HDFS-8499. Refactor BlockInfo class hierarchy with static helper class. Contributed by Zhe Zhang.

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

@@ -626,6 +626,9 @@ Release 2.8.0 - UNRELEASED
     HDFS-7923. The DataNodes should rate-limit their full block reports by
     asking the NN on heartbeat messages (cmccabe)
 
+    HDFS-8499. Refactor BlockInfo class hierarchy with static helper class.
+    (Zhe Zhang via wang)
+
   OPTIMIZATIONS
 
     HDFS-8026. Trace FSOutputSummer#writeChecksumChunks rather than

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockCollection.java

@@ -79,7 +79,7 @@ public interface BlockCollection {
    * Convert the last block of the collection to an under-construction block
    * and set the locations.
    */
-  public BlockInfoContiguousUnderConstruction setLastBlock(BlockInfo lastBlock,
+  public BlockInfoUnderConstruction setLastBlock(BlockInfo lastBlock,
       DatanodeStorageInfo[] targets) throws IOException;
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfo.java

@@ -51,7 +51,7 @@ public abstract class  BlockInfo extends Block
    * per replica is 42 bytes (LinkedList#Entry object per replica) versus 16
    * bytes using the triplets.
    */
-  protected Object[] triplets;
+  Object[] triplets;
 
   /**
    * Construct an entry for blocksmap
@@ -295,7 +295,7 @@ public abstract class  BlockInfo extends Block
   /**
    * BlockInfo represents a block that is not being constructed.
    * In order to start modifying the block, the BlockInfo should be converted
-   * to {@link BlockInfoContiguousUnderConstruction}.
+   * to {@link BlockInfoUnderConstruction}.
    * @return {@link BlockUCState#COMPLETE}
    */
   public BlockUCState getBlockUCState() {
@@ -312,27 +312,29 @@ public abstract class  BlockInfo extends Block
   }
 
   /**
-   * Convert a complete block to an under construction block.
+   * Convert a block to an under construction block.
    * @return BlockInfoUnderConstruction -  an under construction block.
    */
-  public BlockInfoContiguousUnderConstruction convertToBlockUnderConstruction(
+  public BlockInfoUnderConstruction convertToBlockUnderConstruction(
       BlockUCState s, DatanodeStorageInfo[] targets) {
     if(isComplete()) {
-      BlockInfoContiguousUnderConstruction ucBlock =
-          new BlockInfoContiguousUnderConstruction(this,
-          getBlockCollection().getPreferredBlockReplication(), s, targets);
-      ucBlock.setBlockCollection(getBlockCollection());
-      return ucBlock;
+      return convertCompleteBlockToUC(s, targets);
     }
     // the block is already under construction
-    BlockInfoContiguousUnderConstruction ucBlock =
-        (BlockInfoContiguousUnderConstruction)this;
+    BlockInfoUnderConstruction ucBlock =
+        (BlockInfoUnderConstruction)this;
     ucBlock.setBlockUCState(s);
     ucBlock.setExpectedLocations(targets);
     ucBlock.setBlockCollection(getBlockCollection());
     return ucBlock;
   }
 
+  /**
+   * Convert a complete block to an under construction block.
+   */
+  abstract BlockInfoUnderConstruction convertCompleteBlockToUC(
+      BlockUCState s, DatanodeStorageInfo[] targets);
+
   @Override
   public int hashCode() {
     // Super implementation is sufficient

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoContiguous.java

@@ -19,13 +19,13 @@ package org.apache.hadoop.hdfs.server.blockmanagement;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 
 /**
  * Subclass of {@link BlockInfo}, used for a block with replication scheme.
  */
 @InterfaceAudience.Private
 public class BlockInfoContiguous extends BlockInfo {
-  public static final BlockInfoContiguous[] EMPTY_ARRAY = {};
 
   public BlockInfoContiguous(short size) {
     super(size);
@@ -40,84 +40,37 @@ public class BlockInfoContiguous extends BlockInfo {
    * This is used to convert BlockReplicationInfoUnderConstruction
    * @param from BlockReplicationInfo to copy from.
    */
-  protected BlockInfoContiguous(BlockInfoContiguous from) {
+  protected BlockInfoContiguous(BlockInfo from) {
     super(from);
   }
 
-  /**
-   * Ensure that there is enough  space to include num more triplets.
-   * @return first free triplet index.
-   */
-  private int ensureCapacity(int num) {
-    assert this.triplets != null : "BlockInfo is not initialized";
-    int last = numNodes();
-    if (triplets.length >= (last+num)*3) {
-      return last;
-    }
-    /* Not enough space left. Create a new array. Should normally
-     * happen only when replication is manually increased by the user. */
-    Object[] old = triplets;
-    triplets = new Object[(last+num)*3];
-    System.arraycopy(old, 0, triplets, 0, last * 3);
-    return last;
-  }
-
   @Override
   boolean addStorage(DatanodeStorageInfo storage) {
-    // find the last null node
-    int lastNode = ensureCapacity(1);
-    setStorageInfo(lastNode, storage);
-    setNext(lastNode, null);
-    setPrevious(lastNode, null);
-    return true;
+    return ContiguousBlockStorageOp.addStorage(this, storage);
   }
 
   @Override
   boolean removeStorage(DatanodeStorageInfo storage) {
-    int dnIndex = findStorageInfo(storage);
-    if (dnIndex < 0) { // the node is not found
-      return false;
-    }
-    assert getPrevious(dnIndex) == null && getNext(dnIndex) == null :
-        "Block is still in the list and must be removed first.";
-    // find the last not null node
-    int lastNode = numNodes()-1;
-    // replace current node triplet by the lastNode one
-    setStorageInfo(dnIndex, getStorageInfo(lastNode));
-    setNext(dnIndex, getNext(lastNode));
-    setPrevious(dnIndex, getPrevious(lastNode));
-    // set the last triplet to null
-    setStorageInfo(lastNode, null);
-    setNext(lastNode, null);
-    setPrevious(lastNode, null);
-    return true;
+    return ContiguousBlockStorageOp.removeStorage(this, storage);
   }
 
   @Override
   public int numNodes() {
-    assert this.triplets != null : "BlockInfo is not initialized";
-    assert triplets.length % 3 == 0 : "Malformed BlockInfo";
-
-    for (int idx = getCapacity()-1; idx >= 0; idx--) {
-      if (getDatanode(idx) != null) {
-        return idx + 1;
-      }
-    }
-    return 0;
+    return ContiguousBlockStorageOp.numNodes(this);
   }
 
   @Override
   void replaceBlock(BlockInfo newBlock) {
-    assert newBlock instanceof BlockInfoContiguous;
-    for (int i = this.numNodes() - 1; i >= 0; i--) {
-      final DatanodeStorageInfo storage = this.getStorageInfo(i);
-      final boolean removed = storage.removeBlock(this);
-      assert removed : "currentBlock not found.";
+    ContiguousBlockStorageOp.replaceBlock(this, newBlock);
+  }
 
-      final DatanodeStorageInfo.AddBlockResult result = storage.addBlock(
-          newBlock);
-      assert result == DatanodeStorageInfo.AddBlockResult.ADDED :
-          "newBlock already exists.";
-    }
+  @Override
+  BlockInfoUnderConstruction convertCompleteBlockToUC(
+      HdfsServerConstants.BlockUCState s, DatanodeStorageInfo[] targets) {
+    BlockInfoUnderConstructionContiguous ucBlock =
+        new BlockInfoUnderConstructionContiguous(this,
+            getBlockCollection().getPreferredBlockReplication(), s, targets);
+    ucBlock.setBlockCollection(getBlockCollection());
+    return ucBlock;
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoContiguousUnderConstruction.java → hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstruction.java

@@ -22,7 +22,9 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
+import com.google.common.base.Preconditions;
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
@@ -31,15 +33,15 @@ import org.apache.hadoop.hdfs.server.namenode.NameNode;
  * Represents a block that is currently being constructed.<br>
  * This is usually the last block of a file opened for write or append.
  */
-public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
+public abstract class BlockInfoUnderConstruction extends BlockInfo {
   /** Block state. See {@link BlockUCState} */
-  private BlockUCState blockUCState;
+  protected BlockUCState blockUCState;
 
   /**
    * Block replicas as assigned when the block was allocated.
    * This defines the pipeline order.
    */
-  private List<ReplicaUnderConstruction> replicas;
+  protected List<ReplicaUnderConstruction> replicas;
 
   /**
    * Index of the primary data node doing the recovery. Useful for log
@@ -57,12 +59,12 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
   /**
    * The block source to use in the event of copy-on-write truncate.
    */
-  private Block truncateBlock;
+  protected Block truncateBlock;
 
   /**
    * ReplicaUnderConstruction contains information about replicas while
    * they are under construction.
-   * The GS, the length and the state of the replica is as reported by 
+   * The GS, the length and the state of the replica is as reported by
    * the data-node.
    * It is not guaranteed, but expected, that data-nodes actually have
    * corresponding replicas.
@@ -143,7 +145,7 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
       appendStringTo(b);
       return b.toString();
     }
-    
+
     @Override
     public void appendStringTo(StringBuilder sb) {
       sb.append("ReplicaUC[")
@@ -158,45 +160,24 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
    * Create block and set its state to
    * {@link BlockUCState#UNDER_CONSTRUCTION}.
    */
-  public BlockInfoContiguousUnderConstruction(Block blk, short replication) {
+  public BlockInfoUnderConstruction(Block blk, short replication) {
     this(blk, replication, BlockUCState.UNDER_CONSTRUCTION, null);
   }
 
   /**
    * Create a block that is currently being constructed.
    */
-  public BlockInfoContiguousUnderConstruction(Block blk, short replication,
+  public BlockInfoUnderConstruction(Block blk, short replication,
       BlockUCState state, DatanodeStorageInfo[] targets) {
     super(blk, replication);
-    assert getBlockUCState() != BlockUCState.COMPLETE :
-      "BlockInfoUnderConstruction cannot be in COMPLETE state";
+    Preconditions.checkState(getBlockUCState() != BlockUCState.COMPLETE,
+        "BlockInfoUnderConstruction cannot be in COMPLETE state");
     this.blockUCState = state;
     setExpectedLocations(targets);
   }
 
-  /**
-   * Convert an under construction block to a complete block.
-   * 
-   * @return BlockInfo - a complete block.
-   * @throws IOException if the state of the block 
-   * (the generation stamp and the length) has not been committed by 
-   * the client or it does not have at least a minimal number of replicas 
-   * reported from data-nodes. 
-   */
-  BlockInfo convertToCompleteBlock() throws IOException {
-    assert getBlockUCState() != BlockUCState.COMPLETE :
-      "Trying to convert a COMPLETE block";
-    return new BlockInfoContiguous(this);
-  }
-
-  /** Set expected locations */
-  public void setExpectedLocations(DatanodeStorageInfo[] targets) {
-    int numLocations = targets == null ? 0 : targets.length;
-    this.replicas = new ArrayList<ReplicaUnderConstruction>(numLocations);
-    for(int i = 0; i < numLocations; i++)
-      replicas.add(
-        new ReplicaUnderConstruction(this, targets[i], ReplicaState.RBW));
-  }
+  /** Set expected locations. */
+  public abstract void setExpectedLocations(DatanodeStorageInfo[] targets);
 
   /**
    * Create array of expected replica locations
@@ -205,12 +186,13 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
   public DatanodeStorageInfo[] getExpectedStorageLocations() {
     int numLocations = replicas == null ? 0 : replicas.size();
     DatanodeStorageInfo[] storages = new DatanodeStorageInfo[numLocations];
-    for(int i = 0; i < numLocations; i++)
+    for(int i = 0; i < numLocations; i++) {
       storages[i] = replicas.get(i).getExpectedStorageLocation();
+    }
     return storages;
   }
 
-  /** Get the number of expected locations */
+  /** Get the number of expected locations. */
   public int getNumExpectedLocations() {
     return replicas == null ? 0 : replicas.size();
   }
@@ -228,19 +210,15 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
     blockUCState = s;
   }
 
-  /** Get block recovery ID */
+  /** Get block recovery ID. */
   public long getBlockRecoveryId() {
     return blockRecoveryId;
   }
 
-  /** Get recover block */
-  public Block getTruncateBlock() {
-    return truncateBlock;
-  }
+  /** Get recover block. */
+  public abstract Block getTruncateBlock();
 
-  public void setTruncateBlock(Block recoveryBlock) {
-    this.truncateBlock = recoveryBlock;
-  }
+  public abstract void setTruncateBlock(Block recoveryBlock);
 
   /**
    * Process the recorded replicas. When about to commit or finish the
@@ -250,8 +228,9 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
   public void setGenerationStampAndVerifyReplicas(long genStamp) {
     // Set the generation stamp for the block.
     setGenerationStamp(genStamp);
-    if (replicas == null)
+    if (replicas == null) {
       return;
+    }
 
     // Remove the replicas with wrong gen stamp.
     // The replica list is unchanged.
@@ -267,13 +246,14 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
   /**
    * Commit block's length and generation stamp as reported by the client.
    * Set block state to {@link BlockUCState#COMMITTED}.
-   * @param block - contains client reported block length and generation 
+   * @param block - contains client reported block length and generation
    * @throws IOException if block ids are inconsistent.
    */
   void commitBlock(Block block) throws IOException {
-    if(getBlockId() != block.getBlockId())
+    if(getBlockId() != block.getBlockId()) {
       throw new IOException("Trying to commit inconsistent block: id = "
           + block.getBlockId() + ", expected id = " + getBlockId());
+    }
     blockUCState = BlockUCState.COMMITTED;
     this.set(getBlockId(), block.getNumBytes(), block.getGenerationStamp());
     // Sort out invalid replicas.
@@ -289,16 +269,17 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
     setBlockUCState(BlockUCState.UNDER_RECOVERY);
     blockRecoveryId = recoveryId;
     if (replicas.size() == 0) {
-      NameNode.blockStateChangeLog.warn("BLOCK*"
-        + " BlockInfoUnderConstruction.initLeaseRecovery:"
-        + " No blocks found, lease removed.");
+      NameNode.blockStateChangeLog.warn("BLOCK* " +
+          "BlockInfoUnderConstruction.initLeaseRecovery: " +
+          "No blocks found, lease removed.");
     }
     boolean allLiveReplicasTriedAsPrimary = true;
     for (int i = 0; i < replicas.size(); i++) {
       // Check if all replicas have been tried or not.
       if (replicas.get(i).isAlive()) {
         allLiveReplicasTriedAsPrimary =
-            (allLiveReplicasTriedAsPrimary && replicas.get(i).getChosenAsPrimary());
+            (allLiveReplicasTriedAsPrimary &&
+                replicas.get(i).getChosenAsPrimary());
       }
     }
     if (allLiveReplicasTriedAsPrimary) {
@@ -312,7 +293,8 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
     primaryNodeIndex = -1;
     for(int i = 0; i < replicas.size(); i++) {
       // Skip alive replicas which have been chosen for recovery.
-      if (!(replicas.get(i).isAlive() && !replicas.get(i).getChosenAsPrimary())) {
+      if (!(replicas.get(i).isAlive() &&
+          !replicas.get(i).getChosenAsPrimary())) {
         continue;
       }
       final ReplicaUnderConstruction ruc = replicas.get(i);
@@ -325,7 +307,8 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
       }
     }
     if (primary != null) {
-      primary.getExpectedStorageLocation().getDatanodeDescriptor().addBlockToBeRecovered(this);
+      primary.getExpectedStorageLocation().
+          getDatanodeDescriptor().addBlockToBeRecovered(this);
       primary.setChosenAsPrimary(true);
       NameNode.blockStateChangeLog.info(
           "BLOCK* {} recovery started, primary={}", this, primary);
@@ -358,6 +341,25 @@ public class BlockInfoContiguousUnderConstruction extends BlockInfoContiguous {
     replicas.add(new ReplicaUnderConstruction(block, storage, rState));
   }
 
+  /**
+   * Convert an under construction block to a complete block.
+   *
+   * @return a complete block.
+   * @throws IOException
+   *           if the state of the block (the generation stamp and the length)
+   *           has not been committed by the client or it does not have at
+   *           least a minimal number of replicas reported from data-nodes.
+   */
+  public abstract BlockInfo convertToCompleteBlock();
+
+  @Override
+  BlockInfoUnderConstruction convertCompleteBlockToUC
+      (HdfsServerConstants.BlockUCState s, DatanodeStorageInfo[] targets) {
+    BlockManager.LOG.error("convertCompleteBlockToUC should only be applied " +
+        "on complete blocks.");
+    return null;
+  }
+
   @Override // BlockInfo
   // BlockInfoUnderConstruction participates in maps the same way as BlockInfo
   public int hashCode() {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoUnderConstructionContiguous.java

@@ -0,0 +1,110 @@
+/**
+ * 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.blockmanagement;
+
+import com.google.common.base.Preconditions;
+import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
+
+import java.util.ArrayList;
+
+/**
+ * Subclass of {@link BlockInfoUnderConstruction}, representing a block under
+ * the contiguous (instead of striped) layout.
+ */
+public class BlockInfoUnderConstructionContiguous extends
+    BlockInfoUnderConstruction {
+  /**
+   * Create block and set its state to
+   * {@link HdfsServerConstants.BlockUCState#UNDER_CONSTRUCTION}.
+   */
+  public BlockInfoUnderConstructionContiguous(Block blk, short replication) {
+    this(blk, replication, HdfsServerConstants.BlockUCState.UNDER_CONSTRUCTION,
+        null);
+  }
+
+  /**
+   * Create a block that is currently being constructed.
+   */
+  public BlockInfoUnderConstructionContiguous(Block blk, short replication,
+      HdfsServerConstants.BlockUCState state, DatanodeStorageInfo[] targets) {
+    super(blk, replication);
+    Preconditions.checkState(getBlockUCState() !=
+        HdfsServerConstants.BlockUCState.COMPLETE,
+        "BlockInfoUnderConstructionContiguous cannot be in COMPLETE state");
+    this.blockUCState = state;
+    setExpectedLocations(targets);
+  }
+
+  /**
+   * Convert an under construction block to a complete block.
+   *
+   * @return BlockInfo - a complete block.
+   * @throws IOException if the state of the block
+   * (the generation stamp and the length) has not been committed by
+   * the client or it does not have at least a minimal number of replicas
+   * reported from data-nodes.
+   */
+  @Override
+  public BlockInfoContiguous convertToCompleteBlock() {
+    Preconditions.checkState(getBlockUCState() !=
+        HdfsServerConstants.BlockUCState.COMPLETE,
+        "Trying to convert a COMPLETE block");
+    return new BlockInfoContiguous(this);
+  }
+
+  @Override
+  boolean addStorage(DatanodeStorageInfo storage) {
+    return ContiguousBlockStorageOp.addStorage(this, storage);
+  }
+
+  @Override
+  boolean removeStorage(DatanodeStorageInfo storage) {
+    return ContiguousBlockStorageOp.removeStorage(this, storage);
+  }
+
+  @Override
+  public int numNodes() {
+    return ContiguousBlockStorageOp.numNodes(this);
+  }
+
+  @Override
+  void replaceBlock(BlockInfo newBlock) {
+    ContiguousBlockStorageOp.replaceBlock(this, newBlock);
+  }
+
+  @Override
+  public void setExpectedLocations(DatanodeStorageInfo[] targets) {
+    int numLocations = targets == null ? 0 : targets.length;
+    this.replicas = new ArrayList<>(numLocations);
+    for(int i = 0; i < numLocations; i++) {
+      replicas.add(
+          new ReplicaUnderConstruction(this, targets[i], HdfsServerConstants.ReplicaState.RBW));
+    }
+  }
+
+  @Override
+  public Block getTruncateBlock() {
+    return truncateBlock;
+  }
+
+  @Override
+  public void setTruncateBlock(Block recoveryBlock) {
+    this.truncateBlock = recoveryBlock;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -602,7 +602,7 @@ public class BlockManager {
    * of replicas reported from data-nodes.
    */
   private static boolean commitBlock(
-      final BlockInfoContiguousUnderConstruction block, final Block commitBlock)
+      final BlockInfoUnderConstruction block, final Block commitBlock)
       throws IOException {
     if (block.getBlockUCState() == BlockUCState.COMMITTED)
       return false;
@@ -634,7 +634,7 @@ public class BlockManager {
       return false; // already completed (e.g. by syncBlock)
     
     final boolean b = commitBlock(
-        (BlockInfoContiguousUnderConstruction) lastBlock, commitBlock);
+        (BlockInfoUnderConstruction) lastBlock, commitBlock);
     if(countNodes(lastBlock).liveReplicas() >= minReplication)
       completeBlock(bc, bc.numBlocks()-1, false);
     return b;
@@ -654,8 +654,8 @@ public class BlockManager {
     BlockInfo curBlock = bc.getBlocks()[blkIndex];
     if(curBlock.isComplete())
       return curBlock;
-    BlockInfoContiguousUnderConstruction ucBlock =
-        (BlockInfoContiguousUnderConstruction) curBlock;
+    BlockInfoUnderConstruction ucBlock =
+        (BlockInfoUnderConstruction) curBlock;
     int numNodes = ucBlock.numNodes();
     if (!force && numNodes < minReplication)
       throw new IOException("Cannot complete block: " +
@@ -697,7 +697,7 @@ public class BlockManager {
    * when tailing edit logs as a Standby.
    */
   public BlockInfo forceCompleteBlock(final BlockCollection bc,
-      final BlockInfoContiguousUnderConstruction block) throws IOException {
+      final BlockInfoUnderConstruction block) throws IOException {
     block.commitBlock(block);
     return completeBlock(bc, block, true);
   }
@@ -728,7 +728,7 @@ public class BlockManager {
 
     DatanodeStorageInfo[] targets = getStorages(oldBlock);
 
-    BlockInfoContiguousUnderConstruction ucBlock =
+    BlockInfoUnderConstruction ucBlock =
         bc.setLastBlock(oldBlock, targets);
     blocksMap.replaceBlock(ucBlock);
 
@@ -830,14 +830,14 @@ public class BlockManager {
   /** @return a LocatedBlock for the given block */
   private LocatedBlock createLocatedBlock(final BlockInfo blk, final long pos
       ) throws IOException {
-    if (blk instanceof BlockInfoContiguousUnderConstruction) {
+    if (blk instanceof BlockInfoUnderConstruction) {
       if (blk.isComplete()) {
         throw new IOException(
             "blk instanceof BlockInfoUnderConstruction && blk.isComplete()"
             + ", blk=" + blk);
       }
-      final BlockInfoContiguousUnderConstruction uc =
-          (BlockInfoContiguousUnderConstruction) blk;
+      final BlockInfoUnderConstruction uc =
+          (BlockInfoUnderConstruction) blk;
       final DatanodeStorageInfo[] storages = uc.getExpectedStorageLocations();
       final ExtendedBlock eb = new ExtendedBlock(namesystem.getBlockPoolId(), blk);
       return newLocatedBlock(eb, storages, pos, false);
@@ -1744,11 +1744,11 @@ public class BlockManager {
    * reported by the datanode in the block report. 
    */
   static class StatefulBlockInfo {
-    final BlockInfoContiguousUnderConstruction storedBlock;
+    final BlockInfoUnderConstruction storedBlock;
     final Block reportedBlock;
     final ReplicaState reportedState;
     
-    StatefulBlockInfo(BlockInfoContiguousUnderConstruction storedBlock,
+    StatefulBlockInfo(BlockInfoUnderConstruction storedBlock,
         Block reportedBlock, ReplicaState reportedState) {
       this.storedBlock = storedBlock;
       this.reportedBlock = reportedBlock;
@@ -1789,7 +1789,7 @@ public class BlockManager {
 
     BlockToMarkCorrupt(BlockInfo stored, long gs, String reason,
         Reason reasonCode) {
-      this(new BlockInfoContiguous((BlockInfoContiguous)stored), stored,
+      this(new BlockInfoContiguous(stored), stored,
           reason, reasonCode);
       //the corrupted block in datanode has a different generation stamp
       corrupted.setGenerationStamp(gs);
@@ -2148,13 +2148,13 @@ public class BlockManager {
       
       // If block is under construction, add this replica to its list
       if (isBlockUnderConstruction(storedBlock, ucState, reportedState)) {
-        ((BlockInfoContiguousUnderConstruction)storedBlock)
+        ((BlockInfoUnderConstruction)storedBlock)
             .addReplicaIfNotPresent(storageInfo, iblk, reportedState);
         // OpenFileBlocks only inside snapshots also will be added to safemode
         // threshold. So we need to update such blocks to safemode
         // refer HDFS-5283
-        BlockInfoContiguousUnderConstruction blockUC =
-            (BlockInfoContiguousUnderConstruction) storedBlock;
+        BlockInfoUnderConstruction blockUC =
+            (BlockInfoUnderConstruction) storedBlock;
         if (namesystem.isInSnapshot(blockUC)) {
           int numOfReplicas = blockUC.getNumExpectedLocations();
           namesystem.incrementSafeBlockCount(numOfReplicas);
@@ -2309,7 +2309,7 @@ public class BlockManager {
 
     if (isBlockUnderConstruction(storedBlock, ucState, reportedState)) {
       toUC.add(new StatefulBlockInfo(
-          (BlockInfoContiguousUnderConstruction) storedBlock,
+          (BlockInfoUnderConstruction) storedBlock,
           new Block(block), reportedState));
       return storedBlock;
     }
@@ -2500,7 +2500,7 @@ public class BlockManager {
 
   void addStoredBlockUnderConstruction(StatefulBlockInfo ucBlock,
       DatanodeStorageInfo storageInfo) throws IOException {
-    BlockInfoContiguousUnderConstruction block = ucBlock.storedBlock;
+    BlockInfoUnderConstruction block = ucBlock.storedBlock;
     block.addReplicaIfNotPresent(
         storageInfo, ucBlock.reportedBlock, ucBlock.reportedState);
 
@@ -2561,7 +2561,7 @@ public class BlockManager {
     assert block != null && namesystem.hasWriteLock();
     BlockInfo storedBlock;
     DatanodeDescriptor node = storageInfo.getDatanodeDescriptor();
-    if (block instanceof BlockInfoContiguousUnderConstruction) {
+    if (block instanceof BlockInfoUnderConstruction) {
       //refresh our copy in case the block got completed in another thread
       storedBlock = blocksMap.getStoredBlock(block);
     } else {
@@ -3499,8 +3499,8 @@ public class BlockManager {
       String src, BlockInfo[] blocks) {
     for (BlockInfo b: blocks) {
       if (!b.isComplete()) {
-        final BlockInfoContiguousUnderConstruction uc =
-            (BlockInfoContiguousUnderConstruction)b;
+        final BlockInfoUnderConstruction uc =
+            (BlockInfoUnderConstruction)b;
         final int numNodes = b.numNodes();
         LOG.info("BLOCK* " + b + " is not COMPLETE (ucState = "
           + uc.getBlockUCState() + ", replication# = " + numNodes

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/ContiguousBlockStorageOp.java

@@ -0,0 +1,106 @@
+/**
+ * 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.blockmanagement;
+
+import com.google.common.base.Preconditions;
+
+/**
+ * Utility class with logic on managing storage locations shared between
+ * complete and under-construction blocks under the contiguous format --
+ * {@link BlockInfoContiguous} and
+ * {@link BlockInfoUnderConstructionContiguous}.
+ */
+class ContiguousBlockStorageOp {
+  /**
+   * Ensure that there is enough  space to include num more triplets.
+   * @return first free triplet index.
+   */
+  private static int ensureCapacity(BlockInfo b, int num) {
+    Preconditions.checkArgument(b.triplets != null,
+        "BlockInfo is not initialized");
+    int last = b.numNodes();
+    if (b.triplets.length >= (last+num)*3) {
+      return last;
+    }
+    /* Not enough space left. Create a new array. Should normally
+     * happen only when replication is manually increased by the user. */
+    Object[] old = b.triplets;
+    b.triplets = new Object[(last+num)*3];
+    System.arraycopy(old, 0, b.triplets, 0, last * 3);
+    return last;
+  }
+
+  static boolean addStorage(BlockInfo b, DatanodeStorageInfo storage) {
+    // find the last null node
+    int lastNode = ensureCapacity(b, 1);
+    b.setStorageInfo(lastNode, storage);
+    b.setNext(lastNode, null);
+    b.setPrevious(lastNode, null);
+    return true;
+  }
+
+  static boolean removeStorage(BlockInfo b,
+      DatanodeStorageInfo storage) {
+    int dnIndex = b.findStorageInfo(storage);
+    if (dnIndex < 0) { // the node is not found
+      return false;
+    }
+    Preconditions.checkArgument(b.getPrevious(dnIndex) == null &&
+            b.getNext(dnIndex) == null,
+        "Block is still in the list and must be removed first.");
+    // find the last not null node
+    int lastNode = b.numNodes()-1;
+    // replace current node triplet by the lastNode one
+    b.setStorageInfo(dnIndex, b.getStorageInfo(lastNode));
+    b.setNext(dnIndex, b.getNext(lastNode));
+    b.setPrevious(dnIndex, b.getPrevious(lastNode));
+    // set the last triplet to null
+    b.setStorageInfo(lastNode, null);
+    b.setNext(lastNode, null);
+    b.setPrevious(lastNode, null);
+    return true;
+  }
+
+  static int numNodes(BlockInfo b) {
+    Preconditions.checkArgument(b.triplets != null,
+        "BlockInfo is not initialized");
+    Preconditions.checkArgument(b.triplets.length % 3 == 0,
+        "Malformed BlockInfo");
+
+    for (int idx = b.getCapacity()-1; idx >= 0; idx--) {
+      if (b.getDatanode(idx) != null) {
+        return idx + 1;
+      }
+    }
+    return 0;
+  }
+
+  static void replaceBlock(BlockInfo b, BlockInfo newBlock) {
+    for (int i = b.numNodes() - 1; i >= 0; i--) {
+      final DatanodeStorageInfo storage = b.getStorageInfo(i);
+      final boolean removed = storage.removeBlock(b);
+      Preconditions.checkState(removed, "currentBlock not found.");
+
+      final DatanodeStorageInfo.AddBlockResult result = storage.addBlock(
+          newBlock);
+      Preconditions.checkState(
+          result == DatanodeStorageInfo.AddBlockResult.ADDED,
+          "newBlock already exists.");
+    }
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java

@@ -219,8 +219,8 @@ public class DatanodeDescriptor extends DatanodeInfo {
   /** A queue of blocks to be replicated by this datanode */
   private final BlockQueue<BlockTargetPair> replicateBlocks = new BlockQueue<BlockTargetPair>();
   /** A queue of blocks to be recovered by this datanode */
-  private final BlockQueue<BlockInfoContiguousUnderConstruction> recoverBlocks =
-                                new BlockQueue<BlockInfoContiguousUnderConstruction>();
+  private final BlockQueue<BlockInfoUnderConstruction> recoverBlocks =
+                                new BlockQueue<BlockInfoUnderConstruction>();
   /** A set of blocks to be invalidated by this datanode */
   private final LightWeightHashSet<Block> invalidateBlocks = new LightWeightHashSet<Block>();
 
@@ -599,7 +599,7 @@ public class DatanodeDescriptor extends DatanodeInfo {
   /**
    * Store block recovery work.
    */
-  void addBlockToBeRecovered(BlockInfoContiguousUnderConstruction block) {
+  void addBlockToBeRecovered(BlockInfoUnderConstruction block) {
     if(recoverBlocks.contains(block)) {
       // this prevents adding the same block twice to the recovery queue
       BlockManager.LOG.info(block + " is already in the recovery queue");
@@ -641,11 +641,12 @@ public class DatanodeDescriptor extends DatanodeInfo {
     return replicateBlocks.poll(maxTransfers);
   }
 
-  public BlockInfoContiguousUnderConstruction[] getLeaseRecoveryCommand(int maxTransfers) {
-    List<BlockInfoContiguousUnderConstruction> blocks = recoverBlocks.poll(maxTransfers);
+  public BlockInfoUnderConstruction[] getLeaseRecoveryCommand(
+      int maxTransfers) {
+    List<BlockInfoUnderConstruction> blocks = recoverBlocks.poll(maxTransfers);
     if(blocks == null)
       return null;
-    return blocks.toArray(new BlockInfoContiguousUnderConstruction[blocks.size()]);
+    return blocks.toArray(new BlockInfoUnderConstruction[blocks.size()]);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeManager.java

@@ -1380,12 +1380,12 @@ public class DatanodeManager {
         }
 
         //check lease recovery
-        BlockInfoContiguousUnderConstruction[] blocks = nodeinfo
+        BlockInfoUnderConstruction[] blocks = nodeinfo
             .getLeaseRecoveryCommand(Integer.MAX_VALUE);
         if (blocks != null) {
           BlockRecoveryCommand brCommand = new BlockRecoveryCommand(
               blocks.length);
-          for (BlockInfoContiguousUnderConstruction b : blocks) {
+          for (BlockInfoUnderConstruction b : blocks) {
             final DatanodeStorageInfo[] storages = b.getExpectedStorageLocations();
             // Skip stale nodes during recovery - not heart beated for some time (30s by default).
             final List<DatanodeStorageInfo> recoveryLocations =

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

@@ -43,7 +43,8 @@ import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
@@ -73,7 +74,7 @@ class FSDirWriteFileOp {
       Block block) throws IOException {
     // modify file-> block and blocksMap
     // fileNode should be under construction
-    BlockInfoContiguousUnderConstruction uc = fileNode.removeLastBlock(block);
+    BlockInfoUnderConstruction uc = fileNode.removeLastBlock(block);
     if (uc == null) {
       return false;
     }
@@ -236,7 +237,7 @@ class FSDirWriteFileOp {
       } else {
         // add new chosen targets to already allocated block and return
         BlockInfo lastBlockInFile = pendingFile.getLastBlock();
-        ((BlockInfoContiguousUnderConstruction) lastBlockInFile)
+        ((BlockInfoUnderConstruction) lastBlockInFile)
             .setExpectedLocations(targets);
         offset = pendingFile.computeFileSize();
         return makeLocatedBlock(fsn, lastBlockInFile, targets, offset);
@@ -520,8 +521,8 @@ class FSDirWriteFileOp {
           fileINode.getPreferredBlockReplication(), true);
 
       // associate new last block for the file
-      BlockInfoContiguousUnderConstruction blockInfo =
-        new BlockInfoContiguousUnderConstruction(
+      BlockInfoUnderConstruction blockInfo =
+        new BlockInfoUnderConstructionContiguous(
             block,
             fileINode.getFileReplication(),
             HdfsServerConstants.BlockUCState.UNDER_CONSTRUCTION,
@@ -662,8 +663,8 @@ class FSDirWriteFileOp {
             "allocation of a new block in " + src + ". Returning previously" +
             " allocated block " + lastBlockInFile);
         long offset = file.computeFileSize();
-        BlockInfoContiguousUnderConstruction lastBlockUC =
-            (BlockInfoContiguousUnderConstruction) lastBlockInFile;
+        BlockInfoUnderConstruction lastBlockUC =
+            (BlockInfoUnderConstruction) lastBlockInFile;
         onRetryBlock[0] = makeLocatedBlock(fsn, lastBlockInFile,
             lastBlockUC.getExpectedStorageLocations(), offset);
         return new FileState(file, src, iip);

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

@@ -45,7 +45,8 @@ import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.RollingUpgradeStartupOption;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
@@ -960,16 +961,16 @@ public class FSEditLogLoader {
       }
       
       oldLastBlock.setNumBytes(pBlock.getNumBytes());
-      if (oldLastBlock instanceof BlockInfoContiguousUnderConstruction) {
+      if (oldLastBlock instanceof BlockInfoUnderConstruction) {
         fsNamesys.getBlockManager().forceCompleteBlock(file,
-            (BlockInfoContiguousUnderConstruction) oldLastBlock);
+            (BlockInfoUnderConstruction) oldLastBlock);
         fsNamesys.getBlockManager().processQueuedMessagesForBlock(pBlock);
       }
     } else { // the penultimate block is null
       Preconditions.checkState(oldBlocks == null || oldBlocks.length == 0);
     }
     // add the new block
-    BlockInfo newBI = new BlockInfoContiguousUnderConstruction(
+    BlockInfo newBI = new BlockInfoUnderConstructionContiguous(
           newBlock, file.getPreferredBlockReplication());
     fsNamesys.getBlockManager().addBlockCollection(newBI, file);
     file.addBlock(newBI);
@@ -1010,11 +1011,11 @@ public class FSEditLogLoader {
         oldBlock.getGenerationStamp() != newBlock.getGenerationStamp();
       oldBlock.setGenerationStamp(newBlock.getGenerationStamp());
       
-      if (oldBlock instanceof BlockInfoContiguousUnderConstruction &&
+      if (oldBlock instanceof BlockInfoUnderConstruction &&
           (!isLastBlock || op.shouldCompleteLastBlock())) {
         changeMade = true;
         fsNamesys.getBlockManager().forceCompleteBlock(file,
-            (BlockInfoContiguousUnderConstruction) oldBlock);
+            (BlockInfoUnderConstruction) oldBlock);
       }
       if (changeMade) {
         // The state or gen-stamp of the block has changed. So, we may be
@@ -1049,7 +1050,7 @@ public class FSEditLogLoader {
           // TODO: shouldn't this only be true for the last block?
           // what about an old-version fsync() where fsync isn't called
           // until several blocks in?
-          newBI = new BlockInfoContiguousUnderConstruction(
+          newBI = new BlockInfoUnderConstructionContiguous(
               newBlock, file.getPreferredBlockReplication());
         } else {
           // OP_CLOSE should add finalized blocks. This code path

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

@@ -54,7 +54,7 @@ import org.apache.hadoop.hdfs.protocol.LayoutVersion;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion.Feature;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
@@ -777,8 +777,9 @@ public class FSImageFormat {
             // convert the last block to BlockUC
             if (blocks.length > 0) {
               BlockInfo lastBlk = blocks[blocks.length - 1];
-              blocks[blocks.length - 1] = new BlockInfoContiguousUnderConstruction(
-                  lastBlk, replication);
+              blocks[blocks.length - 1] =
+                  new BlockInfoUnderConstructionContiguous(
+                      lastBlk, replication);
             }
           }
         }

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

@@ -44,7 +44,7 @@ import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.BlockProto;
 import org.apache.hadoop.hdfs.protocolPB.PBHelper;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf.LoaderContext;
 import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf.SaverContext;
@@ -364,8 +364,8 @@ public final class FSImageFormatPBINode {
         if (blocks.length > 0) {
           BlockInfo lastBlk = file.getLastBlock();
           // replace the last block of file
-          file.setBlock(file.numBlocks() - 1, new BlockInfoContiguousUnderConstruction(
-              lastBlk, replication));
+          file.setBlock(file.numBlocks() - 1,
+              new BlockInfoUnderConstructionContiguous(lastBlk, replication));
         }
       }
       return file;

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

@@ -35,7 +35,7 @@ import org.apache.hadoop.hdfs.protocol.CachePoolInfo;
 import org.apache.hadoop.hdfs.protocol.LayoutVersion;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotFSImageFormat;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotFSImageFormat.ReferenceMap;
@@ -137,7 +137,7 @@ public class FSImageSerialization {
     // last block is UNDER_CONSTRUCTION
     if(numBlocks > 0) {
       blk.readFields(in);
-      blocks[i] = new BlockInfoContiguousUnderConstruction(
+      blocks[i] = new BlockInfoUnderConstructionContiguous(
         blk, blockReplication, BlockUCState.UNDER_CONSTRUCTION, null);
     }
     PermissionStatus perm = PermissionStatus.read(in);

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

@@ -204,7 +204,8 @@ import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretMan
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockCollection;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockIdManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager;
@@ -2003,7 +2004,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     final BlockInfo last = file.getLastBlock();
     if (last != null && last.getBlockUCState() == BlockUCState.UNDER_RECOVERY) {
       final Block truncateBlock
-          = ((BlockInfoContiguousUnderConstruction)last).getTruncateBlock();
+          = ((BlockInfoUnderConstruction)last).getTruncateBlock();
       if (truncateBlock != null) {
         final long truncateLength = file.computeFileSize(false, false)
             + truncateBlock.getNumBytes();
@@ -2082,11 +2083,11 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
               nextGenerationStamp(blockIdManager.isLegacyBlock(oldBlock)));
     }
 
-    BlockInfoContiguousUnderConstruction truncatedBlockUC;
+    BlockInfoUnderConstruction truncatedBlockUC;
     if(shouldCopyOnTruncate) {
       // Add new truncateBlock into blocksMap and
       // use oldBlock as a source for copy-on-truncate recovery
-      truncatedBlockUC = new BlockInfoContiguousUnderConstruction(newBlock,
+      truncatedBlockUC = new BlockInfoUnderConstructionContiguous(newBlock,
           file.getPreferredBlockReplication());
       truncatedBlockUC.setNumBytes(oldBlock.getNumBytes() - lastBlockDelta);
       truncatedBlockUC.setTruncateBlock(oldBlock);
@@ -2102,7 +2103,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       blockManager.convertLastBlockToUnderConstruction(file, lastBlockDelta);
       oldBlock = file.getLastBlock();
       assert !oldBlock.isComplete() : "oldBlock should be under construction";
-      truncatedBlockUC = (BlockInfoContiguousUnderConstruction) oldBlock;
+      truncatedBlockUC = (BlockInfoUnderConstruction) oldBlock;
       truncatedBlockUC.setTruncateBlock(new Block(oldBlock));
       truncatedBlockUC.getTruncateBlock().setNumBytes(
           oldBlock.getNumBytes() - lastBlockDelta);
@@ -3519,7 +3520,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       throw new AlreadyBeingCreatedException(message);
     case UNDER_CONSTRUCTION:
     case UNDER_RECOVERY:
-      final BlockInfoContiguousUnderConstruction uc = (BlockInfoContiguousUnderConstruction)lastBlock;
+      final BlockInfoUnderConstruction uc =
+          (BlockInfoUnderConstruction)lastBlock;
       // determine if last block was intended to be truncated
       Block recoveryBlock = uc.getTruncateBlock();
       boolean truncateRecovery = recoveryBlock != null;
@@ -3635,7 +3637,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
   
   @Override
-  public boolean isInSnapshot(BlockInfoContiguousUnderConstruction blockUC) {
+  public boolean isInSnapshot(BlockInfoUnderConstruction blockUC) {
     assert hasReadLock();
     final BlockCollection bc = blockUC.getBlockCollection();
     if (bc == null || !(bc instanceof INodeFile)
@@ -3682,7 +3684,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     waitForLoadingFSImage();
     writeLock();
     boolean copyTruncate = false;
-    BlockInfoContiguousUnderConstruction truncatedBlock = null;
+    BlockInfoUnderConstruction truncatedBlock = null;
     try {
       checkOperation(OperationCategory.WRITE);
       // If a DN tries to commit to the standby, the recovery will
@@ -3739,7 +3741,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
         return;
       }
 
-      truncatedBlock = (BlockInfoContiguousUnderConstruction) iFile
+      truncatedBlock = (BlockInfoUnderConstruction) iFile
           .getLastBlock();
       long recoveryId = truncatedBlock.getBlockRecoveryId();
       copyTruncate = truncatedBlock.getBlockId() != storedBlock.getBlockId();
@@ -5774,8 +5776,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     assert hasWriteLock();
     // check the vadility of the block and lease holder name
     final INodeFile pendingFile = checkUCBlock(oldBlock, clientName);
-    final BlockInfoContiguousUnderConstruction blockinfo
-        = (BlockInfoContiguousUnderConstruction)pendingFile.getLastBlock();
+    final BlockInfoUnderConstruction blockinfo
+        = (BlockInfoUnderConstruction)pendingFile.getLastBlock();
 
     // check new GS & length: this is not expected
     if (newBlock.getGenerationStamp() <= blockinfo.getGenerationStamp() ||

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

@@ -21,7 +21,7 @@ import java.io.IOException;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
 
 /**
@@ -61,7 +61,7 @@ public class FileUnderConstructionFeature implements INode.Feature {
     BlockInfo lastBlock = f.getLastBlock();
     assert (lastBlock != null) : "The last block for path "
         + f.getFullPathName() + " is null when updating its length";
-    assert (lastBlock instanceof BlockInfoContiguousUnderConstruction)
+    assert (lastBlock instanceof BlockInfoUnderConstruction)
         : "The last block for path " + f.getFullPathName()
             + " is not a BlockInfoUnderConstruction when updating its length";
     lastBlock.setNumBytes(lastBlockLength);
@@ -76,9 +76,9 @@ public class FileUnderConstructionFeature implements INode.Feature {
       final BlocksMapUpdateInfo collectedBlocks) {
     final BlockInfo[] blocks = f.getBlocks();
     if (blocks != null && blocks.length > 0
-        && blocks[blocks.length - 1] instanceof BlockInfoContiguousUnderConstruction) {
-      BlockInfoContiguousUnderConstruction lastUC =
-          (BlockInfoContiguousUnderConstruction) blocks[blocks.length - 1];
+        && blocks[blocks.length - 1] instanceof BlockInfoUnderConstruction) {
+      BlockInfoUnderConstruction lastUC =
+          (BlockInfoUnderConstruction) blocks[blocks.length - 1];
       if (lastUC.getNumBytes() == 0) {
         // this is a 0-sized block. do not need check its UC state here
         collectedBlocks.addDeleteBlock(lastUC);

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

@@ -37,7 +37,7 @@ import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockCollection;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
@@ -231,7 +231,7 @@ public class INodeFile extends INodeWithAdditionalFields
   }
 
   @Override // BlockCollection, the file should be under construction
-  public BlockInfoContiguousUnderConstruction setLastBlock(
+  public BlockInfoUnderConstruction setLastBlock(
       BlockInfo lastBlock, DatanodeStorageInfo[] locations)
       throws IOException {
     Preconditions.checkState(isUnderConstruction(),
@@ -240,7 +240,7 @@ public class INodeFile extends INodeWithAdditionalFields
     if (numBlocks() == 0) {
       throw new IOException("Failed to set last block: File is empty.");
     }
-    BlockInfoContiguousUnderConstruction ucBlock =
+    BlockInfoUnderConstruction ucBlock =
       lastBlock.convertToBlockUnderConstruction(
           BlockUCState.UNDER_CONSTRUCTION, locations);
     setBlock(numBlocks() - 1, ucBlock);
@@ -251,7 +251,7 @@ public class INodeFile extends INodeWithAdditionalFields
    * Remove a block from the block list. This block should be
    * the last one on the list.
    */
-  BlockInfoContiguousUnderConstruction removeLastBlock(Block oldblock) {
+  BlockInfoUnderConstruction removeLastBlock(Block oldblock) {
     Preconditions.checkState(isUnderConstruction(),
         "file is no longer under construction");
     if (blocks == null || blocks.length == 0) {
@@ -262,8 +262,8 @@ public class INodeFile extends INodeWithAdditionalFields
       return null;
     }
 
-    BlockInfoContiguousUnderConstruction uc =
-        (BlockInfoContiguousUnderConstruction)blocks[size_1];
+    BlockInfoUnderConstruction uc =
+        (BlockInfoUnderConstruction)blocks[size_1];
     //copy to a new list
     BlockInfo[] newlist = new BlockInfo[size_1];
     System.arraycopy(blocks, 0, newlist, 0, size_1);
@@ -689,7 +689,7 @@ public class INodeFile extends INodeWithAdditionalFields
     final int last = blocks.length - 1;
     //check if the last block is BlockInfoUnderConstruction
     long size = blocks[last].getNumBytes();
-    if (blocks[last] instanceof BlockInfoContiguousUnderConstruction) {
+    if (blocks[last] instanceof BlockInfoUnderConstruction) {
        if (!includesLastUcBlock) {
          size = 0;
        } else if (usePreferredBlockSize4LastUcBlock) {

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

@@ -19,7 +19,7 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.hdfs.protocol.Block;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.namenode.NameNode.OperationCategory;
 import org.apache.hadoop.hdfs.util.RwLock;
 import org.apache.hadoop.ipc.StandbyException;
@@ -45,5 +45,5 @@ public interface Namesystem extends RwLock, SafeMode {
 
   public void checkOperation(OperationCategory read) throws StandbyException;
 
-  public boolean isInSnapshot(BlockInfoContiguousUnderConstruction blockUC);
+  public boolean isInSnapshot(BlockInfoUnderConstruction blockUC);
 }

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

@@ -22,7 +22,7 @@ import java.util.List;
 
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.namenode.INode;
 import org.apache.hadoop.hdfs.server.namenode.INode.BlocksMapUpdateInfo;
@@ -133,7 +133,7 @@ public class FileDiffList extends
     Block dontRemoveBlock = null;
     if (lastBlock != null && lastBlock.getBlockUCState().equals(
         HdfsServerConstants.BlockUCState.UNDER_RECOVERY)) {
-      dontRemoveBlock = ((BlockInfoContiguousUnderConstruction) lastBlock)
+      dontRemoveBlock = ((BlockInfoUnderConstruction) lastBlock)
           .getTruncateBlock();
     }
     // Collect the remaining blocks of the file, ignoring truncate block

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DFSTestUtil.java

@@ -109,7 +109,7 @@ import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.BlockOpResponseP
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.security.token.block.ExportedBlockKeys;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
@@ -1612,9 +1612,9 @@ public class DFSTestUtil {
     BlockInfo storedBlock = bm0.getStoredBlock(blk.getLocalBlock());
     assertTrue("Block " + blk + " should be under construction, " +
         "got: " + storedBlock,
-        storedBlock instanceof BlockInfoContiguousUnderConstruction);
-    BlockInfoContiguousUnderConstruction ucBlock =
-      (BlockInfoContiguousUnderConstruction)storedBlock;
+        storedBlock instanceof BlockInfoUnderConstruction);
+    BlockInfoUnderConstruction ucBlock =
+      (BlockInfoUnderConstruction)storedBlock;
     // We expect that the replica with the most recent heart beat will be
     // the one to be in charge of the synchronization / recovery protocol.
     final DatanodeStorageInfo[] storages = ucBlock.getExpectedStorageLocations();

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockInfoUnderConstruction.java

@@ -23,7 +23,6 @@ import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.common.GenerationStamp;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
-import org.apache.hadoop.util.Time;
 import org.junit.Test;
 
 /**
@@ -40,7 +39,8 @@ public class TestBlockInfoUnderConstruction {
     DatanodeDescriptor dd3 = s3.getDatanodeDescriptor();
 
     dd1.isAlive = dd2.isAlive = dd3.isAlive = true;
-    BlockInfoContiguousUnderConstruction blockInfo = new BlockInfoContiguousUnderConstruction(
+    BlockInfoUnderConstruction blockInfo =
+        new BlockInfoUnderConstructionContiguous(
         new Block(0, 0, GenerationStamp.LAST_RESERVED_STAMP),
         (short) 3,
         BlockUCState.UNDER_CONSTRUCTION,
@@ -51,7 +51,7 @@ public class TestBlockInfoUnderConstruction {
     DFSTestUtil.resetLastUpdatesWithOffset(dd2, -1 * 1000);
     DFSTestUtil.resetLastUpdatesWithOffset(dd3, -2 * 1000);
     blockInfo.initializeBlockRecovery(1);
-    BlockInfoContiguousUnderConstruction[] blockInfoRecovery = dd2.getLeaseRecoveryCommand(1);
+    BlockInfoUnderConstruction[] blockInfoRecovery = dd2.getLeaseRecoveryCommand(1);
     assertEquals(blockInfoRecovery[0], blockInfo);
 
     // Recovery attempt #2.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockManager.java

@@ -726,7 +726,7 @@ public class TestBlockManager {
     // verify the storage info is correct
     assertTrue(bm.getStoredBlock(new Block(receivedBlockId)).findStorageInfo
         (ds) >= 0);
-    assertTrue(((BlockInfoContiguousUnderConstruction) bm.
+    assertTrue(((BlockInfoUnderConstruction) bm.
         getStoredBlock(new Block(receivingBlockId))).getNumExpectedLocations() > 0);
     assertTrue(bm.getStoredBlock(new Block(receivingReceivedBlockId))
         .findStorageInfo(ds) >= 0);
@@ -747,8 +747,8 @@ public class TestBlockManager {
 
   private BlockInfo addUcBlockToBM(long blkId) {
     Block block = new Block(blkId);
-    BlockInfoContiguousUnderConstruction blockInfo =
-        new BlockInfoContiguousUnderConstruction(block, (short) 3);
+    BlockInfoUnderConstruction blockInfo =
+        new BlockInfoUnderConstructionContiguous(block, (short) 3);
     BlockCollection bc = Mockito.mock(BlockCollection.class);
     Mockito.doReturn((short) 3).when(bc).getPreferredBlockReplication();
     bm.blocksMap.addBlockCollection(blockInfo, bc);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestHeartbeatHandling.java

@@ -39,7 +39,6 @@ import org.apache.hadoop.hdfs.server.protocol.DatanodeCommand;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
-import org.apache.hadoop.util.Time;
 import org.junit.Test;
 
 /**
@@ -173,7 +172,8 @@ public class TestHeartbeatHandling {
               dd1.getStorageInfos()[0],
               dd2.getStorageInfos()[0],
               dd3.getStorageInfos()[0]};
-          BlockInfoContiguousUnderConstruction blockInfo = new BlockInfoContiguousUnderConstruction(
+          BlockInfoUnderConstruction blockInfo =
+              new BlockInfoUnderConstructionContiguous(
               new Block(0, 0, GenerationStamp.LAST_RESERVED_STAMP), (short) 3,
               BlockUCState.UNDER_RECOVERY, storages);
           dd1.addBlockToBeRecovered(blockInfo);
@@ -195,7 +195,7 @@ public class TestHeartbeatHandling {
           // More than the default stale interval of 30 seconds.
           DFSTestUtil.resetLastUpdatesWithOffset(dd2, -40 * 1000);
           DFSTestUtil.resetLastUpdatesWithOffset(dd3, 0);
-          blockInfo = new BlockInfoContiguousUnderConstruction(
+          blockInfo = new BlockInfoUnderConstructionContiguous(
               new Block(0, 0, GenerationStamp.LAST_RESERVED_STAMP), (short) 3,
               BlockUCState.UNDER_RECOVERY, storages);
           dd1.addBlockToBeRecovered(blockInfo);
@@ -216,7 +216,7 @@ public class TestHeartbeatHandling {
           // More than the default stale interval of 30 seconds.
           DFSTestUtil.resetLastUpdatesWithOffset(dd2, - 40 * 1000);
           DFSTestUtil.resetLastUpdatesWithOffset(dd3, - 80 * 1000);
-          blockInfo = new BlockInfoContiguousUnderConstruction(
+          blockInfo = new BlockInfoUnderConstructionContiguous(
               new Block(0, 0, GenerationStamp.LAST_RESERVED_STAMP), (short) 3,
               BlockUCState.UNDER_RECOVERY, storages);
           dd1.addBlockToBeRecovered(blockInfo);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestReplicationPolicy.java

@@ -1176,7 +1176,8 @@ public class TestReplicationPolicy {
     // block under construction, the BlockManager will realize the expected
     // replication has been achieved and remove it from the under-replicated
     // queue.
-    BlockInfoContiguousUnderConstruction info = new BlockInfoContiguousUnderConstruction(block1, (short) 1);
+    BlockInfoUnderConstruction info =
+        new BlockInfoUnderConstructionContiguous(block1, (short) 1);
     BlockCollection bc = mock(BlockCollection.class);
     when(bc.getPreferredBlockReplication()).thenReturn((short)1);
     bm.addBlockCollection(info, bc);
@@ -1232,7 +1233,7 @@ public class TestReplicationPolicy {
 
     DatanodeStorageInfo[] storageAry = {new DatanodeStorageInfo(
         dataNodes[0], new DatanodeStorage("s1"))};
-    final BlockInfoContiguousUnderConstruction ucBlock =
+    final BlockInfoUnderConstruction ucBlock =
         info.convertToBlockUnderConstruction(BlockUCState.UNDER_CONSTRUCTION,
             storageAry);
     DatanodeStorageInfo storage = mock(DatanodeStorageInfo.class);

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

@@ -36,7 +36,7 @@ import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocols;
 import org.junit.AfterClass;
@@ -170,7 +170,7 @@ public class TestBlockUnderConstruction {
       final List<LocatedBlock> blocks = lb.getLocatedBlocks();
       assertEquals(i, blocks.size());
       final Block b = blocks.get(blocks.size() - 1).getBlock().getLocalBlock();
-      assertTrue(b instanceof BlockInfoContiguousUnderConstruction);
+      assertTrue(b instanceof BlockInfoUnderConstruction);
 
       if (++i < NUM_BLOCKS) {
         // write one more block

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

@@ -24,7 +24,8 @@ import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstructionContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.junit.Test;
@@ -68,8 +69,10 @@ public class TestCommitBlockSynchronization {
     namesystem.dir.getINodeMap().put(file);
 
     FSNamesystem namesystemSpy = spy(namesystem);
-    BlockInfoContiguousUnderConstruction blockInfo = new BlockInfoContiguousUnderConstruction(
-        block, (short) 1, HdfsServerConstants.BlockUCState.UNDER_CONSTRUCTION, targets);
+    BlockInfoUnderConstruction blockInfo =
+        new BlockInfoUnderConstructionContiguous(
+        block, (short) 1, HdfsServerConstants.BlockUCState.UNDER_CONSTRUCTION,
+            targets);
     blockInfo.setBlockCollection(file);
     blockInfo.setGenerationStamp(genStamp);
     blockInfo.initializeBlockRecovery(genStamp);

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

@@ -54,7 +54,7 @@ import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.security.UserGroupInformation;
@@ -1019,7 +1019,7 @@ public class TestFileTruncate {
           is(fsn.getBlockIdManager().getGenerationStampV2()));
       assertThat(file.getLastBlock().getBlockUCState(),
           is(HdfsServerConstants.BlockUCState.UNDER_RECOVERY));
-      long blockRecoveryId = ((BlockInfoContiguousUnderConstruction) file.getLastBlock())
+      long blockRecoveryId = ((BlockInfoUnderConstruction) file.getLastBlock())
           .getBlockRecoveryId();
       assertThat(blockRecoveryId, is(initialGenStamp + 1));
       fsn.getEditLog().logTruncate(
@@ -1052,7 +1052,7 @@ public class TestFileTruncate {
           is(fsn.getBlockIdManager().getGenerationStampV2()));
       assertThat(file.getLastBlock().getBlockUCState(),
           is(HdfsServerConstants.BlockUCState.UNDER_RECOVERY));
-      long blockRecoveryId = ((BlockInfoContiguousUnderConstruction) file.getLastBlock())
+      long blockRecoveryId = ((BlockInfoUnderConstruction) file.getLastBlock())
           .getBlockRecoveryId();
       assertThat(blockRecoveryId, is(initialGenStamp + 1));
       fsn.getEditLog().logTruncate(

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

@@ -72,7 +72,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.INodeFile;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.SnapshotTestHelper;
@@ -752,8 +752,8 @@ public class TestRetryCacheWithHA {
     boolean checkNamenodeBeforeReturn() throws Exception {
       INodeFile fileNode = cluster.getNamesystem(0).getFSDirectory()
           .getINode4Write(file).asFile();
-      BlockInfoContiguousUnderConstruction blkUC =
-          (BlockInfoContiguousUnderConstruction) (fileNode.getBlocks())[1];
+      BlockInfoUnderConstruction blkUC =
+          (BlockInfoUnderConstruction) (fileNode.getBlocks())[1];
       int datanodeNum = blkUC.getExpectedStorageLocations().length;
       for (int i = 0; i < CHECKTIMES && datanodeNum != 2; i++) {
         Thread.sleep(1000);

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

@@ -44,7 +44,7 @@ import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.datanode.BlockPoolSliceStorage;
 import org.apache.hadoop.hdfs.server.datanode.BlockScanner;
@@ -177,7 +177,7 @@ public class SnapshotTestHelper {
    * Specific information for different types of INode: 
    * {@link INodeDirectory}:childrenSize 
    * {@link INodeFile}: fileSize, block list. Check {@link BlockInfo#toString()}
-   * and {@link BlockInfoContiguousUnderConstruction#toString()} for detailed information.
+   * and {@link BlockInfoUnderConstruction#toString()} for detailed information.
    * {@link FileWithSnapshot}: next link
    * </pre>
    * @see INode#dumpTreeRecursively()