imario 2004/05/07 12:09:56
Modified: vfs/src/java/org/apache/commons/vfs Resources.properties
Added: vfs/src/java/org/apache/commons/vfs/cache
FileSystemAndNameKey.java SoftRefFilesCache.java
Log:
a filescache implementation using SoftReference
Revision Changes Path
1.1
jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/cache/FileSystemAndNameKey.java
Index: FileSystemAndNameKey.java
===================================================================
/*
* Copyright 2002, 2003,2004 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.
*/
package org.apache.commons.vfs.cache;
import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileSystem;
/**
* Key for various cache implementations.<br>
* It compares the fileSystem (by hashCode) and the filename.
*
* @author <a href="mailto:[EMAIL PROTECTED]">Mario Ivanovits</a>
* @version $Revision: 1.1 $ $Date: 2004/05/07 19:09:56 $
*/
class FileSystemAndNameKey implements Comparable
{
private final FileSystem fileSystem;
private final FileName fileName;
private final int fileSystemId;
FileSystemAndNameKey(final FileSystem fileSystem, final FileName fileName)
{
this.fileSystem = fileSystem;
this.fileSystemId = System.identityHashCode(fileSystem);
this.fileName = fileName;
}
public int compareTo(Object o)
{
FileSystemAndNameKey other = (FileSystemAndNameKey) o;
if (fileSystemId < other.fileSystemId)
{
return -1;
}
if (fileSystemId > other.fileSystemId)
{
return 1;
}
return fileName.compareTo(other.fileName);
}
FileSystem getFileSystem()
{
return fileSystem;
}
FileName getFileName()
{
return fileName;
}
}
1.1
jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/cache/SoftRefFilesCache.java
Index: SoftRefFilesCache.java
===================================================================
/*
* Copyright 2002, 2003,2004 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.
*/
package org.apache.commons.vfs.cache;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs.FileName;
import org.apache.commons.vfs.FileObject;
import org.apache.commons.vfs.FileSystem;
import org.apache.commons.vfs.FilesCache;
import org.apache.commons.vfs.util.Messages;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
/**
* This implementation caches every file as long as it is strongly reachable by the
java vm.
* As soon as the vm needs memory - every softly reachable file will be discarded.
*
* @author <a href="mailto:[EMAIL PROTECTED]">Mario Ivanovits</a>
* @version $Revision: 1.1 $ $Date: 2004/05/07 19:09:56 $
* @see SoftReference
*/
public class SoftRefFilesCache implements FilesCache
{
/**
* The logger to use.
*/
private Log log = LogFactory.getLog(SoftRefFilesCache.class);
private final Map files = new TreeMap();
private final Map refReverseMap = new HashMap(100);
private final ReferenceQueue refqueue = new ReferenceQueue();
private Thread softRefReleaseThread = null;
/**
* This thread will listen on the ReferenceQueue and remove the entry in the
* filescache as soon as the vm removes the reference
*/
private class SoftRefReleaseThread implements Runnable
{
private SoftRefReleaseThread()
{
}
public void run()
{
loop: while (!Thread.currentThread().isInterrupted())
{
try
{
Reference ref = refqueue.remove(1000);
if (ref == null)
{
continue;
}
if (ref != null)
{
synchronized (SoftRefFilesCache.this)
{
FileSystemAndNameKey key = (FileSystemAndNameKey)
refReverseMap.get(ref);
removeFile(key);
}
}
}
catch (InterruptedException e)
{
log.info(Messages.getString("vfs.impl/SoftRefReleaseThread-interrupt.info"));
break loop;
}
}
}
}
public SoftRefFilesCache()
{
}
private void startThread()
{
if (softRefReleaseThread != null)
{
throw new
IllegalStateException(Messages.getString("vfs.impl/SoftRefReleaseThread-already-running.warn"));
}
softRefReleaseThread = new Thread(new SoftRefReleaseThread());
softRefReleaseThread.setDaemon(true);
softRefReleaseThread.start();
}
private void endThread()
{
if (softRefReleaseThread != null)
{
softRefReleaseThread.interrupt();
softRefReleaseThread = null;
}
}
public void putFile(final FileObject file)
{
synchronized (this)
{
if (files.size() < 1)
{
startThread();
}
SoftReference ref = new SoftReference(file, refqueue);
FileSystemAndNameKey key = new
FileSystemAndNameKey(file.getFileSystem(), file.getName());
files.put(key, ref);
refReverseMap.put(ref, key);
}
}
public FileObject getFile(final FileSystem filesystem, final FileName name)
{
synchronized (this)
{
FileSystemAndNameKey key = new FileSystemAndNameKey(filesystem, name);
SoftReference ref = (SoftReference) files.get(key);
if (ref == null)
{
return null;
}
FileObject fo = (FileObject) ref.get();
if (fo == null)
{
removeFile(key);
}
return fo;
}
}
public void clear(FileSystem filesystem)
{
synchronized (this)
{
Iterator iterKeys = files.keySet().iterator();
while (iterKeys.hasNext())
{
FileSystemAndNameKey key = (FileSystemAndNameKey) iterKeys.next();
if (key.getFileSystem() == filesystem)
{
Object ref = files.get(key);
iterKeys.remove();
refReverseMap.remove(ref);
}
}
if (files.size() < 1)
{
endThread();
}
}
}
public void clear()
{
synchronized (this)
{
endThread();
files.clear();
refReverseMap.clear();
}
}
private void removeFile(final FileSystemAndNameKey key)
{
synchronized (this)
{
Object ref = files.remove(key);
if (ref != null)
{
refReverseMap.remove(ref);
}
if (files.size() < 1)
{
endThread();
}
}
}
}
1.29 +4 -0
jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/Resources.properties
Index: Resources.properties
===================================================================
RCS file:
/home/cvs/jakarta-commons-sandbox/vfs/src/java/org/apache/commons/vfs/Resources.properties,v
retrieving revision 1.28
retrieving revision 1.29
diff -u -r1.28 -r1.29
--- Resources.properties 3 May 2004 19:48:48 -0000 1.28
+++ Resources.properties 7 May 2004 19:09:56 -0000 1.29
@@ -114,6 +114,10 @@
vfs.impl/nested-junction.error=Attempting to create a nested junction at "{0}".
Nested junctions are not supported.
vfs.impl/create-junction.error=Could not create a junction at "{0}".
+# SoftRefFilesCache
+vfs.impl/SoftRefReleaseThread-interrupt.info=SoftRefFilesCache - Release Thread
interrupted.
+vfs.impl/SoftRefReleaseThread-already-running.warn=SoftRefFilesCache - Release
Thread already running.
+
# Local Provider
vfs.provider.local/get-type.error=Could not determine the type of "{0}".
vfs.provider.local/delete-file.error=Could not delete "{0}".
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