DoubleColumnInterpreter (Apache HBase

java.lang.Object
- org.apache.hadoop.hbase.coprocessor.ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
- - org.apache.hadoop.hbase.client.coprocessor.DoubleColumnInterpreter

```
@InterfaceAudience.LimitedPrivate(value="Coprocesssor")
 @InterfaceStability.Evolving
public class DoubleColumnInterpreter
extends ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
```
a concrete column interpreter implementation. The cell value is a Double value and its promoted data type is also a Double 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 TestDoubleColumnInterpreter methods for its sample usage. Its methods handle null arguments gracefully.

Constructor Summary

Constructors
Constructor and Description

DoubleColumnInterpreter()

Constructors
Constructor and Description
`DoubleColumnInterpreter()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`Double`	`add(Double d1, Double d2)`
`Double`	`castToCellType(Double d)` The response message comes as type S.
`Double`	`castToReturnType(Double o)` provides casting opportunity between the data types.
`int`	`compare(Double d1, Double d2)` This takes care if either of arguments are null.
`double`	`divideForAvg(Double d1, Long l2)` used for computing average of <S> data values.
`Double`	`getCellValueFromProto(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg q)` This method gets the PB message corresponding to the cell type
`Double`	`getMaxValue()` returns the maximum value for this type T
`Double`	`getMinValue()`
`Double`	`getPromotedValueFromProto(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg r)` This method gets the promoted type from the proto message
`org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg`	`getProtoForCellType(Double t)` This method gets the PB message corresponding to the cell type
`org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg`	`getProtoForPromotedType(Double s)` This method gets the PB message corresponding to the promoted type
`org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg`	`getRequestData()` This method should return any additional data that is needed on the server side to construct the ColumnInterpreter.
`Double`	`getValue(byte[] colFamily, byte[] colQualifier, Cell c)`
`Double`	`increment(Double o)`
`void`	`initialize(org.apache.hadoop.hbase.protobuf.generated.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).
`Double`	`multiply(Double d1, Double d2)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DoubleColumnInterpreter
```
public DoubleColumnInterpreter()
```
- Method Detail
  - getValue
```
public Double getValue(byte[] colFamily,
                       byte[] colQualifier,
                       Cell c)
                throws IOException
```
    Specified by:
    
    getValue in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    value of type T
    
    Throws:
    
    IOException
  - add
```
public Double add(Double d1,
                  Double d2)
```
    Specified by:
    
    add in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    sum or non null value among (if either of them is null); otherwise returns a null.
  - compare
```
public int compare(Double d1,
                   Double d2)
```
    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<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
  - getMaxValue
```
public Double getMaxValue()
```
    Description copied from class: ColumnInterpreter
    
    returns the maximum value for this type T
    
    Specified by:
    
    getMaxValue in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    max
  - increment
```
public Double increment(Double o)
```
    Specified by:
    
    increment in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    increment
  - multiply
```
public Double multiply(Double d1,
                       Double d2)
```
    Specified by:
    
    multiply in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    multiplication
  - getMinValue
```
public Double getMinValue()
```
    Specified by:
    
    getMinValue in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
  - divideForAvg
```
public double divideForAvg(Double d1,
                           Long l2)
```
    Description copied from class: ColumnInterpreter
    
    used for computing average of <S> data values. Not providing the divide method that takes two <S> values as it is not needed as of now.
    
    Specified by:
    
    divideForAvg in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    Average
  - castToReturnType
```
public Double castToReturnType(Double o)
```
    Description copied from class: ColumnInterpreter
    
    provides casting opportunity between the data types.
    
    Specified by:
    
    castToReturnType in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    cast
  - castToCellType
```
public Double castToCellType(Double d)
```
    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<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    cast
  - getRequestData
```
public org.apache.hadoop.hbase.protobuf.generated.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<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    the PB message
  - initialize
```
public void initialize(org.apache.hadoop.hbase.protobuf.generated.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<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
  - getProtoForCellType
```
public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg getProtoForCellType(Double t)
```
    Description copied from class: ColumnInterpreter
    
    This method gets the PB message corresponding to the cell type
    
    Specified by:
    
    getProtoForCellType in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    the PB message for the cell-type instance
  - getProtoForPromotedType
```
public org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg getProtoForPromotedType(Double s)
```
    Description copied from class: ColumnInterpreter
    
    This method gets the PB message corresponding to the promoted type
    
    Specified by:
    
    getProtoForPromotedType in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    the PB message for the promoted-type instance
  - getPromotedValueFromProto
```
public Double getPromotedValueFromProto(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg r)
```
    Description copied from class: ColumnInterpreter
    
    This method gets the promoted type from the proto message
    
    Specified by:
    
    getPromotedValueFromProto in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    the promoted-type instance from the PB message
  - getCellValueFromProto
```
public Double getCellValueFromProto(org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg q)
```
    Description copied from class: ColumnInterpreter
    
    This method gets the PB message corresponding to the cell type
    
    Specified by:
    
    getCellValueFromProto in class ColumnInterpreter<Double,Double,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg,org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.DoubleMsg>
    
    Returns:
    
    the cell-type instance from the PB message

Class DoubleColumnInterpreter

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DoubleColumnInterpreter

Method Detail

getValue

add

compare

getMaxValue

increment

multiply

getMinValue

divideForAvg

castToReturnType

castToCellType

getRequestData

initialize

getProtoForCellType

getProtoForPromotedType

getPromotedValueFromProto

getCellValueFromProto