Package org.apache.hadoop.io.erasurecode.grouper

Class BlockGrouper

java.lang.Object

org.apache.hadoop.io.erasurecode.grouper.BlockGrouper

@Private
public class BlockGrouper
extends java.lang.Object

As part of a codec, to handle how to form a block group for encoding and provide instructions on how to recover erased blocks from a block group

Constructor Summary

Constructors

Constructor	Description
BlockGrouper()

Method Summary

Modifier and Type	Method	Description
boolean	anyRecoverable(ECBlockGroup blockGroup)	Given a BlockGroup, tell if any of the missing blocks can be recovered, to be called by ECManager
int	getRequiredNumDataBlocks()	Get required data blocks count in a BlockGroup.
int	getRequiredNumParityBlocks()	Get required parity blocks count in a BlockGroup.
protected ECSchema	getSchema()	Get EC schema.
ECBlockGroup	makeBlockGroup(ECBlock[] dataBlocks, ECBlock[] parityBlocks)	Calculating and organizing BlockGroup, to be called by ECManager
void	setSchema(ECSchema schema)	Set EC schema.

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockGrouper

public BlockGrouper()

Method Detail

setSchema

public void setSchema(ECSchema schema)

Set EC schema.

Parameters:

schema - schema.

getSchema

protected ECSchema getSchema()

Get EC schema.

Returns:

ECSchema.

getRequiredNumDataBlocks

public int getRequiredNumDataBlocks()

Get required data blocks count in a BlockGroup.

Returns:

count of required data blocks

getRequiredNumParityBlocks

public int getRequiredNumParityBlocks()

Get required parity blocks count in a BlockGroup.

Returns:

count of required parity blocks

makeBlockGroup

public ECBlockGroup makeBlockGroup(ECBlock[] dataBlocks,
                                   ECBlock[] parityBlocks)

Calculating and organizing BlockGroup, to be called by ECManager

Parameters:

dataBlocks - Data blocks to compute parity blocks against

parityBlocks - To be computed parity blocks

Returns:

ECBlockGroup.

anyRecoverable

public boolean anyRecoverable(ECBlockGroup blockGroup)

Given a BlockGroup, tell if any of the missing blocks can be recovered, to be called by ECManager

Parameters:

blockGroup - a blockGroup that may contain erased blocks but not sure recoverable or not

Returns:

true if any erased block recoverable, false otherwise