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//
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// 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 com.signalfx.shaded.jetty.util.resource;
import java.io.File;
import java.io.IOError;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.DirectoryIteratorException;
import java.nio.file.DirectoryStream;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.InvalidPathException;
import java.nio.file.LinkOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.nio.file.attribute.FileTime;
import java.util.ArrayList;
import java.util.List;
import com.signalfx.shaded.jetty.util.BufferUtil;
import com.signalfx.shaded.jetty.util.IO;
import com.signalfx.shaded.jetty.util.StringUtil;
import com.signalfx.shaded.jetty.util.URIUtil;
import com.signalfx.shaded.jetty.util.log.Log;
import com.signalfx.shaded.jetty.util.log.Logger;
/**
* Java NIO Path equivalent of FileResource.
*/
public class PathResource extends Resource
{
private static final Logger LOG = Log.getLogger(PathResource.class);
private static final LinkOption[] NO_FOLLOW_LINKS = new LinkOption[]{LinkOption.NOFOLLOW_LINKS};
private static final LinkOption[] FOLLOW_LINKS = new LinkOption[]{};
private final Path path;
private final Path alias;
private final URI uri;
private final boolean belongsToDefaultFileSystem;
private Path checkAliasPath()
{
Path abs = path;
/* Catch situation where the Path class has already normalized
* the URI eg. input path "aa./foo.txt"
* from an #addPath(String) is normalized away during
* the creation of a Path object reference.
* If the URI is different then the Path.toUri() then
* we will just use the original URI to construct the
* alias reference Path.
*/
if (!URIUtil.equalsIgnoreEncodings(uri, path.toUri()))
{
try
{
return Paths.get(uri).toRealPath(FOLLOW_LINKS);
}
catch (IOException ignored)
{
// If the toRealPath() call fails, then let
// the alias checking routines continue on
// to other techniques.
LOG.ignore(ignored);
}
}
if (!abs.isAbsolute())
abs = path.toAbsolutePath();
// Any normalization difference means it's an alias,
// and we don't want to bother further to follow
// symlinks as it's an alias anyway.
Path normal = path.normalize();
if (!isSameName(abs, normal))
return normal;
try
{
if (Files.isSymbolicLink(path))
return path.getParent().resolve(Files.readSymbolicLink(path));
if (Files.exists(path))
{
Path real = abs.toRealPath(FOLLOW_LINKS);
if (!isSameName(abs, real))
return real;
}
}
catch (IOException e)
{
LOG.ignore(e);
}
catch (Exception e)
{
LOG.warn("bad alias ({} {}) for {}", e.getClass().getName(), e.getMessage(), path);
}
return null;
}
/**
* Test if the paths are the same name.
*
*
* If the real path is not the same as the absolute path
* then we know that the real path is the alias for the
* provided path.
*
*
*
* For OS's that are case insensitive, this should
* return the real (on-disk / case correct) version
* of the path.
*
*
*
* We have to be careful on Windows and OSX.
*
*
*
* Assume we have the following scenario:
*
*
*
* Path a = new File("foo").toPath();
* Files.createFile(a);
* Path b = new File("FOO").toPath();
*
*
*
* There now exists a file called {@code foo} on disk.
* Using Windows or OSX, with a Path reference of
* {@code FOO}, {@code Foo}, {@code fOO}, etc.. means the following
*
*
*
* | OSX | Windows | Linux
* -----------------------+---------+------------+---------
* Files.exists(a) | True | True | True
* Files.exists(b) | True | True | False
* Files.isSameFile(a,b) | True | True | False
* a.equals(b) | False | True | False
*
*
*
* See the javadoc for Path.equals() for details about this FileSystem
* behavior difference
*
*
*
* We also cannot rely on a.compareTo(b) as this is roughly equivalent
* in implementation to a.equals(b)
*
*/
public static boolean isSameName(Path pathA, Path pathB)
{
int aCount = pathA.getNameCount();
int bCount = pathB.getNameCount();
if (aCount != bCount)
{
// different number of segments
return false;
}
// compare each segment of path, backwards
for (int i = bCount; i-- > 0; )
{
if (!pathA.getName(i).toString().equals(pathB.getName(i).toString()))
{
return false;
}
}
return true;
}
/**
* Construct a new PathResource from a File object.
*
* An invocation of this convenience constructor of the form.
*
*
* new PathResource(file);
*
*
* behaves in exactly the same way as the expression
*
*
* new PathResource(file.toPath());
*
*
* @param file the file to use
*/
public PathResource(File file)
{
this(file.toPath());
}
/**
* Construct a new PathResource from a Path object.
*
* @param path the path to use
*/
public PathResource(Path path)
{
Path absPath = path;
try
{
absPath = path.toRealPath(NO_FOLLOW_LINKS);
}
catch (IOError | IOException e)
{
// Not able to resolve real/canonical path from provided path
// This could be due to a glob reference, or a reference
// to a path that doesn't exist (yet)
if (LOG.isDebugEnabled())
LOG.debug("Unable to get real/canonical path for {}", path, e);
}
this.path = absPath;
assertValidPath(path);
this.uri = this.path.toUri();
this.alias = checkAliasPath();
this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
}
/**
* Construct a new PathResource from a parent PathResource
* and child sub path
*
* @param parent the parent path resource
* @param childPath the child sub path
*/
private PathResource(PathResource parent, String childPath)
{
// Calculate the URI and the path separately, so that any aliasing done by
// FileSystem.getPath(path,childPath) is visible as a difference to the URI
// obtained via URIUtil.addDecodedPath(uri,childPath)
// The checkAliasPath normalization checks will only work correctly if the getPath implementation here does not normalize.
this.path = parent.path.getFileSystem().getPath(parent.path.toString(), childPath);
if (isDirectory() && !childPath.endsWith("/"))
childPath += "/";
this.uri = URIUtil.addPath(parent.uri, childPath);
this.alias = checkAliasPath();
this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
}
/**
* Construct a new PathResource from a URI object.
*
* Must be an absolute URI using the file scheme.
*
* @param uri the URI to build this PathResource from.
* @throws IOException if unable to construct the PathResource from the URI.
*/
public PathResource(URI uri) throws IOException
{
if (!uri.isAbsolute())
{
throw new IllegalArgumentException("not an absolute uri");
}
if (!uri.getScheme().equalsIgnoreCase("file"))
{
throw new IllegalArgumentException("not file: scheme");
}
Path path;
try
{
path = Paths.get(uri);
}
catch (IllegalArgumentException e)
{
throw e;
}
catch (Exception e)
{
LOG.ignore(e);
throw new IOException("Unable to build Path from: " + uri, e);
}
this.path = path.toAbsolutePath();
this.uri = path.toUri();
this.alias = checkAliasPath();
this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
}
/**
* Create a new PathResource from a provided URL object.
*
* An invocation of this convenience constructor of the form.
*
*
* new PathResource(url);
*
*
* behaves in exactly the same way as the expression
*
*
* new PathResource(url.toURI());
*
*
* @param url the url to attempt to create PathResource from
* @throws IOException if URL doesn't point to a location that can be transformed to a PathResource
* @throws URISyntaxException if the provided URL was malformed
*/
public PathResource(URL url) throws IOException, URISyntaxException
{
this(url.toURI());
}
@Override
public boolean isSame(Resource resource)
{
try
{
if (resource instanceof PathResource)
{
Path path = ((PathResource)resource).getPath();
return Files.isSameFile(getPath(), path);
}
if (resource instanceof FileResource)
{
Path path = ((FileResource)resource).getFile().toPath();
return Files.isSameFile(getPath(), path);
}
}
catch (IOException e)
{
if (LOG.isDebugEnabled())
LOG.debug("ignored", e);
}
return false;
}
@Override
public Resource addPath(final String subPath) throws IOException
{
// Check that the path is within the root,
// but use the original path to create the
// resource, to preserve aliasing.
if (URIUtil.canonicalPath(subPath) == null)
throw new MalformedURLException(subPath);
if ("/".equals(subPath))
return this;
// Sub-paths are always under PathResource
// compensate for input sub-paths like "/subdir"
// where default resolve behavior would be
// to treat that like an absolute path
return new PathResource(this, subPath);
}
private void assertValidPath(Path path)
{
// TODO merged from 9.2, check if necessary
String str = path.toString();
int idx = StringUtil.indexOfControlChars(str);
if (idx >= 0)
{
throw new InvalidPathException(str, "Invalid Character at index " + idx);
}
}
@Override
public void close()
{
// not applicable for FileSytem / Path
}
@Override
public boolean delete() throws SecurityException
{
try
{
return Files.deleteIfExists(path);
}
catch (IOException e)
{
LOG.ignore(e);
return false;
}
}
@Override
public boolean equals(Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (getClass() != obj.getClass())
{
return false;
}
PathResource other = (PathResource)obj;
if (path == null)
{
return other.path == null;
}
else
return path.equals(other.path);
}
@Override
public boolean exists()
{
return Files.exists(path, NO_FOLLOW_LINKS);
}
@Override
public File getFile() throws IOException
{
if (!belongsToDefaultFileSystem)
return null;
return path.toFile();
}
/**
* @return the {@link Path} of the resource
*/
public Path getPath()
{
return path;
}
@Override
public InputStream getInputStream() throws IOException
{
return Files.newInputStream(path, StandardOpenOption.READ);
}
@Override
public String getName()
{
return path.toAbsolutePath().toString();
}
@Override
public ReadableByteChannel getReadableByteChannel() throws IOException
{
return newSeekableByteChannel();
}
public SeekableByteChannel newSeekableByteChannel() throws IOException
{
return Files.newByteChannel(path, StandardOpenOption.READ);
}
@Override
public URI getURI()
{
return this.uri;
}
@Override
public URL getURL()
{
try
{
return path.toUri().toURL();
}
catch (MalformedURLException e)
{
return null;
}
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = (prime * result) + ((path == null) ? 0 : path.hashCode());
return result;
}
@Override
public boolean isContainedIn(Resource r) throws MalformedURLException
{
// not applicable for FileSystem / path
return false;
}
@Override
public boolean isDirectory()
{
return Files.isDirectory(path, FOLLOW_LINKS);
}
@Override
public long lastModified()
{
try
{
FileTime ft = Files.getLastModifiedTime(path, FOLLOW_LINKS);
return ft.toMillis();
}
catch (IOException e)
{
LOG.ignore(e);
return 0;
}
}
@Override
public long length()
{
try
{
return Files.size(path);
}
catch (IOException e)
{
// in case of error, use File.length logic of 0L
return 0L;
}
}
@Override
public boolean isAlias()
{
return this.alias != null;
}
/**
* The Alias as a Path.
*
* Note: this cannot return the alias as a DIFFERENT path in 100% of situations,
* due to Java's internal Path/File normalization.
*
*
* @return the alias as a path.
*/
public Path getAliasPath()
{
return this.alias;
}
@Override
public URI getAlias()
{
return this.alias == null ? null : this.alias.toUri();
}
@Override
public String[] list()
{
try (DirectoryStream dir = Files.newDirectoryStream(path))
{
List entries = new ArrayList<>();
for (Path entry : dir)
{
String name = entry.getFileName().toString();
if (Files.isDirectory(entry))
{
name += "/";
}
entries.add(name);
}
int size = entries.size();
return entries.toArray(new String[size]);
}
catch (DirectoryIteratorException | IOException e)
{
LOG.debug(e);
}
return null;
}
@Override
public boolean renameTo(Resource dest) throws SecurityException
{
if (dest instanceof PathResource)
{
PathResource destRes = (PathResource)dest;
try
{
Path result = Files.move(path, destRes.path);
return Files.exists(result, NO_FOLLOW_LINKS);
}
catch (IOException e)
{
LOG.ignore(e);
return false;
}
}
else
{
return false;
}
}
@Override
public void copyTo(File destination) throws IOException
{
if (isDirectory())
{
IO.copyDir(this.path.toFile(), destination);
}
else
{
Files.copy(this.path, destination.toPath());
}
}
/**
* @param outputStream the output stream to write to
* @param start First byte to write
* @param count Bytes to write or -1 for all of them.
* @throws IOException if unable to copy the Resource to the output
*/
@Override
public void writeTo(OutputStream outputStream, long start, long count)
throws IOException
{
long length = count;
if (count < 0)
{
length = Files.size(path) - start;
}
try (SeekableByteChannel channel = Files.newByteChannel(path, StandardOpenOption.READ))
{
ByteBuffer buffer = BufferUtil.allocate(IO.bufferSize);
skipTo(channel, buffer, start);
// copy from channel to output stream
long readTotal = 0;
while (readTotal < length)
{
BufferUtil.clearToFill(buffer);
int size = (int)Math.min(IO.bufferSize, length - readTotal);
buffer.limit(size);
int readLen = channel.read(buffer);
BufferUtil.flipToFlush(buffer, 0);
BufferUtil.writeTo(buffer, outputStream);
readTotal += readLen;
}
}
}
private void skipTo(SeekableByteChannel channel, ByteBuffer buffer, long skipTo) throws IOException
{
try
{
if (channel.position() != skipTo)
{
channel.position(skipTo);
}
}
catch (UnsupportedOperationException e)
{
final int NO_PROGRESS_LIMIT = 3;
if (skipTo > 0)
{
long pos = 0;
long readLen;
int noProgressLoopLimit = NO_PROGRESS_LIMIT;
// loop till we reach desired point, break out on lack of progress.
while (noProgressLoopLimit > 0 && pos < skipTo)
{
BufferUtil.clearToFill(buffer);
int len = (int)Math.min(IO.bufferSize, (skipTo - pos));
buffer.limit(len);
readLen = channel.read(buffer);
if (readLen == 0)
{
noProgressLoopLimit--;
}
else if (readLen > 0)
{
pos += readLen;
noProgressLoopLimit = NO_PROGRESS_LIMIT;
}
else
{
// negative values means the stream was closed or reached EOF
// either way, we've hit a state where we can no longer
// fulfill the requested range write.
throw new IOException("EOF reached before SeekableByteChannel skip destination");
}
}
if (noProgressLoopLimit <= 0)
{
throw new IOException("No progress made to reach SeekableByteChannel skip position " + skipTo);
}
}
}
}
@Override
public String toString()
{
return this.uri.toASCIIString();
}
}
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