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/*
* 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.
*/
package org.apache.commons.vfs2.provider;
import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.vfs2.CacheStrategy;
import org.apache.commons.vfs2.Capability;
import org.apache.commons.vfs2.FileListener;
import org.apache.commons.vfs2.FileName;
import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSelector;
import org.apache.commons.vfs2.FileSystem;
import org.apache.commons.vfs2.FileSystemConfigBuilder;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemManager;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.FilesCache;
import org.apache.commons.vfs2.VfsLog;
import org.apache.commons.vfs2.cache.OnCallRefreshFileObject;
import org.apache.commons.vfs2.events.AbstractFileChangeEvent;
import org.apache.commons.vfs2.events.ChangedEvent;
import org.apache.commons.vfs2.events.CreateEvent;
import org.apache.commons.vfs2.events.DeleteEvent;
import org.apache.commons.vfs2.impl.DefaultFileSystemConfigBuilder;
import org.apache.commons.vfs2.util.Messages;
/**
* A partial {@link org.apache.commons.vfs2.FileSystem} implementation.
*/
public abstract class AbstractFileSystem extends AbstractVfsComponent implements FileSystem {
private static final Log LOG = LogFactory.getLog(AbstractFileSystem.class);
/**
* The "root" of the file system. This is always "/" so it isn't always the "real" root.
*/
private final FileName rootName;
/**
* The root URI of the file system. The base path specified as a file system option when the file system was
* created.
*/
private final String rootURI;
private final Collection caps = new HashSet<>();
private FileObject parentLayer;
/**
* Map from FileName to an ArrayList of listeners for that file.
*/
private final Map> listenerMap = new HashMap<>();
/**
* FileSystemOptions used for configuration
*/
private final FileSystemOptions fileSystemOptions;
/**
* How many fileObjects are handed out
*/
private final AtomicLong useCount = new AtomicLong(0);
private FileSystemKey cacheKey;
/**
* open streams counter for this filesystem
*/
private final AtomicInteger openStreams = new AtomicInteger(0);
protected AbstractFileSystem(final FileName rootName, final FileObject parentLayer,
final FileSystemOptions fileSystemOptions) {
this.parentLayer = parentLayer;
this.rootName = rootName;
this.fileSystemOptions = fileSystemOptions;
final FileSystemConfigBuilder builder = DefaultFileSystemConfigBuilder.getInstance();
String uri = builder.getRootURI(fileSystemOptions);
if (uri == null) {
uri = rootName.getURI();
}
this.rootURI = uri;
}
/**
* Initializes this component.
*
* @throws FileSystemException if an error occurs.
*/
@Override
public void init() throws FileSystemException {
addCapabilities(caps);
}
/**
* Closes this component.
*/
@Override
public void close() {
closeCommunicationLink();
parentLayer = null;
}
/**
* Close the underlying link used to access the files.
*/
public void closeCommunicationLink() {
synchronized (this) {
doCloseCommunicationLink();
}
}
/**
* Close the underlying link used to access the files
*/
protected void doCloseCommunicationLink() {
}
/**
* Creates a file object.
*
* This method is called only if the requested file is not cached.
*
* @param name name referencing the new file.
* @return new created FileObject.
* @throws Exception might throw an Exception, which is then wrapped in FileSystemException.
*/
protected abstract FileObject createFile(final AbstractFileName name) throws Exception;
/**
* Adds the capabilities of this file system.
*
* @param caps collections of Capabilities, can be immutable.
*/
protected abstract void addCapabilities(Collection caps);
/**
* Returns the name of the root of this file system.
*
* @return the root FileName.
*/
@Override
public FileName getRootName() {
return rootName;
}
/**
* Returns the root URI specified for this file System.
*
* @return The root URI used in this file system.
* @since 2.0
*/
@Override
public String getRootURI() {
return rootURI;
}
/**
* Adds a file object to the cache.
*
* @param file the file to add.
*/
protected void putFileToCache(final FileObject file) {
getCache().putFile(file);
}
private FilesCache getCache() {
FilesCache files;
files = getContext().getFileSystemManager().getFilesCache();
if (files == null) {
throw new RuntimeException(Messages.getString("vfs.provider/files-cache-missing.error"));
}
return files;
}
/**
* Returns a cached file.
*
* @param name name to search for.
* @return file object or null if not found.
*/
protected FileObject getFileFromCache(final FileName name) {
return getCache().getFile(this, name);
}
/**
* Remove a cached file.
*
* @param name The file name to remove.
*/
protected void removeFileFromCache(final FileName name) {
getCache().removeFile(this, name);
}
/**
* Determines if this file system has a particular capability.
*
* @param capability the Capability to check for.
* @return true if the FileSystem has the Capability, false otherwise.
*/
@Override
public boolean hasCapability(final Capability capability) {
return caps.contains(capability);
}
/**
* Retrieves the attribute with the specified name. The default implementation simply throws an exception.
*
* @param attrName The name of the attribute.
* @return the Object associated with the attribute or null if no object is.
* @throws FileSystemException if an error occurs.
*/
@Override
public Object getAttribute(final String attrName) throws FileSystemException {
throw new FileSystemException("vfs.provider/get-attribute-not-supported.error");
}
/**
* Sets the attribute with the specified name. The default implementation simply throws an exception.
*
* @param attrName the attribute name.
* @param value The object to associate with the attribute.
* @throws FileSystemException if an error occurs.
*/
@Override
public void setAttribute(final String attrName, final Object value) throws FileSystemException {
throw new FileSystemException("vfs.provider/set-attribute-not-supported.error");
}
/**
* Returns the parent layer if this is a layered file system.
*
* @return The FileObject for the parent layer.
* @throws FileSystemException if an error occurs.
*/
@Override
public FileObject getParentLayer() throws FileSystemException {
return parentLayer;
}
/**
* Returns the root file of this file system.
*
* @return The root FileObject of the FileSystem
* @throws FileSystemException if an error occurs.
*/
@Override
public FileObject getRoot() throws FileSystemException {
return resolveFile(rootName);
}
/**
* Finds a file in this file system.
*
* @param nameStr The name of the file to resolve.
* @return The located FileObject or null if none could be located.
* @throws FileSystemException if an error occurs.
*/
@Override
public FileObject resolveFile(final String nameStr) throws FileSystemException {
// Resolve the name, and create the file
final FileName name = getFileSystemManager().resolveName(rootName, nameStr);
return resolveFile(name);
}
/**
* Finds a file in this file system.
*
* @param name The name of the file to locate.
* @return The located FileObject or null if none could be located.
* @throws FileSystemException if an error occurs.
*/
@Override
public FileObject resolveFile(final FileName name) throws FileSystemException {
return resolveFile(name, true);
}
private synchronized FileObject resolveFile(final FileName name, final boolean useCache)
throws FileSystemException {
if (!rootName.getRootURI().equals(name.getRootURI())) {
throw new FileSystemException("vfs.provider/mismatched-fs-for-name.error", name, rootName,
name.getRootURI());
}
// [email protected] ==> use getFileFromCache
FileObject file;
if (useCache) {
file = getFileFromCache(name);
} else {
file = null;
}
if (file == null) {
try {
file = createFile((AbstractFileName) name);
} catch (final Exception e) {
throw new FileSystemException("vfs.provider/resolve-file.error", name, e);
}
file = decorateFileObject(file);
// [email protected] ==> use putFileToCache
if (useCache) {
putFileToCache(file);
}
}
/**
* resync the file information if requested
*/
if (getFileSystemManager().getCacheStrategy().equals(CacheStrategy.ON_RESOLVE)) {
file.refresh();
}
return file;
}
protected FileObject decorateFileObject(FileObject file) throws FileSystemException {
if (getFileSystemManager().getCacheStrategy().equals(CacheStrategy.ON_CALL)) {
file = new OnCallRefreshFileObject(file);
}
if (getFileSystemManager().getFileObjectDecoratorConst() != null) {
try {
file = (FileObject) getFileSystemManager().getFileObjectDecoratorConst()
.newInstance(new Object[] { file });
} catch (final InstantiationException e) {
throw new FileSystemException("vfs.impl/invalid-decorator.error",
getFileSystemManager().getFileObjectDecorator().getName(), e);
} catch (final IllegalAccessException e) {
throw new FileSystemException("vfs.impl/invalid-decorator.error",
getFileSystemManager().getFileObjectDecorator().getName(), e);
} catch (final InvocationTargetException e) {
throw new FileSystemException("vfs.impl/invalid-decorator.error",
getFileSystemManager().getFileObjectDecorator().getName(), e);
}
}
return file;
}
/**
* Creates a temporary local copy of a file and its descendants.
*
* @param file The FileObject to replicate.
* @param selector The FileSelector.
* @return The replicated File.
* @throws FileSystemException if an error occurs.
*/
@Override
public File replicateFile(final FileObject file, final FileSelector selector) throws FileSystemException {
if (!file.exists()) {
throw new FileSystemException("vfs.provider/replicate-missing-file.error", file.getName());
}
try {
return doReplicateFile(file, selector);
} catch (final Exception e) {
throw new FileSystemException("vfs.provider/replicate-file.error", file.getName(), e);
}
}
/**
* Return the FileSystemOptions used to instantiate this filesystem.
*
* @return the FileSystemOptions.
*/
@Override
public FileSystemOptions getFileSystemOptions() {
return fileSystemOptions;
}
/**
* Return the FileSystemManager used to instantiate this filesystem.
*
* @return the FileSystemManager.
*/
@Override
public FileSystemManager getFileSystemManager() {
return getContext().getFileSystemManager();
}
/**
* Returns the accuracy of the last modification time.
*
* @return ms 0 perfectly accurate, {@literal >0} might be off by this value e.g. sftp 1000ms
*/
@Override
public double getLastModTimeAccuracy() {
return 0;
}
/**
* Creates a temporary local copy of a file and its descendants.
*
* @param file the start of the tree.
* @param selector selection what to do with childs.
* @return replicated root file.
* @throws Exception any Exception is wrapped as FileSystemException.
*/
protected File doReplicateFile(final FileObject file, final FileSelector selector) throws Exception {
return getContext().getReplicator().replicateFile(file, selector);
}
/**
* Adds a junction to this file system.
*
* @param junctionPoint The junction point.
* @param targetFile The target to add.
* @throws FileSystemException if an error occurs.
*/
@Override
public void addJunction(final String junctionPoint, final FileObject targetFile) throws FileSystemException {
throw new FileSystemException("vfs.provider/junctions-not-supported.error", rootName);
}
/**
* Removes a junction from this file system.
*
* @param junctionPoint The junction point.
* @throws FileSystemException if an error occurs
*/
@Override
public void removeJunction(final String junctionPoint) throws FileSystemException {
throw new FileSystemException("vfs.provider/junctions-not-supported.error", rootName);
}
/**
* Adds a listener on a file in this file system.
*
* @param file The FileObject to be monitored.
* @param listener The FileListener
*/
@Override
public void addListener(final FileObject file, final FileListener listener) {
synchronized (listenerMap) {
ArrayList listeners = listenerMap.get(file.getName());
if (listeners == null) {
listeners = new ArrayList<>();
listenerMap.put(file.getName(), listeners);
}
listeners.add(listener);
}
}
/**
* Removes a listener from a file in this file system.
*
* @param file The FileObject to be monitored.
* @param listener The FileListener
*/
@Override
public void removeListener(final FileObject file, final FileListener listener) {
synchronized (listenerMap) {
final ArrayList listeners = listenerMap.get(file.getName());
if (listeners != null) {
listeners.remove(listener);
if (listeners.isEmpty()) {
listenerMap.remove(file.getName());
}
}
}
}
/**
* Fires a file create event.
*
* @param file The FileObject that was created.
*/
public void fireFileCreated(final FileObject file) {
fireEvent(new CreateEvent(file));
}
/**
* Fires a file delete event.
*
* @param file The FileObject that was deleted.
*/
public void fireFileDeleted(final FileObject file) {
fireEvent(new DeleteEvent(file));
}
/**
* Fires a file changed event.
*
* This will only happen if you monitor the file using {@link org.apache.commons.vfs2.FileMonitor}.
*
* @param file The FileObject that changed.
*/
public void fireFileChanged(final FileObject file) {
fireEvent(new ChangedEvent(file));
}
/**
* Returns true if no file is using this filesystem.
*
* @return true if no file is using this FileSystem.
*/
public boolean isReleaseable() {
return useCount.get() < 1;
}
void freeResources() {
}
/**
* Fires an event.
*/
private void fireEvent(final AbstractFileChangeEvent event) {
FileListener[] fileListeners = null;
final FileObject file = event.getFile();
synchronized (listenerMap) {
final ArrayList listeners = listenerMap.get(file.getName());
if (listeners != null) {
fileListeners = listeners.toArray(new FileListener[listeners.size()]);
}
}
if (fileListeners != null) {
for (final FileListener fileListener : fileListeners) {
try {
event.notify(fileListener);
} catch (final Exception e) {
final String message = Messages.getString("vfs.provider/notify-listener.warn", file);
// getLogger().warn(message, e);
VfsLog.warn(getLogger(), LOG, message, e);
}
}
}
}
void fileObjectHanded(final FileObject fileObject) {
useCount.incrementAndGet();
}
void fileObjectDestroyed(final FileObject fileObject) {
useCount.decrementAndGet();
}
void setCacheKey(final FileSystemKey cacheKey) {
this.cacheKey = cacheKey;
}
FileSystemKey getCacheKey() {
return this.cacheKey;
}
void streamOpened() {
openStreams.incrementAndGet();
}
void streamClosed() {
if (openStreams.decrementAndGet() == 0) {
notifyAllStreamsClosed();
}
}
/**
* will be called after all file-objects closed their streams.
*/
protected void notifyAllStreamsClosed() {
}
/**
* check if this filesystem has open streams.
*
* @return true if the FileSystem has open streams.
*/
public boolean isOpen() {
return openStreams.get() > 0;
}
}