Package org.apache.hadoop.hdfs.server.blockmanagement

Class BlockInfo

java.lang.Object
org.apache.hadoop.hdfs.protocol.Block
org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo
All Implemented Interfaces:
Comparable<org.apache.hadoop.hdfs.protocol.Block>, org.apache.hadoop.io.Writable, org.apache.hadoop.util.LightWeightGSet.LinkedElement
Direct Known Subclasses:
BlockInfoContiguous, BlockInfoStriped
@Private public abstract class BlockInfo extends org.apache.hadoop.hdfs.protocol.Block implements org.apache.hadoop.util.LightWeightGSet.LinkedElement
For a given block (or an erasure coding block group), BlockInfo class maintains 1) the BlockCollection it is part of, and 2) datanodes where the replicas of the block, or blocks belonging to the erasure coding block group, are stored.

  • Field Details

    • EMPTY_ARRAY

      public static final BlockInfo[] EMPTY_ARRAY

    • triplets

      protected Object[] triplets
      This array contains triplets of references. For each i-th storage, the block belongs to triplets[3*i] is the reference to the DatanodeStorageInfo and triplets[3*i+1] and triplets[3*i+2] are references to the previous and the next blocks, respectively, in the list of blocks belonging to this storage. Using previous and next in Object triplets is done instead of a LinkedList list to efficiently use memory. With LinkedList the cost per replica is 42 bytes (LinkedList#Entry object per replica) versus 16 bytes using the triplets.

  • Constructor Details

    • BlockInfo

      public BlockInfo(short size)
      Construct an entry for blocksmap
      Parameters:
      size - the block's replication factor, or the total number of blocks in the block group

    • BlockInfo

      public BlockInfo(org.apache.hadoop.hdfs.protocol.Block blk, short size)

  • Method Details

    • getReplication

      public short getReplication()

    • setReplication

      public void setReplication(short repl)

    • getBlockCollectionId

      public long getBlockCollectionId()

    • setBlockCollectionId

      public void setBlockCollectionId(long id)

    • delete

      public void delete()

    • isDeleted

      public boolean isDeleted()

    • getStorageInfos

      public Iterator<DatanodeStorageInfo> getStorageInfos()

    • getDatanode

      public DatanodeDescriptor getDatanode(int index)

    • getCapacity

      public int getCapacity()

    • numNodes

      public abstract int numNodes()
      Count the number of data-nodes the block currently belongs to (i.e., NN has received block reports from the DN).

    • isStriped

      public abstract boolean isStriped()

    • getBlockType

      public abstract org.apache.hadoop.hdfs.protocol.BlockType getBlockType()

    • moveBlockToHead

      public BlockInfo moveBlockToHead(BlockInfo head, DatanodeStorageInfo storage, int curIndex, int headIndex)
      Remove this block from the list of blocks related to the specified DatanodeDescriptor. Insert it into the head of the list of blocks.
      Returns:
      the new head of the list.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class org.apache.hadoop.hdfs.protocol.Block

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class org.apache.hadoop.hdfs.protocol.Block

    • getNext

      public org.apache.hadoop.util.LightWeightGSet.LinkedElement getNext()
      Specified by:
      getNext in interface org.apache.hadoop.util.LightWeightGSet.LinkedElement

    • setNext

      public void setNext(org.apache.hadoop.util.LightWeightGSet.LinkedElement next)
      Specified by:
      setNext in interface org.apache.hadoop.util.LightWeightGSet.LinkedElement

    • getUnderConstructionFeature

      public BlockUnderConstructionFeature getUnderConstructionFeature()

    • getBlockUCState

      public HdfsServerConstants.BlockUCState getBlockUCState()

    • isComplete

      public boolean isComplete()
      Is this block complete?
      Returns:
      true if the state of the block is HdfsServerConstants.BlockUCState.COMPLETE

    • isUnderRecovery

      public boolean isUnderRecovery()

    • isCompleteOrCommitted

      public final boolean isCompleteOrCommitted()

    • convertToBlockUnderConstruction

      public void convertToBlockUnderConstruction(HdfsServerConstants.BlockUCState s, DatanodeStorageInfo[] targets)
      Add/Update the under construction feature.

    • setGenerationStampAndVerifyReplicas

      public List<org.apache.hadoop.hdfs.server.blockmanagement.ReplicaUnderConstruction> setGenerationStampAndVerifyReplicas(long genStamp)
      Process the recorded replicas. When about to commit or finish the pipeline recovery sort out bad replicas.
      Parameters:
      genStamp - The final generation stamp for the block.
      Returns:
      staleReplica's List.