svn commit: r536904 [12/38] - in /jakarta/jcs/trunk: ./ auxiliary-builds/javagroups/ auxiliary-builds/javagroups/src/java/org/apache/jcs/auxiliary/javagroups/ auxiliary-builds/javagroups/src/test/org/apache/jcs/auxiliary/javagroups/ auxiliary-builds/jd...

Modified: 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCache.java
URL: 
http://svn.apache.org/viewvc/jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCache.java?view=diff&rev=536904&r1=536903&r2=536904
==============================================================================
--- 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCache.java
 (original)
+++ 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCache.java
 Thu May 10 09:03:42 2007
@@ -1,719 +1,729 @@
-package org.apache.jcs.auxiliary.disk.block;
-
-/*
- * Copyright 2001-2004 The Apache Software Foundation. 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.
- */
-
-import java.io.File;
-import java.io.IOException;
-import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
-import org.apache.jcs.auxiliary.disk.AbstractDiskCache;
-import org.apache.jcs.engine.CacheConstants;
-import org.apache.jcs.engine.behavior.ICacheElement;
-import org.apache.jcs.engine.control.group.GroupAttrName;
-import org.apache.jcs.engine.control.group.GroupId;
-import org.apache.jcs.engine.stats.StatElement;
-import org.apache.jcs.engine.stats.Stats;
-import org.apache.jcs.engine.stats.behavior.IStatElement;
-import org.apache.jcs.engine.stats.behavior.IStats;
-
-import EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock;
-
-/**
- * There is one BlockDiskCache per region. It manages the key and data store.
- * <p>
- * @author Aaron Smuts
- */
-public class BlockDiskCache
-    extends AbstractDiskCache
-{
-    /** Don't change */
-    private static final long serialVersionUID = 1L;
-
-    /** The logger. */
-    private static final Log log = LogFactory.getLog( BlockDiskCache.class );
-
-    /** The name to prefix all log messages with. */
-    private final String logCacheName;
-
-    /** The name of the file to store data. */
-    private String fileName;
-
-    /** The data access object */
-    private BlockDisk dataFile;
-
-    /** Attributes governing the behavior of the block disk cache. */
-    private BlockDiskCacheAttributes blockDiskCacheAttributes;
-
-    /** The root directory for keys and data. */
-    private File rootDirectory;
-
-    /** Store, loads, and persists the keys */
-    private BlockDiskKeyStore keyStore;
-
-    /**
-     * Use this lock to synchronize reads and writes to the underlying storage 
mechansism. We don't
-     * need a reentrant lock, since we only lock one level.
-     */
-    // private ReentrantWriterPreferenceReadWriteLock storageLock = new
-    // ReentrantWriterPreferenceReadWriteLock();
-    private WriterPreferenceReadWriteLock storageLock = new 
WriterPreferenceReadWriteLock();
-
-    /**
-     * Constructs the BlockDisk after setting up the root directory.
-     * <p>
-     * @param cacheAttributes
-     */
-    public BlockDiskCache( BlockDiskCacheAttributes cacheAttributes )
-    {
-        super( cacheAttributes );
-
-        this.blockDiskCacheAttributes = cacheAttributes;
-        this.logCacheName = "Region [" + getCacheName() + "] ";
-
-        if ( log.isInfoEnabled() )
-        {
-            log.info( logCacheName + "Constructing BlockDiskCache with 
attributes " + cacheAttributes );
-        }
-
-        this.fileName = getCacheName();
-        String rootDirName = cacheAttributes.getDiskPath();
-        this.rootDirectory = new File( rootDirName );
-        this.rootDirectory.mkdirs();
-
-        if ( log.isInfoEnabled() )
-        {
-            log.info( logCacheName + "Cache file root directory: [" + 
rootDirName + "]" );
-        }
-
-        try
-        {
-            if ( this.blockDiskCacheAttributes.getBlockSizeBytes() > 0 )
-            {
-                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ),
-                                               
this.blockDiskCacheAttributes.getBlockSizeBytes() );
-            }
-            else
-            {
-                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ) );
-            }
-
-            keyStore = new BlockDiskKeyStore( this.blockDiskCacheAttributes, 
this );
-
-            boolean alright = verifyDisk();
-
-            if ( keyStore.size() == 0 || !alright )
-            {
-                this.reset();
-            }
-
-            // Initialization finished successfully, so set alive to true.
-            alive = true;
-            if ( log.isInfoEnabled() )
-            {
-                log.info( logCacheName + "Block Disk Cache is alive." );
-            }
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Failure initializing for fileName: " + 
fileName + " and root directory: "
-                + rootDirName, e );
-        }
-        ShutdownHook shutdownHook = new ShutdownHook();
-        Runtime.getRuntime().addShutdownHook( shutdownHook );
-    }
-
-    /**
-     * We need to verify that the file on disk uses the same block size and 
that the file is the
-     * proper size.
-     * <p>
-     * @return true if it looks ok
-     */
-    protected boolean verifyDisk()
-    {
-        boolean alright = false;
-        // simply try to read a few. If it works, then the file is probably ok.
-        // TODO add more.
-        try
-        {
-            int maxToTest = 100;
-            int count = 0;
-            Set keySet = this.keyStore.entrySet();
-            Iterator it = keySet.iterator();
-            while ( it.hasNext() && count < maxToTest )
-            {
-                count++;
-                Map.Entry entry = (Map.Entry) it.next();
-                Object data = this.dataFile.read( (int[]) entry.getValue() );
-                if ( data == null )
-                {
-                    throw new Exception( "Couldn't find data for key [" + 
entry.getKey() + "]" );
-                }
-            }
-            alright = true;
-        }
-        catch ( Exception e )
-        {
-            log.warn( "Problem verifying disk.  Message [" + e.getMessage() + 
"]" );
-            alright = false;
-        }
-        return alright;
-    }
-
-    /**
-     * This requires a full iteration through the keys.
-     * <p>
-     * (non-Javadoc)
-     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#getGroupKeys(java.lang.String)
-     */
-    public Set getGroupKeys( String groupName )
-    {
-        GroupId groupId = new GroupId( cacheName, groupName );
-        HashSet keys = new HashSet();
-        try
-        {
-            storageLock.readLock().acquire();
-
-            for ( Iterator itr = this.keyStore.keySet().iterator(); 
itr.hasNext(); )
-            {
-                Object k = itr.next();
-                if ( k instanceof GroupAttrName && ( (GroupAttrName) k 
).groupId.equals( groupId ) )
-                {
-                    keys.add( ( (GroupAttrName) k ).attrName );
-                }
-            }
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Failure getting from disk, group = " + 
groupName, e );
-        }
-        finally
-        {
-            storageLock.readLock().release();
-        }
-
-        return keys;
-    }
-
-    /**
-     * Returns the number of keys.
-     * <p>
-     * (non-Javadoc)
-     * @see org.apache.jcs.auxiliary.disk.AbstractDiskCache#getSize()
-     */
-    public int getSize()
-    {
-        return this.keyStore.size();
-    }
-
-    /**
-     * Gets the ICacheElement for the key if it is in the cache. The program 
flow is as follows:
-     * <ol>
-     * <li>Make sure the disk cache is alive.</li>
-     * <li>Get a read lock.</li>
-     * <li>See if the key is in the key store.</li>
-     * <li>If we found a key, ask the BlockDisk for the object at the 
blocks..</li>
-     * <li>Release the lock.</li>
-     * </ol>
-     * (non-Javadoc)
-     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doGet(java.io.Serializable)
-     */
-    protected ICacheElement doGet( Serializable key )
-    {
-        if ( !alive )
-        {
-            if ( log.isDebugEnabled() )
-            {
-                log.debug( logCacheName + "No longer alive so returning null 
for key = " + key );
-            }
-            return null;
-        }
-
-        if ( log.isDebugEnabled() )
-        {
-            log.debug( logCacheName + "Trying to get from disk: " + key );
-        }
-
-        ICacheElement object = null;
-        try
-        {
-            storageLock.readLock().acquire();
-            try
-            {
-                int[] ded = this.keyStore.get( key );
-                if ( ded != null )
-                {
-                    object = (ICacheElement) this.dataFile.read( ded );
-                }
-            }
-            finally
-            {
-                storageLock.readLock().release();
-            }
-        }
-        catch ( IOException ioe )
-        {
-            log.error( logCacheName + "Failure getting from disk--IOException, 
key = " + key, ioe );
-            reset();
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Failure getting from disk, key = " + 
key, e );
-        }
-
-        return object;
-    }
-
-    /**
-     * Writes an element to disk. The program flow is as follows:
-     * <ol>
-     * <li>Aquire write lock.</li>
-     * <li>See id an item exists for this key.</li>
-     * <li>If an itme already exists, add its blocks to the remove list.</li>
-     * <li>Have the Block disk write the item.</li>
-     * <li>Create a descriptor and add it to the key map.</li>
-     * <li>Release the write lock.</li>
-     * </ol>
-     * (non-Javadoc)
-     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doUpdate(org.apache.jcs.engine.behavior.ICacheElement)
-     */
-    protected void doUpdate( ICacheElement element )
-    {
-        if ( !alive )
-        {
-            if ( log.isDebugEnabled() )
-            {
-                log.debug( logCacheName + "No longer alive; aborting put of 
key = " + element.getKey() );
-            }
-            return;
-        }
-
-        int[] old = null;
-        try
-        {
-            // make sure this only locks for one particular cache region
-            storageLock.writeLock().acquire();
-            try
-            {
-                old = this.keyStore.get( element.getKey() );
-
-                if ( old != null )
-                {
-                    this.dataFile.freeBlocks( old );
-                }
-
-                int[] blocks = this.dataFile.write( element );
-
-                this.keyStore.put( element.getKey(), blocks );
-            }
-            finally
-            {
-                storageLock.writeLock().release();
-            }
-
-            if ( log.isDebugEnabled() )
-            {
-                log.debug( logCacheName + "Put to file [" + fileName + "] key 
[" + element.getKey() + "]" );
-            }
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Failure updating element, key: " + 
element.getKey() + " old: " + old, e );
-        }
-        if ( log.isDebugEnabled() )
-        {
-            log.debug( logCacheName + "Storing element on disk, key: " + 
element.getKey() );
-        }
-    }
-
-    /**
-     * Returns true if the removal was succesful; or false if there is nothing 
to remove. Current
-     * implementation always result in a disk orphan.
-     * <p>
-     * (non-Javadoc)
-     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doRemove(java.io.Serializable)
-     */
-    protected boolean doRemove( Serializable key )
-    {
-        if ( !alive )
-        {
-            if ( log.isDebugEnabled() )
-            {
-                log.debug( logCacheName + "No longer alive so returning false 
for key = " + key );
-            }
-            return false;
-        }
-
-        boolean reset = false;
-        boolean removed = false;
-        try
-        {
-            storageLock.writeLock().acquire();
-
-            if ( key instanceof String && key.toString().endsWith( 
CacheConstants.NAME_COMPONENT_DELIMITER ) )
-            {
-                // remove all keys of the same name group.
-
-                Iterator iter = this.keyStore.entrySet().iterator();
-
-                while ( iter.hasNext() )
-                {
-                    Map.Entry entry = (Map.Entry) iter.next();
-
-                    Object k = entry.getKey();
-
-                    if ( k instanceof String && k.toString().startsWith( 
key.toString() ) )
-                    {
-                        int[] ded = this.keyStore.get( key );
-                        this.dataFile.freeBlocks( ded );
-                        iter.remove();
-                        removed = true;
-                        // TODO this needs to update the rmove count separately
-                    }
-                }
-            }
-            else if ( key instanceof GroupId )
-            {
-                // remove all keys of the same name hierarchy.
-                Iterator iter = this.keyStore.entrySet().iterator();
-                while ( iter.hasNext() )
-                {
-                    Map.Entry entry = (Map.Entry) iter.next();
-                    Object k = entry.getKey();
-
-                    if ( k instanceof GroupAttrName && ( (GroupAttrName) k 
).groupId.equals( key ) )
-                    {
-                        int[] ded = this.keyStore.get( key );
-                        this.dataFile.freeBlocks( ded );
-                        iter.remove();
-                        removed = true;
-                    }
-                }
-            }
-            else
-            {
-                // remove single item.
-                int[] ded = this.keyStore.remove( key );
-                removed = ( ded != null );
-                if ( ded != null )
-                {
-                    this.dataFile.freeBlocks( ded );
-                }
-
-                if ( log.isDebugEnabled() )
-                {
-                    log.debug( logCacheName + "Disk removal: Removed from key 
hash, key [" + key + "] removed = "
-                        + removed );
-                }
-            }
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Problem removing element.", e );
-            reset = true;
-        }
-        finally
-        {
-            storageLock.writeLock().release();
-        }
-
-        if ( reset )
-        {
-            reset();
-        }
-
-        return removed;
-    }
-
-    /**
-     * Resets the keyfile, the disk file, and the memory key map.
-     * <p>
-     * (non-Javadoc)
-     * @see org.apache.jcs.auxiliary.disk.AbstractDiskCache#doRemoveAll()
-     */
-    protected void doRemoveAll()
-    {
-        try
-        {
-            reset();
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Problem removing all.", e );
-            reset();
-        }
-    }
-
-    /**
-     * Dispose of the disk cache in a background thread. Joins against this 
thread to put a cap on
-     * the disposal time.
-     * <p>
-     * @todo make dispose window configurable.
-     */
-    public void doDispose()
-    {
-        Runnable disR = new Runnable()
-        {
-            public void run()
-            {
-                try
-                {
-                    disposeInternal();
-                }
-                catch ( InterruptedException e )
-                {
-                    log.warn( "Interrupted while diposing." );
-                }
-            }
-        };
-        Thread t = new Thread( disR, "BlockDiskCache-DisposalThread" );
-        t.start();
-        // wait up to 60 seconds for dispose and then quit if not done.
-        try
-        {
-            t.join( 60 * 1000 );
-        }
-        catch ( InterruptedException ex )
-        {
-            log.error( logCacheName + "Interrupted while waiting for disposal 
thread to finish.", ex );
-        }
-    }
-
-    /**
-     * Internal method that handles the disposal.
-     * @throws InterruptedException
-     */
-    private void disposeInternal()
-        throws InterruptedException
-    {
-        if ( !alive )
-        {
-            log.error( logCacheName + "Not alive and dispose was called, 
filename: " + fileName );
-            return;
-        }
-        storageLock.writeLock().acquire();
-        try
-        {
-            // Prevents any interaction with the cache while we're shutting 
down.
-            alive = false;
-
-            this.keyStore.saveKeys();
-
-            try
-            {
-                if ( log.isDebugEnabled() )
-                {
-                    log.debug( logCacheName + "Closing files, base filename: " 
+ fileName );
-                }
-                dataFile.close();
-                // dataFile = null;
-
-                // TOD make a close
-                // keyFile.close();
-                // keyFile = null;
-            }
-            catch ( IOException e )
-            {
-                log.error( logCacheName + "Failure closing files in dispose, 
filename: " + fileName, e );
-            }
-        }
-        finally
-        {
-            storageLock.writeLock().release();
-        }
-
-        if ( log.isInfoEnabled() )
-        {
-            log.info( logCacheName + "Shutdown complete." );
-        }
-    }
-
-    /**
-     * Returns the attributes.
-     * <p>
-     * (non-Javadoc)
-     * @see 
org.apache.jcs.auxiliary.AuxiliaryCache#getAuxiliaryCacheAttributes()
-     */
-    public AuxiliaryCacheAttributes getAuxiliaryCacheAttributes()
-    {
-        return this.blockDiskCacheAttributes;
-    }
-
-    /**
-     * Reset effectively clears the disk cache, creating new files, 
recyclebins, and keymaps.
-     * <p>
-     * It can be used to handle errors by last resort, force content update, 
or removeall.
-     */
-    private void reset()
-    {
-        if ( log.isWarnEnabled() )
-        {
-            log.warn( logCacheName + "Reseting cache" );
-        }
-
-        try
-        {
-            storageLock.writeLock().acquire();
-
-            if ( dataFile != null )
-            {
-                dataFile.close();
-            }
-            // TODO have the BlockDisk do this itself
-            File dataFileTemp = new File( this.rootDirectory, fileName + 
".data" );
-            dataFileTemp.delete();
-
-            if ( this.blockDiskCacheAttributes.getBlockSizeBytes() > 0 )
-            {
-                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ),
-                                               
this.blockDiskCacheAttributes.getBlockSizeBytes() );
-            }
-            else
-            {
-                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ) );
-            }
-
-            this.keyStore.reset();
-        }
-        catch ( Exception e )
-        {
-            log.error( logCacheName + "Failure reseting state", e );
-        }
-        finally
-        {
-            storageLock.writeLock().release();
-        }
-    }
-
-    /**
-     * Add these blocks to the emptyBlock list.
-     * <p>
-     * @param blocksToFree
-     */
-    protected void freeBlocks( int[] blocksToFree )
-    {
-        this.dataFile.freeBlocks( blocksToFree );
-    }
-
-    /**
-     * Called on shutdown. This gives use a chance to store the keys even if 
the cache manager's
-     * shutdown method was not called.
-     */
-    class ShutdownHook
-        extends Thread
-    {
-        /** Disposes of the cache. This will result force the keys to be 
persisted. */
-        public void run()
-        {
-            if ( alive )
-            {
-                log.warn( logCacheName + "Disk cache not shutdown properly, 
shutting down now." );
-                doDispose();
-            }
-        }
-    }
-
-    /**
-     * Gets basic stats for the disk cache.
-     * <p>
-     * @return String
-     */
-    public String getStats()
-    {
-        return getStatistics().toString();
-    }
-
-    /**
-     * Returns info about the disk cache.
-     * <p>
-     * (non-Javadoc)
-     * @see org.apache.jcs.auxiliary.AuxiliaryCache#getStatistics()
-     */
-    public IStats getStatistics()
-    {
-        IStats stats = new Stats();
-        stats.setTypeName( "Block Disk Cache" );
-
-        ArrayList elems = new ArrayList();
-
-        IStatElement se = null;
-
-        se = new StatElement();
-        se.setName( "Is Alive" );
-        se.setData( "" + alive );
-        elems.add( se );
-
-        se = new StatElement();
-        se.setName( "Key Map Size" );
-        se.setData( "" + this.keyStore.size() );
-        elems.add( se );
-
-        try
-        {
-            se = new StatElement();
-            se.setName( "Data File Length" );
-            if ( this.dataFile != null )
-            {
-                se.setData( "" + this.dataFile.length() );
-            }
-            else
-            {
-                se.setData( "-1" );
-            }
-            elems.add( se );
-        }
-        catch ( Exception e )
-        {
-            log.error( e );
-        }
-
-        se = new StatElement();
-        se.setName( "Block Size Bytes" );
-        se.setData( "" + this.dataFile.getBlockSizeBytes() );
-        elems.add( se );
-
-        se = new StatElement();
-        se.setName( "Number Of Blocks" );
-        se.setData( "" + this.dataFile.getNumberOfBlocks() );
-        elems.add( se );
-
-        se = new StatElement();
-        se.setName( "Average Put Size Bytes" );
-        se.setData( "" + this.dataFile.getAveragePutSizeBytes() );
-        elems.add( se );
-
-        se = new StatElement();
-        se.setName( "Empty Blocks" );
-        se.setData( "" + this.dataFile.getEmptyBlocks() );
-        elems.add( se );
-
-        // get the stats from the super too
-        // get as array, convert to list, add list to our outer list
-        IStats sStats = super.getStatistics();
-        IStatElement[] sSEs = sStats.getStatElements();
-        List sL = Arrays.asList( sSEs );
-        elems.addAll( sL );
-
-        // get an array and put them in the Stats object
-        IStatElement[] ses = (IStatElement[]) elems.toArray( new 
StatElement[0] );
-        stats.setStatElements( ses );
-
-        return stats;
-    }
-}
+package org.apache.jcs.auxiliary.disk.block;
+
+/*
+ * 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.
+ */
+
+import java.io.File;
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
+import org.apache.jcs.auxiliary.disk.AbstractDiskCache;
+import org.apache.jcs.engine.CacheConstants;
+import org.apache.jcs.engine.behavior.ICacheElement;
+import org.apache.jcs.engine.control.group.GroupAttrName;
+import org.apache.jcs.engine.control.group.GroupId;
+import org.apache.jcs.engine.stats.StatElement;
+import org.apache.jcs.engine.stats.Stats;
+import org.apache.jcs.engine.stats.behavior.IStatElement;
+import org.apache.jcs.engine.stats.behavior.IStats;
+
+import EDU.oswego.cs.dl.util.concurrent.WriterPreferenceReadWriteLock;
+
+/**
+ * There is one BlockDiskCache per region. It manages the key and data store.
+ * <p>
+ * @author Aaron Smuts
+ */
+public class BlockDiskCache
+    extends AbstractDiskCache
+{
+    /** Don't change */
+    private static final long serialVersionUID = 1L;
+
+    /** The logger. */
+    private static final Log log = LogFactory.getLog( BlockDiskCache.class );
+
+    /** The name to prefix all log messages with. */
+    private final String logCacheName;
+
+    /** The name of the file to store data. */
+    private String fileName;
+
+    /** The data access object */
+    private BlockDisk dataFile;
+
+    /** Attributes governing the behavior of the block disk cache. */
+    private BlockDiskCacheAttributes blockDiskCacheAttributes;
+
+    /** The root directory for keys and data. */
+    private File rootDirectory;
+
+    /** Store, loads, and persists the keys */
+    private BlockDiskKeyStore keyStore;
+
+    /**
+     * Use this lock to synchronize reads and writes to the underlying storage 
mechansism. We don't
+     * need a reentrant lock, since we only lock one level.
+     */
+    // private ReentrantWriterPreferenceReadWriteLock storageLock = new
+    // ReentrantWriterPreferenceReadWriteLock();
+    private WriterPreferenceReadWriteLock storageLock = new 
WriterPreferenceReadWriteLock();
+
+    /**
+     * Constructs the BlockDisk after setting up the root directory.
+     * <p>
+     * @param cacheAttributes
+     */
+    public BlockDiskCache( BlockDiskCacheAttributes cacheAttributes )
+    {
+        super( cacheAttributes );
+
+        this.blockDiskCacheAttributes = cacheAttributes;
+        this.logCacheName = "Region [" + getCacheName() + "] ";
+
+        if ( log.isInfoEnabled() )
+        {
+            log.info( logCacheName + "Constructing BlockDiskCache with 
attributes " + cacheAttributes );
+        }
+
+        this.fileName = getCacheName();
+        String rootDirName = cacheAttributes.getDiskPath();
+        this.rootDirectory = new File( rootDirName );
+        this.rootDirectory.mkdirs();
+
+        if ( log.isInfoEnabled() )
+        {
+            log.info( logCacheName + "Cache file root directory: [" + 
rootDirName + "]" );
+        }
+
+        try
+        {
+            if ( this.blockDiskCacheAttributes.getBlockSizeBytes() > 0 )
+            {
+                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ),
+                                               
this.blockDiskCacheAttributes.getBlockSizeBytes() );
+            }
+            else
+            {
+                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ) );
+            }
+
+            keyStore = new BlockDiskKeyStore( this.blockDiskCacheAttributes, 
this );
+
+            boolean alright = verifyDisk();
+
+            if ( keyStore.size() == 0 || !alright )
+            {
+                this.reset();
+            }
+
+            // Initialization finished successfully, so set alive to true.
+            alive = true;
+            if ( log.isInfoEnabled() )
+            {
+                log.info( logCacheName + "Block Disk Cache is alive." );
+            }
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Failure initializing for fileName: " + 
fileName + " and root directory: "
+                + rootDirName, e );
+        }
+        ShutdownHook shutdownHook = new ShutdownHook();
+        Runtime.getRuntime().addShutdownHook( shutdownHook );
+    }
+
+    /**
+     * We need to verify that the file on disk uses the same block size and 
that the file is the
+     * proper size.
+     * <p>
+     * @return true if it looks ok
+     */
+    protected boolean verifyDisk()
+    {
+        boolean alright = false;
+        // simply try to read a few. If it works, then the file is probably ok.
+        // TODO add more.
+        try
+        {
+            int maxToTest = 100;
+            int count = 0;
+            Set keySet = this.keyStore.entrySet();
+            Iterator it = keySet.iterator();
+            while ( it.hasNext() && count < maxToTest )
+            {
+                count++;
+                Map.Entry entry = (Map.Entry) it.next();
+                Object data = this.dataFile.read( (int[]) entry.getValue() );
+                if ( data == null )
+                {
+                    throw new Exception( "Couldn't find data for key [" + 
entry.getKey() + "]" );
+                }
+            }
+            alright = true;
+        }
+        catch ( Exception e )
+        {
+            log.warn( "Problem verifying disk.  Message [" + e.getMessage() + 
"]" );
+            alright = false;
+        }
+        return alright;
+    }
+
+    /**
+     * This requires a full iteration through the keys.
+     * <p>
+     * (non-Javadoc)
+     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#getGroupKeys(java.lang.String)
+     */
+    public Set getGroupKeys( String groupName )
+    {
+        GroupId groupId = new GroupId( cacheName, groupName );
+        HashSet keys = new HashSet();
+        try
+        {
+            storageLock.readLock().acquire();
+
+            for ( Iterator itr = this.keyStore.keySet().iterator(); 
itr.hasNext(); )
+            {
+                Object k = itr.next();
+                if ( k instanceof GroupAttrName && ( (GroupAttrName) k 
).groupId.equals( groupId ) )
+                {
+                    keys.add( ( (GroupAttrName) k ).attrName );
+                }
+            }
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Failure getting from disk, group = " + 
groupName, e );
+        }
+        finally
+        {
+            storageLock.readLock().release();
+        }
+
+        return keys;
+    }
+
+    /**
+     * Returns the number of keys.
+     * <p>
+     * (non-Javadoc)
+     * @see org.apache.jcs.auxiliary.disk.AbstractDiskCache#getSize()
+     */
+    public int getSize()
+    {
+        return this.keyStore.size();
+    }
+
+    /**
+     * Gets the ICacheElement for the key if it is in the cache. The program 
flow is as follows:
+     * <ol>
+     * <li>Make sure the disk cache is alive.</li>
+     * <li>Get a read lock.</li>
+     * <li>See if the key is in the key store.</li>
+     * <li>If we found a key, ask the BlockDisk for the object at the 
blocks..</li>
+     * <li>Release the lock.</li>
+     * </ol>
+     * (non-Javadoc)
+     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doGet(java.io.Serializable)
+     */
+    protected ICacheElement doGet( Serializable key )
+    {
+        if ( !alive )
+        {
+            if ( log.isDebugEnabled() )
+            {
+                log.debug( logCacheName + "No longer alive so returning null 
for key = " + key );
+            }
+            return null;
+        }
+
+        if ( log.isDebugEnabled() )
+        {
+            log.debug( logCacheName + "Trying to get from disk: " + key );
+        }
+
+        ICacheElement object = null;
+        try
+        {
+            storageLock.readLock().acquire();
+            try
+            {
+                int[] ded = this.keyStore.get( key );
+                if ( ded != null )
+                {
+                    object = (ICacheElement) this.dataFile.read( ded );
+                }
+            }
+            finally
+            {
+                storageLock.readLock().release();
+            }
+        }
+        catch ( IOException ioe )
+        {
+            log.error( logCacheName + "Failure getting from disk--IOException, 
key = " + key, ioe );
+            reset();
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Failure getting from disk, key = " + 
key, e );
+        }
+
+        return object;
+    }
+
+    /**
+     * Writes an element to disk. The program flow is as follows:
+     * <ol>
+     * <li>Aquire write lock.</li>
+     * <li>See id an item exists for this key.</li>
+     * <li>If an itme already exists, add its blocks to the remove list.</li>
+     * <li>Have the Block disk write the item.</li>
+     * <li>Create a descriptor and add it to the key map.</li>
+     * <li>Release the write lock.</li>
+     * </ol>
+     * (non-Javadoc)
+     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doUpdate(org.apache.jcs.engine.behavior.ICacheElement)
+     */
+    protected void doUpdate( ICacheElement element )
+    {
+        if ( !alive )
+        {
+            if ( log.isDebugEnabled() )
+            {
+                log.debug( logCacheName + "No longer alive; aborting put of 
key = " + element.getKey() );
+            }
+            return;
+        }
+
+        int[] old = null;
+        try
+        {
+            // make sure this only locks for one particular cache region
+            storageLock.writeLock().acquire();
+            try
+            {
+                old = this.keyStore.get( element.getKey() );
+
+                if ( old != null )
+                {
+                    this.dataFile.freeBlocks( old );
+                }
+
+                int[] blocks = this.dataFile.write( element );
+
+                this.keyStore.put( element.getKey(), blocks );
+            }
+            finally
+            {
+                storageLock.writeLock().release();
+            }
+
+            if ( log.isDebugEnabled() )
+            {
+                log.debug( logCacheName + "Put to file [" + fileName + "] key 
[" + element.getKey() + "]" );
+            }
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Failure updating element, key: " + 
element.getKey() + " old: " + old, e );
+        }
+        if ( log.isDebugEnabled() )
+        {
+            log.debug( logCacheName + "Storing element on disk, key: " + 
element.getKey() );
+        }
+    }
+
+    /**
+     * Returns true if the removal was succesful; or false if there is nothing 
to remove. Current
+     * implementation always result in a disk orphan.
+     * <p>
+     * (non-Javadoc)
+     * @see 
org.apache.jcs.auxiliary.disk.AbstractDiskCache#doRemove(java.io.Serializable)
+     */
+    protected boolean doRemove( Serializable key )
+    {
+        if ( !alive )
+        {
+            if ( log.isDebugEnabled() )
+            {
+                log.debug( logCacheName + "No longer alive so returning false 
for key = " + key );
+            }
+            return false;
+        }
+
+        boolean reset = false;
+        boolean removed = false;
+        try
+        {
+            storageLock.writeLock().acquire();
+
+            if ( key instanceof String && key.toString().endsWith( 
CacheConstants.NAME_COMPONENT_DELIMITER ) )
+            {
+                // remove all keys of the same name group.
+
+                Iterator iter = this.keyStore.entrySet().iterator();
+
+                while ( iter.hasNext() )
+                {
+                    Map.Entry entry = (Map.Entry) iter.next();
+
+                    Object k = entry.getKey();
+
+                    if ( k instanceof String && k.toString().startsWith( 
key.toString() ) )
+                    {
+                        int[] ded = this.keyStore.get( key );
+                        this.dataFile.freeBlocks( ded );
+                        iter.remove();
+                        removed = true;
+                        // TODO this needs to update the rmove count separately
+                    }
+                }
+            }
+            else if ( key instanceof GroupId )
+            {
+                // remove all keys of the same name hierarchy.
+                Iterator iter = this.keyStore.entrySet().iterator();
+                while ( iter.hasNext() )
+                {
+                    Map.Entry entry = (Map.Entry) iter.next();
+                    Object k = entry.getKey();
+
+                    if ( k instanceof GroupAttrName && ( (GroupAttrName) k 
).groupId.equals( key ) )
+                    {
+                        int[] ded = this.keyStore.get( key );
+                        this.dataFile.freeBlocks( ded );
+                        iter.remove();
+                        removed = true;
+                    }
+                }
+            }
+            else
+            {
+                // remove single item.
+                int[] ded = this.keyStore.remove( key );
+                removed = ( ded != null );
+                if ( ded != null )
+                {
+                    this.dataFile.freeBlocks( ded );
+                }
+
+                if ( log.isDebugEnabled() )
+                {
+                    log.debug( logCacheName + "Disk removal: Removed from key 
hash, key [" + key + "] removed = "
+                        + removed );
+                }
+            }
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Problem removing element.", e );
+            reset = true;
+        }
+        finally
+        {
+            storageLock.writeLock().release();
+        }
+
+        if ( reset )
+        {
+            reset();
+        }
+
+        return removed;
+    }
+
+    /**
+     * Resets the keyfile, the disk file, and the memory key map.
+     * <p>
+     * (non-Javadoc)
+     * @see org.apache.jcs.auxiliary.disk.AbstractDiskCache#doRemoveAll()
+     */
+    protected void doRemoveAll()
+    {
+        try
+        {
+            reset();
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Problem removing all.", e );
+            reset();
+        }
+    }
+
+    /**
+     * Dispose of the disk cache in a background thread. Joins against this 
thread to put a cap on
+     * the disposal time.
+     * <p>
+     * @todo make dispose window configurable.
+     */
+    public void doDispose()
+    {
+        Runnable disR = new Runnable()
+        {
+            public void run()
+            {
+                try
+                {
+                    disposeInternal();
+                }
+                catch ( InterruptedException e )
+                {
+                    log.warn( "Interrupted while diposing." );
+                }
+            }
+        };
+        Thread t = new Thread( disR, "BlockDiskCache-DisposalThread" );
+        t.start();
+        // wait up to 60 seconds for dispose and then quit if not done.
+        try
+        {
+            t.join( 60 * 1000 );
+        }
+        catch ( InterruptedException ex )
+        {
+            log.error( logCacheName + "Interrupted while waiting for disposal 
thread to finish.", ex );
+        }
+    }
+
+    /**
+     * Internal method that handles the disposal.
+     * @throws InterruptedException
+     */
+    private void disposeInternal()
+        throws InterruptedException
+    {
+        if ( !alive )
+        {
+            log.error( logCacheName + "Not alive and dispose was called, 
filename: " + fileName );
+            return;
+        }
+        storageLock.writeLock().acquire();
+        try
+        {
+            // Prevents any interaction with the cache while we're shutting 
down.
+            alive = false;
+
+            this.keyStore.saveKeys();
+
+            try
+            {
+                if ( log.isDebugEnabled() )
+                {
+                    log.debug( logCacheName + "Closing files, base filename: " 
+ fileName );
+                }
+                dataFile.close();
+                // dataFile = null;
+
+                // TOD make a close
+                // keyFile.close();
+                // keyFile = null;
+            }
+            catch ( IOException e )
+            {
+                log.error( logCacheName + "Failure closing files in dispose, 
filename: " + fileName, e );
+            }
+        }
+        finally
+        {
+            storageLock.writeLock().release();
+        }
+
+        if ( log.isInfoEnabled() )
+        {
+            log.info( logCacheName + "Shutdown complete." );
+        }
+    }
+
+    /**
+     * Returns the attributes.
+     * <p>
+     * (non-Javadoc)
+     * @see 
org.apache.jcs.auxiliary.AuxiliaryCache#getAuxiliaryCacheAttributes()
+     */
+    public AuxiliaryCacheAttributes getAuxiliaryCacheAttributes()
+    {
+        return this.blockDiskCacheAttributes;
+    }
+
+    /**
+     * Reset effectively clears the disk cache, creating new files, 
recyclebins, and keymaps.
+     * <p>
+     * It can be used to handle errors by last resort, force content update, 
or removeall.
+     */
+    private void reset()
+    {
+        if ( log.isWarnEnabled() )
+        {
+            log.warn( logCacheName + "Reseting cache" );
+        }
+
+        try
+        {
+            storageLock.writeLock().acquire();
+
+            if ( dataFile != null )
+            {
+                dataFile.close();
+            }
+            // TODO have the BlockDisk do this itself
+            File dataFileTemp = new File( this.rootDirectory, fileName + 
".data" );
+            dataFileTemp.delete();
+
+            if ( this.blockDiskCacheAttributes.getBlockSizeBytes() > 0 )
+            {
+                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ),
+                                               
this.blockDiskCacheAttributes.getBlockSizeBytes() );
+            }
+            else
+            {
+                this.dataFile = new BlockDisk( new File( rootDirectory, 
fileName + ".data" ) );
+            }
+
+            this.keyStore.reset();
+        }
+        catch ( Exception e )
+        {
+            log.error( logCacheName + "Failure reseting state", e );
+        }
+        finally
+        {
+            storageLock.writeLock().release();
+        }
+    }
+
+    /**
+     * Add these blocks to the emptyBlock list.
+     * <p>
+     * @param blocksToFree
+     */
+    protected void freeBlocks( int[] blocksToFree )
+    {
+        this.dataFile.freeBlocks( blocksToFree );
+    }
+
+    /**
+     * Called on shutdown. This gives use a chance to store the keys even if 
the cache manager's
+     * shutdown method was not called.
+     */
+    class ShutdownHook
+        extends Thread
+    {
+        /** Disposes of the cache. This will result force the keys to be 
persisted. */
+        public void run()
+        {
+            if ( alive )
+            {
+                log.warn( logCacheName + "Disk cache not shutdown properly, 
shutting down now." );
+                doDispose();
+            }
+        }
+    }
+
+    /**
+     * Gets basic stats for the disk cache.
+     * <p>
+     * @return String
+     */
+    public String getStats()
+    {
+        return getStatistics().toString();
+    }
+
+    /**
+     * Returns info about the disk cache.
+     * <p>
+     * (non-Javadoc)
+     * @see org.apache.jcs.auxiliary.AuxiliaryCache#getStatistics()
+     */
+    public IStats getStatistics()
+    {
+        IStats stats = new Stats();
+        stats.setTypeName( "Block Disk Cache" );
+
+        ArrayList elems = new ArrayList();
+
+        IStatElement se = null;
+
+        se = new StatElement();
+        se.setName( "Is Alive" );
+        se.setData( "" + alive );
+        elems.add( se );
+
+        se = new StatElement();
+        se.setName( "Key Map Size" );
+        se.setData( "" + this.keyStore.size() );
+        elems.add( se );
+
+        try
+        {
+            se = new StatElement();
+            se.setName( "Data File Length" );
+            if ( this.dataFile != null )
+            {
+                se.setData( "" + this.dataFile.length() );
+            }
+            else
+            {
+                se.setData( "-1" );
+            }
+            elems.add( se );
+        }
+        catch ( Exception e )
+        {
+            log.error( e );
+        }
+
+        se = new StatElement();
+        se.setName( "Block Size Bytes" );
+        se.setData( "" + this.dataFile.getBlockSizeBytes() );
+        elems.add( se );
+
+        se = new StatElement();
+        se.setName( "Number Of Blocks" );
+        se.setData( "" + this.dataFile.getNumberOfBlocks() );
+        elems.add( se );
+
+        se = new StatElement();
+        se.setName( "Average Put Size Bytes" );
+        se.setData( "" + this.dataFile.getAveragePutSizeBytes() );
+        elems.add( se );
+
+        se = new StatElement();
+        se.setName( "Empty Blocks" );
+        se.setData( "" + this.dataFile.getEmptyBlocks() );
+        elems.add( se );
+
+        // get the stats from the super too
+        // get as array, convert to list, add list to our outer list
+        IStats sStats = super.getStatistics();
+        IStatElement[] sSEs = sStats.getStatElements();
+        List sL = Arrays.asList( sSEs );
+        elems.addAll( sL );
+
+        // get an array and put them in the Stats object
+        IStatElement[] ses = (IStatElement[]) elems.toArray( new 
StatElement[0] );
+        stats.setStatElements( ses );
+
+        return stats;
+    }
+}

Modified: 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheAttributes.java
URL: 
http://svn.apache.org/viewvc/jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheAttributes.java?view=diff&rev=536904&r1=536903&r2=536904
==============================================================================
--- 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheAttributes.java
 (original)
+++ 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheAttributes.java
 Thu May 10 09:03:42 2007
@@ -1,97 +1,116 @@
-package org.apache.jcs.auxiliary.disk.block;
-
-import org.apache.jcs.auxiliary.disk.AbstractDiskCacheAttributes;
-
-/**
- * This holds attributes for Block Disk Cache configuration.
- * <p>
- * @author Aaron Smuts
- */
-public class BlockDiskCacheAttributes
-    extends AbstractDiskCacheAttributes
-{
-    /** Don't change */
-    private static final long serialVersionUID = 6568840097657265989L;
-
-    /** The size per block in bytes. */
-    private int blockSizeBytes;
-
-    /** Maximum number of keys to be kept in memory */
-    private static final int DEFAULT_MAX_KEY_SIZE = 5000;
-
-    /** -1 means no limit. */
-    private int maxKeySize = DEFAULT_MAX_KEY_SIZE;
-    
-    /** How often should we persist the keys. */
-    private static final long DEFAULT_KEY_PERSISTENCE_INTERVAL_SECONDS = 5 * 
60;
-    
-    /** The keys will be persisted at this interval.  -1 mean never. */
-    private long keyPersistenceIntervalSeconds = 
DEFAULT_KEY_PERSISTENCE_INTERVAL_SECONDS;
-        
-    /**
-     * The size of the blocks. All blocks are the same size.
-     * <p>
-     * @param blockSizeBytes The blockSizeBytes to set.
-     */
-    public void setBlockSizeBytes( int blockSizeBytes )
-    {
-        this.blockSizeBytes = blockSizeBytes;
-    }
-
-    /**
-     * @return Returns the blockSizeBytes.
-     */
-    public int getBlockSizeBytes()
-    {
-        return blockSizeBytes;
-    }
-
-    /**
-     * @param maxKeySize The maxKeySize to set.
-     */
-    public void setMaxKeySize( int maxKeySize )
-    {
-        this.maxKeySize = maxKeySize;
-    }
-
-    /**
-     * @return Returns the maxKeySize.
-     */
-    public int getMaxKeySize()
-    {
-        return maxKeySize;
-    }
-
-    /**
-     * @param keyPersistenceIntervalSeconds The keyPersistenceIntervalSeconds 
to set.
-     */
-    public void setKeyPersistenceIntervalSeconds( long 
keyPersistenceIntervalSeconds )
-    {
-        this.keyPersistenceIntervalSeconds = keyPersistenceIntervalSeconds;
-    }
-
-    /**
-     * @return Returns the keyPersistenceIntervalSeconds.
-     */
-    public long getKeyPersistenceIntervalSeconds()
-    {
-        return keyPersistenceIntervalSeconds;
-    }
-
-    /**
-     * Write out the values for debugging purposes.
-     * <p>
-     * @return String
-     */
-    public String toString()
-    {
-        StringBuffer str = new StringBuffer();
-        str.append( "\nBlockDiskAttributes " );
-        str.append( "\n DiskPath [" + this.getDiskPath() + "]" );
-        str.append( "\n MaxKeySize [" + this.getMaxKeySize() + "]" );
-        str.append( "\n MaxPurgatorySize [" + this.getMaxPurgatorySize() + "]" 
);
-        str.append( "\n BlockSizeBytes [" + this.getBlockSizeBytes() + "]" );
-        str.append( "\n KeyPersistenceIntervalSeconds [" + 
this.getKeyPersistenceIntervalSeconds() + "]" );
-        return str.toString();
-    }
-}
+package org.apache.jcs.auxiliary.disk.block;
+
+/*
+ * 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.
+ */
+
+import org.apache.jcs.auxiliary.disk.AbstractDiskCacheAttributes;
+
+/**
+ * This holds attributes for Block Disk Cache configuration.
+ * <p>
+ * @author Aaron Smuts
+ */
+public class BlockDiskCacheAttributes
+    extends AbstractDiskCacheAttributes
+{
+    /** Don't change */
+    private static final long serialVersionUID = 6568840097657265989L;
+
+    /** The size per block in bytes. */
+    private int blockSizeBytes;
+
+    /** Maximum number of keys to be kept in memory */
+    private static final int DEFAULT_MAX_KEY_SIZE = 5000;
+
+    /** -1 means no limit. */
+    private int maxKeySize = DEFAULT_MAX_KEY_SIZE;
+
+    /** How often should we persist the keys. */
+    private static final long DEFAULT_KEY_PERSISTENCE_INTERVAL_SECONDS = 5 * 
60;
+
+    /** The keys will be persisted at this interval.  -1 mean never. */
+    private long keyPersistenceIntervalSeconds = 
DEFAULT_KEY_PERSISTENCE_INTERVAL_SECONDS;
+
+    /**
+     * The size of the blocks. All blocks are the same size.
+     * <p>
+     * @param blockSizeBytes The blockSizeBytes to set.
+     */
+    public void setBlockSizeBytes( int blockSizeBytes )
+    {
+        this.blockSizeBytes = blockSizeBytes;
+    }
+
+    /**
+     * @return Returns the blockSizeBytes.
+     */
+    public int getBlockSizeBytes()
+    {
+        return blockSizeBytes;
+    }
+
+    /**
+     * @param maxKeySize The maxKeySize to set.
+     */
+    public void setMaxKeySize( int maxKeySize )
+    {
+        this.maxKeySize = maxKeySize;
+    }
+
+    /**
+     * @return Returns the maxKeySize.
+     */
+    public int getMaxKeySize()
+    {
+        return maxKeySize;
+    }
+
+    /**
+     * @param keyPersistenceIntervalSeconds The keyPersistenceIntervalSeconds 
to set.
+     */
+    public void setKeyPersistenceIntervalSeconds( long 
keyPersistenceIntervalSeconds )
+    {
+        this.keyPersistenceIntervalSeconds = keyPersistenceIntervalSeconds;
+    }
+
+    /**
+     * @return Returns the keyPersistenceIntervalSeconds.
+     */
+    public long getKeyPersistenceIntervalSeconds()
+    {
+        return keyPersistenceIntervalSeconds;
+    }
+
+    /**
+     * Write out the values for debugging purposes.
+     * <p>
+     * @return String
+     */
+    public String toString()
+    {
+        StringBuffer str = new StringBuffer();
+        str.append( "\nBlockDiskAttributes " );
+        str.append( "\n DiskPath [" + this.getDiskPath() + "]" );
+        str.append( "\n MaxKeySize [" + this.getMaxKeySize() + "]" );
+        str.append( "\n MaxPurgatorySize [" + this.getMaxPurgatorySize() + "]" 
);
+        str.append( "\n BlockSizeBytes [" + this.getBlockSizeBytes() + "]" );
+        str.append( "\n KeyPersistenceIntervalSeconds [" + 
this.getKeyPersistenceIntervalSeconds() + "]" );
+        return str.toString();
+    }
+}

Modified: 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheFactory.java
URL: 
http://svn.apache.org/viewvc/jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheFactory.java?view=diff&rev=536904&r1=536903&r2=536904
==============================================================================
--- 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheFactory.java
 (original)
+++ 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheFactory.java
 Thu May 10 09:03:42 2007
@@ -1,75 +1,85 @@
-package org.apache.jcs.auxiliary.disk.block;
-
-/*
- * Copyright 2001-2004 The Apache Software Foundation. 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.
- */
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.jcs.auxiliary.AuxiliaryCache;
-import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
-import org.apache.jcs.auxiliary.AuxiliaryCacheFactory;
-import org.apache.jcs.engine.behavior.ICompositeCacheManager;
-
-/**
- * Creates disk cache instances.
- */
-public class BlockDiskCacheFactory
-    implements AuxiliaryCacheFactory
-{
-    /** The logger */
-    private final static Log log = LogFactory.getLog( 
BlockDiskCacheFactory.class );
-
-    /** The auxiliary name */
-    private String name;
-
-    /**
-     * Get an instance of the BlockDiskCacheManager for the attributes and 
then get an
-     * IndexedDiskCache from the manager.
-     * <p>
-     * The manager is a singleton.
-     * <p>
-     * One disk cache is returned per region fromt he maanger.
-     * <p>
-     * @param iaca
-     * @param cacheMgr This allows auxiliaries to reference the manager 
without assuming that it is
-     *            a singleton. This will allow JCS to be a nonsingleton. Also, 
it makes it easier to
-     *            test.
-     * @return AuxiliaryCache
-     */
-    public AuxiliaryCache createCache( AuxiliaryCacheAttributes iaca, 
ICompositeCacheManager cacheMgr )
-    {
-        BlockDiskCacheAttributes idca = (BlockDiskCacheAttributes) iaca;
-        if ( log.isDebugEnabled() )
-        {
-            log.debug( "Creating DiskCache for attributes = " + idca );
-        }
-        BlockDiskCacheManager dcm = BlockDiskCacheManager.getInstance( idca );
-        return dcm.getCache( idca );
-    }
-
-    /**
-     * Gets the name attribute of the DiskCacheFactory object
-     * <p>
-     * @return The name value
-     */
-    public String getName()
-    {
-        return this.name;
-    }
-
-    /**
-     * Sets the name attribute of the DiskCacheFactory object
-     * <p>
-     * @param name The new name value
-     */
-    public void setName( String name )
-    {
-        this.name = name;
-    }
-}
+package org.apache.jcs.auxiliary.disk.block;
+
+/*
+ * 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.
+ */
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.jcs.auxiliary.AuxiliaryCache;
+import org.apache.jcs.auxiliary.AuxiliaryCacheAttributes;
+import org.apache.jcs.auxiliary.AuxiliaryCacheFactory;
+import org.apache.jcs.engine.behavior.ICompositeCacheManager;
+
+/**
+ * Creates disk cache instances.
+ */
+public class BlockDiskCacheFactory
+    implements AuxiliaryCacheFactory
+{
+    /** The logger */
+    private final static Log log = LogFactory.getLog( 
BlockDiskCacheFactory.class );
+
+    /** The auxiliary name */
+    private String name;
+
+    /**
+     * Get an instance of the BlockDiskCacheManager for the attributes and 
then get an
+     * IndexedDiskCache from the manager.
+     * <p>
+     * The manager is a singleton.
+     * <p>
+     * One disk cache is returned per region fromt he maanger.
+     * <p>
+     * @param iaca
+     * @param cacheMgr This allows auxiliaries to reference the manager 
without assuming that it is
+     *            a singleton. This will allow JCS to be a nonsingleton. Also, 
it makes it easier to
+     *            test.
+     * @return AuxiliaryCache
+     */
+    public AuxiliaryCache createCache( AuxiliaryCacheAttributes iaca, 
ICompositeCacheManager cacheMgr )
+    {
+        BlockDiskCacheAttributes idca = (BlockDiskCacheAttributes) iaca;
+        if ( log.isDebugEnabled() )
+        {
+            log.debug( "Creating DiskCache for attributes = " + idca );
+        }
+        BlockDiskCacheManager dcm = BlockDiskCacheManager.getInstance( idca );
+        return dcm.getCache( idca );
+    }
+
+    /**
+     * Gets the name attribute of the DiskCacheFactory object
+     * <p>
+     * @return The name value
+     */
+    public String getName()
+    {
+        return this.name;
+    }
+
+    /**
+     * Sets the name attribute of the DiskCacheFactory object
+     * <p>
+     * @param name The new name value
+     */
+    public void setName( String name )
+    {
+        this.name = name;
+    }
+}

Modified: 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheManager.java
URL: 
http://svn.apache.org/viewvc/jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheManager.java?view=diff&rev=536904&r1=536903&r2=536904
==============================================================================
--- 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheManager.java
 (original)
+++ 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskCacheManager.java
 Thu May 10 09:03:42 2007
@@ -1,206 +1,214 @@
-package org.apache.jcs.auxiliary.disk.block;
-
-/*
- * Copyright 2001-2004 The Apache Software Foundation. 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.
- */
-
-import java.util.Enumeration;
-import java.util.Hashtable;
-
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.apache.jcs.auxiliary.AuxiliaryCache;
-import org.apache.jcs.auxiliary.AuxiliaryCacheManager;
-import org.apache.jcs.engine.behavior.ICache;
-
-/**
- * Cache manager for BlockDiskCaches. This manages the instances of the disk
- * cache.
- */
-public class BlockDiskCacheManager
-    implements AuxiliaryCacheManager
-{
-    /** Don't change */
-    private static final long serialVersionUID = -4153287154512274626L;
-
-    /** The logger */
-    private final static Log log = LogFactory.getLog( 
BlockDiskCacheManager.class );
-
-    /** ? */
-    private static int clients;
-
-    /** The singleton instance */
-    private static BlockDiskCacheManager instance;
-
-    /** block disks for a region. */
-    private Hashtable caches = new Hashtable();
-
-    /** Attributes. */
-    private BlockDiskCacheAttributes defaultCacheAttributes;
-
-    /**
-     * Constructor for the BlockDiskCacheManager object
-     * <p>
-     * @param defaultCacheAttributes
-     *            Default attributes for caches managed by the instance.
-     */
-    private BlockDiskCacheManager( BlockDiskCacheAttributes 
defaultCacheAttributes )
-    {
-        this.defaultCacheAttributes = defaultCacheAttributes;
-    }
-
-    /**
-     * Gets the singleton instance of the manager
-     * <p>
-     * @param defaultCacheAttributes
-     *            If the instance has not yet been created, it will be
-     *            initialized with this set of default attributes.
-     * @return The instance value
-     */
-    public static BlockDiskCacheManager getInstance( BlockDiskCacheAttributes 
defaultCacheAttributes )
-    {
-        synchronized ( BlockDiskCacheManager.class )
-        {
-            if ( instance == null )
-            {
-                instance = new BlockDiskCacheManager( defaultCacheAttributes );
-            }
-        }
-
-        clients++;
-
-        return instance;
-    }
-
-    /**
-     * Gets an BlockDiskCache for the supplied name using the default
-     * attributes.
-     * <p>
-     * @param cacheName
-     *            Name that will be used when creating attributes.
-     * @return A cache.
-     */
-    public AuxiliaryCache getCache( String cacheName )
-    {
-        BlockDiskCacheAttributes cacheAttributes = (BlockDiskCacheAttributes) 
defaultCacheAttributes.copy();
-
-        cacheAttributes.setCacheName( cacheName );
-
-        return getCache( cacheAttributes );
-    }
-
-    /**
-     * Get an BlockDiskCache for the supplied attributes. Will provide an
-     * existing cache for the name attribute if one has been created, or will
-     * create a new cache.
-     * <p>
-     * @param cacheAttributes
-     *            Attributes the cache should have.
-     * @return A cache, either from the existing set or newly created.
-     */
-    public AuxiliaryCache getCache( BlockDiskCacheAttributes cacheAttributes )
-    {
-        AuxiliaryCache cache = null;
-
-        String cacheName = cacheAttributes.getCacheName();
-
-        log.debug( "Getting cache named: " + cacheName );
-
-        synchronized ( caches )
-        {
-            // Try to load the cache from the set that have already been
-            // created. This only looks at the name attribute.
-
-            cache = (AuxiliaryCache) caches.get( cacheName );
-
-            // If it was not found, create a new one using the supplied
-            // attributes
-
-            if ( cache == null )
-            {
-                cache = new BlockDiskCache( cacheAttributes );
-
-                caches.put( cacheName, cache );
-            }
-        }
-
-        return cache;
-    }
-
-    /**
-     * Disposes the cache with the given name, if found in the set of managed
-     * caches.
-     * <p>
-     * @param cacheName
-     *            Name of cache to dispose.
-     */
-    public void freeCache( String cacheName )
-    {
-        ICache cache = (ICache) caches.get( cacheName );
-
-        if ( cache != null )
-        {
-            try
-            {
-                cache.dispose();
-            }
-            catch ( Exception e )
-            {
-                log.error( "Failure disposing cache: " + cacheName, e );
-            }
-        }
-    }
-
-    /**
-     * Gets the cacheType attribute of the DiskCacheManager object
-     * <p>
-     * @return The cacheType value
-     */
-    public int getCacheType()
-    {
-        return DISK_CACHE;
-    }
-
-    /**
-     * Releases the cache manager instance. When all clients have released the
-     * cache manager, all contained caches will be disposed.
-     */
-    public void release()
-    {
-        clients--;
-
-        if ( --clients != 0 )
-        {
-            return;
-        }
-
-        synchronized ( caches )
-        {
-            Enumeration allCaches = caches.elements();
-
-            while ( allCaches.hasMoreElements() )
-            {
-                ICache cache = (ICache) allCaches.nextElement();
-
-                if ( cache != null )
-                {
-                    try
-                    {
-                        cache.dispose();
-                    }
-                    catch ( Exception e )
-                    {
-                        log.error( "Failure disposing cache: " + 
cache.getCacheName(), e );
-                    }
-                }
-            }
-        }
-    }
-}
+package org.apache.jcs.auxiliary.disk.block;
+
+/*
+ * 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.
+ */
+
+import java.util.Enumeration;
+import java.util.Hashtable;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.jcs.auxiliary.AuxiliaryCache;
+import org.apache.jcs.auxiliary.AuxiliaryCacheManager;
+import org.apache.jcs.engine.behavior.ICache;
+
+/**
+ * Cache manager for BlockDiskCaches. This manages the instances of the disk
+ * cache.
+ */
+public class BlockDiskCacheManager
+    implements AuxiliaryCacheManager
+{
+    /** Don't change */
+    private static final long serialVersionUID = -4153287154512274626L;
+
+    /** The logger */
+    private final static Log log = LogFactory.getLog( 
BlockDiskCacheManager.class );
+
+    /** ? */
+    private static int clients;
+
+    /** The singleton instance */
+    private static BlockDiskCacheManager instance;
+
+    /** block disks for a region. */
+    private Hashtable caches = new Hashtable();
+
+    /** Attributes. */
+    private BlockDiskCacheAttributes defaultCacheAttributes;
+
+    /**
+     * Constructor for the BlockDiskCacheManager object
+     * <p>
+     * @param defaultCacheAttributes
+     *            Default attributes for caches managed by the instance.
+     */
+    private BlockDiskCacheManager( BlockDiskCacheAttributes 
defaultCacheAttributes )
+    {
+        this.defaultCacheAttributes = defaultCacheAttributes;
+    }
+
+    /**
+     * Gets the singleton instance of the manager
+     * <p>
+     * @param defaultCacheAttributes
+     *            If the instance has not yet been created, it will be
+     *            initialized with this set of default attributes.
+     * @return The instance value
+     */
+    public static BlockDiskCacheManager getInstance( BlockDiskCacheAttributes 
defaultCacheAttributes )
+    {
+        synchronized ( BlockDiskCacheManager.class )
+        {
+            if ( instance == null )
+            {
+                instance = new BlockDiskCacheManager( defaultCacheAttributes );
+            }
+        }
+
+        clients++;
+
+        return instance;
+    }
+
+    /**
+     * Gets an BlockDiskCache for the supplied name using the default
+     * attributes.
+     * <p>
+     * @param cacheName
+     *            Name that will be used when creating attributes.
+     * @return A cache.
+     */
+    public AuxiliaryCache getCache( String cacheName )
+    {
+        BlockDiskCacheAttributes cacheAttributes = (BlockDiskCacheAttributes) 
defaultCacheAttributes.copy();
+
+        cacheAttributes.setCacheName( cacheName );
+
+        return getCache( cacheAttributes );
+    }
+
+    /**
+     * Get an BlockDiskCache for the supplied attributes. Will provide an
+     * existing cache for the name attribute if one has been created, or will
+     * create a new cache.
+     * <p>
+     * @param cacheAttributes
+     *            Attributes the cache should have.
+     * @return A cache, either from the existing set or newly created.
+     */
+    public AuxiliaryCache getCache( BlockDiskCacheAttributes cacheAttributes )
+    {
+        AuxiliaryCache cache = null;
+
+        String cacheName = cacheAttributes.getCacheName();
+
+        log.debug( "Getting cache named: " + cacheName );
+
+        synchronized ( caches )
+        {
+            // Try to load the cache from the set that have already been
+            // created. This only looks at the name attribute.
+
+            cache = (AuxiliaryCache) caches.get( cacheName );
+
+            // If it was not found, create a new one using the supplied
+            // attributes
+
+            if ( cache == null )
+            {
+                cache = new BlockDiskCache( cacheAttributes );
+
+                caches.put( cacheName, cache );
+            }
+        }
+
+        return cache;
+    }
+
+    /**
+     * Disposes the cache with the given name, if found in the set of managed
+     * caches.
+     * <p>
+     * @param cacheName
+     *            Name of cache to dispose.
+     */
+    public void freeCache( String cacheName )
+    {
+        ICache cache = (ICache) caches.get( cacheName );
+
+        if ( cache != null )
+        {
+            try
+            {
+                cache.dispose();
+            }
+            catch ( Exception e )
+            {
+                log.error( "Failure disposing cache: " + cacheName, e );
+            }
+        }
+    }
+
+    /**
+     * Gets the cacheType attribute of the DiskCacheManager object
+     * <p>
+     * @return The cacheType value
+     */
+    public int getCacheType()
+    {
+        return DISK_CACHE;
+    }
+
+    /**
+     * Releases the cache manager instance. When all clients have released the
+     * cache manager, all contained caches will be disposed.
+     */
+    public void release()
+    {
+        clients--;
+
+        if ( --clients != 0 )
+        {
+            return;
+        }
+
+        synchronized ( caches )
+        {
+            Enumeration allCaches = caches.elements();
+
+            while ( allCaches.hasMoreElements() )
+            {
+                ICache cache = (ICache) allCaches.nextElement();
+
+                if ( cache != null )
+                {
+                    try
+                    {
+                        cache.dispose();
+                    }
+                    catch ( Exception e )
+                    {
+                        log.error( "Failure disposing cache: " + 
cache.getCacheName(), e );
+                    }
+                }
+            }
+        }
+    }
+}

Modified: 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskElementDescriptor.java
URL: 
http://svn.apache.org/viewvc/jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskElementDescriptor.java?view=diff&rev=536904&r1=536903&r2=536904
==============================================================================
--- 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskElementDescriptor.java
 (original)
+++ 
jakarta/jcs/trunk/src/java/org/apache/jcs/auxiliary/disk/block/BlockDiskElementDescriptor.java
 Thu May 10 09:03:42 2007
@@ -1,118 +1,128 @@
-package org.apache.jcs.auxiliary.disk.block;
-
-/*
- * Copyright 2001-2004 The Apache Software Foundation. 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.
- */
-
-import java.io.Externalizable;
-import java.io.IOException;
-import java.io.ObjectInput;
-import java.io.ObjectOutput;
-import java.io.Serializable;
-
-/**
- * This represents an element on disk. This is used when we persist the keys. 
We only store the
- * block addresses in memory. We don't need the length here, since all the 
blocks are the same size
- * receyle bin.
- * <p>
- * @author Aaron Smuts
- */
-public class BlockDiskElementDescriptor
-    implements Serializable, Externalizable
-{
-    /** Don't change */
-    private static final long serialVersionUID = -1400659301208101411L;
-
-    /** The key */
-    private Serializable key;
-
-    /** The array of block numbers */
-    private int[] blocks;
-
-    /**
-     * @param key The key to set.
-     */
-    public void setKey( Serializable key )
-    {
-        this.key = key;
-    }
-
-    /**
-     * @return Returns the key.
-     */
-    public Serializable getKey()
-    {
-        return key;
-    }
-
-    /**
-     * @param blocks The blocks to set.
-     */
-    public void setBlocks( int[] blocks )
-    {
-        this.blocks = blocks;
-    }
-
-    /**
-     * This holds the block numbers. An item my be dispersed between multiple 
blocks.
-     * <p>
-     * @return Returns the blocks.
-     */
-    public int[] getBlocks()
-    {
-        return blocks;
-    }
-
-    /**
-     * For debugging.
-     * <p>
-     * @return Info on the descriptor. 
-     */
-    public String toString()
-    {
-        StringBuffer buf = new StringBuffer();
-        buf.append( "\nBlockDiskElementDescriptor" );
-        buf.append( "\n key [" + this.getKey() + "]" );
-        buf.append( "\n blocks [" );
-        if ( this.getBlocks() != null )
-        {
-            for ( int i = 0; i < blocks.length; i++ )
-            {
-                buf.append( this.getBlocks()[i] );
-            }
-        }
-        buf.append( "]" );
-        return buf.toString();
-    }
-
-    /**
-     * Saves on reflection.
-     * <p>
-     * (non-Javadoc)
-     * @see java.io.Externalizable#readExternal(java.io.ObjectInput)
-     */
-    public void readExternal( ObjectInput input )
-        throws IOException, ClassNotFoundException
-    {
-        this.key = (Serializable) input.readObject();
-        this.blocks = (int[]) input.readObject();
-    }
-
-    /**
-     * Saves on reflection.
-     * <p>
-     * (non-Javadoc)
-     * @see java.io.Externalizable#writeExternal(java.io.ObjectOutput)
-     */
-    public void writeExternal( ObjectOutput output )
-        throws IOException
-    {
-        output.writeObject( this.key );
-        output.writeObject( this.blocks );
-    }
-}
+package org.apache.jcs.auxiliary.disk.block;
+
+/*
+ * 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.
+ */
+
+import java.io.Externalizable;
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.Serializable;
+
+/**
+ * This represents an element on disk. This is used when we persist the keys. 
We only store the
+ * block addresses in memory. We don't need the length here, since all the 
blocks are the same size
+ * receyle bin.
+ * <p>
+ * @author Aaron Smuts
+ */
+public class BlockDiskElementDescriptor
+    implements Serializable, Externalizable
+{
+    /** Don't change */
+    private static final long serialVersionUID = -1400659301208101411L;
+
+    /** The key */
+    private Serializable key;
+
+    /** The array of block numbers */
+    private int[] blocks;
+
+    /**
+     * @param key The key to set.
+     */
+    public void setKey( Serializable key )
+    {
+        this.key = key;
+    }
+
+    /**
+     * @return Returns the key.
+     */
+    public Serializable getKey()
+    {
+        return key;
+    }
+
+    /**
+     * @param blocks The blocks to set.
+     */
+    public void setBlocks( int[] blocks )
+    {
+        this.blocks = blocks;
+    }
+
+    /**
+     * This holds the block numbers. An item my be dispersed between multiple 
blocks.
+     * <p>
+     * @return Returns the blocks.
+     */
+    public int[] getBlocks()
+    {
+        return blocks;
+    }
+
+    /**
+     * For debugging.
+     * <p>
+     * @return Info on the descriptor.
+     */
+    public String toString()
+    {
+        StringBuffer buf = new StringBuffer();
+        buf.append( "\nBlockDiskElementDescriptor" );
+        buf.append( "\n key [" + this.getKey() + "]" );
+        buf.append( "\n blocks [" );
+        if ( this.getBlocks() != null )
+        {
+            for ( int i = 0; i < blocks.length; i++ )
+            {
+                buf.append( this.getBlocks()[i] );
+            }
+        }
+        buf.append( "]" );
+        return buf.toString();
+    }
+
+    /**
+     * Saves on reflection.
+     * <p>
+     * (non-Javadoc)
+     * @see java.io.Externalizable#readExternal(java.io.ObjectInput)
+     */
+    public void readExternal( ObjectInput input )
+        throws IOException, ClassNotFoundException
+    {
+        this.key = (Serializable) input.readObject();
+        this.blocks = (int[]) input.readObject();
+    }
+
+    /**
+     * Saves on reflection.
+     * <p>
+     * (non-Javadoc)
+     * @see java.io.Externalizable#writeExternal(java.io.ObjectOutput)
+     */
+    public void writeExternal( ObjectOutput output )
+        throws IOException
+    {
+        output.writeObject( this.key );
+        output.writeObject( this.blocks );
+    }
+}