HDFS-4129. Add utility methods to dump NameNode in memory tree for testing. Contributed by Tsz Wo (Nicholas), SZE.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1403956 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -148,6 +148,9 @@ Trunk (Unreleased)
     HDFS-4124. Refactor INodeDirectory#getExistingPathINodes() to enable 
     returningmore than INode array. (Jing Zhao via suresh)
 
+    HDFS-4129. Add utility methods to dump NameNode in memory tree for 
+    testing. (szetszwo via suresh)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -5453,6 +5453,10 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   public BlockManager getBlockManager() {
     return blockManager;
   }
+  /** @return the FSDirectory. */
+  public FSDirectory getFSDirectory() {
+    return dir;
+  }
 
   /**
    * Verifies that the given identifier and password are valid and match.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INode.java

@@ -17,6 +17,8 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -32,6 +34,7 @@ import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.util.StringUtils;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.primitives.SignedBytes;
 
 /**
@@ -225,11 +228,10 @@ abstract class INode implements Comparable<byte[]> {
   abstract DirCounts spaceConsumedInTree(DirCounts counts);
   
   /**
-   * Get local file name
+   * @return null if the local name is null; otherwise, return the local name.
-   * @return local file name
    */
   String getLocalName() {
-    return DFSUtil.bytes2String(name);
+    return name == null? null: DFSUtil.bytes2String(name);
   }
 
 
@@ -239,8 +241,8 @@ abstract class INode implements Comparable<byte[]> {
   }
 
   /**
-   * Get local file name
+   * @return null if the local name is null;
-   * @return local file name
+   *         otherwise, return the local name byte array.
    */
   byte[] getLocalNameBytes() {
     return name;
@@ -458,4 +460,30 @@ abstract class INode implements Comparable<byte[]> {
     return new INodeFile(permissions, blocks, replication,
         modificationTime, atime, preferredBlockSize);
   }
+
+  /**
+   * Dump the subtree starting from this inode.
+   * @return a text representation of the tree.
+   */
+  @VisibleForTesting
+  public StringBuffer dumpTreeRecursively() {
+    final StringWriter out = new StringWriter(); 
+    dumpTreeRecursively(new PrintWriter(out, true), new StringBuilder());
+    return out.getBuffer();
+  }
+
+  /**
+   * Dump tree recursively.
+   * @param prefix The prefix string that each line should print.
+   */
+  @VisibleForTesting
+  public void dumpTreeRecursively(PrintWriter out, StringBuilder prefix) {
+    out.print(prefix);
+    out.print(" ");
+    out.print(getLocalName());
+    out.print("   (");
+    final String s = super.toString();
+    out.print(s.substring(s.lastIndexOf(getClass().getSimpleName())));
+    out.println(")");
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/INodeDirectory.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -29,6 +30,8 @@ import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.UnresolvedPathException;
 
+import com.google.common.annotations.VisibleForTesting;
+
 /**
  * Directory INode class.
  */
@@ -460,4 +463,52 @@ class INodeDirectory extends INode {
       return inodes;
     }
   }
+
+  /*
+   * The following code is to dump the tree recursively for testing.
+   * 
+   *      \- foo   (INodeDirectory@33dd2717)
+   *        \- sub1   (INodeDirectory@442172)
+   *          +- file1   (INodeFile@78392d4)
+   *          +- file2   (INodeFile@78392d5)
+   *          +- sub11   (INodeDirectory@8400cff)
+   *            \- file3   (INodeFile@78392d6)
+   *          \- z_file4   (INodeFile@45848712)
+   */
+  static final String DUMPTREE_EXCEPT_LAST_ITEM = "+-"; 
+  static final String DUMPTREE_LAST_ITEM = "\\-";
+  @VisibleForTesting
+  @Override
+  public void dumpTreeRecursively(PrintWriter out, StringBuilder prefix) {
+    super.dumpTreeRecursively(out, prefix);
+    if (prefix.length() >= 2) {
+      prefix.setLength(prefix.length() - 2);
+      prefix.append("  ");
+    }
+    dumpTreeRecursively(out, prefix, children);
+  }
+
+  /**
+   * Dump the given subtrees.
+   * @param prefix The prefix string that each line should print.
+   * @param subs The subtrees.
+   */
+  @VisibleForTesting
+  protected static void dumpTreeRecursively(PrintWriter out,
+      StringBuilder prefix, List<? extends INode> subs) {
+    prefix.append(DUMPTREE_EXCEPT_LAST_ITEM);
+    if (subs != null && subs.size() != 0) {
+      int i = 0;
+      for(; i < subs.size() - 1; i++) {
+        subs.get(i).dumpTreeRecursively(out, prefix);
+        prefix.setLength(prefix.length() - 2);
+        prefix.append(DUMPTREE_EXCEPT_LAST_ITEM);
+      }
+
+      prefix.setLength(prefix.length() - 2);
+      prefix.append(DUMPTREE_LAST_ITEM);
+      subs.get(i).dumpTreeRecursively(out, prefix);
+    }
+    prefix.setLength(prefix.length() - 2);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSDirectory.java

@@ -0,0 +1,141 @@
+/**
+ * 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.hdfs.server.namenode;
+
+
+import java.io.BufferedReader;
+import java.io.StringReader;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Test {@link FSDirectory}, the in-memory namespace tree.
+ */
+public class TestFSDirectory {
+  public static final Log LOG = LogFactory.getLog(TestFSDirectory.class);
+
+  private static final long seed = 0;
+  private static final short REPLICATION = 3;
+
+  private final Path dir = new Path("/" + getClass().getSimpleName());
+  
+  private final Path sub1 = new Path(dir, "sub1");
+  private final Path file1 = new Path(sub1, "file1");
+  private final Path file2 = new Path(sub1, "file2");
+
+  private final Path sub11 = new Path(sub1, "sub11");
+  private final Path file3 = new Path(sub11, "file3");
+  private final Path file4 = new Path(sub1, "z_file4");
+  private final Path file5 = new Path(sub1, "z_file5");
+
+  private final Path sub2 = new Path(dir, "sub2");
+
+  private Configuration conf;
+  private MiniDFSCluster cluster;
+  private FSNamesystem fsn;
+  private FSDirectory fsdir;
+
+  private DistributedFileSystem hdfs;
+
+  @Before
+  public void setUp() throws Exception {
+    conf = new Configuration();
+    cluster = new MiniDFSCluster.Builder(conf)
+      .numDataNodes(REPLICATION)
+      .build();
+    cluster.waitActive();
+    
+    fsn = cluster.getNamesystem();
+    fsdir = fsn.getFSDirectory();
+    
+    hdfs = cluster.getFileSystem();
+    DFSTestUtil.createFile(hdfs, file1, 1024, REPLICATION, seed);
+    DFSTestUtil.createFile(hdfs, file2, 1024, REPLICATION, seed);
+    DFSTestUtil.createFile(hdfs, file3, 1024, REPLICATION, seed);
+
+    DFSTestUtil.createFile(hdfs, file5, 1024, REPLICATION, seed);
+    hdfs.mkdirs(sub2);
+
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    if (cluster != null) {
+      cluster.shutdown();
+    }
+  }
+
+  /** Dump the tree, make some changes, and then dump the tree again. */
+  @Test
+  public void testDumpTree() throws Exception {
+    final INode root = fsdir.getINode("/");
+
+    LOG.info("Original tree");
+    final StringBuffer b1 = root.dumpTreeRecursively();
+    System.out.println("b1=" + b1);
+
+    final BufferedReader in = new BufferedReader(new StringReader(b1.toString()));
+    
+    String line = in.readLine();
+    checkClassName(line);
+
+    for(; (line = in.readLine()) != null; ) {
+      line = line.trim();
+      Assert.assertTrue(line.startsWith(INodeDirectory.DUMPTREE_LAST_ITEM)
+          || line.startsWith(INodeDirectory.DUMPTREE_EXCEPT_LAST_ITEM));
+      checkClassName(line);
+    }
+
+    LOG.info("Create a new file " + file4);
+    DFSTestUtil.createFile(hdfs, file4, 1024, REPLICATION, seed);
+
+    final StringBuffer b2 = root.dumpTreeRecursively();
+    System.out.println("b2=" + b2);
+
+    int i = 0;
+    int j = b1.length() - 1;
+    for(; b1.charAt(i) == b2.charAt(i); i++);
+    int k = b2.length() - 1;
+    for(; b1.charAt(j) == b2.charAt(k); j--, k--);
+    final String diff = b2.substring(i, k + 1);
+    System.out.println("i=" + i + ", j=" + j + ", k=" + k);
+    System.out.println("diff=" + diff);
+    Assert.assertTrue(i > j);
+    Assert.assertTrue(diff.contains(file4.getName()));
+  }
+  
+  static void checkClassName(String line) {
+    int i = line.lastIndexOf('(');
+    int j = line.lastIndexOf('@');
+    final String classname = line.substring(i+1, j);
+    Assert.assertTrue(classname.equals(INodeFile.class.getSimpleName())
+        || classname.equals(INodeDirectory.class.getSimpleName())
+        || classname.equals(INodeDirectoryWithQuota.class.getSimpleName()));
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFsLimits.java

@@ -32,7 +32,6 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
-import org.apache.hadoop.hdfs.protocol.FSLimitException;
 import org.apache.hadoop.hdfs.protocol.FSLimitException.MaxDirectoryItemsExceededException;
 import org.apache.hadoop.hdfs.protocol.FSLimitException.PathComponentTooLongException;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
@@ -60,17 +59,11 @@ public class TestFsLimits {
     return fsn;
   }
   
-  private static class TestFSDirectory extends FSDirectory {
+  private static class MockFSDirectory extends FSDirectory {
-    public TestFSDirectory() throws IOException {
+    public MockFSDirectory() throws IOException {
       super(new FSImage(conf), getMockNamesystem(), conf);
       setReady(fsIsReady);
     }
-    
-    @Override
-    public <T extends INode> void verifyFsLimits(INode[] pathComponents,
-        int pos, T child) throws FSLimitException {
-      super.verifyFsLimits(pathComponents, pos, child);
-    }
   }
 
   @Before
@@ -157,7 +150,7 @@ public class TestFsLimits {
   private void addChildWithName(String name, Class<?> expected)
   throws Exception {
     // have to create after the caller has had a chance to set conf values
-    if (fs == null) fs = new TestFSDirectory();
+    if (fs == null) fs = new MockFSDirectory();
 
     INode child = new INodeDirectory(name, perms);
     child.setLocalName(name);