HADOOP-11713. ViewFileSystem should support snapshot methods. Contributed by Rakesh R.

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -566,6 +566,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-9723. Improve error message when hadoop archive output path already
     exists. (Jean-Baptiste Onofré and Yongjun Zhang via aajisak)
 
+    HADOOP-11713. ViewFileSystem should support snapshot methods.
+    (Rakesh R via cnauroth)
+
   OPTIMIZATIONS
 
     HADOOP-11785. Reduce the number of listStatus operation in distcp

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ChRootedFileSystem.java

@@ -363,6 +363,23 @@ class ChRootedFileSystem extends FilterFileSystem {
     super.removeXAttr(fullPath(path), name);
   }
 
+  @Override
+  public Path createSnapshot(Path path, String name) throws IOException {
+    return super.createSnapshot(fullPath(path), name);
+  }
+
+  @Override
+  public void renameSnapshot(Path path, String snapshotOldName,
+      String snapshotNewName) throws IOException {
+    super.renameSnapshot(fullPath(path), snapshotOldName, snapshotNewName);
+  }
+
+  @Override
+  public void deleteSnapshot(Path snapshotDir, String snapshotName)
+      throws IOException {
+    super.deleteSnapshot(fullPath(snapshotDir), snapshotName);
+  }
+
   @Override
   public Path resolvePath(final Path p) throws IOException {
     return super.resolvePath(fullPath(p));

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ChRootedFs.java

@@ -361,7 +361,24 @@ class ChRootedFs extends AbstractFileSystem {
   }
 
   @Override
-  public void setVerifyChecksum(final boolean verifyChecksum) 
+  public Path createSnapshot(Path path, String name) throws IOException {
+    return myFs.createSnapshot(fullPath(path), name);
+  }
+
+  @Override
+  public void renameSnapshot(Path path, String snapshotOldName,
+      String snapshotNewName) throws IOException {
+    myFs.renameSnapshot(fullPath(path), snapshotOldName, snapshotNewName);
+  }
+
+  @Override
+  public void deleteSnapshot(Path snapshotDir, String snapshotName)
+      throws IOException {
+    myFs.deleteSnapshot(fullPath(snapshotDir), snapshotName);
+  }
+
+  @Override
+  public void setVerifyChecksum(final boolean verifyChecksum)
       throws IOException, UnresolvedLinkException {
     myFs.setVerifyChecksum(verifyChecksum);
   }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFileSystem.java

@@ -726,7 +726,32 @@ public class ViewFileSystem extends FileSystem {
     }
     return result;
   }
-  
+
+  @Override
+  public Path createSnapshot(Path path, String snapshotName)
+      throws IOException {
+    InodeTree.ResolveResult<FileSystem> res = fsState.resolve(getUriPath(path),
+        true);
+    return res.targetFileSystem.createSnapshot(res.remainingPath, snapshotName);
+  }
+
+  @Override
+  public void renameSnapshot(Path path, String snapshotOldName,
+      String snapshotNewName) throws IOException {
+    InodeTree.ResolveResult<FileSystem> res = fsState.resolve(getUriPath(path),
+        true);
+    res.targetFileSystem.renameSnapshot(res.remainingPath, snapshotOldName,
+        snapshotNewName);
+  }
+
+  @Override
+  public void deleteSnapshot(Path path, String snapshotName)
+      throws IOException {
+    InodeTree.ResolveResult<FileSystem> res = fsState.resolve(getUriPath(path),
+        true);
+    res.targetFileSystem.deleteSnapshot(res.remainingPath, snapshotName);
+  }
+
   /*
    * An instance of this class represents an internal dir of the viewFs 
    * that is internal dir of the mount table.
@@ -1020,5 +1045,26 @@ public class ViewFileSystem extends FileSystem {
       checkPathIsSlash(path);
       throw readOnlyMountTable("removeXAttr", path);
     }
+
+    @Override
+    public Path createSnapshot(Path path, String snapshotName)
+        throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("createSnapshot", path);
+    }
+
+    @Override
+    public void renameSnapshot(Path path, String snapshotOldName,
+        String snapshotNewName) throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("renameSnapshot", path);
+    }
+
+    @Override
+    public void deleteSnapshot(Path path, String snapshotName)
+        throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("deleteSnapshot", path);
+    }
   }
 }

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ViewFs.java

@@ -621,7 +621,8 @@ public class ViewFs extends AbstractFileSystem {
 
   @Override
   public boolean isValidName(String src) {
-    // Prefix validated at mount time and rest of path validated by mount target.
+    // Prefix validated at mount time and rest of path validated by mount
+    // target.
     return true;
   }
 
@@ -714,8 +715,31 @@ public class ViewFs extends AbstractFileSystem {
         fsState.resolve(getUriPath(path), true);
     res.targetFileSystem.removeXAttr(res.remainingPath, name);
   }
-  
-  
+
+  @Override
+  public Path createSnapshot(Path path, String snapshotName)
+      throws IOException {
+    InodeTree.ResolveResult<AbstractFileSystem> res = fsState.resolve(
+        getUriPath(path), true);
+    return res.targetFileSystem.createSnapshot(res.remainingPath, snapshotName);
+  }
+
+  @Override
+  public void renameSnapshot(Path path, String snapshotOldName,
+      String snapshotNewName) throws IOException {
+    InodeTree.ResolveResult<AbstractFileSystem> res = fsState.resolve(
+        getUriPath(path), true);
+    res.targetFileSystem.renameSnapshot(res.remainingPath, snapshotOldName,
+        snapshotNewName);
+  }
+
+  @Override
+  public void deleteSnapshot(Path path, String snapshotName) throws IOException {
+    InodeTree.ResolveResult<AbstractFileSystem> res = fsState.resolve(
+        getUriPath(path), true);
+    res.targetFileSystem.deleteSnapshot(res.remainingPath, snapshotName);
+  }
+
   /*
    * An instance of this class represents an internal dir of the viewFs 
    * ie internal dir of the mount table.
@@ -1025,5 +1049,26 @@ public class ViewFs extends AbstractFileSystem {
       checkPathIsSlash(path);
       throw readOnlyMountTable("removeXAttr", path);
     }
+
+    @Override
+    public Path createSnapshot(Path path, String snapshotName)
+        throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("createSnapshot", path);
+    }
+
+    @Override
+    public void renameSnapshot(Path path, String snapshotOldName,
+        String snapshotNewName) throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("renameSnapshot", path);
+    }
+
+    @Override
+    public void deleteSnapshot(Path path, String snapshotName)
+        throws IOException {
+      checkPathIsSlash(path);
+      throw readOnlyMountTable("deleteSnapshot", path);
+    }
   }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestChRootedFileSystem.java

@@ -416,4 +416,56 @@ public class TestChRootedFileSystem {
     @Override
     public void initialize(URI name, Configuration conf) throws IOException {}
   }
+
+  @Test(timeout = 30000)
+  public void testCreateSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path("/a/b/snapPath");
+
+    Configuration conf = new Configuration();
+    conf.setClass("fs.mockfs.impl", MockFileSystem.class, FileSystem.class);
+
+    URI chrootUri = URI.create("mockfs://foo/a/b");
+    ChRootedFileSystem chrootFs = new ChRootedFileSystem(chrootUri, conf);
+    FileSystem mockFs = ((FilterFileSystem) chrootFs.getRawFileSystem())
+        .getRawFileSystem();
+
+    chrootFs.createSnapshot(snapRootPath, "snap1");
+    verify(mockFs).createSnapshot(chRootedSnapRootPath, "snap1");
+  }
+
+  @Test(timeout = 30000)
+  public void testDeleteSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path("/a/b/snapPath");
+
+    Configuration conf = new Configuration();
+    conf.setClass("fs.mockfs.impl", MockFileSystem.class, FileSystem.class);
+
+    URI chrootUri = URI.create("mockfs://foo/a/b");
+    ChRootedFileSystem chrootFs = new ChRootedFileSystem(chrootUri, conf);
+    FileSystem mockFs = ((FilterFileSystem) chrootFs.getRawFileSystem())
+        .getRawFileSystem();
+
+    chrootFs.deleteSnapshot(snapRootPath, "snap1");
+    verify(mockFs).deleteSnapshot(chRootedSnapRootPath, "snap1");
+  }
+
+  @Test(timeout = 30000)
+  public void testRenameSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path("/a/b/snapPath");
+
+    Configuration conf = new Configuration();
+    conf.setClass("fs.mockfs.impl", MockFileSystem.class, FileSystem.class);
+
+    URI chrootUri = URI.create("mockfs://foo/a/b");
+    ChRootedFileSystem chrootFs = new ChRootedFileSystem(chrootUri, conf);
+    FileSystem mockFs = ((FilterFileSystem) chrootFs.getRawFileSystem())
+        .getRawFileSystem();
+
+    chrootFs.renameSnapshot(snapRootPath, "snapOldName", "snapNewName");
+    verify(mockFs).renameSnapshot(chRootedSnapRootPath, "snapOldName",
+        "snapNewName");
+  }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/TestChRootedFs.java

@@ -327,4 +327,45 @@ public class TestChRootedFs {
     Assert.assertFalse(chRootedFs.isValidName("/test"));
     Mockito.verify(baseFs).isValidName("/chroot/test");
   }
+
+  @Test(timeout = 30000)
+  public void testCreateSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path(
+        Path.getPathWithoutSchemeAndAuthority(chrootedTo), "snapPath");
+    AbstractFileSystem baseFs = Mockito.spy(fc.getDefaultFileSystem());
+    ChRootedFs chRootedFs = new ChRootedFs(baseFs, chrootedTo);
+    Mockito.doReturn(snapRootPath).when(baseFs)
+        .createSnapshot(chRootedSnapRootPath, "snap1");
+    Assert.assertEquals(snapRootPath,
+        chRootedFs.createSnapshot(snapRootPath, "snap1"));
+    Mockito.verify(baseFs).createSnapshot(chRootedSnapRootPath, "snap1");
+  }
+
+  @Test(timeout = 30000)
+  public void testDeleteSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path(
+        Path.getPathWithoutSchemeAndAuthority(chrootedTo), "snapPath");
+    AbstractFileSystem baseFs = Mockito.spy(fc.getDefaultFileSystem());
+    ChRootedFs chRootedFs = new ChRootedFs(baseFs, chrootedTo);
+    Mockito.doNothing().when(baseFs)
+        .deleteSnapshot(chRootedSnapRootPath, "snap1");
+    chRootedFs.deleteSnapshot(snapRootPath, "snap1");
+    Mockito.verify(baseFs).deleteSnapshot(chRootedSnapRootPath, "snap1");
+  }
+
+  @Test(timeout = 30000)
+  public void testRenameSnapshot() throws Exception {
+    Path snapRootPath = new Path("/snapPath");
+    Path chRootedSnapRootPath = new Path(
+        Path.getPathWithoutSchemeAndAuthority(chrootedTo), "snapPath");
+    AbstractFileSystem baseFs = Mockito.spy(fc.getDefaultFileSystem());
+    ChRootedFs chRootedFs = new ChRootedFs(baseFs, chrootedTo);
+    Mockito.doNothing().when(baseFs)
+        .renameSnapshot(chRootedSnapRootPath, "snapOldName", "snapNewName");
+    chRootedFs.renameSnapshot(snapRootPath, "snapOldName", "snapNewName");
+    Mockito.verify(baseFs).renameSnapshot(chRootedSnapRootPath, "snapOldName",
+        "snapNewName");
+  }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFileSystemBaseTest.java

@@ -865,4 +865,24 @@ public class ViewFileSystemBaseTest {
     fsView.removeXAttr(new Path("/internalDir"), "xattrName");
   }
 
+  @Test(expected = AccessControlException.class)
+  public void testInternalCreateSnapshot1() throws IOException {
+    fsView.createSnapshot(new Path("/internalDir"));
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalCreateSnapshot2() throws IOException {
+    fsView.createSnapshot(new Path("/internalDir"), "snap1");
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalRenameSnapshot() throws IOException {
+    fsView.renameSnapshot(new Path("/internalDir"), "snapOldName",
+        "snapNewName");
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalDeleteSnapshot() throws IOException {
+    fsView.deleteSnapshot(new Path("/internalDir"), "snap1");
+  }
 }

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java

@@ -777,4 +777,25 @@ public class ViewFsBaseTest {
   public void testInternalRemoveXAttr() throws IOException {
     fcView.removeXAttr(new Path("/internalDir"), "xattrName");
   }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalCreateSnapshot1() throws IOException {
+    fcView.createSnapshot(new Path("/internalDir"));
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalCreateSnapshot2() throws IOException {
+    fcView.createSnapshot(new Path("/internalDir"), "snap1");
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalRenameSnapshot() throws IOException {
+    fcView.renameSnapshot(new Path("/internalDir"), "snapOldName",
+        "snapNewName");
+  }
+
+  @Test(expected = AccessControlException.class)
+  public void testInternalDeleteSnapshot() throws IOException {
+    fcView.deleteSnapshot(new Path("/internalDir"), "snap1");
+  }
 }