org.apache.crunch.types.writable

Class WritableType<T,W extends org.apache.hadoop.io.Writable>

java.lang.Object

org.apache.crunch.types.writable.WritableType<T,W>

All Implemented Interfaces:

Serializable, PType<T>

public class WritableType<T,W extends org.apache.hadoop.io.Writable>
extends Object
implements PType<T>

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
WritableType(Class<T> typeClass, Class<W> writableClass, MapFn<W,T> inputDoFn, MapFn<T,W> outputDoFn, PType... subTypes)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
Converter	getConverter()
SourceTarget<T>	getDefaultFileSource(org.apache.hadoop.fs.Path path) Returns a SourceTarget that is able to read/write data using the serialization format specified by this PType.
T	getDetachedValue(T value) Returns a copy of a value (or the value itself) that can safely be retained.
PTypeFamily	getFamily() Returns the PTypeFamily that this PType belongs to.
MapFn	getInputMapFn()
MapFn	getOutputMapFn()
Class<W>	getSerializationClass()
List<PType>	getSubTypes() Returns the sub-types that make up this PType if it is a composite instance, such as a tuple.
Class<T>	getTypeClass() Returns the Java type represented by this PType.
int	hashCode()
void	initialize(org.apache.hadoop.conf.Configuration conf) Initialize this PType for use within a DoFn.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WritableType

public WritableType(Class<T> typeClass,
            Class<W> writableClass,
            MapFn<W,T> inputDoFn,
            MapFn<T,W> outputDoFn,
            PType... subTypes)

Method Detail

getFamily

public PTypeFamily getFamily()

Description copied from interface: PType

Returns the PTypeFamily that this PType belongs to.

Specified by:

getFamily in interface PType<T>

getTypeClass

public Class<T> getTypeClass()

Description copied from interface: PType

Returns the Java type represented by this PType.

Specified by:

getTypeClass in interface PType<T>

getConverter

public Converter getConverter()

Specified by:

getConverter in interface PType<T>

getInputMapFn

public MapFn getInputMapFn()

Specified by:

getInputMapFn in interface PType<T>

getOutputMapFn

public MapFn getOutputMapFn()

Specified by:

getOutputMapFn in interface PType<T>

getSubTypes

public List<PType> getSubTypes()

Description copied from interface: PType

Returns the sub-types that make up this PType if it is a composite instance, such as a tuple.

Specified by:

getSubTypes in interface PType<T>

getSerializationClass

public Class<W> getSerializationClass()

getDefaultFileSource

public SourceTarget<T> getDefaultFileSource(org.apache.hadoop.fs.Path path)

Description copied from interface: PType

Returns a SourceTarget that is able to read/write data using the serialization format specified by this PType.

Specified by:

getDefaultFileSource in interface PType<T>

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

initialize

public void initialize(org.apache.hadoop.conf.Configuration conf)

Description copied from interface: PType

Initialize this PType for use within a DoFn. This generally only needs to be called when using a PType for PType.getDetachedValue(Object).

Specified by:

initialize in interface PType<T>

Parameters:

conf - Configuration object

See Also:

PType.getDetachedValue(Object)

getDetachedValue

public T getDetachedValue(T value)

Description copied from interface: PType

Returns a copy of a value (or the value itself) that can safely be retained.

This is useful when iterable values being processed in a DoFn (via a reducer) need to be held on to for more than the scope of a single iteration, as a reducer (and therefore also a DoFn that has an Iterable as input) re-use deserialized values. More information on object reuse is available in the DoFn class documentation.

Specified by:

getDetachedValue in interface PType<T>

Parameters:

value - The value to be deep-copied

Returns:

A deep copy of the input value

hashCode

public int hashCode()

Overrides:

hashCode in class Object