[HADOOP-12009] Clarify FileSystem.listStatus() sorting order & fix FileSystemContractBaseTest:testListStatus

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: documentation, fs, test
• Hadoop Flags: Reviewed
• Assignee: J.Andreina
• Reporter: Jakob Homan
• Created: 20/May/15 21:50
• Updated: 21/Jul/16 21:00
• Resolved: 24/Jul/15 01:00

Description

FileSystem.listStatus does not guarantee that implementations will return sorted entries:

  /**
   * List the statuses of the files/directories in the given path if the path is
   * a directory.
   * 
   * @param f given path
   * @return the statuses of the files/directories in the given patch
   * @throws FileNotFoundException when the path does not exist;
   *         IOException see specific implementation
   */
  public abstract FileStatus[] listStatus(Path f) throws FileNotFoundException, 
                                                         IOException;

However, FileSystemContractBaseTest, expects the elements to come back sorted:

    Path[] testDirs = { path("/test/hadoop/a"),
                        path("/test/hadoop/b"),
                        path("/test/hadoop/c/1"), };
   
    // ...

    paths = fs.listStatus(path("/test/hadoop"));
    assertEquals(3, paths.length);
    assertEquals(path("/test/hadoop/a"), paths[0].getPath());
    assertEquals(path("/test/hadoop/b"), paths[1].getPath());
    assertEquals(path("/test/hadoop/c"), paths[2].getPath());

We should pass this test as long as all the paths are there, regardless of their ordering.

Issue Links

• breaks: HADOOP-12152 Fix test case failures o.a.h.h.TestHDFSFileSystemContract and TestWebHdfsFileSystemContract.testListStatus
• duplicates: HADOOP-12152 Fix test case failures o.a.h.h.TestHDFSFileSystemContract and TestWebHdfsFileSystemContract.testListStatus
• is depended upon by: HADOOP-12177 [Umbrella] Update and extend filesystem specification