Package org.apache.hadoop.mapred.lib.aggregate

Class ValueAggregatorBaseDescriptor

java.lang.Object

org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorBaseDescriptor

org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorBaseDescriptor

All Implemented Interfaces:

ValueAggregatorDescriptor, ValueAggregatorDescriptor

@Public
@Stable
public class ValueAggregatorBaseDescriptor
extends ValueAggregatorBaseDescriptor
implements ValueAggregatorDescriptor

This class implements the common functionalities of the subclasses of ValueAggregatorDescriptor class.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DOUBLE_VALUE_SUM
static final String	LONG_VALUE_MAX
static final String	LONG_VALUE_MIN
static final String	LONG_VALUE_SUM
static final String	STRING_VALUE_MAX
static final String	STRING_VALUE_MIN
static final String	UNIQ_VALUE_COUNT
static final String	VALUE_HISTOGRAM

Fields inherited from class org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorBaseDescriptor

inputFile

Fields inherited from interface org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorDescriptor

ONE, TYPE_SEPARATOR

Fields inherited from interface org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorDescriptor

ONE, TYPE_SEPARATOR

Constructor Summary

Constructors

Constructor	Description
ValueAggregatorBaseDescriptor()

Method Summary

Modifier and Type	Method	Description
void	configure(JobConf job)	get the input file name.
static Map.Entry<Text,Text>	generateEntry(String type, String id, Text val)
static ValueAggregator	generateValueAggregator(String type)

Methods inherited from class org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorBaseDescriptor

configure, generateKeyValPairs, generateValueAggregator

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.mapreduce.lib.aggregate.ValueAggregatorDescriptor

configure, generateKeyValPairs

Field Details

UNIQ_VALUE_COUNT

public static final String UNIQ_VALUE_COUNT

See Also:

• Constant Field Values

LONG_VALUE_SUM

public static final String LONG_VALUE_SUM

See Also:

• Constant Field Values

DOUBLE_VALUE_SUM

public static final String DOUBLE_VALUE_SUM

See Also:

• Constant Field Values

VALUE_HISTOGRAM

public static final String VALUE_HISTOGRAM

See Also:

• Constant Field Values

LONG_VALUE_MAX

public static final String LONG_VALUE_MAX

See Also:

• Constant Field Values

LONG_VALUE_MIN

public static final String LONG_VALUE_MIN

See Also:

• Constant Field Values

STRING_VALUE_MAX

public static final String STRING_VALUE_MAX

See Also:

• Constant Field Values

STRING_VALUE_MIN

public static final String STRING_VALUE_MIN

See Also:

• Constant Field Values

Constructor Details

ValueAggregatorBaseDescriptor

public ValueAggregatorBaseDescriptor()

Method Details

generateEntry

public static Map.Entry<Text,Text> generateEntry(String type,
 String id,
 Text val)

Parameters:

type - the aggregation type

id - the aggregation id

val - the val associated with the id to be aggregated

Returns:

an Entry whose key is the aggregation id prefixed with the aggregation type.

generateValueAggregator

public static ValueAggregator generateValueAggregator(String type)

Parameters:

type - the aggregation type

Returns:

a value aggregator of the given type.

configure

public void configure(JobConf job)

get the input file name.

Specified by:

configure in interface ValueAggregatorDescriptor

Parameters:

job - a job configuration object