+                               && name.equals(executionStackBeanName.get())) {
+                       return executionStack.get();
+               }
+
+               if (executionContextBeanName.get() != null
+                               && name.equals(executionContextBeanName.get())) {
+                       return executionContext.get();
+               }
 
-               // check if an execution context is defined for this thread
+               // execution context must be defined first
                if (executionContext.get() == null) {
-                       // if not, we expect objectFactory to produce an ExecutionContext
                        Object obj = objectFactory.getObject();
                        if (obj instanceof ExecutionContext) {
-                               // Check whether we are in an execution
-                               // FIXME: do it more properly (not static)
-                               // see https://www.argeo.org/bugzilla/show_bug.cgi?id=82
-                               if (!ExecutionAspect.inModuleExecution.get()) {
-                                       log
-                                                       .error("An execution context is being instantiated outside a module execution."
-                                                                       + " Please check your references to execution contexts."
-                                                                       + " This may lead to unexpected behaviour and will be rejected in the future.");
-                                       //Thread.dumpStack();
-                               }
-
-                               // store the ExecutionContext in the ThreadLocal
-                               executionContext.set((ExecutionContext) obj);
-                               executionContextBeanName.set(name);
-                               if (log.isDebugEnabled()) {
-                                       log.debug("Execution context #"
-                                                       + executionContext.get().getUuid()
-                                                       + " instantiated. (beanName="
-                                                       + executionContextBeanName.get() + ")");
-                                       // Thread.dumpStack();
-                               }
-                               return obj;
+                               return dealWithSpecialScopedObject(name, executionContext,
+                                               executionContextBeanName, (ExecutionContext) obj);
                        } else {
-                               throw new SlcException(
-                                               "Expected an ExecutionContext, got an object of class "
-                                                               + obj.getClass()
-                                                               + " for bean "
-                                                               + name
-                                                               + ": make sure that you have porperly set scope=\"execution\" where required");
+                               // TODO: use execution context wrapper
+                               throw new SlcException("No execution context has been defined.");
                        }
                }
 
-               if (name.equals(executionContextBeanName.get())) {
-                       return executionContext.get();
-               } else {
-                       // see if the executionContext already knows the object
-                       Object obj = executionContext.get().findScopedObject(name);
-                       if (obj == null) {
-                               obj = objectFactory.getObject();
-                               if (!(obj instanceof ExecutionContext)) {
-                                       executionContext.get().addScopedObject(name, obj);
-                               } else {
-                                       throw new SlcException(
-                                                       "Only one ExecutionContext can be defined per Thread");
-                               }
+               // for other scoped objects, an executions stack must be available
+               if (executionStack.get() == null) {
+                       Object obj = objectFactory.getObject();
+                       if (obj instanceof ExecutionStack) {
+                               return dealWithSpecialScopedObject(name, executionStack,
+                                               executionStackBeanName, (ExecutionStack) obj);
+                       } else {
+                               throw new SlcException("No execution stack has been defined.");
                        }
-                       return obj;
                }
 
-               // if (ExecutionContext.getScopedObjects().containsKey(name)) {
-               // // returns cached instance
-               // Object obj = ExecutionContext.getScopedObjects().get(name);
-               // if (log.isTraceEnabled())
-               // log.trace("Return cached scoped object " + obj);
-               // return obj;
-               // } else {
-               // // creates instance
-               // Object obj = objectFactory.getObject();
-               // ExecutionContext.getScopedObjects().put(name, obj);
-               // if (log.isTraceEnabled())
-               // log.trace("Created regular scoped object " + obj);
-               // return obj;
-               // }
+               // see if the execution stack already knows the object
+               Object obj = executionStack.get().findScopedObject(name);
+               if (obj == null) {
+                       obj = objectFactory.getObject();
+                       if (obj instanceof ExecutionContext)
+                               throw new SlcException(
+                                               "Only one execution context can be defined per thread");
+                       if (obj instanceof ExecutionStack)
+                               throw new SlcException(
+                                               "Only one execution stack can be defined per thread");
+
+                       checkForbiddenClasses(obj);
+
+                       executionStack.get().addScopedObject(name, obj);
+               }
+               return obj;
+
        }
 
-       public String getConversationId() {
+       protected <T> T dealWithSpecialScopedObject(String name,
+                       ThreadLocal<T> threadLocal,
+                       ThreadLocal<String> threadLocalBeanName, T newObj) {
+
+               T obj = threadLocal.get();
+               if (obj == null) {
+                       obj = newObj;
+                       threadLocal.set(obj);
+                       threadLocalBeanName.set(name);
+                       if (log.isTraceEnabled()) {
+                               log.debug(obj.getClass() + " instantiated. (beanName=" + name
+                                               + ")");
+                       }
+                       return obj;
+               } else {
+                       throw new SlcException("Only one scoped " + obj.getClass()
+                                       + " can be defined per thread");
+               }
 
-               return executionContext.get().getUuid();
        }
 
-       public Boolean hasExecutionContext() {
-               return executionContext.get() != null;
+       protected void checkForbiddenClasses(Object obj) {
+               Class<?> clss = obj.getClass();
+               if (ExecutionFlow.class.isAssignableFrom(clss)
+                               || ExecutionSpec.class.isAssignableFrom(clss)) {
+                       throw new UnsupportedException("Execution scoped object", clss);
+               }
+       }
+
+       public String getConversationId() {
+               // TODO: is it the most relevant?
+               return executionContext.get().getUuid();
        }
 
        public void registerDestructionCallback(String name, Runnable callback) {
-               // TODO: implement it
-               // throw new UnsupportedOperationException();
+               if (Thread.currentThread() instanceof ExecutionThread) {
+                       ExecutionThread executionThread = (ExecutionThread) Thread
+                                       .currentThread();
+                       executionThread.registerDestructionCallback(name, callback);
+               }
        }
 
        public Object remove(String name) {
-               log.debug("Remove object " + name);
+               if (log.isDebugEnabled())
+                       log.debug("Remove object " + name);
                throw new UnsupportedOperationException();
        }
 
+       public Object resolveContextualObject(String key) {
+               return executionContext.get().getVariable(key);
+       }
+
 }