org.apache.hadoop.hdfs.server.datanode
Class ReplicaInPipeline

java.lang.Object
  org.apache.hadoop.hdfs.protocol.Block
      org.apache.hadoop.hdfs.server.datanode.ReplicaInfo
          org.apache.hadoop.hdfs.server.datanode.ReplicaInPipeline

All Implemented Interfaces:

Comparable<org.apache.hadoop.hdfs.protocol.Block>, org.apache.hadoop.hdfs.server.datanode.Replica, ReplicaInPipelineInterface, org.apache.hadoop.io.Writable

Direct Known Subclasses:

ReplicaBeingWritten

public class ReplicaInPipeline
extends org.apache.hadoop.hdfs.server.datanode.ReplicaInfo
implements ReplicaInPipelineInterface

This class defines a replica in a pipeline, which includes a persistent replica being written to by a dfs client or a temporary replica being replicated by a source datanode or being copied for the balancing purpose. The base class implements a temporary replica

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.datanode.ReplicaInfo

ReplicaInfo.ReplicaDirInfo

Field Summary

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

BLOCK_FILE_PREFIX, blockFilePattern, METADATA_EXTENSION, metaFilePattern

Constructor Summary

ReplicaInPipeline(long blockId, long genStamp, FsVolumeSpi vol, File dir)
Constructor for a zero length replica

ReplicaInPipeline(ReplicaInPipeline from)
Copy constructor.

Method Summary

ReplicaOutputStreams	createStreams(boolean isCreate, org.apache.hadoop.util.DataChecksum requestedChecksum) Create output streams for writing to this replica, one for block file and one for CRC file
boolean	equals(Object o)
long	getBytesAcked() Get the number of bytes acked
long	getBytesOnDisk() Get the number of bytes that have written to disk
org.apache.hadoop.hdfs.server.datanode.ChunkChecksum	getLastChecksumAndDataLen() gets the last chunk checksum and the length of the block corresponding to that checksum
HdfsServerConstants.ReplicaState	getState() Get the replica state
long	getVisibleLength() Get the number of bytes that are visible to readers
int	hashCode()
void	setBytesAcked(long bytesAcked) Set the number bytes that have acked
void	setLastChecksumAndDataLen(long dataLength, byte[] lastChecksum) store the checksum for the last chunk along with the data length
void	setWriter(Thread writer) Set the thread that is writing to this replica
void	stopWriter(long xceiverStopTimeout) Interrupt the writing thread and wait until it dies
String	toString()

Methods inherited from class org.apache.hadoop.hdfs.server.datanode.ReplicaInfo

getBlockFile, getMetaFile, getVolume, isUnlinked, parseSubDirs, setDir, setUnlinked, unlinkBlock

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hdfs.server.datanode.ReplicaInPipelineInterface

setNumBytes

Methods inherited from interface org.apache.hadoop.hdfs.server.datanode.Replica

getBlockId, getGenerationStamp, getNumBytes

Constructor Detail

ReplicaInPipeline

public ReplicaInPipeline(long blockId,
                         long genStamp,
                         FsVolumeSpi vol,
                         File dir)

Constructor for a zero length replica

Parameters:

blockId - block id

genStamp - replica generation stamp

vol - volume where replica is located

dir - directory path where block and meta files are located

ReplicaInPipeline

public ReplicaInPipeline(ReplicaInPipeline from)

Copy constructor.

Parameters:

from -

Method Detail

getVisibleLength

public long getVisibleLength()

Description copied from interface: org.apache.hadoop.hdfs.server.datanode.Replica

Get the number of bytes that are visible to readers

Specified by:

getVisibleLength in interface org.apache.hadoop.hdfs.server.datanode.Replica

Returns:

the number of bytes that are visible to readers

getState

public HdfsServerConstants.ReplicaState getState()

Description copied from interface: org.apache.hadoop.hdfs.server.datanode.Replica

Get the replica state

Specified by:

getState in interface org.apache.hadoop.hdfs.server.datanode.Replica

Returns:

the replica state

getBytesAcked

public long getBytesAcked()

Description copied from interface: ReplicaInPipelineInterface

Get the number of bytes acked

Specified by:

getBytesAcked in interface ReplicaInPipelineInterface

Returns:

the number of bytes acked

setBytesAcked

public void setBytesAcked(long bytesAcked)

Description copied from interface: ReplicaInPipelineInterface

Set the number bytes that have acked

Specified by:

setBytesAcked in interface ReplicaInPipelineInterface

getBytesOnDisk

public long getBytesOnDisk()

Description copied from interface: org.apache.hadoop.hdfs.server.datanode.Replica

Get the number of bytes that have written to disk

Specified by:

getBytesOnDisk in interface org.apache.hadoop.hdfs.server.datanode.Replica

Returns:

the number of bytes that have written to disk

setLastChecksumAndDataLen

public void setLastChecksumAndDataLen(long dataLength,
                                      byte[] lastChecksum)

Description copied from interface: ReplicaInPipelineInterface

store the checksum for the last chunk along with the data length

Specified by:

setLastChecksumAndDataLen in interface ReplicaInPipelineInterface

Parameters:

dataLength - number of bytes on disk

lastChecksum - - checksum bytes for the last chunk

getLastChecksumAndDataLen

public org.apache.hadoop.hdfs.server.datanode.ChunkChecksum getLastChecksumAndDataLen()

Description copied from interface: ReplicaInPipelineInterface

gets the last chunk checksum and the length of the block corresponding to that checksum

Specified by:

getLastChecksumAndDataLen in interface ReplicaInPipelineInterface

setWriter

public void setWriter(Thread writer)

Set the thread that is writing to this replica

Parameters:

writer - a thread writing to this replica

equals

public boolean equals(Object o)

Overrides:

equals in class org.apache.hadoop.hdfs.protocol.Block

stopWriter

public void stopWriter(long xceiverStopTimeout)
                throws IOException

Interrupt the writing thread and wait until it dies

Throws:

IOException - the waiting is interrupted

hashCode

public int hashCode()

Overrides:

hashCode in class org.apache.hadoop.hdfs.protocol.Block

createStreams

public ReplicaOutputStreams createStreams(boolean isCreate,
                                          org.apache.hadoop.util.DataChecksum requestedChecksum)
                                   throws IOException

Description copied from interface: ReplicaInPipelineInterface

Create output streams for writing to this replica, one for block file and one for CRC file

Specified by:

createStreams in interface ReplicaInPipelineInterface

Parameters:

isCreate - if it is for creation

requestedChecksum - the checksum the writer would prefer to use

Returns:

output streams for writing

Throws:

IOException - if any error occurs

toString

public String toString()

Overrides:

toString in class org.apache.hadoop.hdfs.server.datanode.ReplicaInfo