HDFS-5537. Remove FileWithSnapshot interface. Contributed by jing9

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1546184 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -224,6 +224,8 @@ Trunk (Unreleased)
     HDFS-5545. Allow specifying endpoints for listeners in HttpServer. (Haohui
     Mai via jing9)
 
+    HDFS-5537. Remove FileWithSnapshot interface.  (jing9 via szetszwo)
+
   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/FSDirectory.java

@@ -455,8 +455,8 @@ public class FSDirectory implements Closeable {
   
   boolean unprotectedRemoveBlock(String path,
       INodeFile fileNode, Block block) throws IOException {
-    Preconditions.checkArgument(fileNode.isUnderConstruction());
     // modify file-> block and blocksMap
+    // fileNode should be under construction
     boolean removed = fileNode.removeLastBlock(block);
     if (!removed) {
       return false;

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

@@ -52,7 +52,7 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.common.InconsistentFSStateException;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiffList;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.FileDiffList;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectorySnapshottable;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileWithSnapshot;

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

@@ -26,7 +26,7 @@ import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
 
 /**
- * I-node for file being written.
+ * Feature for under-construction file.
  */
 @InterfaceAudience.Private
 public class FileUnderConstructionFeature extends INodeFile.Feature {

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

@@ -35,7 +35,6 @@ import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference.DstReference;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithName;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;
 import org.apache.hadoop.hdfs.util.ChunkedArrayList;
@@ -315,7 +314,7 @@ public abstract class INode implements INodeAttributes, Diff.Element<byte[]> {
    * 1.2.2 Else do nothing with the current INode. Recursively clean its 
    * children.
    * 
-   * 1.3 The current inode is a {@link FileWithSnapshot}.
+   * 1.3 The current inode is a file with snapshot.
    * Call recordModification(..) to capture the current states.
    * Mark the INode as deleted.
    * 
@@ -328,7 +327,7 @@ public abstract class INode implements INodeAttributes, Diff.Element<byte[]> {
    * 2. When deleting a snapshot.
    * 2.1 To clean {@link INodeFile}: do nothing.
    * 2.2 To clean {@link INodeDirectory}: recursively clean its children.
-   * 2.3 To clean {@link FileWithSnapshot}: delete the corresponding snapshot in
+   * 2.3 To clean INodeFile with snapshot: delete the corresponding snapshot in
    * its diff list.
    * 2.4 To clean {@link INodeDirectoryWithSnapshot}: delete the corresponding 
    * snapshot in its diff list. Recursively clean its children.

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

@@ -32,10 +32,8 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiff;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiffList;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.Util;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.FileDiff;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.FileDiffList;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;
 
@@ -188,7 +186,7 @@ public class INodeFile extends INodeWithAdditionalFields
   INodeFile toUnderConstruction(String clientName, String clientMachine,
       DatanodeDescriptor clientNode) {
     Preconditions.checkState(!isUnderConstruction(),
-        "file is already an INodeFileUnderConstruction");
+        "file is already under construction");
     FileUnderConstructionFeature uc = new FileUnderConstructionFeature(
         clientName, clientMachine, clientNode);
     addFeature(uc);
@@ -200,6 +198,8 @@ public class INodeFile extends INodeWithAdditionalFields
    * feature.
    */
   public INodeFile toCompleteFile(long mtime) {
+    Preconditions.checkState(isUnderConstruction(),
+        "file is no longer under construction");
     FileUnderConstructionFeature uc = getFileUnderConstructionFeature();
     if (uc != null) {
       assertAllBlocksComplete();
@@ -221,15 +221,16 @@ public class INodeFile extends INodeWithAdditionalFields
     }
   }
 
-  @Override //BlockCollection
+  @Override // BlockCollection
   public void setBlock(int index, BlockInfo blk) {
     this.blocks[index] = blk;
   }
 
-  @Override // BlockCollection
+  @Override // BlockCollection, the file should be under construction
   public BlockInfoUnderConstruction setLastBlock(BlockInfo lastBlock,
       DatanodeDescriptor[] locations) throws IOException {
-    Preconditions.checkState(isUnderConstruction());
+    Preconditions.checkState(isUnderConstruction(),
+        "file is no longer under construction");
 
     if (numBlocks() == 0) {
       throw new IOException("Failed to set last block: File is empty.");
@@ -247,6 +248,8 @@ public class INodeFile extends INodeWithAdditionalFields
    * the last one on the list.
    */
   boolean removeLastBlock(Block oldblock) {
+    Preconditions.checkState(isUnderConstruction(),
+        "file is no longer under construction");
     if (blocks == null || blocks.length == 0) {
       return false;
     }
@@ -298,10 +301,8 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   @Override
-  public final short getBlockReplication() {
-    return this instanceof FileWithSnapshot?
-        Util.getBlockReplication((FileWithSnapshot)this)
-        : getFileReplication(null);
+  public short getBlockReplication() {
+    return getFileReplication(null);
   }
 
   /** Set the replication factor of this file. */
@@ -421,8 +422,8 @@ public class INodeFile extends INodeWithAdditionalFields
     clear();
     removedINodes.add(this);
     
-    if (this instanceof FileWithSnapshot) {
-      ((FileWithSnapshot) this).getDiffs().clear();
+    if (this instanceof INodeFileWithSnapshot) {
+      ((INodeFileWithSnapshot) this).getDiffs().clear();
     }
   }
   
@@ -437,8 +438,8 @@ public class INodeFile extends INodeWithAdditionalFields
       boolean useCache, int lastSnapshotId) {
     long nsDelta = 1;
     final long dsDelta;
-    if (this instanceof FileWithSnapshot) {
-      FileDiffList fileDiffList = ((FileWithSnapshot) this).getDiffs();
+    if (this instanceof INodeFileWithSnapshot) {
+      FileDiffList fileDiffList = ((INodeFileWithSnapshot) this).getDiffs();
       Snapshot last = fileDiffList.getLastSnapshot();
       List<FileDiff> diffs = fileDiffList.asList();
 
@@ -470,8 +471,8 @@ public class INodeFile extends INodeWithAdditionalFields
   private void computeContentSummary4Snapshot(final Content.Counts counts) {
     // file length and diskspace only counted for the latest state of the file
     // i.e. either the current state or the last snapshot
-    if (this instanceof FileWithSnapshot) {
-      final FileWithSnapshot withSnapshot = (FileWithSnapshot)this;
+    if (this instanceof INodeFileWithSnapshot) {
+      final INodeFileWithSnapshot withSnapshot = (INodeFileWithSnapshot) this;
       final FileDiffList diffs = withSnapshot.getDiffs();
       final int n = diffs.asList().size();
       counts.add(Content.FILE, n);
@@ -487,8 +488,8 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   private void computeContentSummary4Current(final Content.Counts counts) {
-    if (this instanceof FileWithSnapshot
-        && ((FileWithSnapshot)this).isCurrentFileDeleted()) {
+    if (this instanceof INodeFileWithSnapshot
+        && ((INodeFileWithSnapshot) this).isCurrentFileDeleted()) {
       return;
     }
 
@@ -507,8 +508,9 @@ public class INodeFile extends INodeWithAdditionalFields
    * otherwise, get the file size from the given snapshot.
    */
   public final long computeFileSize(Snapshot snapshot) {
-    if (snapshot != null && this instanceof FileWithSnapshot) {
-      final FileDiff d = ((FileWithSnapshot)this).getDiffs().getDiff(snapshot);
+    if (snapshot != null && this instanceof INodeFileWithSnapshot) {
+      final FileDiff d = ((INodeFileWithSnapshot) this).getDiffs().getDiff(
+          snapshot);
       if (d != null) {
         return d.getFileSize();
       }

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

@@ -26,8 +26,8 @@ import java.util.List;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeFileWithSnapshot;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;
 
 import com.google.common.base.Preconditions;
@@ -102,8 +102,8 @@ public abstract class INodeReference extends INode {
     }
     if (wn != null) {
       INode referred = wc.getReferredINode();
-      if (referred instanceof FileWithSnapshot) {
-        return ((FileWithSnapshot) referred).getDiffs().getPrior(
+      if (referred instanceof INodeFileWithSnapshot) {
+        return ((INodeFileWithSnapshot) referred).getDiffs().getPrior(
             wn.lastSnapshotId);
       } else if (referred instanceof INodeDirectoryWithSnapshot) { 
         return ((INodeDirectoryWithSnapshot) referred).getDiffs().getPrior(
@@ -547,8 +547,8 @@ public abstract class INodeReference extends INode {
     private Snapshot getSelfSnapshot() {
       INode referred = getReferredINode().asReference().getReferredINode();
       Snapshot snapshot = null;
-      if (referred instanceof FileWithSnapshot) {
-        snapshot = ((FileWithSnapshot) referred).getDiffs().getPrior(
+      if (referred instanceof INodeFileWithSnapshot) {
+        snapshot = ((INodeFileWithSnapshot) referred).getDiffs().getPrior(
             lastSnapshotId);
       } else if (referred instanceof INodeDirectoryWithSnapshot) {
         snapshot = ((INodeDirectoryWithSnapshot) referred).getDiffs().getPrior(
@@ -637,10 +637,10 @@ public abstract class INodeReference extends INode {
         Snapshot snapshot = getSelfSnapshot(prior);
         
         INode referred = getReferredINode().asReference().getReferredINode();
-        if (referred instanceof FileWithSnapshot) {
+        if (referred instanceof INodeFileWithSnapshot) {
           // if referred is a file, it must be a FileWithSnapshot since we did
           // recordModification before the rename
-          FileWithSnapshot sfile = (FileWithSnapshot) referred;
+          INodeFileWithSnapshot sfile = (INodeFileWithSnapshot) referred;
           // make sure we mark the file as deleted
           sfile.deleteCurrentFile();
           try {
@@ -671,8 +671,8 @@ public abstract class INodeReference extends INode {
       WithCount wc = (WithCount) getReferredINode().asReference();
       INode referred = wc.getReferredINode();
       Snapshot lastSnapshot = null;
-      if (referred instanceof FileWithSnapshot) {
-        lastSnapshot = ((FileWithSnapshot) referred).getDiffs()
+      if (referred instanceof INodeFileWithSnapshot) {
+        lastSnapshot = ((INodeFileWithSnapshot) referred).getDiffs()
             .getLastSnapshot(); 
       } else if (referred instanceof INodeDirectoryWithSnapshot) {
         lastSnapshot = ((INodeDirectoryWithSnapshot) referred)

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

@@ -0,0 +1,92 @@
+/**
+ * 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.snapshot;
+
+import java.io.DataOutput;
+import java.io.IOException;
+import java.util.List;
+
+import org.apache.hadoop.hdfs.server.namenode.FSImageSerialization;
+import org.apache.hadoop.hdfs.server.namenode.INode;
+import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
+import org.apache.hadoop.hdfs.server.namenode.INodeFile;
+import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
+import org.apache.hadoop.hdfs.server.namenode.Quota;
+import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotFSImageFormat.ReferenceMap;
+
+/**
+ * The difference of an {@link INodeFile} between two snapshots.
+ */
+public class FileDiff extends
+    AbstractINodeDiff<INodeFileWithSnapshot, INodeFileAttributes, FileDiff> {
+
+  /** The file size at snapshot creation time. */
+  private final long fileSize;
+
+  FileDiff(Snapshot snapshot, INodeFile file) {
+    super(snapshot, null, null);
+    fileSize = file.computeFileSize();
+  }
+
+  /** Constructor used by FSImage loading */
+  FileDiff(Snapshot snapshot, INodeFileAttributes snapshotINode,
+      FileDiff posteriorDiff, long fileSize) {
+    super(snapshot, snapshotINode, posteriorDiff);
+    this.fileSize = fileSize;
+  }
+
+  /** @return the file size in the snapshot. */
+  public long getFileSize() {
+    return fileSize;
+  }
+  
+  @Override
+  Quota.Counts combinePosteriorAndCollectBlocks(
+      INodeFileWithSnapshot currentINode, FileDiff posterior,
+      BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
+    return currentINode.updateQuotaAndCollectBlocks(posterior, collectedBlocks,
+        removedINodes);
+  }
+  
+  @Override
+  public String toString() {
+    return super.toString() + " fileSize=" + fileSize + ", rep="
+        + (snapshotINode == null? "?": snapshotINode.getFileReplication());
+  }
+
+  @Override
+  void write(DataOutput out, ReferenceMap referenceMap) throws IOException {
+    writeSnapshot(out);
+    out.writeLong(fileSize);
+
+    // write snapshotINode
+    if (snapshotINode != null) {
+      out.writeBoolean(true);
+      FSImageSerialization.writeINodeFileAttributes(snapshotINode, out);
+    } else {
+      out.writeBoolean(false);
+    }
+  }
+
+  @Override
+  Quota.Counts destroyDiffAndCollectBlocks(INodeFileWithSnapshot currentINode,
+      BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
+    return currentINode.updateQuotaAndCollectBlocks(this, collectedBlocks,
+        removedINodes);
+  }
+}

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

@@ -0,0 +1,35 @@
+/**
+ * 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.snapshot;
+
+import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
+
+/** A list of FileDiffs for storing snapshot data. */
+public class FileDiffList extends
+    AbstractINodeDiffList<INodeFileWithSnapshot, INodeFileAttributes, FileDiff> {
+  
+  @Override
+  FileDiff createDiff(Snapshot snapshot, INodeFileWithSnapshot file) {
+    return new FileDiff(snapshot, file);
+  }
+  
+  @Override
+  INodeFileAttributes createSnapshotCopy(INodeFileWithSnapshot currentINode) {
+    return new INodeFileAttributes.SnapshotCopy(currentINode);
+  }
+}

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

@@ -1,227 +0,0 @@
-/**
- * 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.snapshot;
-
-import java.io.DataOutput;
-import java.io.IOException;
-import java.util.List;
-
-import org.apache.hadoop.classification.InterfaceAudience;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.namenode.FSImageSerialization;
-import org.apache.hadoop.hdfs.server.namenode.INode;
-import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
-import org.apache.hadoop.hdfs.server.namenode.INodeFile;
-import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
-import org.apache.hadoop.hdfs.server.namenode.Quota;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotFSImageFormat.ReferenceMap;
-
-/**
- * An interface for {@link INodeFile} to support snapshot.
- */
-@InterfaceAudience.Private
-public interface FileWithSnapshot {
-  /**
-   * The difference of an {@link INodeFile} between two snapshots.
-   */
-  public static class FileDiff extends AbstractINodeDiff<INodeFile, INodeFileAttributes, FileDiff> {
-    /** The file size at snapshot creation time. */
-    private final long fileSize;
-
-    private FileDiff(Snapshot snapshot, INodeFile file) {
-      super(snapshot, null, null);
-      fileSize = file.computeFileSize();
-    }
-
-    /** Constructor used by FSImage loading */
-    FileDiff(Snapshot snapshot, INodeFileAttributes snapshotINode,
-        FileDiff posteriorDiff, long fileSize) {
-      super(snapshot, snapshotINode, posteriorDiff);
-      this.fileSize = fileSize;
-    }
-
-    /** @return the file size in the snapshot. */
-    public long getFileSize() {
-      return fileSize;
-    }
-
-    private static Quota.Counts updateQuotaAndCollectBlocks(
-        INodeFile currentINode, FileDiff removed,
-        BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
-      FileWithSnapshot sFile = (FileWithSnapshot) currentINode;
-      long oldDiskspace = currentINode.diskspaceConsumed();
-      if (removed.snapshotINode != null) {
-        short replication = removed.snapshotINode.getFileReplication();
-        short currentRepl = currentINode.getBlockReplication();
-        if (currentRepl == 0) {
-          oldDiskspace = currentINode.computeFileSize(true, true) * replication;
-        } else if (replication > currentRepl) {  
-          oldDiskspace = oldDiskspace / currentINode.getBlockReplication()
-              * replication;
-        }
-      }
-      
-      Util.collectBlocksAndClear(sFile, collectedBlocks, removedINodes);
-      
-      long dsDelta = oldDiskspace - currentINode.diskspaceConsumed();
-      return Quota.Counts.newInstance(0, dsDelta);
-    }
-    
-    @Override
-    Quota.Counts combinePosteriorAndCollectBlocks(INodeFile currentINode,
-        FileDiff posterior, BlocksMapUpdateInfo collectedBlocks,
-        final List<INode> removedINodes) {
-      return updateQuotaAndCollectBlocks(currentINode, posterior,
-          collectedBlocks, removedINodes);
-    }
-    
-    @Override
-    public String toString() {
-      return super.toString() + " fileSize=" + fileSize + ", rep="
-          + (snapshotINode == null? "?": snapshotINode.getFileReplication());
-    }
-
-    @Override
-    void write(DataOutput out, ReferenceMap referenceMap) throws IOException {
-      writeSnapshot(out);
-      out.writeLong(fileSize);
-
-      // write snapshotINode
-      if (snapshotINode != null) {
-        out.writeBoolean(true);
-        FSImageSerialization.writeINodeFileAttributes(snapshotINode, out);
-      } else {
-        out.writeBoolean(false);
-      }
-    }
-
-    @Override
-    Quota.Counts destroyDiffAndCollectBlocks(INodeFile currentINode,
-        BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
-      return updateQuotaAndCollectBlocks(currentINode, this,
-          collectedBlocks, removedINodes);
-    }
-  }
-
-  /** A list of FileDiffs for storing snapshot data. */
-  public static class FileDiffList
-      extends AbstractINodeDiffList<INodeFile, INodeFileAttributes, FileDiff> {
-
-    @Override
-    FileDiff createDiff(Snapshot snapshot, INodeFile file) {
-      return new FileDiff(snapshot, file);
-    }
-    
-    @Override
-    INodeFileAttributes createSnapshotCopy(INodeFile currentINode) {
-      return new INodeFileAttributes.SnapshotCopy(currentINode);
-    }
-  }
-
-  /** @return the {@link INodeFile} view of this object. */
-  public INodeFile asINodeFile();
-
-  /** @return the file diff list. */
-  public FileDiffList getDiffs();
-
-  /** Is the current file deleted? */
-  public boolean isCurrentFileDeleted();
-  
-  /** Delete the file from the current tree */
-  public void deleteCurrentFile();
-
-  /** Utility methods for the classes which implement the interface. */
-  public static class Util {
-    /** 
-     * @return block replication, which is the max file replication among
-     *         the file and the diff list.
-     */
-    public static short getBlockReplication(final FileWithSnapshot file) {
-      short max = file.isCurrentFileDeleted()? 0
-          : file.asINodeFile().getFileReplication();
-      for(FileDiff d : file.getDiffs()) {
-        if (d.snapshotINode != null) {
-          final short replication = d.snapshotINode.getFileReplication();
-          if (replication > max) {
-            max = replication;
-          }
-        }
-      }
-      return max;
-    }
-
-    /**
-     * If some blocks at the end of the block list no longer belongs to
-     * any inode, collect them and update the block list.
-     */
-    static void collectBlocksAndClear(final FileWithSnapshot file,
-        final BlocksMapUpdateInfo info, final List<INode> removedINodes) {
-      // check if everything is deleted.
-      if (file.isCurrentFileDeleted()
-          && file.getDiffs().asList().isEmpty()) {
-        file.asINodeFile().destroyAndCollectBlocks(info, removedINodes);
-        return;
-      }
-
-      // find max file size.
-      final long max;
-      if (file.isCurrentFileDeleted()) {
-        final FileDiff last = file.getDiffs().getLast();
-        max = last == null? 0: last.fileSize;
-      } else { 
-        max = file.asINodeFile().computeFileSize();
-      }
-
-      collectBlocksBeyondMax(file, max, info);
-    }
-
-    private static void collectBlocksBeyondMax(final FileWithSnapshot file,
-        final long max, final BlocksMapUpdateInfo collectedBlocks) {
-      final BlockInfo[] oldBlocks = file.asINodeFile().getBlocks();
-      if (oldBlocks != null) {
-        //find the minimum n such that the size of the first n blocks > max
-        int n = 0;
-        for(long size = 0; n < oldBlocks.length && max > size; n++) {
-          size += oldBlocks[n].getNumBytes();
-        }
-        
-        // starting from block n, the data is beyond max.
-        if (n < oldBlocks.length) {
-          // resize the array.  
-          final BlockInfo[] newBlocks;
-          if (n == 0) {
-            newBlocks = null;
-          } else {
-            newBlocks = new BlockInfo[n];
-            System.arraycopy(oldBlocks, 0, newBlocks, 0, n);
-          }
-          
-          // set new blocks
-          file.asINodeFile().setBlocks(newBlocks);
-
-          // collect the blocks beyond max.  
-          if (collectedBlocks != null) {
-            for(; n < oldBlocks.length; n++) {
-              collectedBlocks.addDeleteBlock(oldBlocks[n]);
-            }
-          }
-        }
-      }
-    }
-  }
-}

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

@@ -432,8 +432,8 @@ public class INodeDirectorySnapshottable extends INodeDirectoryWithSnapshot {
           parentPath.remove(parentPath.size() - 1);
         }
       }
-    } else if (node.isFile() && node.asFile() instanceof FileWithSnapshot) {
-      FileWithSnapshot file = (FileWithSnapshot) node.asFile();
+    } else if (node.isFile() && node.asFile() instanceof INodeFileWithSnapshot) {
+      INodeFileWithSnapshot file = (INodeFileWithSnapshot) node.asFile();
       Snapshot earlierSnapshot = diffReport.isFromEarlier() ? diffReport.from
           : diffReport.to;
       Snapshot laterSnapshot = diffReport.isFromEarlier() ? diffReport.to
@@ -441,7 +441,7 @@ public class INodeDirectorySnapshottable extends INodeDirectoryWithSnapshot {
       boolean change = file.getDiffs().changedBetweenSnapshots(earlierSnapshot,
           laterSnapshot);
       if (change) {
-        diffReport.addFileDiff(file.asINodeFile(), relativePath);
+        diffReport.addFileDiff(file, relativePath);
       }
     }
   }

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

@@ -804,10 +804,10 @@ public class INodeDirectoryWithSnapshot extends INodeDirectory {
         // For DstReference node, since the node is not in the created list of
         // prior, we should treat it as regular file/dir
       } else if (topNode.isFile()
-          && topNode.asFile() instanceof FileWithSnapshot) {
-        FileWithSnapshot fs = (FileWithSnapshot) topNode.asFile();
-        counts.add(fs.getDiffs().deleteSnapshotDiff(post, prior,
-            topNode.asFile(), collectedBlocks, removedINodes, countDiffChange));
+          && topNode.asFile() instanceof INodeFileWithSnapshot) {
+        INodeFileWithSnapshot fs = (INodeFileWithSnapshot) topNode.asFile();
+        counts.add(fs.getDiffs().deleteSnapshotDiff(post, prior, fs,
+            collectedBlocks, removedINodes, countDiffChange));
       } else if (topNode.isDirectory()) {
         INodeDirectory dir = topNode.asDirectory();
         ChildrenDiff priorChildrenDiff = null;

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

@@ -21,6 +21,7 @@ import java.util.List;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.namenode.INode;
 import org.apache.hadoop.hdfs.server.namenode.INodeFile;
 import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
@@ -31,14 +32,13 @@ import org.apache.hadoop.hdfs.server.namenode.Quota;
  * Represent an {@link INodeFile} that is snapshotted.
  */
 @InterfaceAudience.Private
-public class INodeFileWithSnapshot extends INodeFile
-    implements FileWithSnapshot {
+public class INodeFileWithSnapshot extends INodeFile {
   private final FileDiffList diffs;
   private boolean isCurrentFileDeleted = false;
 
   public INodeFileWithSnapshot(INodeFile f) {
-    this(f, f instanceof FileWithSnapshot?
-        ((FileWithSnapshot)f).getDiffs(): null);
+    this(f, f instanceof INodeFileWithSnapshot ? 
+        ((INodeFileWithSnapshot) f).getDiffs() : null);
   }
 
   public INodeFileWithSnapshot(INodeFile f, FileDiffList diffs) {
@@ -46,12 +46,12 @@ public class INodeFileWithSnapshot extends INodeFile
     this.diffs = diffs != null? diffs: new FileDiffList();
   }
 
-  @Override
+  /** Is the current file deleted? */
   public boolean isCurrentFileDeleted() {
     return isCurrentFileDeleted;
   }
   
-  @Override
+  /** Delete the file from the current tree */
   public void deleteCurrentFile() {
     isCurrentFileDeleted = true;
   }
@@ -70,12 +70,7 @@ public class INodeFileWithSnapshot extends INodeFile
     return this;
   }
 
-  @Override
-  public INodeFile asINodeFile() {
-    return this;
-  }
-
-  @Override
+  /** @return the file diff list. */
   public FileDiffList getDiffs() {
     return diffs;
   }
@@ -90,7 +85,7 @@ public class INodeFileWithSnapshot extends INodeFile
         recordModification(prior, null);
         deleteCurrentFile();
       }
-      Util.collectBlocksAndClear(this, collectedBlocks, removedINodes);
+      this.collectBlocksAndClear(collectedBlocks, removedINodes);
       return Quota.Counts.newInstance();
     } else { // delete a snapshot
       prior = getDiffs().updatePrior(snapshot, prior);
@@ -104,4 +99,100 @@ public class INodeFileWithSnapshot extends INodeFile
     return super.toDetailString()
         + (isCurrentFileDeleted()? "(DELETED), ": ", ") + diffs;
   }
+  
+  /** 
+   * @return block replication, which is the max file replication among
+   *         the file and the diff list.
+   */
+  @Override
+  public short getBlockReplication() {
+    short max = isCurrentFileDeleted() ? 0 : getFileReplication();
+    for(FileDiff d : getDiffs()) {
+      if (d.snapshotINode != null) {
+        final short replication = d.snapshotINode.getFileReplication();
+        if (replication > max) {
+          max = replication;
+        }
+      }
+    }
+    return max;
+  }
+  
+  /**
+   * If some blocks at the end of the block list no longer belongs to
+   * any inode, collect them and update the block list.
+   */
+  void collectBlocksAndClear(final BlocksMapUpdateInfo info,
+      final List<INode> removedINodes) {
+    // check if everything is deleted.
+    if (isCurrentFileDeleted() && getDiffs().asList().isEmpty()) {
+      destroyAndCollectBlocks(info, removedINodes);
+      return;
+    }
+
+    // find max file size.
+    final long max;
+    if (isCurrentFileDeleted()) {
+      final FileDiff last = getDiffs().getLast();
+      max = last == null? 0: last.getFileSize();
+    } else { 
+      max = computeFileSize();
+    }
+
+    collectBlocksBeyondMax(max, info);
+  }
+
+  private void collectBlocksBeyondMax(final long max,
+      final BlocksMapUpdateInfo collectedBlocks) {
+    final BlockInfo[] oldBlocks = getBlocks();
+    if (oldBlocks != null) {
+      //find the minimum n such that the size of the first n blocks > max
+      int n = 0;
+      for(long size = 0; n < oldBlocks.length && max > size; n++) {
+        size += oldBlocks[n].getNumBytes();
+      }
+      
+      // starting from block n, the data is beyond max.
+      if (n < oldBlocks.length) {
+        // resize the array.  
+        final BlockInfo[] newBlocks;
+        if (n == 0) {
+          newBlocks = null;
+        } else {
+          newBlocks = new BlockInfo[n];
+          System.arraycopy(oldBlocks, 0, newBlocks, 0, n);
+        }
+        
+        // set new blocks
+        setBlocks(newBlocks);
+
+        // collect the blocks beyond max.  
+        if (collectedBlocks != null) {
+          for(; n < oldBlocks.length; n++) {
+            collectedBlocks.addDeleteBlock(oldBlocks[n]);
+          }
+        }
+      }
+    }
+  }
+  
+  Quota.Counts updateQuotaAndCollectBlocks(FileDiff removed,
+      BlocksMapUpdateInfo collectedBlocks, final List<INode> removedINodes) {
+    long oldDiskspace = this.diskspaceConsumed();
+    if (removed.snapshotINode != null) {
+      short replication = removed.snapshotINode.getFileReplication();
+      short currentRepl = getBlockReplication();
+      if (currentRepl == 0) {
+        oldDiskspace = computeFileSize(true, true) * replication;
+      } else if (replication > currentRepl) {  
+        oldDiskspace = oldDiskspace / getBlockReplication()
+            * replication;
+      }
+    }
+    
+    this.collectBlocksAndClear(collectedBlocks, removedINodes);
+    
+    long dsDelta = oldDiskspace - diskspaceConsumed();
+    return Quota.Counts.newInstance(0, dsDelta);
+  }
 }

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

@@ -36,8 +36,6 @@ import org.apache.hadoop.hdfs.server.namenode.INodeDirectoryAttributes;
 import org.apache.hadoop.hdfs.server.namenode.INodeFile;
 import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiff;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiffList;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot.DirectoryDiff;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot.DirectoryDiffList;
 import org.apache.hadoop.hdfs.tools.snapshot.SnapshotDiff;
@@ -99,8 +97,8 @@ public class SnapshotFSImageFormat {
   
   public static void saveFileDiffList(final INodeFile file,
       final DataOutput out) throws IOException {
-    saveINodeDiffs(file instanceof FileWithSnapshot?
-        ((FileWithSnapshot)file).getDiffs(): null, out, null);
+    saveINodeDiffs(file instanceof INodeFileWithSnapshot?
+        ((INodeFileWithSnapshot) file).getDiffs(): null, out, null);
   }
 
   public static FileDiffList loadFileDiffList(DataInput in,

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

@@ -63,7 +63,6 @@ import org.apache.hadoop.hdfs.server.namenode.INodeMap;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithCount;
 import org.apache.hadoop.hdfs.server.namenode.Quota;
-import org.apache.hadoop.hdfs.server.namenode.snapshot.FileWithSnapshot.FileDiff;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot.ChildrenDiff;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.INodeDirectoryWithSnapshot.DirectoryDiff;
 import org.apache.hadoop.hdfs.util.Diff.ListType;