| /** |
| * 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.hadoop.fs.local; |
| |
| import java.io.IOException; |
| import java.io.FileNotFoundException; |
| import java.net.URI; |
| import java.net.URISyntaxException; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.FileStatus; |
| import org.apache.hadoop.fs.DelegateToFileSystem; |
| import org.apache.hadoop.fs.FsConstants; |
| import org.apache.hadoop.fs.FsServerDefaults; |
| import org.apache.hadoop.fs.RawLocalFileSystem; |
| import org.apache.hadoop.fs.permission.FsPermission; |
| import org.apache.hadoop.util.Shell; |
| |
| /** |
| * The RawLocalFs implementation of AbstractFileSystem. |
| * This impl delegates to the old FileSystem |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving /*Evolving for a release,to be changed to Stable */ |
| public class RawLocalFs extends DelegateToFileSystem { |
| |
| RawLocalFs(final Configuration conf) throws IOException, URISyntaxException { |
| this(FsConstants.LOCAL_FS_URI, conf); |
| } |
| |
| /** |
| * This constructor has the signature needed by |
| * {@link AbstractFileSystem#createFileSystem(URI, Configuration)}. |
| * |
| * @param theUri which must be that of localFs |
| * @param conf |
| * @throws IOException |
| * @throws URISyntaxException |
| */ |
| RawLocalFs(final URI theUri, final Configuration conf) throws IOException, |
| URISyntaxException { |
| super(theUri, new RawLocalFileSystem(), conf, |
| FsConstants.LOCAL_FS_URI.getScheme(), false); |
| } |
| |
| @Override |
| public int getUriDefaultPort() { |
| return -1; // No default port for file:/// |
| } |
| |
| @Override |
| public FsServerDefaults getServerDefaults() throws IOException { |
| return LocalConfigKeys.getServerDefaults(); |
| } |
| |
| @Override |
| public boolean supportsSymlinks() { |
| return true; |
| } |
| |
| @Override |
| public void createSymlink(Path target, Path link, boolean createParent) |
| throws IOException { |
| final String targetScheme = target.toUri().getScheme(); |
| if (targetScheme != null && !"file".equals(targetScheme)) { |
| throw new IOException("Unable to create symlink to non-local file "+ |
| "system: "+target.toString()); |
| } |
| if (createParent) { |
| mkdir(link.getParent(), FsPermission.getDirDefault(), true); |
| } |
| // NB: Use createSymbolicLink in java.nio.file.Path once available |
| try { |
| Shell.execCommand(Shell.LINK_COMMAND, "-s", |
| new URI(target.toString()).getPath(), |
| new URI(link.toString()).getPath()); |
| } catch (URISyntaxException x) { |
| throw new IOException("Invalid symlink path: "+x.getMessage()); |
| } catch (IOException x) { |
| throw new IOException("Unable to create symlink: "+x.getMessage()); |
| } |
| } |
| |
| /** |
| * Returns the target of the given symlink. Returns the empty string if |
| * the given path does not refer to a symlink or there is an error |
| * acessing the symlink. |
| */ |
| private String readLink(Path p) { |
| /* NB: Use readSymbolicLink in java.nio.file.Path once available. Could |
| * use getCanonicalPath in File to get the target of the symlink but that |
| * does not indicate if the given path refers to a symlink. |
| */ |
| try { |
| final String path = p.toUri().getPath(); |
| return Shell.execCommand(Shell.READ_LINK_COMMAND, path).trim(); |
| } catch (IOException x) { |
| return ""; |
| } |
| } |
| |
| /** |
| * Return a FileStatus representing the given path. If the path refers |
| * to a symlink return a FileStatus representing the link rather than |
| * the object the link refers to. |
| */ |
| @Override |
| public FileStatus getFileLinkStatus(final Path f) throws IOException { |
| String target = readLink(f); |
| try { |
| FileStatus fs = getFileStatus(f); |
| // If f refers to a regular file or directory |
| if ("".equals(target)) { |
| return fs; |
| } |
| // Otherwise f refers to a symlink |
| return new FileStatus(fs.getLen(), |
| false, |
| fs.getReplication(), |
| fs.getBlockSize(), |
| fs.getModificationTime(), |
| fs.getAccessTime(), |
| fs.getPermission(), |
| fs.getOwner(), |
| fs.getGroup(), |
| new Path(target), |
| f); |
| } catch (FileNotFoundException e) { |
| /* The exists method in the File class returns false for dangling |
| * links so we can get a FileNotFoundException for links that exist. |
| * It's also possible that we raced with a delete of the link. Use |
| * the readBasicFileAttributes method in java.nio.file.attributes |
| * when available. |
| */ |
| if (!"".equals(target)) { |
| return new FileStatus(0, false, 0, 0, 0, 0, FsPermission.getDefault(), |
| "", "", new Path(target), f); |
| } |
| // f refers to a file or directory that does not exist |
| throw e; |
| } |
| } |
| |
| @Override |
| public Path getLinkTarget(Path f) throws IOException { |
| /* We should never get here. Valid local links are resolved transparently |
| * by the underlying local file system and accessing a dangling link will |
| * result in an IOException, not an UnresolvedLinkException, so FileContext |
| * should never call this function. |
| */ |
| throw new AssertionError(); |
| } |
| } |