cascading.scheme.hadoop
Class TextLine

java.lang.Object
  cascading.scheme.Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>
      cascading.scheme.hadoop.TextLine

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

TextDelimited

public class TextLine
extends Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

A TextLine is a type of Scheme for plain text files. Files are broken into lines. Either line-feed or carriage-return are used to signal end of line.

By default, this scheme returns a Tuple with two fields, "offset" and "line".

Many of the constructors take both "sourceFields" and "sinkFields". sourceFields denote the field names to be used instead of the names "offset" and "line". sinkFields is a selector and is by default Fields.ALL. Any available field names can be given if only a subset of the incoming fields should be used.

If a Fields instance is passed on the constructor as sourceFields having only one field, the return tuples will simply be the "line" value using the given field name.

Note that TextLine will concatenate all the Tuple values for the selected fields with a TAB delimiter before writing out the line.

Note sink compression is TextLine.Compress.DISABLE by default. If null is passed to the constructor for the compression value, it will remain disabled.

If any of the input files end with ".zip", an error will be thrown. *

By default, all text is encoded/decoded as UTF-8. This can be changed via the charsetName constructor argument.

See Also:

Serialized Form

Nested Class Summary

static class

TextLine.Compress

Field Summary

static String	DEFAULT_CHARSET
static Fields	DEFAULT_SOURCE_FIELDS Field DEFAULT_SOURCE_FIELDS

Constructor Summary

TextLine()
Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

TextLine(Fields sourceFields)
Creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields)
Creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, int numSinkParts)
Creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, String charsetName)
Creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, TextLine.Compress sinkCompression)
Constructor TextLine creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, TextLine.Compress sinkCompression, int numSinkParts)
Constructor TextLine creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, TextLine.Compress sinkCompression, int numSinkParts, String charsetName)
Constructor TextLine creates a new TextLine instance.

TextLine(Fields sourceFields, Fields sinkFields, TextLine.Compress sinkCompression, String charsetName)
Constructor TextLine creates a new TextLine instance.

TextLine(Fields sourceFields, int numSinkParts)
Creates a new TextLine instance.

TextLine(Fields sourceFields, String charsetName)
Creates a new TextLine instance.

TextLine(int numSinkParts)
Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

TextLine(TextLine.Compress sinkCompression)
Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

Method Summary

TextLine.Compress	getSinkCompression() Method getSinkCompression returns the sinkCompression of this TextLine object.
protected String	makeEncodedString(Object[] context)
void	presentSinkFields(FlowProcess<JobConf> flowProcess, Tap tap, Fields fields)
void	presentSourceFields(FlowProcess<JobConf> flowProcess, Tap tap, Fields fields)
protected void	setCharsetName(String charsetName)
void	setSinkCompression(TextLine.Compress sinkCompression) Method setSinkCompression sets the sinkCompression of this TextLine object.
void	sink(FlowProcess<JobConf> flowProcess, SinkCall<Object[],OutputCollector> sinkCall)
void	sinkConfInit(FlowProcess<JobConf> flowProcess, Tap<JobConf,RecordReader,OutputCollector> tap, JobConf conf)
void	sinkPrepare(FlowProcess<JobConf> flowProcess, SinkCall<Object[],OutputCollector> sinkCall)
boolean	source(FlowProcess<JobConf> flowProcess, SourceCall<Object[],RecordReader> sourceCall)
void	sourceCleanup(FlowProcess<JobConf> flowProcess, SourceCall<Object[],RecordReader> sourceCall)
void	sourceConfInit(FlowProcess<JobConf> flowProcess, Tap<JobConf,RecordReader,OutputCollector> tap, JobConf conf)
protected void	sourceHandleInput(SourceCall<Object[],RecordReader> sourceCall)
void	sourcePrepare(FlowProcess<JobConf> flowProcess, SourceCall<Object[],RecordReader> sourceCall)
protected void	verify(Fields sourceFields)

Methods inherited from class cascading.scheme.Scheme

equals, getNumSinkParts, getSinkFields, getSourceFields, getTrace, hashCode, isSink, isSource, isSymmetrical, presentSinkFieldsInternal, presentSourceFieldsInternal, retrieveSinkFields, retrieveSourceFields, setNumSinkParts, setSinkFields, setSourceFields, sinkCleanup, toString

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CHARSET

public static final String DEFAULT_CHARSET

See Also:

Constant Field Values

DEFAULT_SOURCE_FIELDS

public static final Fields DEFAULT_SOURCE_FIELDS

Field DEFAULT_SOURCE_FIELDS

Constructor Detail

TextLine

public TextLine()

Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

TextLine

@ConstructorProperties(value="numSinkParts")
public TextLine(int numSinkParts)

Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

Parameters:

numSinkParts - of type int

TextLine

@ConstructorProperties(value="sinkCompression")
public TextLine(TextLine.Compress sinkCompression)

Creates a new TextLine instance that sources "offset" and "line" fields, and sinks all incoming fields, where "offset" is the byte offset in the input file.

Parameters:

sinkCompression - of type Compress

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - the source fields for this scheme

sinkFields - the sink fields for this scheme

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","charsetName"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           String charsetName)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - the source fields for this scheme

sinkFields - the sink fields for this scheme

charsetName - of type String

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","numSinkParts"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           int numSinkParts)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - the source fields for this scheme

sinkFields - the sink fields for this scheme

numSinkParts - of type int

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","sinkCompression"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           TextLine.Compress sinkCompression)

Constructor TextLine creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - of type Fields

sinkFields - of type Fields

sinkCompression - of type Compress

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","sinkCompression","charsetName"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           TextLine.Compress sinkCompression,
                                           String charsetName)

Constructor TextLine creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - of type Fields

sinkFields - of type Fields

sinkCompression - of type Compress

charsetName - of type String

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","sinkCompression","numSinkParts"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           TextLine.Compress sinkCompression,
                                           int numSinkParts)

Constructor TextLine creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - of type Fields

sinkFields - of type Fields

sinkCompression - of type Compress

numSinkParts - of type int

TextLine

@ConstructorProperties(value={"sourceFields","sinkFields","sinkCompression","numSinkParts","charsetName"})
public TextLine(Fields sourceFields,
                                           Fields sinkFields,
                                           TextLine.Compress sinkCompression,
                                           int numSinkParts,
                                           String charsetName)

Constructor TextLine creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - of type Fields

sinkFields - of type Fields

sinkCompression - of type Compress

numSinkParts - of type int

charsetName - of type String

TextLine

@ConstructorProperties(value="sourceFields")
public TextLine(Fields sourceFields)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - the source fields for this scheme

TextLine

@ConstructorProperties(value={"sourceFields","charsetName"})
public TextLine(Fields sourceFields,
                                           String charsetName)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples.

Parameters:

sourceFields - the source fields for this scheme

charsetName - of type String

TextLine

@ConstructorProperties(value={"sourceFields","numSinkParts"})
public TextLine(Fields sourceFields,
                                           int numSinkParts)

Creates a new TextLine instance. If sourceFields has one field, only the text line will be returned in the subsequent tuples. The resulting data set will have numSinkParts.

Parameters:

sourceFields - the source fields for this scheme

numSinkParts - of type int

Method Detail

setCharsetName

protected void setCharsetName(String charsetName)

verify

protected void verify(Fields sourceFields)

getSinkCompression

public TextLine.Compress getSinkCompression()

Method getSinkCompression returns the sinkCompression of this TextLine object.

Returns:

the sinkCompression (type Compress) of this TextLine object.

setSinkCompression

public void setSinkCompression(TextLine.Compress sinkCompression)

Method setSinkCompression sets the sinkCompression of this TextLine object. If null, compression will remain disabled.

Parameters:

sinkCompression - the sinkCompression of this TextLine object.

sourceConfInit

public void sourceConfInit(FlowProcess<JobConf> flowProcess,
                           Tap<JobConf,RecordReader,OutputCollector> tap,
                           JobConf conf)

Specified by:

sourceConfInit in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

presentSourceFields

public void presentSourceFields(FlowProcess<JobConf> flowProcess,
                                Tap tap,
                                Fields fields)

Overrides:

presentSourceFields in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

presentSinkFields

public void presentSinkFields(FlowProcess<JobConf> flowProcess,
                              Tap tap,
                              Fields fields)

Overrides:

presentSinkFields in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

sinkConfInit

public void sinkConfInit(FlowProcess<JobConf> flowProcess,
                         Tap<JobConf,RecordReader,OutputCollector> tap,
                         JobConf conf)

Specified by:

sinkConfInit in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

sourcePrepare

public void sourcePrepare(FlowProcess<JobConf> flowProcess,
                          SourceCall<Object[],RecordReader> sourceCall)

Overrides:

sourcePrepare in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

source

public boolean source(FlowProcess<JobConf> flowProcess,
                      SourceCall<Object[],RecordReader> sourceCall)
               throws IOException

Specified by:

source in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

Throws:

IOException

sourceHandleInput

protected void sourceHandleInput(SourceCall<Object[],RecordReader> sourceCall)

makeEncodedString

protected String makeEncodedString(Object[] context)

sourceCleanup

public void sourceCleanup(FlowProcess<JobConf> flowProcess,
                          SourceCall<Object[],RecordReader> sourceCall)

Overrides:

sourceCleanup in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

sinkPrepare

public void sinkPrepare(FlowProcess<JobConf> flowProcess,
                        SinkCall<Object[],OutputCollector> sinkCall)
                 throws IOException

Overrides:

sinkPrepare in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

Throws:

IOException

sink

public void sink(FlowProcess<JobConf> flowProcess,
                 SinkCall<Object[],OutputCollector> sinkCall)
          throws IOException

Specified by:

sink in class Scheme<JobConf,RecordReader,OutputCollector,Object[],Object[]>

Throws:

IOException