001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.fs;
020
021import java.io.File;
022import java.io.IOException;
023import java.net.URI;
024import java.util.Random;
025
026import org.apache.hadoop.classification.InterfaceAudience;
027import org.apache.hadoop.classification.InterfaceStability;
028import org.apache.hadoop.conf.Configuration;
029
030/****************************************************************
031 * Implement the FileSystem API for the checksumed local filesystem.
032 *
033 *****************************************************************/
034@InterfaceAudience.Public
035@InterfaceStability.Stable
036public class LocalFileSystem extends ChecksumFileSystem {
037  static final URI NAME = URI.create("file:///");
038  static private Random rand = new Random();
039  
040  public LocalFileSystem() {
041    this(new RawLocalFileSystem());
042  }
043  
044  @Override
045  public void initialize(URI name, Configuration conf) throws IOException {
046    if (fs.getConf() == null) {
047      fs.initialize(name, conf);
048    }
049    String scheme = name.getScheme();
050    if (!scheme.equals(fs.getUri().getScheme())) {
051      swapScheme = scheme;
052    }
053  }
054
055  /**
056   * Return the protocol scheme for the FileSystem.
057   * <p/>
058   *
059   * @return <code>file</code>
060   */
061  @Override
062  public String getScheme() {
063    return "file";
064  }
065
066  public FileSystem getRaw() {
067    return getRawFileSystem();
068  }
069    
070  public LocalFileSystem(FileSystem rawLocalFileSystem) {
071    super(rawLocalFileSystem);
072  }
073    
074  /** Convert a path to a File. */
075  public File pathToFile(Path path) {
076    return ((RawLocalFileSystem)fs).pathToFile(path);
077  }
078
079  @Override
080  public void copyFromLocalFile(boolean delSrc, Path src, Path dst)
081    throws IOException {
082    FileUtil.copy(this, src, this, dst, delSrc, getConf());
083  }
084
085  @Override
086  public void copyToLocalFile(boolean delSrc, Path src, Path dst)
087    throws IOException {
088    FileUtil.copy(this, src, this, dst, delSrc, getConf());
089  }
090
091  /**
092   * Moves files to a bad file directory on the same device, so that their
093   * storage will not be reused.
094   */
095  @Override
096  public boolean reportChecksumFailure(Path p, FSDataInputStream in,
097                                       long inPos,
098                                       FSDataInputStream sums, long sumsPos) {
099    try {
100      // canonicalize f
101      File f = ((RawLocalFileSystem)fs).pathToFile(p).getCanonicalFile();
102      
103      // find highest writable parent dir of f on the same device
104      String device = new DF(f, getConf()).getMount();
105      File parent = f.getParentFile();
106      File dir = null;
107      while (parent != null && FileUtil.canWrite(parent) &&
108          parent.toString().startsWith(device)) {
109        dir = parent;
110        parent = parent.getParentFile();
111      }
112
113      if (dir==null) {
114        throw new IOException(
115                              "not able to find the highest writable parent dir");
116      }
117        
118      // move the file there
119      File badDir = new File(dir, "bad_files");
120      if (!badDir.mkdirs()) {
121        if (!badDir.isDirectory()) {
122          throw new IOException("Mkdirs failed to create " + badDir.toString());
123        }
124      }
125      String suffix = "." + rand.nextInt();
126      File badFile = new File(badDir, f.getName()+suffix);
127      LOG.warn("Moving bad file " + f + " to " + badFile);
128      in.close();                               // close it first
129      boolean b = f.renameTo(badFile);                      // rename it
130      if (!b) {
131        LOG.warn("Ignoring failure of renameTo");
132      }
133      // move checksum file too
134      File checkFile = ((RawLocalFileSystem)fs).pathToFile(getChecksumFile(p));
135      // close the stream before rename to release the file handle
136      sums.close();
137      b = checkFile.renameTo(new File(badDir, checkFile.getName()+suffix));
138      if (!b) {
139          LOG.warn("Ignoring failure of renameTo");
140        }
141    } catch (IOException e) {
142      LOG.warn("Error moving bad file " + p + ": " + e);
143    }
144    return false;
145  }
146
147  @Override
148  public boolean supportsSymlinks() {
149    return true;
150  }
151
152  @Override
153  public void createSymlink(Path target, Path link, boolean createParent)
154      throws IOException {
155    fs.createSymlink(target, link, createParent);
156  }
157
158  @Override
159  public FileStatus getFileLinkStatus(final Path f) throws IOException {
160    return fs.getFileLinkStatus(f);
161  }
162
163  @Override
164  public Path getLinkTarget(Path f) throws IOException {
165    return fs.getLinkTarget(f);
166  }
167}