Class SoftRefFilesCache

java.lang.Object

org.apache.commons.vfs2.provider.AbstractVfsComponent

org.apache.commons.vfs2.cache.AbstractFilesCache

org.apache.commons.vfs2.cache.SoftRefFilesCache

All Implemented Interfaces:

Closeable, AutoCloseable, FilesCache, VfsComponent

Direct Known Subclasses:

WeakRefFilesCache

public class SoftRefFilesCache
extends AbstractFilesCache

This implementation caches every file as long as it is strongly reachable by the JVM. As soon as the JVM needs memory - every softly reachable file will be discarded.

See Also:

• SoftReference

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private final class	SoftRefFilesCache.ReleaseThread	This thread will listen on the ReferenceQueue and remove the entry in the file cache as soon as the JVM removes the reference.

Field Summary

Fields

Modifier and Type	Field	Description
private final Map<FileSystem, Map<FileName, Reference<FileObject>>>	fileSystemCache
private static final org.apache.commons.logging.Log	log
private final ReferenceQueue<FileObject>	refQueue
private final Map<Reference<FileObject>, FileSystemAndNameKey>	refReverseMap
private SoftRefFilesCache.ReleaseThread	releaseThread

Constructor Summary

Constructors

Constructor	Description
SoftRefFilesCache()	Constructs a new instance.

Method Summary

Modifier and Type	Method	Description
void	clear(FileSystem fileSystem)	Purges the entries corresponding to the FileSystem.
void	close()	Closes the provider.
private void	close(FileSystem fileSystem)
protected Reference<FileObject>	createReference(FileObject file, ReferenceQueue<FileObject> refqueue)
private void	endThread()
FileObject	getFile(FileSystem fileSystem, FileName fileName)	Retrieves a FileObject from the cache by name.
protected Map<FileName, Reference<FileObject>>	getOrCreateFilesystemCache(FileSystem fileSystem)
private String	getSafeName(FileName fileName)
private String	getSafeName(FileObject fileObject)
void	putFile(FileObject fileObject)	Adds a FileObject to the cache.
boolean	putFileIfAbsent(FileObject fileObject)	Adds a FileObject to the cache if it isn't already present.
private void	removeFile(Reference<?> ref)
private boolean	removeFile(FileSystemAndNameKey key)
void	removeFile(FileSystem fileSystem, FileName fileName)	Removes a file from cache.
private void	startThread()
String	toString()

Methods inherited from class AbstractFilesCache

touchFile

Methods inherited from class AbstractVfsComponent

getContext, getLogger, init, setContext, setLogger

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

log

private static final org.apache.commons.logging.Log log

fileSystemCache

private final Map<FileSystem, Map<FileName, Reference<FileObject>>> fileSystemCache

refReverseMap

private final Map<Reference<FileObject>, FileSystemAndNameKey> refReverseMap

refQueue

private final ReferenceQueue<FileObject> refQueue

releaseThread

private SoftRefFilesCache.ReleaseThread releaseThread

Constructor Details

SoftRefFilesCache

public SoftRefFilesCache()

Constructs a new instance.

Method Details

clear

public void clear(FileSystem fileSystem)

Description copied from interface: FilesCache

Purges the entries corresponding to the FileSystem.

Parameters:

fileSystem - The FileSystem.

close

public void close()

Description copied from class: AbstractVfsComponent

Closes the provider. This implementation does nothing.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface FilesCache

Specified by:

close in interface VfsComponent

Overrides:

close in class AbstractVfsComponent

close

private void close(FileSystem fileSystem)

Parameters:

fileSystem - The file system to close.

createReference

protected Reference<FileObject> createReference(FileObject file,
 ReferenceQueue<FileObject> refqueue)

endThread

private void endThread()

getFile

public FileObject getFile(FileSystem fileSystem,
 FileName fileName)

Description copied from interface: FilesCache

Retrieves a FileObject from the cache by name.

Parameters:

fileSystem - The FileSystem.

fileName - the name

Returns:

the file object or null if file is not cached

getOrCreateFilesystemCache

protected Map<FileName, Reference<FileObject>> getOrCreateFilesystemCache(FileSystem fileSystem)

getSafeName

private String getSafeName(FileName fileName)

getSafeName

private String getSafeName(FileObject fileObject)

putFile

public void putFile(FileObject fileObject)

Description copied from interface: FilesCache

Adds a FileObject to the cache.

Parameters:

fileObject - the file

putFileIfAbsent

public boolean putFileIfAbsent(FileObject fileObject)

Description copied from interface: FilesCache

Adds a FileObject to the cache if it isn't already present.

Parameters:

fileObject - the file

Returns:

true if the file was stored, false otherwise.

removeFile

public void removeFile(FileSystem fileSystem,
 FileName fileName)

Description copied from interface: FilesCache

Removes a file from cache.

Parameters:

fileSystem - file system

fileName - file name

removeFile

private boolean removeFile(FileSystemAndNameKey key)

removeFile

private void removeFile(Reference<?> ref)

startThread

private void startThread()

toString

public String toString()

Overrides:

toString in class Object