org.apache.giraph.writable.kryo

Class KryoWritableWrapper<T>

java.lang.Object

org.apache.giraph.writable.kryo.KryoWritableWrapper<T>

Type Parameters:

T - Object type

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public class KryoWritableWrapper<T>
extends Object
implements org.apache.hadoop.io.Writable

Generic wrapper object, making any object writable. Uses Kryo inside for serialization. Current configuration is not optimized for performance, but Writable interface doesn't allow much room for it. Note - Java8 lambdas need to implement Serializable to work.

Constructor Summary

Constructors

Constructor and Description
KryoWritableWrapper() Creates wrapper initialized with null.
KryoWritableWrapper(T object) Create wrapper given an object.

Method Summary

Modifier and Type	Method and Description
static <T> T	convertFromByteArray(byte[] arr) Converting from byte array
static <T> byte[]	convertToByteArray(T object) Converting the object to byte array.
T	get() Unwrap the object value
void	readFields(DataInput in)
void	set(T object) Set wrapped object value
static <T> T	unwrapIfNeeded(org.apache.hadoop.io.Writable value) Unwrap Writable object if it was wrapped initially, inverse of wrapIfNeeded function.
static <T> T	wrapAndCopy(T object) Wrap object with KryoWritableWrapper, create a writable copy of it, and then unwrap it, allowing any object to be copied.
static org.apache.hadoop.io.Writable	wrapIfNeeded(Object object) Returns Writable instance, wrapping given object only if it is not already writable.
void	write(DataOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

KryoWritableWrapper

public KryoWritableWrapper(T object)

Create wrapper given an object.

Parameters:

object - Object instance

KryoWritableWrapper

public KryoWritableWrapper()

Creates wrapper initialized with null.

Method Detail

get

public T get()

Unwrap the object value

Returns:

Object value

set

public void set(T object)

Set wrapped object value

Parameters:

object - New object value

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

wrapIfNeeded

public static org.apache.hadoop.io.Writable wrapIfNeeded(Object object)

Returns Writable instance, wrapping given object only if it is not already writable.

Parameters:

object - Object to potentially wrap

Returns:

Writable object holding argument

unwrapIfNeeded

public static <T> T unwrapIfNeeded(org.apache.hadoop.io.Writable value)

Unwrap Writable object if it was wrapped initially, inverse of wrapIfNeeded function.

Type Parameters:

T - Type of returned object.

Parameters:

value - Potentially wrapped value

Returns:

Original unwrapped value

wrapAndCopy

public static <T> T wrapAndCopy(T object)

Wrap object with KryoWritableWrapper, create a writable copy of it, and then unwrap it, allowing any object to be copied.

Type Parameters:

T - Type of the object

Parameters:

object - Object to copy

Returns:

copy of the object

convertToByteArray

public static <T> byte[] convertToByteArray(T object)

Converting the object to byte array.

Type Parameters:

T - Type

Parameters:

object - Object

Returns:

byte array

convertFromByteArray

public static <T> T convertFromByteArray(byte[] arr)

Converting from byte array

Type Parameters:

T - type

Parameters:

arr - byte array

Returns:

original object