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

@InterfaceAudience.Public
@InterfaceStability.Stable
public class ValueAggregatorBaseDescriptor
extends ValueAggregatorBaseDescriptor
implements ValueAggregatorDescriptor

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

Field Summary

static String	DOUBLE_VALUE_SUM
static String	LONG_VALUE_MAX
static String	LONG_VALUE_MIN
static String	LONG_VALUE_SUM
static String	STRING_VALUE_MAX
static String	STRING_VALUE_MIN
static String	UNIQ_VALUE_COUNT
static 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

Constructor Summary

ValueAggregatorBaseDescriptor()

Method Summary

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 Detail

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 Detail

ValueAggregatorBaseDescriptor

public ValueAggregatorBaseDescriptor()

Method Detail

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.

Parameters:

job - a job configuration object