Package org.apache.hadoop.io.erasurecode

Class ECSchema

java.lang.Object

org.apache.hadoop.io.erasurecode.ECSchema

All Implemented Interfaces:

Serializable

@Public
@Evolving
public final class ECSchema
extends Object
implements Serializable

Erasure coding schema to housekeeper relevant information.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CODEC_NAME_KEY
static final String	NUM_DATA_UNITS_KEY
static final String	NUM_PARITY_UNITS_KEY

Constructor Summary

Constructors

Constructor	Description
ECSchema(String codecName, int numDataUnits, int numParityUnits)	Constructor with key parameters provided.
ECSchema(String codecName, int numDataUnits, int numParityUnits, Map<String,String> extraOptions)	Constructor with key parameters provided.
ECSchema(Map<String,String> allOptions)	Constructor with schema name and provided all options.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
String	getCodecName()	Get the codec name
Map<String,String>	getExtraOptions()	Get extra options specific to an erasure code.
int	getNumDataUnits()	Get required data units count in a coding group
int	getNumParityUnits()	Get required parity units count in a coding group
int	hashCode()
String	toString()	Make a meaningful string representation for log output.

Methods inherited from class java.lang.Object

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

Field Details

NUM_DATA_UNITS_KEY

public static final String NUM_DATA_UNITS_KEY

See Also:

• Constant Field Values

NUM_PARITY_UNITS_KEY

public static final String NUM_PARITY_UNITS_KEY

See Also:

• Constant Field Values

CODEC_NAME_KEY

public static final String CODEC_NAME_KEY

See Also:

• Constant Field Values

Constructor Details

ECSchema

public ECSchema(Map<String,String> allOptions)

Constructor with schema name and provided all options. Note the options may contain additional information for the erasure codec to interpret further.

Parameters:

allOptions - all schema options

ECSchema

public ECSchema(String codecName,
 int numDataUnits,
 int numParityUnits)

Constructor with key parameters provided.

Parameters:

codecName - codec name

numDataUnits - number of data units used in the schema

numParityUnits - number os parity units used in the schema

ECSchema

public ECSchema(String codecName,
 int numDataUnits,
 int numParityUnits,
 Map<String,String> extraOptions)

Constructor with key parameters provided. Note the extraOptions may contain additional information for the erasure codec to interpret further.

Parameters:

codecName - codec name

numDataUnits - number of data units used in the schema

numParityUnits - number os parity units used in the schema

extraOptions - extra options to configure the codec

Method Details

getCodecName

public String getCodecName()

Get the codec name

Returns:

codec name

getExtraOptions

public Map<String,String> getExtraOptions()

Get extra options specific to an erasure code.

Returns:

extra options

getNumDataUnits

public int getNumDataUnits()

Get required data units count in a coding group

Returns:

count of data units

getNumParityUnits

public int getNumParityUnits()

Get required parity units count in a coding group

Returns:

count of parity units

toString

public String toString()

Make a meaningful string representation for log output.

Overrides:

toString in class Object

Returns:

string representation

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object