ALF-9613: numerous changes including use of ReentrantReadWriteLock for locking and introduction of a custom cleanup job that does not delete files that are in use by the cache.

git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@30066 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/content/caching/CacheFileProps.java

@@ -0,0 +1,184 @@
+/*
+ * Copyright (C) 2005-2011 Alfresco Software Limited.
+ *
+ * This file is part of Alfresco
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.alfresco.repo.content.caching;
+
+import java.io.BufferedOutputStream;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.Properties;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+/**
+ * Manage a cache file's associated properties.
+ * 
+ * @author Matt Ward
+ */
+public class CacheFileProps
+{
+    private static final String CONTENT_URL = "contentUrl";
+    private static final String DELETE_WATCH_COUNT = "deleteWatchCount";
+    private static final Log log = LogFactory.getLog(CacheFileProps.class);
+    private final Properties properties = new Properties();
+    private final File cacheFile;
+    private final File propsFile;
+    
+    /**
+     * Construct a CacheFileProps specifying which cache file the properties belong to.
+     * 
+     * @param cachedFile
+     */
+    public CacheFileProps(File cacheFile)
+    {
+        this.cacheFile = cacheFile;
+        this.propsFile = fileForCacheFile();
+    }
+
+    /**
+     * Load properties from the cache file's associated properties file.
+     */
+    public void load()
+    {
+        properties.clear();
+        
+        if (propsFile.exists())
+        {
+            try
+            {
+                BufferedReader reader = new BufferedReader(new FileReader(propsFile));
+                properties.load(reader);
+                reader.close();
+            }
+            catch (FileNotFoundException error)
+            {
+                log.error("File disappeared after exists() check: " + cacheFile);
+            }
+            catch (IOException e)
+            {
+                throw new RuntimeException("Unable to read properties file " + cacheFile, e);
+            }
+        }
+    }
+
+    /**
+     * Save properties to the cache file's associated properties file.
+     */
+    public void store()
+    {
+        BufferedOutputStream out = null;
+        try
+        {
+            out = new BufferedOutputStream(new FileOutputStream(propsFile));
+            properties.store(out, "Properties for " + cacheFile);
+        }
+        catch(FileNotFoundException e)
+        {
+            throw new RuntimeException("Couldn't create output stream for file: " + propsFile, e);
+        }
+        catch(IOException e)
+        {
+            throw new RuntimeException("Couldn't write file: " + propsFile, e);
+        }
+        finally 
+        {
+            try
+            {
+                if (out != null) out.close();
+            }
+            catch(IOException e)
+            {
+                // Couldn't close it, just log that it wasn't possible.
+                if (log.isErrorEnabled())
+                {
+                    log.error("Couldn't close file: " + propsFile);
+                }
+            }
+        }
+    }
+    
+    /**
+     * Delete the cache file's associated properties file.
+     */
+    public void delete()
+    {
+        propsFile.delete();
+    }
+    
+    /**
+     * Does a properties file exist for the cache file?
+     * 
+     * @return true if the file exists
+     */
+    public boolean exists()
+    {
+        return propsFile.exists();
+    }
+    
+    /**
+     * Set the value of the contentUrl property.
+     * 
+     * @param url
+     */
+    public void setContentUrl(String url)
+    {
+        properties.setProperty(CONTENT_URL, url);
+    }
+    
+    /**
+     * Get the value of the contentUrl property.
+     * 
+     * @return contentUrl
+     */
+    public String getContentUrl()
+    {
+        return properties.getProperty(CONTENT_URL);
+    }
+    
+    /**
+     * Set the value of the deleteWatchCount property.
+     * 
+     * @param watchCount
+     */
+    public void setDeleteWatchCount(Integer watchCount)
+    {
+        properties.setProperty(DELETE_WATCH_COUNT, watchCount.toString());
+    }
+    
+    /**
+     * Get the value of the deleteWatchCount property.
+     * 
+     * @return deleteWatchCount
+     */
+    public Integer getDeleteWatchCount()
+    {
+        String watchCountStr = properties.getProperty(DELETE_WATCH_COUNT, "0");
+        return Integer.parseInt(watchCountStr);
+    }
+
+    // Generate the path for the properties file, based upon the cache file's path.
+    private File fileForCacheFile()
+    {
+        return new File(cacheFile.getAbsolutePath() + ".properties");
+    }
+}