cascading.scheme
Class SequenceFile

java.lang.Object
  cascading.scheme.Scheme
      cascading.scheme.SequenceFile

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

WritableSequenceFile

public class SequenceFile
extends Scheme

A SequenceFile is a type of Scheme, which is a flat file consisting of binary key/value pairs. This is a space and time efficient means to store data.

See Also:

Serialized Form

Constructor Summary

protected	SequenceFile() Protected for use by TempDfs and other subclasses.
	SequenceFile(Fields fields) Creates a new SequenceFile instance that stores the given field names.

Method Summary

void	sink(TupleEntry tupleEntry, OutputCollector outputCollector) Method sink writes out the given Tuple instance to the outputCollector.
void	sinkInit(Tap tap, JobConf conf) Method sinkInit initializes this instance as a sink.
Tuple	source(Object key, Object value) Method source takes the given Hadoop key and value and returns a new Tuple instance.
void	sourceInit(Tap tap, JobConf conf) Method sourceInit initializes this instance as a source.

Methods inherited from class cascading.scheme.Scheme

equals, getNumSinkParts, getSinkFields, getSourceFields, getTrace, hashCode, isSink, isSource, isSymmetrical, isWriteDirect, setNumSinkParts, setSinkFields, setSourceFields, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceFile

protected SequenceFile()

Protected for use by TempDfs and other subclasses. Not for general consumption.

SequenceFile

@ConstructorProperties(value="fields")
public SequenceFile(Fields fields)

Creates a new SequenceFile instance that stores the given field names.

Parameters:

fields -

Method Detail

sourceInit

public void sourceInit(Tap tap,
                       JobConf conf)

Description copied from class: Scheme

Method sourceInit initializes this instance as a source.

Specified by:

sourceInit in class Scheme

Parameters:

tap - of type Tap

conf - of type JobConf

sinkInit

public void sinkInit(Tap tap,
                     JobConf conf)

Description copied from class: Scheme

Method sinkInit initializes this instance as a sink.

Specified by:

sinkInit in class Scheme

Parameters:

tap - of type Tap

conf - of type JobConf

source

public Tuple source(Object key,
                    Object value)

Description copied from class: Scheme

Method source takes the given Hadoop key and value and returns a new Tuple instance.

Specified by:

source in class Scheme

Parameters:

key - of type WritableComparable

value - of type Writable

Returns:

Tuple

sink

public void sink(TupleEntry tupleEntry,
                 OutputCollector outputCollector)
          throws IOException

Description copied from class: Scheme

Method sink writes out the given Tuple instance to the outputCollector.

Specified by:

sink in class Scheme

outputCollector - of type OutputCollector @throws IOException when

Throws:

IOException