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:

java.lang.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 Summary

Fields

Modifier and Type	Field	Description
static BlockInfo[]	EMPTY_ARRAY
protected java.lang.Object[]	triplets	This array contains triplets of references.

Fields inherited from class org.apache.hadoop.hdfs.protocol.Block

BLOCK_FILE_PREFIX, blockFilePattern, METADATA_EXTENSION, metaFilePattern, metaOrBlockFilePattern

Constructor Summary

Constructors

Constructor	Description
BlockInfo(short size)	Construct an entry for blocksmap
BlockInfo(org.apache.hadoop.hdfs.protocol.Block blk, short size)

Method Summary

Modifier and Type	Method	Description
void	convertToBlockUnderConstruction(HdfsServerConstants.BlockUCState s, DatanodeStorageInfo[] targets)	Add/Update the under construction feature.
void	delete()
boolean	equals(java.lang.Object obj)
long	getBlockCollectionId()
abstract org.apache.hadoop.hdfs.protocol.BlockType	getBlockType()
HdfsServerConstants.BlockUCState	getBlockUCState()
int	getCapacity()
DatanodeDescriptor	getDatanode(int index)
org.apache.hadoop.util.LightWeightGSet.LinkedElement	getNext()
short	getReplication()
java.util.Iterator<DatanodeStorageInfo>	getStorageInfos()
BlockUnderConstructionFeature	getUnderConstructionFeature()
int	hashCode()
boolean	isComplete()	Is this block complete?
boolean	isCompleteOrCommitted()
boolean	isDeleted()
abstract boolean	isStriped()
boolean	isUnderRecovery()
BlockInfo	moveBlockToHead(BlockInfo head, DatanodeStorageInfo storage, int curIndex, int headIndex)	Remove this block from the list of blocks related to the specified DatanodeDescriptor.
abstract int	numNodes()	Count the number of data-nodes the block currently belongs to (i.e., NN has received block reports from the DN).
void	setBlockCollectionId(long id)
java.util.List<org.apache.hadoop.hdfs.server.blockmanagement.ReplicaUnderConstruction>	setGenerationStampAndVerifyReplicas(long genStamp)	Process the recorded replicas.
void	setNext(org.apache.hadoop.util.LightWeightGSet.LinkedElement next)
void	setReplication(short repl)

Methods inherited from class org.apache.hadoop.hdfs.protocol.Block

appendStringTo, compareTo, filename2id, getBlockId, getBlockId, getBlockName, getGenerationStamp, getGenerationStamp, getNumBytes, isBlockFilename, isMetaFilename, matchingIdAndGenStamp, metaToBlockFile, readFields, readId, set, setBlockId, setGenerationStamp, setNumBytes, toString, toString, write, writeId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_ARRAY

public static final BlockInfo[] EMPTY_ARRAY

triplets

protected java.lang.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 Detail

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 Detail

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 java.util.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(java.lang.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 java.util.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.