HDFS-5647. Merge INodeDirectory.Feature and INodeFile.Feature. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1550469 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -246,6 +246,9 @@ Trunk (Unreleased)
     HDFS-5629. Support HTTPS in JournalNode and SecondaryNameNode. 
     (Haohui Mai via jing9)
 
+    HDFS-5647. Merge INodeDirectory.Feature and INodeFile.Feature. (Haohui Mai
+    via jing9)
+
   OPTIMIZATIONS
     HDFS-5349. DNA_CACHE and DNA_UNCACHE should be by blockId only. (cmccabe)
 

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

@@ -25,7 +25,7 @@ import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 /**
  * Quota feature for {@link INodeDirectory}. 
  */
-public final class DirectoryWithQuotaFeature extends INodeDirectory.Feature {
+public final class DirectoryWithQuotaFeature implements INode.Feature {
   public static final long DEFAULT_NAMESPACE_QUOTA = Long.MAX_VALUE;
   public static final long DEFAULT_DISKSPACE_QUOTA = HdfsConstants.QUOTA_RESET;
 

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

@@ -29,7 +29,7 @@ import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
  * Feature for under-construction file.
  */
 @InterfaceAudience.Private
-public class FileUnderConstructionFeature extends INodeFile.Feature {
+public class FileUnderConstructionFeature implements INode.Feature {
   private String clientName; // lease holder
   private final String clientMachine;
   // if client is a cluster node too.

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

@@ -756,47 +756,6 @@ public abstract class INode implements INodeAttributes, Diff.Element<byte[]> {
   /** INode feature such as {@link FileUnderConstructionFeature}
    *  and {@link DirectoryWithQuotaFeature}.
    */
-  interface Feature<F extends Feature<F>> {
-    /** @return the next feature. */
-    public F getNextFeature();
-
-    /** Set the next feature. */
-    public void setNextFeature(F next);
-
-    /** Utility methods such as addFeature and removeFeature. */
-    static class Util {
-      /**
-       * Add a feature to the linked list.
-       * @return the new head.
-       */
-      static <F extends Feature<F>> F addFeature(F feature, F head) {
-        feature.setNextFeature(head);
-        return feature;
-      }
-
-      /**
-       * Remove a feature from the linked list.
-       * @return the new head.
-       */
-      static <F extends Feature<F>> F removeFeature(F feature, F head) {
-        if (feature == head) {
-          final F newHead = head.getNextFeature();
-          head.setNextFeature(null);
-          return newHead;
-        } else if (head != null) {
-          F prev = head;
-          F curr = head.getNextFeature();
-          for (; curr != null && curr != feature;
-              prev = curr, curr = curr.getNextFeature())
-            ;
-          if (curr != null) {
-            prev.setNextFeature(curr.getNextFeature());
-            curr.setNextFeature(null);
-            return head;
-          }
-        }
-        throw new IllegalStateException("Feature " + feature + " not found.");
-      }
-    }
+  public interface Feature {
   }
 }

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

@@ -45,20 +45,6 @@ import com.google.common.base.Preconditions;
  */
 public class INodeDirectory extends INodeWithAdditionalFields
     implements INodeDirectoryAttributes {
-  /** Directory related features such as quota and snapshots. */
-  public static abstract class Feature implements INode.Feature<Feature> {
-    private Feature nextFeature;
-
-    @Override
-    public Feature getNextFeature() {
-      return nextFeature;
-    }
-
-    @Override
-    public void setNextFeature(Feature next) {
-      this.nextFeature = next;
-    }
-  }
 
   /** Cast INode to INodeDirectory. */
   public static INodeDirectory valueOf(INode inode, Object path
@@ -78,9 +64,6 @@ public class INodeDirectory extends INodeWithAdditionalFields
 
   private List<INode> children = null;
   
-  /** A linked list of {@link Feature}s. */
-  private Feature headFeature = null;
-
   /** constructor */
   public INodeDirectory(long id, byte[] name, PermissionStatus permissions,
       long mtime) {
@@ -102,7 +85,7 @@ public class INodeDirectory extends INodeWithAdditionalFields
       }
     }
     if (copyFeatures) {
-      this.headFeature = other.headFeature;
+      this.features = other.features;
     }
   }
 
@@ -160,7 +143,7 @@ public class INodeDirectory extends INodeWithAdditionalFields
    * otherwise, return null.
    */
   public final DirectoryWithQuotaFeature getDirectoryWithQuotaFeature() {
-    for(Feature f = headFeature; f != null; f = f.nextFeature) {
+    for (Feature f : features) {
       if (f instanceof DirectoryWithQuotaFeature) {
         return (DirectoryWithQuotaFeature)f;
       }
@@ -182,14 +165,6 @@ public class INodeDirectory extends INodeWithAdditionalFields
     return quota;
   }
 
-  private void addFeature(Feature f) {
-    headFeature = INode.Feature.Util.addFeature(f, headFeature);
-  }
-
-  private void removeFeature(Feature f) {
-    headFeature = INode.Feature.Util.removeFeature(f, headFeature);
-  }
-
   private int searchChildren(byte[] name) {
     return children == null? -1: Collections.binarySearch(children, name);
   }

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

@@ -41,23 +41,6 @@ import com.google.common.base.Preconditions;
 @InterfaceAudience.Private
 public class INodeFile extends INodeWithAdditionalFields
     implements INodeFileAttributes, BlockCollection {
-  /**
-   * A feature contains specific information for a type of INodeFile. E.g.,
-   * we can have separate features for Under-Construction and Snapshot.
-   */
-  public static abstract class Feature implements INode.Feature<Feature> {
-    private Feature nextFeature;
-
-    @Override
-    public Feature getNextFeature() {
-      return nextFeature;
-    }
-
-    @Override
-    public void setNextFeature(Feature next) {
-      this.nextFeature = next;
-    }
-  }
 
   /** The same as valueOf(inode, path, false). */
   public static INodeFile valueOf(INode inode, String path
@@ -120,8 +103,6 @@ public class INodeFile extends INodeWithAdditionalFields
 
   private BlockInfo[] blocks;
 
-  private Feature headFeature;
-
   INodeFile(long id, byte[] name, PermissionStatus permissions, long mtime,
       long atime, BlockInfo[] blklist, short replication,
       long preferredBlockSize) {
@@ -135,7 +116,7 @@ public class INodeFile extends INodeWithAdditionalFields
     super(that);
     this.header = that.header;
     this.blocks = that.blocks;
-    this.headFeature = that.headFeature;
+    this.features = that.features;
   }
   
   public INodeFile(INodeFile that, FileDiffList diffs) {
@@ -144,14 +125,6 @@ public class INodeFile extends INodeWithAdditionalFields
     this.addSnapshotFeature(diffs);
   }
 
-  private void addFeature(Feature f) {
-    headFeature = INode.Feature.Util.addFeature(f, headFeature);
-  }
-
-  private void removeFeature(Feature f) {
-    headFeature = INode.Feature.Util.removeFeature(f, headFeature);
-  }
-
   /** @return true unconditionally. */
   @Override
   public final boolean isFile() {
@@ -171,7 +144,7 @@ public class INodeFile extends INodeWithAdditionalFields
    * otherwise, return null.
    */
   public final FileUnderConstructionFeature getFileUnderConstructionFeature() {
-    for (Feature f = this.headFeature; f != null; f = f.nextFeature) {
+    for (Feature f : features) {
       if (f instanceof FileUnderConstructionFeature) {
         return (FileUnderConstructionFeature) f;
       }
@@ -283,7 +256,7 @@ public class INodeFile extends INodeWithAdditionalFields
    * otherwise, return null.
    */
   public final FileWithSnapshotFeature getFileWithSnapshotFeature() {
-    for (Feature f = headFeature; f != null; f = f.nextFeature) {
+    for (Feature f: features) {
       if (f instanceof FileWithSnapshotFeature) {
         return (FileWithSnapshotFeature) f;
       }

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

@@ -95,6 +95,9 @@ public abstract class INodeWithAdditionalFields extends INode
 
   /** For implementing {@link LinkedElement}. */
   private LinkedElement next = null;
+  /** An array {@link Feature}s. */
+  private static final Feature[] EMPTY_FEATURE = new Feature[0];
+  protected Feature[] features = EMPTY_FEATURE;
 
   private INodeWithAdditionalFields(INode parent, long id, byte[] name,
       long permission, long modificationTime, long accessTime) {
@@ -262,4 +265,45 @@ public abstract class INodeWithAdditionalFields extends INode
   public final void setAccessTime(long accessTime) {
     this.accessTime = accessTime;
   }
+
+  protected void addFeature(Feature f) {
+    int size = features.length;
+    Feature[] arr = new Feature[size + 1];
+    if (size != 0) {
+      System.arraycopy(features, 0, arr, 0, size);
+    }
+    arr[size] = f;
+    features = arr;
+  }
+
+  protected void removeFeature(Feature f) {
+    int size = features.length;
+    Preconditions.checkState(size > 0, "Feature "
+        + f.getClass().getSimpleName() + " not found.");
+
+    if (size == 1) {
+      Preconditions.checkState(features[0] == f, "Feature "
+          + f.getClass().getSimpleName() + " not found.");
+      features = EMPTY_FEATURE;
+      return;
+    }
+
+    Feature[] arr = new Feature[size - 1];
+    int j = 0;
+    boolean overflow = false;
+    for (Feature f1 : features) {
+      if (f1 != f) {
+        if (j == size - 1) {
+          overflow = true;
+          break;
+        } else {
+          arr[j++] = f1;
+        }
+      }
+    }
+
+    Preconditions.checkState(!overflow && j == size - 1, "Feature "
+        + f.getClass().getSimpleName() + " not found.");
+    features = arr;
+  }
 }

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

@@ -32,7 +32,7 @@ import org.apache.hadoop.hdfs.server.namenode.Quota;
  * Feature for file with snapshot-related information.
  */
 @InterfaceAudience.Private
-public class FileWithSnapshotFeature extends INodeFile.Feature {
+public class FileWithSnapshotFeature implements INode.Feature {
   private final FileDiffList diffs;
   private boolean isCurrentFileDeleted = false;
   

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

@@ -61,6 +61,7 @@ import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
+import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.util.Time;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -921,6 +922,7 @@ public class TestINodeFile {
   public void testDotdotInodePath() throws Exception {
     final Configuration conf = new Configuration();
     MiniDFSCluster cluster = null;
+    DFSClient client = null;
     try {
       cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
       cluster.waitActive();
@@ -933,7 +935,7 @@ public class TestINodeFile {
       long parentId = fsdir.getINode("/").getId();
       String testPath = "/.reserved/.inodes/" + dirId + "/..";
 
-      DFSClient client = new DFSClient(NameNode.getAddress(conf), conf);
+      client = new DFSClient(NameNode.getAddress(conf), conf);
       HdfsFileStatus status = client.getFileInfo(testPath);
       assertTrue(parentId == status.getFileId());
       
@@ -943,6 +945,7 @@ public class TestINodeFile {
       assertTrue(parentId == status.getFileId());
       
     } finally {
+      IOUtils.cleanup(LOG, client);
       if (cluster != null) {
         cluster.shutdown();
       }