Checkpoint of file state refactoring.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/BRANCHES/WCM-DEV2/root@4417 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/filesys/server/state/FileStateReaper.java

@@ -0,0 +1,215 @@
+/*
+ * Copyright (C) 2006 Alfresco, Inc.
+ *
+ * Licensed under the Mozilla Public License version 1.1 
+ * with a permitted attribution clause. You may obtain a
+ * copy of the License at
+ *
+ *   http://www.alfresco.org/legal/license.txt
+ *
+ * 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.alfresco.filesys.server.state;
+
+import java.util.Enumeration;
+import java.util.Hashtable;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * File State Reaper Class
+ * 
+ * <p>FileStateTable objects register with the file state reaper to periodically check for expired file states.
+ *
+ * @author gkspencer
+ */
+public class FileStateReaper implements Runnable {
+
+	// Logging
+	
+    private static final Log logger = LogFactory.getLog(FileStateReaper.class);
+
+    // Default expire check thread interval
+
+    private static final long DEFAULT_EXPIRECHECK = 15000;
+
+    // Wakeup interval for the expire file state checker thread
+
+    private long m_expireInterval = DEFAULT_EXPIRECHECK;
+    
+    //	File state checker thread
+    
+    private Thread m_thread;
+    
+    //	Shutdown request flag
+    
+    private boolean m_shutdown;
+
+    // List of file state tables to be scanned for expired file states
+
+    private Hashtable<String, FileStateTable> m_stateTables;
+    
+    /**
+     * Default constructor
+     */
+    public FileStateReaper()
+    {
+    	// Create the reaper thread
+    	
+        m_thread = new Thread(this);
+        m_thread.setDaemon(true);
+        m_thread.setName("FileStateReaper");
+        m_thread.start();
+        
+        // Create the file state table list
+        
+        m_stateTables = new Hashtable<String, FileStateTable>();
+    }
+    
+    /**
+     * Return the expired file state checker interval, in milliseconds
+     * 
+     * @return long
+     */
+    public final long getCheckInterval()
+    {
+        return m_expireInterval;
+    }
+
+    /**
+     * Set the expired file state checker interval, in milliseconds
+     * 
+     * @param chkIntval long
+     */
+    public final void setCheckInterval(long chkIntval)
+    {
+        m_expireInterval = chkIntval;
+    }
+
+    /**
+     * Add a file state table to the reaper list
+     * 
+     * @param filesysName String
+     * @param stateTable FileStateTable
+     */
+    public final void addStateTable( String filesysName, FileStateTable stateTable)
+    {
+    	// DEBUG
+    	
+    	if ( logger.isDebugEnabled())
+    		logger.debug( "Added file state table for " + filesysName);
+    	
+    	m_stateTables.put( filesysName, stateTable);
+    }
+    
+    /**
+     * Remove a state table from the reaper list
+     * 
+     * @param filesysName String
+     */
+    public final void removeStateTable( String filesysName)
+    {
+    	m_stateTables.remove( filesysName);
+
+    	// DEBUG
+    	
+    	if ( logger.isDebugEnabled())
+    		logger.debug( "Removed file state table for " + filesysName);
+    	
+    }
+    
+    /**
+     * Expired file state checker thread
+     */
+    public void run()
+    {
+        // Loop forever
+
+    	m_shutdown = false;
+    	
+        while ( m_shutdown == false)
+        {
+
+            // Sleep for the required interval
+
+            try
+            {
+                Thread.sleep(getCheckInterval());
+            }
+            catch (InterruptedException ex)
+            {
+            }
+
+            //	Check for shutdown
+            
+            if ( m_shutdown == true)
+            {
+            	//	Debug
+            	
+            	if ( logger.isDebugEnabled())
+            		logger.debug("FileStateReaper thread closing");
+
+            	return;
+            }
+            
+            // Check if there are any state tables registered
+            
+            if ( m_stateTables != null && m_stateTables.size() > 0)
+            {
+	            try
+	            {
+	            	// Loop through the registered file state tables and remove expired file states
+	            	
+	            	Enumeration<String> filesysNames = m_stateTables.keys();
+	            	
+	            	while ( filesysNames.hasMoreElements())
+	            	{
+	            		// Get the current filesystem name and associated state table
+	            		
+	            		String filesysName = filesysNames.nextElement();
+	            		FileStateTable stateTable = m_stateTables.get( filesysName);
+	            		
+		                // Check for expired file states
+		
+		                int cnt = stateTable.removeExpiredFileStates();
+		
+		                // Debug
+		
+		                if (logger.isDebugEnabled() && cnt > 0)
+		                    logger.debug("Expired " + cnt + " file states for " + filesysName + ", cache=" + stateTable.numberOfStates());
+	            	}
+	            }
+	            catch (Exception ex)
+	            {
+	            	// Log errors if not shutting down
+	            	
+	            	if ( m_shutdown == false)
+	            		logger.debug(ex);
+	            }
+            }
+        }
+    }
+
+	/**
+	 * Request the file state checker thread to shutdown
+	 */
+	public final void shutdownRequest() {
+		m_shutdown = true;
+		
+		if ( m_thread != null)
+		{
+			try {
+				m_thread.interrupt();
+			}
+			catch (Exception ex) {
+			}
+		}
+	}
+}