Added monitoring of node service to generate CIFS change notifications and update file server state cache, ALFCOM-1205. Should also fix ALFCOM-1021, ALFCOM-1052 and JLAN-9.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@10287 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/filesys/repo/NodeEventQueue.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2006-2008 Alfresco Software Limited.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+
+ * This program 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 General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+ * As a special exception to the terms and conditions of version 2.0 of 
+ * the GPL, you may redistribute this Program in connection with Free/Libre 
+ * and Open Source Software ("FLOSS") applications as described in Alfresco's 
+ * FLOSS exception.  You should have recieved a copy of the text describing 
+ * the FLOSS exception, and it is also available here: 
+ * http://www.alfresco.com/legal/licensing"
+ */
+
+package org.alfresco.filesys.repo;
+
+import java.util.LinkedList;
+
+/**
+ * Node Event Queue Class
+ * 
+ * @author gkspencer
+ */
+public class NodeEventQueue {
+
+	// List of node events
+
+	private LinkedList<NodeEvent> m_queue;
+
+	/**
+	 * Class constructor
+	 */
+	public NodeEventQueue() {
+		m_queue = new LinkedList<NodeEvent>();
+	}
+
+	/**
+	 * Return the number of events in the queue
+	 * 
+	 * @return int
+	 */
+	public final synchronized int numberOfEvents() {
+		return m_queue.size();
+	}
+
+	/**
+	 * Add an event to the queue
+	 * 
+	 * @param evetn NodeEvent
+	 */
+	public final synchronized void addEvent(NodeEvent event) {
+
+		// Add the event to the queue
+
+		m_queue.add( event);
+
+		// Notify a listener that there is an event to process
+
+		notify();
+	}
+
+	/**
+	 * Remove an event from the head of the queue
+	 * 
+	 * @return NodeEvent
+	 * @exception InterruptedException
+	 */
+	public final synchronized NodeEvent removeEvent()
+		throws InterruptedException {
+
+		// Wait until there is an event
+
+		waitWhileEmpty();
+
+		// Get the event from the head of the queue
+
+		return m_queue.removeFirst();
+	}
+
+	/**
+	 * Remove an event from the queue, without waiting if there are no events in the queue
+	 * 
+	 * @return NodeEvent
+	 */
+	public final synchronized NodeEvent removeSessionNoWait() {
+		
+		NodeEvent event = null;
+		
+		if ( m_queue.size() > 0)
+			event = m_queue.removeFirst();
+			
+		return event;
+	}
+	
+	/**
+	 * Wait for an event to be added to the queue
+	 * 
+	 * @exception InterruptedException
+	 */
+	public final synchronized void waitWhileEmpty()
+		throws InterruptedException {
+
+		// Wait until an event arrives on the queue
+
+		while (m_queue.size() == 0)
+			wait();
+	}
+
+	/**
+	 * Wait for the event queue to be emptied
+	 * 
+	 * @exception InterruptedException
+	 */
+	public final synchronized void waitUntilEmpty()
+		throws InterruptedException {
+
+		// Wait until the event queue is empty
+
+		while (m_queue.size() != 0)
+			wait();
+	}
+}