| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.directory.server.core.invocation; |
| |
| |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.IdentityHashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import javax.naming.Context; |
| |
| |
| /** |
| * Keeps track of recursive {@link Invocation}s. This stack assumes an invocation |
| * occurs in the same thread since it is called first, so we manages stacks |
| * for each invocation in {@link ThreadLocal}-like manner. You can just use |
| * {@link #getInstance()} to get current invocation stack. |
| * <p> |
| * Using {@link InvocationStack}, you can find out current effective JNDI |
| * {@link Context} or detect infinite recursions. |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| * @version $Rev$, $Date$ |
| */ |
| public final class InvocationStack |
| { |
| // I didn't use ThreadLocal to release contexts explicitly. |
| // It seems like JDK 1.5 supports explicit release by introducing |
| // <tt>ThreadLocal.remove()</tt>, but we're still targetting 1.4. |
| private static final Map<Thread, InvocationStack> stacks = |
| Collections.synchronizedMap( new IdentityHashMap<Thread, InvocationStack>() ); |
| |
| private final Thread thread; |
| private final List<Invocation> stack = new ArrayList<Invocation>(); |
| |
| /** |
| * Returns the invocation stack of current thread. |
| */ |
| public static InvocationStack getInstance() |
| { |
| Thread currentThread = Thread.currentThread(); |
| InvocationStack ctx; |
| ctx = stacks.get( currentThread ); |
| |
| if ( ctx == null ) |
| { |
| ctx = new InvocationStack( currentThread ); |
| } |
| |
| return ctx; |
| } |
| |
| private InvocationStack( Thread currentThread ) |
| { |
| thread = currentThread; |
| stacks.put( currentThread, this ); |
| } |
| |
| |
| /** |
| * Returns an array of {@link Invocation}s. 0th element is the |
| * latest invocation. |
| */ |
| public Invocation[] toArray() |
| { |
| Invocation[] result = new Invocation[stack.size()]; |
| result = stack.toArray( result ); |
| return result; |
| } |
| |
| |
| /** |
| * Returns the latest invocation. |
| */ |
| public Invocation peek() |
| { |
| return stack.get( 0 ); |
| } |
| |
| |
| /** |
| * Returns true if the stack is empty false otherwise. |
| */ |
| public boolean isEmpty() |
| { |
| return stack.isEmpty(); |
| } |
| |
| |
| /** |
| * Pushes the specified invocation to this stack. |
| */ |
| public void push( Invocation invocation ) |
| { |
| stack.add( 0, invocation ); |
| } |
| |
| |
| /** |
| * Pops the latest invocation from this stack. This stack is released |
| * automatically if you pop all items from this stack. |
| */ |
| public Invocation pop() |
| { |
| Invocation invocation = stack.remove( 0 ); |
| |
| if ( stack.size() == 0 ) |
| { |
| stacks.remove( thread ); |
| } |
| |
| return invocation; |
| } |
| } |