src/java/org/eclipse/jetty/server/ResourceCache.java - platform/external/jetty - Git at Google

 //
 //  ========================================================================
 //  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
 //  ------------------------------------------------------------------------
 //  All rights reserved. This program and the accompanying materials
 //  are made available under the terms of the Eclipse Public License v1.0
 //  and Apache License v2.0 which accompanies this distribution.
 //
 //      The Eclipse Public License is available at
 //      http://www.eclipse.org/legal/epl-v10.html
 //
 //      The Apache License v2.0 is available at
 //      http://www.opensource.org/licenses/apache2.0.php
 //
 //  You may elect to redistribute this code under either of these licenses.
 //  ========================================================================
 //

 package org.eclipse.jetty.server;

 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Comparator;
 import java.util.SortedSet;
 import java.util.TreeSet;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;

 import org.eclipse.jetty.http.HttpContent;
 import org.eclipse.jetty.http.HttpContent.ResourceAsHttpContent;
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.MimeTypes;
 import org.eclipse.jetty.io.Buffer;
 import org.eclipse.jetty.io.ByteArrayBuffer;
 import org.eclipse.jetty.io.View;
 import org.eclipse.jetty.io.nio.DirectNIOBuffer;
 import org.eclipse.jetty.io.nio.IndirectNIOBuffer;
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
 import org.eclipse.jetty.util.resource.Resource;
 import org.eclipse.jetty.util.resource.ResourceFactory;


 /* ------------------------------------------------------------ */
 /**
  *
  */
 public class ResourceCache
 {
     private static final Logger LOG = Log.getLogger(ResourceCache.class);

     private final ConcurrentMap<String,Content> _cache;
     private final AtomicInteger _cachedSize;
     private final AtomicInteger _cachedFiles;
     private final ResourceFactory _factory;
     private final ResourceCache _parent;
     private final MimeTypes _mimeTypes;
     private final boolean _etags;

     private boolean  _useFileMappedBuffer=true;
     private int _maxCachedFileSize =4*1024*1024;
     private int _maxCachedFiles=2048;
     private int _maxCacheSize =32*1024*1024;

     /* ------------------------------------------------------------ */
     /** Constructor.
      * @param mimeTypes Mimetype to use for meta data
      */
     public ResourceCache(ResourceCache parent, ResourceFactory factory, MimeTypes mimeTypes,boolean useFileMappedBuffer,boolean etags)
     {
         _factory = factory;
         _cache=new ConcurrentHashMap<String,Content>();
         _cachedSize=new AtomicInteger();
         _cachedFiles=new AtomicInteger();
         _mimeTypes=mimeTypes;
         _parent=parent;
         _etags=etags;
         _useFileMappedBuffer=useFileMappedBuffer;
     }

     /* ------------------------------------------------------------ */
     public int getCachedSize()
     {
         return _cachedSize.get();
     }

     /* ------------------------------------------------------------ */
     public int getCachedFiles()
     {
         return _cachedFiles.get();
     }

     /* ------------------------------------------------------------ */
     public int getMaxCachedFileSize()
     {
         return _maxCachedFileSize;
     }

     /* ------------------------------------------------------------ */
     public void setMaxCachedFileSize(int maxCachedFileSize)
     {
         _maxCachedFileSize = maxCachedFileSize;
         shrinkCache();
     }

     /* ------------------------------------------------------------ */
     public int getMaxCacheSize()
     {
         return _maxCacheSize;
     }

     /* ------------------------------------------------------------ */
     public void setMaxCacheSize(int maxCacheSize)
     {
         _maxCacheSize = maxCacheSize;
         shrinkCache();
     }

     /* ------------------------------------------------------------ */
     /**
      * @return Returns the maxCachedFiles.
      */
     public int getMaxCachedFiles()
     {
         return _maxCachedFiles;
     }

     /* ------------------------------------------------------------ */
     /**
      * @param maxCachedFiles The maxCachedFiles to set.
      */
     public void setMaxCachedFiles(int maxCachedFiles)
     {
         _maxCachedFiles = maxCachedFiles;
         shrinkCache();
     }

     /* ------------------------------------------------------------ */
     public boolean isUseFileMappedBuffer()
     {
         return _useFileMappedBuffer;
     }

     /* ------------------------------------------------------------ */
     public void setUseFileMappedBuffer(boolean useFileMappedBuffer)
     {
         _useFileMappedBuffer = useFileMappedBuffer;
     }

     /* ------------------------------------------------------------ */
     public void flushCache()
     {
         if (_cache!=null)
         {
             while (_cache.size()>0)
             {
                 for (String path : _cache.keySet())
                 {
                     Content content = _cache.remove(path);
                     if (content!=null)
                         content.invalidate();
                 }
             }
         }
     }

     /* ------------------------------------------------------------ */
     /** Get a Entry from the cache.
      * Get either a valid entry object or create a new one if possible.
      *
      * @param pathInContext The key into the cache
      * @return The entry matching <code>pathInContext</code>, or a new entry
      * if no matching entry was found. If the content exists but is not cachable,
      * then a {@link ResourceAsHttpContent} instance is return. If
      * the resource does not exist, then null is returned.
      * @throws IOException Problem loading the resource
      */
     public HttpContent lookup(String pathInContext)
         throws IOException
     {
         // Is the content in this cache?
         Content content =_cache.get(pathInContext);
         if (content!=null && (content).isValid())
             return content;

         // try loading the content from our factory.
         Resource resource=_factory.getResource(pathInContext);
         HttpContent loaded = load(pathInContext,resource);
         if (loaded!=null)
             return loaded;

         // Is the content in the parent cache?
         if (_parent!=null)
         {
             HttpContent httpContent=_parent.lookup(pathInContext);
             if (httpContent!=null)
                 return httpContent;
         }

         return null;
     }

     /* ------------------------------------------------------------ */
     /**
      * @param resource
      * @return True if the resource is cacheable. The default implementation tests the cache sizes.
      */
     protected boolean isCacheable(Resource resource)
     {
         long len = resource.length();

         // Will it fit in the cache?
         return  (len>0 && len<_maxCachedFileSize && len<_maxCacheSize);
     }

     /* ------------------------------------------------------------ */
     private HttpContent load(String pathInContext, Resource resource)
         throws IOException
     {
         Content content=null;

         if (resource==null || !resource.exists())
             return null;

         // Will it fit in the cache?
         if (!resource.isDirectory() && isCacheable(resource))
         {
             // Create the Content (to increment the cache sizes before adding the content
             content = new Content(pathInContext,resource);

             // reduce the cache to an acceptable size.
             shrinkCache();

             // Add it to the cache.
             Content added = _cache.putIfAbsent(pathInContext,content);
             if (added!=null)
             {
                 content.invalidate();
                 content=added;
             }

             return content;
         }

         return new HttpContent.ResourceAsHttpContent(resource,_mimeTypes.getMimeByExtension(resource.toString()),getMaxCachedFileSize(),_etags);

     }

     /* ------------------------------------------------------------ */
     private void shrinkCache()
     {
         // While we need to shrink
         while (_cache.size()>0 && (_cachedFiles.get()>_maxCachedFiles || _cachedSize.get()>_maxCacheSize))
         {
             // Scan the entire cache and generate an ordered list by last accessed time.
             SortedSet<Content> sorted= new TreeSet<Content>(
                     new Comparator<Content>()
                     {
                         public int compare(Content c1, Content c2)
                         {
                             if (c1._lastAccessed<c2._lastAccessed)
                                 return -1;

                             if (c1._lastAccessed>c2._lastAccessed)
                                 return 1;

                             if (c1._length<c2._length)
                                 return -1;

                             return c1._key.compareTo(c2._key);
                         }
                     });
             for (Content content : _cache.values())
                 sorted.add(content);

             // Invalidate least recently used first
             for (Content content : sorted)
             {
                 if (_cachedFiles.get()<=_maxCachedFiles && _cachedSize.get()<=_maxCacheSize)
                     break;
                 if (content==_cache.remove(content.getKey()))
                     content.invalidate();
             }
         }
     }

     /* ------------------------------------------------------------ */
     protected Buffer getIndirectBuffer(Resource resource)
     {
         try
         {
             int len=(int)resource.length();
             if (len<0)
             {
                 LOG.warn("invalid resource: "+String.valueOf(resource)+" "+len);
                 return null;
             }
             Buffer buffer = new IndirectNIOBuffer(len);
             InputStream is = resource.getInputStream();
             buffer.readFrom(is,len);
             is.close();
             return buffer;
         }
         catch(IOException e)
         {
             LOG.warn(e);
             return null;
         }
     }

     /* ------------------------------------------------------------ */
     protected Buffer getDirectBuffer(Resource resource)
     {
         try
         {
             if (_useFileMappedBuffer && resource.getFile()!=null)
                 return new DirectNIOBuffer(resource.getFile());

             int len=(int)resource.length();
             if (len<0)
             {
                 LOG.warn("invalid resource: "+String.valueOf(resource)+" "+len);
                 return null;
             }
             Buffer buffer = new DirectNIOBuffer(len);
             InputStream is = resource.getInputStream();
             buffer.readFrom(is,len);
             is.close();
             return buffer;
         }
         catch(IOException e)
         {
             LOG.warn(e);
             return null;
         }
     }

     /* ------------------------------------------------------------ */
     @Override
     public String toString()
     {
         return "ResourceCache["+_parent+","+_factory+"]@"+hashCode();
     }

     /* ------------------------------------------------------------ */
     /* ------------------------------------------------------------ */
     /** MetaData associated with a context Resource.
      */
     public class Content implements HttpContent
     {
         final Resource _resource;
         final int _length;
         final String _key;
         final long _lastModified;
         final Buffer _lastModifiedBytes;
         final Buffer _contentType;
         final Buffer _etagBuffer;

         volatile long _lastAccessed;
         AtomicReference<Buffer> _indirectBuffer=new AtomicReference<Buffer>();
         AtomicReference<Buffer> _directBuffer=new AtomicReference<Buffer>();

         /* ------------------------------------------------------------ */
         Content(String pathInContext,Resource resource)
         {
             _key=pathInContext;
             _resource=resource;

             _contentType=_mimeTypes.getMimeByExtension(_resource.toString());
             boolean exists=resource.exists();
             _lastModified=exists?resource.lastModified():-1;
             _lastModifiedBytes=_lastModified<0?null:new ByteArrayBuffer(HttpFields.formatDate(_lastModified));

             _length=exists?(int)resource.length():0;
             _cachedSize.addAndGet(_length);
             _cachedFiles.incrementAndGet();
             _lastAccessed=System.currentTimeMillis();

             _etagBuffer=_etags?new ByteArrayBuffer(resource.getWeakETag()):null;
         }


         /* ------------------------------------------------------------ */
         public String getKey()
         {
             return _key;
         }

         /* ------------------------------------------------------------ */
         public boolean isCached()
         {
             return _key!=null;
         }

         /* ------------------------------------------------------------ */
         public boolean isMiss()
         {
             return false;
         }

         /* ------------------------------------------------------------ */
         public Resource getResource()
         {
             return _resource;
         }

         /* ------------------------------------------------------------ */
         public Buffer getETag()
         {
             return _etagBuffer;
         }

         /* ------------------------------------------------------------ */
         boolean isValid()
         {
             if (_lastModified==_resource.lastModified() && _length==_resource.length())
             {
                 _lastAccessed=System.currentTimeMillis();
                 return true;
             }

             if (this==_cache.remove(_key))
                 invalidate();
             return false;
         }

         /* ------------------------------------------------------------ */
         protected void invalidate()
         {
             // Invalidate it
             _cachedSize.addAndGet(-_length);
             _cachedFiles.decrementAndGet();
             _resource.release();
         }

         /* ------------------------------------------------------------ */
         public Buffer getLastModified()
         {
             return _lastModifiedBytes;
         }

         /* ------------------------------------------------------------ */
         public Buffer getContentType()
         {
             return _contentType;
         }

         /* ------------------------------------------------------------ */
         public void release()
         {
             // don't release while cached. Release when invalidated.
         }

         /* ------------------------------------------------------------ */
         public Buffer getIndirectBuffer()
         {
             Buffer buffer = _indirectBuffer.get();
             if (buffer==null)
             {
                 Buffer buffer2=ResourceCache.this.getIndirectBuffer(_resource);

                 if (buffer2==null)
                     LOG.warn("Could not load "+this);
                 else if (_indirectBuffer.compareAndSet(null,buffer2))
                     buffer=buffer2;
                 else
                     buffer=_indirectBuffer.get();
             }
             if (buffer==null)
                 return null;
             return new View(buffer);
         }


         /* ------------------------------------------------------------ */
         public Buffer getDirectBuffer()
         {
             Buffer buffer = _directBuffer.get();
             if (buffer==null)
             {
                 Buffer buffer2=ResourceCache.this.getDirectBuffer(_resource);

                 if (buffer2==null)
                     LOG.warn("Could not load "+this);
                 else if (_directBuffer.compareAndSet(null,buffer2))
                     buffer=buffer2;
                 else
                     buffer=_directBuffer.get();
             }
             if (buffer==null)
                 return null;

             return new View(buffer);
         }

         /* ------------------------------------------------------------ */
         public long getContentLength()
         {
             return _length;
         }

         /* ------------------------------------------------------------ */
         public InputStream getInputStream() throws IOException
         {
             Buffer indirect = getIndirectBuffer();
             if (indirect!=null && indirect.array()!=null)
                 return new ByteArrayInputStream(indirect.array(),indirect.getIndex(),indirect.length());

             return _resource.getInputStream();
         }

         /* ------------------------------------------------------------ */
         @Override
         public String toString()
         {
             return String.format("%s %s %d %s %s",_resource,_resource.exists(),_resource.lastModified(),_contentType,_lastModifiedBytes);
         }
     }
 }
	//
	// ========================================================================
	// Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
	// ------------------------------------------------------------------------
	// All rights reserved. This program and the accompanying materials
	// are made available under the terms of the Eclipse Public License v1.0
	// and Apache License v2.0 which accompanies this distribution.
	//
	// The Eclipse Public License is available at
	// http://www.eclipse.org/legal/epl-v10.html
	//
	// The Apache License v2.0 is available at
	// http://www.opensource.org/licenses/apache2.0.php
	//
	// You may elect to redistribute this code under either of these licenses.
	// ========================================================================
	//

	package org.eclipse.jetty.server;

	import java.io.ByteArrayInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.util.Comparator;
	import java.util.SortedSet;
	import java.util.TreeSet;
	import java.util.concurrent.ConcurrentHashMap;
	import java.util.concurrent.ConcurrentMap;
	import java.util.concurrent.atomic.AtomicInteger;
	import java.util.concurrent.atomic.AtomicReference;

	import org.eclipse.jetty.http.HttpContent;
	import org.eclipse.jetty.http.HttpContent.ResourceAsHttpContent;
	import org.eclipse.jetty.http.HttpFields;
	import org.eclipse.jetty.http.MimeTypes;
	import org.eclipse.jetty.io.Buffer;
	import org.eclipse.jetty.io.ByteArrayBuffer;
	import org.eclipse.jetty.io.View;
	import org.eclipse.jetty.io.nio.DirectNIOBuffer;
	import org.eclipse.jetty.io.nio.IndirectNIOBuffer;
	import org.eclipse.jetty.util.log.Log;
	import org.eclipse.jetty.util.log.Logger;
	import org.eclipse.jetty.util.resource.Resource;
	import org.eclipse.jetty.util.resource.ResourceFactory;


	/* ------------------------------------------------------------ */
	/**
	*
	*/
	public class ResourceCache
	{
	private static final Logger LOG = Log.getLogger(ResourceCache.class);

	private final ConcurrentMap<String,Content> _cache;
	private final AtomicInteger _cachedSize;
	private final AtomicInteger _cachedFiles;
	private final ResourceFactory _factory;
	private final ResourceCache _parent;
	private final MimeTypes _mimeTypes;
	private final boolean _etags;

	private boolean _useFileMappedBuffer=true;
	private int _maxCachedFileSize =410241024;
	private int _maxCachedFiles=2048;
	private int _maxCacheSize =3210241024;

	/* ------------------------------------------------------------ */
	/** Constructor.
	* @param mimeTypes Mimetype to use for meta data
	*/
	public ResourceCache(ResourceCache parent, ResourceFactory factory, MimeTypes mimeTypes,boolean useFileMappedBuffer,boolean etags)
	{
	_factory = factory;
	_cache=new ConcurrentHashMap<String,Content>();
	_cachedSize=new AtomicInteger();
	_cachedFiles=new AtomicInteger();
	_mimeTypes=mimeTypes;
	_parent=parent;
	_etags=etags;
	_useFileMappedBuffer=useFileMappedBuffer;
	}

	/* ------------------------------------------------------------ */
	public int getCachedSize()
	{
	return _cachedSize.get();
	}

	/* ------------------------------------------------------------ */
	public int getCachedFiles()
	{
	return _cachedFiles.get();
	}

	/* ------------------------------------------------------------ */
	public int getMaxCachedFileSize()
	{
	return _maxCachedFileSize;
	}

	/* ------------------------------------------------------------ */
	public void setMaxCachedFileSize(int maxCachedFileSize)
	{
	_maxCachedFileSize = maxCachedFileSize;
	shrinkCache();
	}

	/* ------------------------------------------------------------ */
	public int getMaxCacheSize()
	{
	return _maxCacheSize;
	}

	/* ------------------------------------------------------------ */
	public void setMaxCacheSize(int maxCacheSize)
	{
	_maxCacheSize = maxCacheSize;
	shrinkCache();
	}

	/* ------------------------------------------------------------ */
	/**
	* @return Returns the maxCachedFiles.
	*/
	public int getMaxCachedFiles()
	{
	return _maxCachedFiles;
	}

	/* ------------------------------------------------------------ */
	/**
	* @param maxCachedFiles The maxCachedFiles to set.
	*/
	public void setMaxCachedFiles(int maxCachedFiles)
	{
	_maxCachedFiles = maxCachedFiles;
	shrinkCache();
	}

	/* ------------------------------------------------------------ */
	public boolean isUseFileMappedBuffer()
	{
	return _useFileMappedBuffer;
	}

	/* ------------------------------------------------------------ */
	public void setUseFileMappedBuffer(boolean useFileMappedBuffer)
	{
	_useFileMappedBuffer = useFileMappedBuffer;
	}

	/* ------------------------------------------------------------ */
	public void flushCache()
	{
	if (_cache!=null)
	{
	while (_cache.size()>0)
	{
	for (String path : _cache.keySet())
	{
	Content content = _cache.remove(path);
	if (content!=null)
	content.invalidate();
	}
	}
	}
	}

	/* ------------------------------------------------------------ */
	/** Get a Entry from the cache.
	* Get either a valid entry object or create a new one if possible.
	*
	* @param pathInContext The key into the cache
	* @return The entry matching <code>pathInContext</code>, or a new entry
	* if no matching entry was found. If the content exists but is not cachable,
	* then a {@link ResourceAsHttpContent} instance is return. If
	* the resource does not exist, then null is returned.
	* @throws IOException Problem loading the resource
	*/
	public HttpContent lookup(String pathInContext)
	throws IOException
	{
	// Is the content in this cache?
	Content content =_cache.get(pathInContext);
	if (content!=null && (content).isValid())
	return content;

	// try loading the content from our factory.
	Resource resource=_factory.getResource(pathInContext);
	HttpContent loaded = load(pathInContext,resource);
	if (loaded!=null)
	return loaded;

	// Is the content in the parent cache?
	if (_parent!=null)
	{
	HttpContent httpContent=_parent.lookup(pathInContext);
	if (httpContent!=null)
	return httpContent;
	}

	return null;
	}

	/* ------------------------------------------------------------ */
	/**
	* @param resource
	* @return True if the resource is cacheable. The default implementation tests the cache sizes.
	*/
	protected boolean isCacheable(Resource resource)
	{
	long len = resource.length();

	// Will it fit in the cache?
	return (len>0 && len<_maxCachedFileSize && len<_maxCacheSize);
	}

	/* ------------------------------------------------------------ */
	private HttpContent load(String pathInContext, Resource resource)
	throws IOException
	{
	Content content=null;

	if (resource==null \|\| !resource.exists())
	return null;

	// Will it fit in the cache?
	if (!resource.isDirectory() && isCacheable(resource))
	{
	// Create the Content (to increment the cache sizes before adding the content
	content = new Content(pathInContext,resource);

	// reduce the cache to an acceptable size.
	shrinkCache();

	// Add it to the cache.
	Content added = _cache.putIfAbsent(pathInContext,content);
	if (added!=null)
	{
	content.invalidate();
	content=added;
	}

	return content;
	}

	return new HttpContent.ResourceAsHttpContent(resource,_mimeTypes.getMimeByExtension(resource.toString()),getMaxCachedFileSize(),_etags);

	}

	/* ------------------------------------------------------------ */
	private void shrinkCache()
	{
	// While we need to shrink
	while (_cache.size()>0 && (_cachedFiles.get()>_maxCachedFiles \|\| _cachedSize.get()>_maxCacheSize))
	{
	// Scan the entire cache and generate an ordered list by last accessed time.
	SortedSet<Content> sorted= new TreeSet<Content>(
	new Comparator<Content>()
	{
	public int compare(Content c1, Content c2)
	{
	if (c1._lastAccessed<c2._lastAccessed)
	return -1;

	if (c1._lastAccessed>c2._lastAccessed)
	return 1;

	if (c1._length<c2._length)
	return -1;

	return c1._key.compareTo(c2._key);
	}
	});
	for (Content content : _cache.values())
	sorted.add(content);

	// Invalidate least recently used first
	for (Content content : sorted)
	{
	if (_cachedFiles.get()<=_maxCachedFiles && _cachedSize.get()<=_maxCacheSize)
	break;
	if (content==_cache.remove(content.getKey()))
	content.invalidate();
	}
	}
	}

	/* ------------------------------------------------------------ */
	protected Buffer getIndirectBuffer(Resource resource)
	{
	try
	{
	int len=(int)resource.length();
	if (len<0)
	{
	LOG.warn("invalid resource: "+String.valueOf(resource)+" "+len);
	return null;
	}
	Buffer buffer = new IndirectNIOBuffer(len);
	InputStream is = resource.getInputStream();
	buffer.readFrom(is,len);
	is.close();
	return buffer;
	}
	catch(IOException e)
	{
	LOG.warn(e);
	return null;
	}
	}

	/* ------------------------------------------------------------ */
	protected Buffer getDirectBuffer(Resource resource)
	{
	try
	{
	if (_useFileMappedBuffer && resource.getFile()!=null)
	return new DirectNIOBuffer(resource.getFile());

	int len=(int)resource.length();
	if (len<0)
	{
	LOG.warn("invalid resource: "+String.valueOf(resource)+" "+len);
	return null;
	}
	Buffer buffer = new DirectNIOBuffer(len);
	InputStream is = resource.getInputStream();
	buffer.readFrom(is,len);
	is.close();
	return buffer;
	}
	catch(IOException e)
	{
	LOG.warn(e);
	return null;
	}
	}

	/* ------------------------------------------------------------ */
	@Override
	public String toString()
	{
	return "ResourceCache["+_parent+","+_factory+"]@"+hashCode();
	}

	/* ------------------------------------------------------------ */
	/* ------------------------------------------------------------ */
	/** MetaData associated with a context Resource.
	*/
	public class Content implements HttpContent
	{
	final Resource _resource;
	final int _length;
	final String _key;
	final long _lastModified;
	final Buffer _lastModifiedBytes;
	final Buffer _contentType;
	final Buffer _etagBuffer;

	volatile long _lastAccessed;
	AtomicReference<Buffer> _indirectBuffer=new AtomicReference<Buffer>();
	AtomicReference<Buffer> _directBuffer=new AtomicReference<Buffer>();

	/* ------------------------------------------------------------ */
	Content(String pathInContext,Resource resource)
	{
	_key=pathInContext;
	_resource=resource;

	_contentType=_mimeTypes.getMimeByExtension(_resource.toString());
	boolean exists=resource.exists();
	_lastModified=exists?resource.lastModified():-1;
	_lastModifiedBytes=_lastModified<0?null:new ByteArrayBuffer(HttpFields.formatDate(_lastModified));

	_length=exists?(int)resource.length():0;
	_cachedSize.addAndGet(_length);
	_cachedFiles.incrementAndGet();
	_lastAccessed=System.currentTimeMillis();

	_etagBuffer=_etags?new ByteArrayBuffer(resource.getWeakETag()):null;
	}


	/* ------------------------------------------------------------ */
	public String getKey()
	{
	return _key;
	}

	/* ------------------------------------------------------------ */
	public boolean isCached()
	{
	return _key!=null;
	}

	/* ------------------------------------------------------------ */
	public boolean isMiss()
	{
	return false;
	}

	/* ------------------------------------------------------------ */
	public Resource getResource()
	{
	return _resource;
	}

	/* ------------------------------------------------------------ */
	public Buffer getETag()
	{
	return _etagBuffer;
	}

	/* ------------------------------------------------------------ */
	boolean isValid()
	{
	if (_lastModified==_resource.lastModified() && _length==_resource.length())
	{
	_lastAccessed=System.currentTimeMillis();
	return true;
	}

	if (this==_cache.remove(_key))
	invalidate();
	return false;
	}

	/* ------------------------------------------------------------ */
	protected void invalidate()
	{
	// Invalidate it
	_cachedSize.addAndGet(-_length);
	_cachedFiles.decrementAndGet();
	_resource.release();
	}

	/* ------------------------------------------------------------ */
	public Buffer getLastModified()
	{
	return _lastModifiedBytes;
	}

	/* ------------------------------------------------------------ */
	public Buffer getContentType()
	{
	return _contentType;
	}

	/* ------------------------------------------------------------ */
	public void release()
	{
	// don't release while cached. Release when invalidated.
	}

	/* ------------------------------------------------------------ */
	public Buffer getIndirectBuffer()
	{
	Buffer buffer = _indirectBuffer.get();
	if (buffer==null)
	{
	Buffer buffer2=ResourceCache.this.getIndirectBuffer(_resource);

	if (buffer2==null)
	LOG.warn("Could not load "+this);
	else if (_indirectBuffer.compareAndSet(null,buffer2))
	buffer=buffer2;
	else
	buffer=_indirectBuffer.get();
	}
	if (buffer==null)
	return null;
	return new View(buffer);
	}


	/* ------------------------------------------------------------ */
	public Buffer getDirectBuffer()
	{
	Buffer buffer = _directBuffer.get();
	if (buffer==null)
	{
	Buffer buffer2=ResourceCache.this.getDirectBuffer(_resource);

	if (buffer2==null)
	LOG.warn("Could not load "+this);
	else if (_directBuffer.compareAndSet(null,buffer2))
	buffer=buffer2;
	else
	buffer=_directBuffer.get();
	}
	if (buffer==null)
	return null;

	return new View(buffer);
	}

	/* ------------------------------------------------------------ */
	public long getContentLength()
	{
	return _length;
	}

	/* ------------------------------------------------------------ */
	public InputStream getInputStream() throws IOException
	{
	Buffer indirect = getIndirectBuffer();
	if (indirect!=null && indirect.array()!=null)
	return new ByteArrayInputStream(indirect.array(),indirect.getIndex(),indirect.length());

	return _resource.getInputStream();
	}

	/* ------------------------------------------------------------ */
	@Override
	public String toString()
	{
	return String.format("%s %s %d %s %s",_resource,_resource.exists(),_resource.lastModified(),_contentType,_lastModifiedBytes);
	}
	}
	}