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    
019    package org.apache.hadoop.fs;
020    
021    import java.io.*;
022    import java.net.URI;
023    import java.net.URISyntaxException;
024    import java.util.EnumSet;
025    import org.apache.hadoop.classification.InterfaceAudience;
026    import org.apache.hadoop.classification.InterfaceStability;
027    import org.apache.hadoop.conf.Configuration;
028    import org.apache.hadoop.fs.permission.FsPermission;
029    import org.apache.hadoop.fs.ContentSummary;
030    import org.apache.hadoop.fs.Options.ChecksumOpt;
031    import org.apache.hadoop.security.AccessControlException;
032    import org.apache.hadoop.util.Progressable;
033    
034    /****************************************************************
035     * A <code>FilterFileSystem</code> contains
036     * some other file system, which it uses as
037     * its  basic file system, possibly transforming
038     * the data along the way or providing  additional
039     * functionality. The class <code>FilterFileSystem</code>
040     * itself simply overrides all  methods of
041     * <code>FileSystem</code> with versions that
042     * pass all requests to the contained  file
043     * system. Subclasses of <code>FilterFileSystem</code>
044     * may further override some of  these methods
045     * and may also provide additional methods
046     * and fields.
047     *
048     *****************************************************************/
049    @InterfaceAudience.Public
050    @InterfaceStability.Stable
051    public class FilterFileSystem extends FileSystem {
052      
053      protected FileSystem fs;
054      protected String swapScheme;
055      
056      /*
057       * so that extending classes can define it
058       */
059      public FilterFileSystem() {
060      }
061      
062      public FilterFileSystem(FileSystem fs) {
063        this.fs = fs;
064        this.statistics = fs.statistics;
065      }
066    
067      /**
068       * Get the raw file system 
069       * @return FileSystem being filtered
070       */
071      public FileSystem getRawFileSystem() {
072        return fs;
073      }
074    
075      /** Called after a new FileSystem instance is constructed.
076       * @param name a uri whose authority section names the host, port, etc.
077       *   for this FileSystem
078       * @param conf the configuration
079       */
080      @Override
081      public void initialize(URI name, Configuration conf) throws IOException {
082        super.initialize(name, conf);
083        // this is less than ideal, but existing filesystems sometimes neglect
084        // to initialize the embedded filesystem
085        if (fs.getConf() == null) {
086          fs.initialize(name, conf);
087        }
088        String scheme = name.getScheme();
089        if (!scheme.equals(fs.getUri().getScheme())) {
090          swapScheme = scheme;
091        }
092      }
093    
094      /** Returns a URI whose scheme and authority identify this FileSystem.*/
095      @Override
096      public URI getUri() {
097        return fs.getUri();
098      }
099      
100      
101      @Override
102      protected URI getCanonicalUri() {
103        return fs.getCanonicalUri();
104      }
105    
106      @Override
107      protected URI canonicalizeUri(URI uri) {
108        return fs.canonicalizeUri(uri);
109      }
110    
111      /** Make sure that a path specifies a FileSystem. */
112      @Override
113      public Path makeQualified(Path path) {
114        Path fqPath = fs.makeQualified(path);
115        // swap in our scheme if the filtered fs is using a different scheme
116        if (swapScheme != null) {
117          try {
118            // NOTE: should deal with authority, but too much other stuff is broken 
119            fqPath = new Path(
120                new URI(swapScheme, fqPath.toUri().getSchemeSpecificPart(), null)
121            );
122          } catch (URISyntaxException e) {
123            throw new IllegalArgumentException(e);
124          }
125        }
126        return fqPath;
127      }
128      
129      ///////////////////////////////////////////////////////////////
130      // FileSystem
131      ///////////////////////////////////////////////////////////////
132    
133      /** Check that a Path belongs to this FileSystem. */
134      @Override
135      protected void checkPath(Path path) {
136        fs.checkPath(path);
137      }
138    
139      @Override
140      public BlockLocation[] getFileBlockLocations(FileStatus file, long start,
141        long len) throws IOException {
142          return fs.getFileBlockLocations(file, start, len);
143      }
144    
145      @Override
146      public Path resolvePath(final Path p) throws IOException {
147        return fs.resolvePath(p);
148      }
149      /**
150       * Opens an FSDataInputStream at the indicated Path.
151       * @param f the file name to open
152       * @param bufferSize the size of the buffer to be used.
153       */
154      @Override
155      public FSDataInputStream open(Path f, int bufferSize) throws IOException {
156        return fs.open(f, bufferSize);
157      }
158    
159      @Override
160      public FSDataOutputStream append(Path f, int bufferSize,
161          Progressable progress) throws IOException {
162        return fs.append(f, bufferSize, progress);
163      }
164    
165      @Override
166      public void concat(Path f, Path[] psrcs) throws IOException {
167        fs.concat(f, psrcs);
168      }
169    
170      @Override
171      public FSDataOutputStream create(Path f, FsPermission permission,
172          boolean overwrite, int bufferSize, short replication, long blockSize,
173          Progressable progress) throws IOException {
174        return fs.create(f, permission,
175            overwrite, bufferSize, replication, blockSize, progress);
176      }
177      
178    
179      
180      @Override
181      @Deprecated
182      public FSDataOutputStream createNonRecursive(Path f, FsPermission permission,
183          EnumSet<CreateFlag> flags, int bufferSize, short replication, long blockSize,
184          Progressable progress) throws IOException {
185        
186        return fs.createNonRecursive(f, permission, flags, bufferSize, replication, blockSize,
187            progress);
188      }
189    
190      /**
191       * Set replication for an existing file.
192       * 
193       * @param src file name
194       * @param replication new replication
195       * @throws IOException
196       * @return true if successful;
197       *         false if file does not exist or is a directory
198       */
199      @Override
200      public boolean setReplication(Path src, short replication) throws IOException {
201        return fs.setReplication(src, replication);
202      }
203      
204      /**
205       * Renames Path src to Path dst.  Can take place on local fs
206       * or remote DFS.
207       */
208      @Override
209      public boolean rename(Path src, Path dst) throws IOException {
210        return fs.rename(src, dst);
211      }
212      
213      /** Delete a file */
214      @Override
215      public boolean delete(Path f, boolean recursive) throws IOException {
216        return fs.delete(f, recursive);
217      }
218      
219      /** List files in a directory. */
220      @Override
221      public FileStatus[] listStatus(Path f) throws IOException {
222        return fs.listStatus(f);
223      }
224    
225      @Override
226      public RemoteIterator<Path> listCorruptFileBlocks(Path path)
227        throws IOException {
228        return fs.listCorruptFileBlocks(path);
229      }
230    
231      /** List files and its block locations in a directory. */
232      @Override
233      public RemoteIterator<LocatedFileStatus> listLocatedStatus(Path f)
234      throws IOException {
235        return fs.listLocatedStatus(f);
236      }
237      
238      @Override
239      public Path getHomeDirectory() {
240        return fs.getHomeDirectory();
241      }
242    
243    
244      /**
245       * Set the current working directory for the given file system. All relative
246       * paths will be resolved relative to it.
247       * 
248       * @param newDir
249       */
250      @Override
251      public void setWorkingDirectory(Path newDir) {
252        fs.setWorkingDirectory(newDir);
253      }
254      
255      /**
256       * Get the current working directory for the given file system
257       * 
258       * @return the directory pathname
259       */
260      @Override
261      public Path getWorkingDirectory() {
262        return fs.getWorkingDirectory();
263      }
264      
265      @Override
266      protected Path getInitialWorkingDirectory() {
267        return fs.getInitialWorkingDirectory();
268      }
269      
270      @Override
271      public FsStatus getStatus(Path p) throws IOException {
272        return fs.getStatus(p);
273      }
274      
275      @Override
276      public boolean mkdirs(Path f, FsPermission permission) throws IOException {
277        return fs.mkdirs(f, permission);
278      }
279    
280    
281      /**
282       * The src file is on the local disk.  Add it to FS at
283       * the given dst name.
284       * delSrc indicates if the source should be removed
285       */
286      @Override
287      public void copyFromLocalFile(boolean delSrc, Path src, Path dst)
288        throws IOException {
289        fs.copyFromLocalFile(delSrc, src, dst);
290      }
291      
292      /**
293       * The src files are on the local disk.  Add it to FS at
294       * the given dst name.
295       * delSrc indicates if the source should be removed
296       */
297      @Override
298      public void copyFromLocalFile(boolean delSrc, boolean overwrite, 
299                                    Path[] srcs, Path dst)
300        throws IOException {
301        fs.copyFromLocalFile(delSrc, overwrite, srcs, dst);
302      }
303      
304      /**
305       * The src file is on the local disk.  Add it to FS at
306       * the given dst name.
307       * delSrc indicates if the source should be removed
308       */
309      @Override
310      public void copyFromLocalFile(boolean delSrc, boolean overwrite, 
311                                    Path src, Path dst)
312        throws IOException {
313        fs.copyFromLocalFile(delSrc, overwrite, src, dst);
314      }
315    
316      /**
317       * The src file is under FS, and the dst is on the local disk.
318       * Copy it from FS control to the local dst name.
319       * delSrc indicates if the src will be removed or not.
320       */   
321      @Override
322      public void copyToLocalFile(boolean delSrc, Path src, Path dst)
323        throws IOException {
324        fs.copyToLocalFile(delSrc, src, dst);
325      }
326      
327      /**
328       * Returns a local File that the user can write output to.  The caller
329       * provides both the eventual FS target name and the local working
330       * file.  If the FS is local, we write directly into the target.  If
331       * the FS is remote, we write into the tmp local area.
332       */
333      @Override
334      public Path startLocalOutput(Path fsOutputFile, Path tmpLocalFile)
335        throws IOException {
336        return fs.startLocalOutput(fsOutputFile, tmpLocalFile);
337      }
338    
339      /**
340       * Called when we're all done writing to the target.  A local FS will
341       * do nothing, because we've written to exactly the right place.  A remote
342       * FS will copy the contents of tmpLocalFile to the correct target at
343       * fsOutputFile.
344       */
345      @Override
346      public void completeLocalOutput(Path fsOutputFile, Path tmpLocalFile)
347        throws IOException {
348        fs.completeLocalOutput(fsOutputFile, tmpLocalFile);
349      }
350    
351      /** Return the total size of all files in the filesystem.*/
352      @Override
353      public long getUsed() throws IOException{
354        return fs.getUsed();
355      }
356      
357      @Override
358      public long getDefaultBlockSize() {
359        return fs.getDefaultBlockSize();
360      }
361      
362      @Override
363      public short getDefaultReplication() {
364        return fs.getDefaultReplication();
365      }
366    
367      @Override
368      public FsServerDefaults getServerDefaults() throws IOException {
369        return fs.getServerDefaults();
370      }
371    
372      // path variants delegate to underlying filesystem 
373      @Override
374      public ContentSummary getContentSummary(Path f) throws IOException {
375        return fs.getContentSummary(f);
376      }
377    
378      @Override
379      public long getDefaultBlockSize(Path f) {
380        return fs.getDefaultBlockSize(f);
381      }
382    
383      @Override
384      public short getDefaultReplication(Path f) {
385        return fs.getDefaultReplication(f);
386      }
387    
388      @Override
389      public FsServerDefaults getServerDefaults(Path f) throws IOException {
390        return fs.getServerDefaults(f);
391      }
392    
393      /**
394       * Get file status.
395       */
396      @Override
397      public FileStatus getFileStatus(Path f) throws IOException {
398        return fs.getFileStatus(f);
399      }
400    
401      public void createSymlink(final Path target, final Path link,
402          final boolean createParent) throws AccessControlException,
403          FileAlreadyExistsException, FileNotFoundException,
404          ParentNotDirectoryException, UnsupportedFileSystemException, 
405          IOException {
406        fs.createSymlink(target, link, createParent);
407      }
408    
409      public FileStatus getFileLinkStatus(final Path f)
410          throws AccessControlException, FileNotFoundException,
411          UnsupportedFileSystemException, IOException {
412        return fs.getFileLinkStatus(f);
413      }
414    
415      public boolean supportsSymlinks() {
416        return fs.supportsSymlinks();
417      }
418    
419      public Path getLinkTarget(Path f) throws IOException {
420        return fs.getLinkTarget(f);
421      }
422    
423      protected Path resolveLink(Path f) throws IOException {
424        return fs.resolveLink(f);
425      }
426    
427      @Override
428      public FileChecksum getFileChecksum(Path f) throws IOException {
429        return fs.getFileChecksum(f);
430      }
431      
432      @Override
433      public void setVerifyChecksum(boolean verifyChecksum) {
434        fs.setVerifyChecksum(verifyChecksum);
435      }
436      
437      @Override
438      public void setWriteChecksum(boolean writeChecksum) {
439        fs.setWriteChecksum(writeChecksum);
440      }
441    
442      @Override
443      public Configuration getConf() {
444        return fs.getConf();
445      }
446      
447      @Override
448      public void close() throws IOException {
449        super.close();
450        fs.close();
451      }
452    
453      @Override
454      public void setOwner(Path p, String username, String groupname
455          ) throws IOException {
456        fs.setOwner(p, username, groupname);
457      }
458    
459      @Override
460      public void setTimes(Path p, long mtime, long atime
461          ) throws IOException {
462        fs.setTimes(p, mtime, atime);
463      }
464    
465      @Override
466      public void setPermission(Path p, FsPermission permission
467          ) throws IOException {
468        fs.setPermission(p, permission);
469      }
470    
471      @Override
472      protected FSDataOutputStream primitiveCreate(Path f,
473          FsPermission absolutePermission, EnumSet<CreateFlag> flag,
474          int bufferSize, short replication, long blockSize,
475          Progressable progress, ChecksumOpt checksumOpt)
476          throws IOException {
477        return fs.primitiveCreate(f, absolutePermission, flag,
478            bufferSize, replication, blockSize, progress, checksumOpt);
479      }
480    
481      @Override
482      @SuppressWarnings("deprecation")
483      protected boolean primitiveMkdir(Path f, FsPermission abdolutePermission)
484          throws IOException {
485        return fs.primitiveMkdir(f, abdolutePermission);
486      }
487      
488      @Override // FileSystem
489      public FileSystem[] getChildFileSystems() {
490        return new FileSystem[]{fs};
491      }
492    
493      @Override // FileSystem
494      public Path createSnapshot(Path path, String snapshotName)
495          throws IOException {
496        return fs.createSnapshot(path, snapshotName);
497      }
498      
499      @Override // FileSystem
500      public void renameSnapshot(Path path, String snapshotOldName,
501          String snapshotNewName) throws IOException {
502        fs.renameSnapshot(path, snapshotOldName, snapshotNewName);
503      }
504      
505      @Override // FileSystem
506      public void deleteSnapshot(Path path, String snapshotName)
507          throws IOException {
508        fs.deleteSnapshot(path, snapshotName);
509      }
510    }