org.apache.hadoop.hbase.client.coprocessor

Class LongColumnInterpreter

java.lang.Object

org.apache.hadoop.hbase.coprocessor.ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

org.apache.hadoop.hbase.client.coprocessor.LongColumnInterpreter

@InterfaceAudience.Private
public class LongColumnInterpreter
extends ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

a concrete column interpreter implementation. The cell value is a Long value and its promoted data type is also a Long value. For computing aggregation function, this class is used to find the datatype of the cell value. Client is supposed to instantiate it and passed along as a parameter. See TestAggregateProtocol methods for its sample usage. Its methods handle null arguments gracefully.

Constructor Summary

Constructors

Constructor and Description
LongColumnInterpreter()

Method Summary

Methods

Modifier and Type	Method and Description
Long	add(Long l1, Long l2)
Long	castToCellType(Long l) The response message comes as type S.
Long	castToReturnType(Long o) provides casting opportunity between the data types.
int	compare(Long l1, Long l2) This takes care if either of arguments are null.
double	divideForAvg(Long l1, Long l2) used for computing average of data values.
Long	getCellValueFromProto(HBaseProtos.LongMsg q) This method gets the PB message corresponding to the cell type
Long	getMaxValue() returns the maximum value for this type T
Long	getMinValue()
Long	getPromotedValueFromProto(HBaseProtos.LongMsg r) This method gets the promoted type from the proto message
HBaseProtos.LongMsg	getProtoForCellType(Long t) This method gets the PB message corresponding to the cell type
HBaseProtos.LongMsg	getProtoForPromotedType(Long s) This method gets the PB message corresponding to the promoted type
HBaseProtos.EmptyMsg	getRequestData() This method should return any additional data that is needed on the server side to construct the ColumnInterpreter.
Long	getValue(byte[] colFamily, byte[] colQualifier, Cell kv)
Long	increment(Long o)
void	initialize(HBaseProtos.EmptyMsg msg) This method should initialize any field(s) of the ColumnInterpreter with a parsing of the passed message bytes (used on the server side).
Long	multiply(Long l1, Long l2)

Methods inherited from class java.lang.Object

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

Constructor Detail

LongColumnInterpreter

public LongColumnInterpreter()

Method Detail

getValue

public Long getValue(byte[] colFamily,
            byte[] colQualifier,
            Cell kv)
              throws IOException

Specified by:

getValue in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

value of type T

Throws:

IOException

add

public Long add(Long l1,
       Long l2)

Specified by:

add in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

sum or non null value among (if either of them is null); otherwise returns a null.

compare

public int compare(Long l1,
          Long l2)

Description copied from class: ColumnInterpreter

This takes care if either of arguments are null. returns 0 if they are equal or both are null;

• >0 if l1 > l2 or l1 is not null and l2 is null.
• < 0 if l1 < l2 or l1 is null and l2 is not null.

Specified by:

compare in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

getMaxValue

public Long getMaxValue()

Description copied from class: ColumnInterpreter

returns the maximum value for this type T

Specified by:

getMaxValue in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

max

increment

public Long increment(Long o)

Specified by:

increment in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

increment

multiply

public Long multiply(Long l1,
            Long l2)

Specified by:

multiply in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

multiplication

getMinValue

public Long getMinValue()

Specified by:

getMinValue in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

divideForAvg

public double divideForAvg(Long l1,
                  Long l2)

Description copied from class: ColumnInterpreter

used for computing average of data values. Not providing the divide method that takes two values as it is not needed as of now.

Specified by:

divideForAvg in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

Average

castToReturnType

public Long castToReturnType(Long o)

Description copied from class: ColumnInterpreter

provides casting opportunity between the data types.

Specified by:

castToReturnType in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

cast

castToCellType

public Long castToCellType(Long l)

Description copied from class: ColumnInterpreter

The response message comes as type S. This will convert/cast it to T. In some sense, performs the opposite of ColumnInterpreter.castToReturnType(Object)

Specified by:

castToCellType in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

cast

getRequestData

public HBaseProtos.EmptyMsg getRequestData()

Description copied from class: ColumnInterpreter

This method should return any additional data that is needed on the server side to construct the ColumnInterpreter. The server will pass this to the ColumnInterpreter.initialize(P) method. If there is no ColumnInterpreter specific data (for e.g., LongColumnInterpreter) then null should be returned.

Specified by:

getRequestData in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

the PB message

initialize

public void initialize(HBaseProtos.EmptyMsg msg)

Description copied from class: ColumnInterpreter

This method should initialize any field(s) of the ColumnInterpreter with a parsing of the passed message bytes (used on the server side).

Specified by:

initialize in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

getProtoForCellType

public HBaseProtos.LongMsg getProtoForCellType(Long t)

Description copied from class: ColumnInterpreter

This method gets the PB message corresponding to the cell type

Specified by:

getProtoForCellType in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

the PB message for the cell-type instance

getProtoForPromotedType

public HBaseProtos.LongMsg getProtoForPromotedType(Long s)

Description copied from class: ColumnInterpreter

This method gets the PB message corresponding to the promoted type

Specified by:

getProtoForPromotedType in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

the PB message for the promoted-type instance

getPromotedValueFromProto

public Long getPromotedValueFromProto(HBaseProtos.LongMsg r)

Description copied from class: ColumnInterpreter

This method gets the promoted type from the proto message

Specified by:

getPromotedValueFromProto in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

the promoted-type instance from the PB message

getCellValueFromProto

public Long getCellValueFromProto(HBaseProtos.LongMsg q)

Description copied from class: ColumnInterpreter

This method gets the PB message corresponding to the cell type

Specified by:

getCellValueFromProto in class ColumnInterpreter<Long,Long,HBaseProtos.EmptyMsg,HBaseProtos.LongMsg,HBaseProtos.LongMsg>

Returns:

the cell-type instance from the PB message