org.apache.giraph.writable.kryo

Class HadoopKryo

java.lang.Object

com.esotericsoftware.kryo.Kryo

org.apache.giraph.writable.kryo.HadoopKryo

public class HadoopKryo
extends com.esotericsoftware.kryo.Kryo

Kryo instance that provides serialization through DataInput/DataOutput that org.apache.hadoop.io.Writable uses. All public APIs are static. It extends Kryo to reuse KryoPool functionality, but have additional needed objects cached as well. If we move to ThreadLocal or other caching technique, we can use composition, instead of inheritance here. TODO: Refactor this class into two separate classes depending on whether the reference tracking is enabled or disabled.

Nested Class Summary

Nested classes/interfaces inherited from class com.esotericsoftware.kryo.Kryo

com.esotericsoftware.kryo.Kryo.DefaultInstantiatorStrategy

Field Summary

Fields inherited from class com.esotericsoftware.kryo.Kryo

NOT_NULL, NULL

Method Summary

Modifier and Type	Method and Description
static <T> T	createCopy(T object) Create copy of the object, by magically recursively copying all of its fields, keeping reference structures (like cycles)
static HadoopKryo	getNontrackingKryo() Returns a kryo which doesn't track objects, hence serialization of recursive/nested objects is not supported.
static <T> T	readClassAndObj(DataInput in) Read object from the input stream, by reading first type of the object, and then all of its fields.
static void	readIntoObject(DataInput in, Object object) Reads an object, from input, into a given object, allowing object reuse.
static <T> T	readWithKryo(HadoopKryo kryo, com.esotericsoftware.kryo.io.Input in) Reads class and object from specified input stream with specified kryo object.
static void	readWithKryoIntoObject(HadoopKryo kryo, com.esotericsoftware.kryo.io.Input in, Object object) Read into object with given kryo.
static void	writeClassAndObj(DataOutput out, Object object) Write type of given object and the object itself to the output stream.
static void	writeOutOfObject(DataOutput out, Object object) Write an object to output, in a way that can be read by readIntoObject.
static void	writeWithKryo(HadoopKryo kryo, com.esotericsoftware.kryo.io.Output out, Object object) Writes class and object to specified output stream with specified Kryo object.
static void	writeWithKryoOutOfObject(HadoopKryo kryo, com.esotericsoftware.kryo.io.Output out, Object object) Write out of object with given kryo

Methods inherited from class com.esotericsoftware.kryo.Kryo

addDefaultSerializer, addDefaultSerializer, addDefaultSerializer, copy, copy, copyShallow, copyShallow, getAsmEnabled, getClassLoader, getClassResolver, getContext, getDefaultSerializer, getDefaultSerializerForAnnotatedType, getDepth, getFieldSerializerConfig, getGenericsResolver, getGraphContext, getInstantiatorStrategy, getNextRegistrationId, getOriginalToCopyMap, getReferenceResolver, getReferences, getRegistration, getRegistration, getSerializer, getStreamFactory, getTaggedFieldSerializerConfig, isClosure, isFinal, isRegistrationRequired, isWarnUnregisteredClasses, newDefaultSerializer, newInstance, newInstantiator, readClass, readClassAndObject, readObject, readObject, readObjectOrNull, readObjectOrNull, reference, register, register, register, register, register, reset, setAsmEnabled, setAutoReset, setClassLoader, setCopyReferences, setDefaultSerializer, setDefaultSerializer, setInstantiatorStrategy, setMaxDepth, setReferenceResolver, setReferences, setRegistrationRequired, setStreamFactory, setWarnUnregisteredClasses, unregisteredClassMessage, writeClass, writeClassAndObject, writeObject, writeObject, writeObjectOrNull, writeObjectOrNull

Methods inherited from class java.lang.Object

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

Method Detail

writeClassAndObj

public static void writeClassAndObj(DataOutput out,
                                    Object object)

Write type of given object and the object itself to the output stream. Inverse of readClassAndObj.

Parameters:

out - Output stream

object - Object to write

readClassAndObj

public static <T> T readClassAndObj(DataInput in)

Read object from the input stream, by reading first type of the object, and then all of its fields. Inverse of writeClassAndObject.

Type Parameters:

T - Type of the object being read

Parameters:

in - Input stream

Returns:

Deserialized object

writeOutOfObject

public static void writeOutOfObject(DataOutput out,
                                    Object object)

Write an object to output, in a way that can be read by readIntoObject.

Parameters:

out - Output stream

object - Object to be written

readIntoObject

public static void readIntoObject(DataInput in,
                                  Object object)

Reads an object, from input, into a given object, allowing object reuse. Inverse of writeOutOfObject.

Parameters:

in - Input stream

object - Object to fill from input

writeWithKryo

public static void writeWithKryo(HadoopKryo kryo,
                                 com.esotericsoftware.kryo.io.Output out,
                                 Object object)

Writes class and object to specified output stream with specified Kryo object. It does not use interim buffers.

Parameters:

kryo - Kryo object

out - Output stream

object - Object

writeWithKryoOutOfObject

public static void writeWithKryoOutOfObject(HadoopKryo kryo,
                                            com.esotericsoftware.kryo.io.Output out,
                                            Object object)

Write out of object with given kryo

Parameters:

kryo - Kryo object

out - Output

object - Object to write

readWithKryo

public static <T> T readWithKryo(HadoopKryo kryo,
                                 com.esotericsoftware.kryo.io.Input in)

Reads class and object from specified input stream with specified kryo object. it does not use interim buffers.

Type Parameters:

T - Object type parameter

Parameters:

kryo - Kryo object

in - Input buffer

Returns:

Object

readWithKryoIntoObject

public static void readWithKryoIntoObject(HadoopKryo kryo,
                                          com.esotericsoftware.kryo.io.Input in,
                                          Object object)

Read into object with given kryo.

Parameters:

kryo - Kryo object

in - Input

object - Object to read into

createCopy

public static <T> T createCopy(T object)

Create copy of the object, by magically recursively copying all of its fields, keeping reference structures (like cycles)

Type Parameters:

T - Type of the object

Parameters:

object - Object to be copied

Returns:

Copy of the object.

getNontrackingKryo

public static HadoopKryo getNontrackingKryo()

Returns a kryo which doesn't track objects, hence serialization of recursive/nested objects is not supported. Reference tracking significantly degrades the performance since kryo has to store all serialized objects and search the history to check if an object has been already serialized.

Returns:

Hadoop kryo which doesn't track objects.