com.google.appengine.tools.mapreduce.impl

Class KeyValueMarshaller<K,V>

java.lang.Object

com.google.appengine.tools.mapreduce.Marshaller<KeyValue<K,V>>

com.google.appengine.tools.mapreduce.impl.KeyValueMarshaller<K,V>

Type Parameters:

K - key type

V - value type

All Implemented Interfaces:

Serializable

public class KeyValueMarshaller<K,V>
extends Marshaller<KeyValue<K,V>>

Marshalls KeyValue pairs given a Marshaller for the Key and the Value. Used to marshall and unmarshall data from the Mapper to the Sort. For internal use only. User code cannot safely depend on this class.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
KeyValueMarshaller(Marshaller<K> keyMarshaller, Marshaller<V> valueMarshaller)

Method Summary

Methods

Modifier and Type	Method and Description
KeyValue<K,V>	fromBytes(ByteBuffer input) Returns the object whose serialized representation is in b between b.position() and b.limit().
ByteBuffer	toBytes(KeyValue<K,V> keyValues) Returns a new ByteBuffer b with a serialized representation of object between b.position() and b.limit().

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyValueMarshaller

public KeyValueMarshaller(Marshaller<K> keyMarshaller,
                  Marshaller<V> valueMarshaller)

Method Detail

toBytes

public ByteBuffer toBytes(KeyValue<K,V> keyValues)

Description copied from class: Marshaller

Returns a new ByteBuffer b with a serialized representation of object between b.position() and b.limit(). b.order() is undefined.

Specified by:

toBytes in class Marshaller<KeyValue<K,V>>

fromBytes

public KeyValue<K,V> fromBytes(ByteBuffer input)

Description copied from class: Marshaller

Returns the object whose serialized representation is in b between b.position() and b.limit(). The value of b.order() when the method is called is undefined, and this method may modify it as well as b.position() and b.limit().

The method may throw a RuntimeException if it determines that the sequence of bytes in b was not generated by Marshaller.toBytes(T). This includes corrupted data as well as trailing bytes.

Specified by:

fromBytes in class Marshaller<KeyValue<K,V>>