/*
* Copyright 2002-2005 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.provider.tar;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.zip.GZIPInputStream;
import org.apache.commons.compress.archivers.tar.TarEntry;
import org.apache.commons.compress.archivers.tar.TarInputStream;
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.FileSystemException;
import org.apache.commons.vfs.FileSystemOptions;
import org.apache.commons.vfs.Selectors;
import org.apache.commons.vfs.VfsLog;
import org.apache.commons.vfs.provider.AbstractFileSystem;
import org.apache.commons.vfs.provider.UriParser;
import org.apache.commons.vfs.provider.bzip2.Bzip2FileObject;
/**
* A read-only file system for Tar files.
*
* @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
*/
public class TarFileSystem
extends AbstractFileSystem
implements FileSystem
{
private final static Log log = LogFactory.getLog(TarFileSystem.class);
private final File file;
private TarInputStream tarFile;
protected TarFileSystem(final FileName rootName,
final FileObject parentLayer,
final FileSystemOptions fileSystemOptions)
throws FileSystemException
{
super(rootName, parentLayer, fileSystemOptions);
// Make a local copy of the file
file = parentLayer.getFileSystem().replicateFile(parentLayer, Selectors.SELECT_SELF);
// Open the Tar file
if (!file.exists())
{
// Don't need to do anything
tarFile = null;
return;
}
// tarFile = createTarFile(this.file);
}
public void init() throws FileSystemException
{
super.init();
// Build the index
try
{
List strongRef = new ArrayList(100);
TarEntry entry;
while ((entry = getTarFile().getNextEntry()) != null)
{
FileName name = getFileSystemManager().resolveName(getRootName(), UriParser.encode(entry.getName()));
// Create the file
TarFileObject fileObj;
if (entry.isDirectory() && getFileFromCache(name) != null)
{
fileObj = (TarFileObject) getFileFromCache(name);
fileObj.setTarEntry(entry);
continue;
}
fileObj = createTarFileObject(name, entry);
putFileToCache(fileObj);
strongRef.add(fileObj);
fileObj.holdObject(strongRef);
// Make sure all ancestors exist
// TODO - create these on demand
TarFileObject parent = null;
for (FileName parentName = name.getParent();
parentName != null;
fileObj = parent, parentName = parentName.getParent())
{
// Locate the parent
parent = (TarFileObject) getFileFromCache(parentName);
if (parent == null)
{
parent = createTarFileObject(parentName, null);
putFileToCache(parent);
strongRef.add(parent);
parent.holdObject(strongRef);
}
// Attach child to parent
parent.attachChild(fileObj.getName());
}
}
}
catch (IOException e)
{
throw new FileSystemException(e);
}
finally
{
closeCommunicationLink();
}
}
public InputStream getInputStream(TarEntry entry) throws FileSystemException
{
resetTarFile();
try
{
while (!tarFile.getNextEntry().equals(entry))
{
}
return tarFile;
}
catch (IOException e)
{
throw new FileSystemException(e);
}
}
protected void resetTarFile() throws FileSystemException
{
// Reading specific entries requires skipping through the tar file from the beginning
// Not especially elegant, but we don't have the ability to seek to specific positions
// with an input stream.
if (this.file.exists())
{
recreateTarFile();
}
}
private void recreateTarFile() throws FileSystemException
{
if (this.tarFile != null)
{
try
{
this.tarFile.close();
}
catch (IOException e)
{
throw new FileSystemException("vfs.provider.tar/close-tar-file.error", file, e);
}
tarFile = null;
}
TarInputStream tarFile = createTarFile(this.file);
this.tarFile = tarFile;
}
protected TarInputStream getTarFile() throws FileSystemException
{
if (tarFile == null && this.file.exists())
{
recreateTarFile();
}
return tarFile;
}
protected TarFileObject createTarFileObject(final FileName name,
final TarEntry entry) throws FileSystemException
{
return new TarFileObject(name, entry, this, true);
}
protected TarInputStream createTarFile(final File file) throws FileSystemException
{
try
{
if ("tgz".equalsIgnoreCase(getRootName().getScheme()))
{
return new TarInputStream(new GZIPInputStream(new FileInputStream(file)));
}
else if ("tbz2".equalsIgnoreCase(getRootName().getScheme()))
{
return new TarInputStream(Bzip2FileObject.wrapInputStream(file.getAbsolutePath(), new FileInputStream(file)));
}
return new TarInputStream(new FileInputStream(file));
}
catch (IOException ioe)
{
throw new FileSystemException("vfs.provider.tar/open-tar-file.error", file, ioe);
}
}
protected void doCloseCommunicationLink()
{
// Release the tar file
try
{
if (tarFile != null)
{
tarFile.close();
tarFile = null;
}
}
catch (final IOException e)
{
// getLogger().warn("vfs.provider.tar/close-tar-file.error :" + file, e);
VfsLog.warn(getLogger(), log, "vfs.provider.tar/close-tar-file.error :" + file, e);
}
}
/**
* Returns the capabilities of this file system.
*/
protected void addCapabilities(final Collection caps)
{
caps.addAll(TarFileProvider.capabilities);
}
/**
* Creates a file object.
*/
protected FileObject createFile(final FileName name) throws FileSystemException
{
// This is only called for files which do not exist in the Tar file
return new TarFileObject(name, null, this, false);
}
/**
* will be called after all file-objects closed their streams.
*/
protected void notifyAllStreamsClosed()
{
closeCommunicationLink();
}
}