Package org.apache.hadoop.hdfs.server.common.blockaliasmap.impl

Class InMemoryLevelDBAliasMapClient

java.lang.Object

org.apache.hadoop.hdfs.server.common.blockaliasmap.BlockAliasMap<FileRegion>

org.apache.hadoop.hdfs.server.common.blockaliasmap.impl.InMemoryLevelDBAliasMapClient

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable

@Private
@Unstable
public class InMemoryLevelDBAliasMapClient
extends BlockAliasMap<FileRegion>
implements org.apache.hadoop.conf.Configurable

InMemoryLevelDBAliasMapClient is the client for the InMemoryAliasMapServer. This is used by the Datanode and fs2img to store and retrieve FileRegions based on the given Block.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hdfs.server.common.blockaliasmap.BlockAliasMap

BlockAliasMap.ImmutableIterator, BlockAliasMap.Reader<U extends BlockAlias>, BlockAliasMap.Writer<U extends BlockAlias>

Method Summary

Modifier and Type	Method	Description
void	close()
org.apache.hadoop.conf.Configuration	getConf()
BlockAliasMap.Reader<FileRegion>	getReader(BlockAliasMap.Reader.Options opts, String blockPoolID)	Returns a reader to the alias map.
BlockAliasMap.Writer<FileRegion>	getWriter(BlockAliasMap.Writer.Options opts, String blockPoolID)	Returns the writer for the alias map.
void	refresh()	Refresh the alias map.
void	setConf(org.apache.hadoop.conf.Configuration conf)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

close

public void close()

Specified by:

close in class BlockAliasMap<FileRegion>

getReader

public BlockAliasMap.Reader<FileRegion> getReader(BlockAliasMap.Reader.Options opts,
 String blockPoolID)
                                           throws IOException

Description copied from class: BlockAliasMap

Returns a reader to the alias map.

Specified by:

getReader in class BlockAliasMap<FileRegion>

Parameters:

opts - reader options

blockPoolID - block pool id to use

Returns:

BlockAliasMap.Reader to the alias map. If a Reader for the blockPoolID cannot be created, this will return null.

Throws:

IOException

getWriter

public BlockAliasMap.Writer<FileRegion> getWriter(BlockAliasMap.Writer.Options opts,
 String blockPoolID)
                                           throws IOException

Description copied from class: BlockAliasMap

Returns the writer for the alias map.

Specified by:

getWriter in class BlockAliasMap<FileRegion>

Parameters:

opts - writer options.

blockPoolID - block pool id to use

Returns:

BlockAliasMap.Writer to the alias map.

Throws:

IOException

setConf

public void setConf(org.apache.hadoop.conf.Configuration conf)

Specified by:

setConf in interface org.apache.hadoop.conf.Configurable

getConf

public org.apache.hadoop.conf.Configuration getConf()

Specified by:

getConf in interface org.apache.hadoop.conf.Configurable

refresh

public void refresh()
             throws IOException

Description copied from class: BlockAliasMap

Refresh the alias map.

Specified by:

refresh in class BlockAliasMap<FileRegion>

Throws:

IOException