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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.spark.serializer
import java.io._
import java.nio.ByteBuffer
import java.util.Locale
import javax.annotation.Nullable
import scala.collection.JavaConverters._
import scala.collection.mutable.ArrayBuffer
import scala.reflect.ClassTag
import scala.util.control.NonFatal
import com.esotericsoftware.kryo.{Kryo, KryoException, Serializer => KryoClassSerializer}
import com.esotericsoftware.kryo.io.{Input => KryoInput, Output => KryoOutput}
import com.esotericsoftware.kryo.io.{UnsafeInput => KryoUnsafeInput, UnsafeOutput => KryoUnsafeOutput}
import com.esotericsoftware.kryo.serializers.{JavaSerializer => KryoJavaSerializer}
import com.twitter.chill.{AllScalaRegistrar, EmptyScalaKryoInstantiator}
import org.apache.avro.generic.{GenericData, GenericRecord}
import org.roaringbitmap.RoaringBitmap
import org.apache.spark._
import org.apache.spark.api.python.PythonBroadcast
import org.apache.spark.internal.Logging
import org.apache.spark.network.util.ByteUnit
import org.apache.spark.scheduler.{CompressedMapStatus, HighlyCompressedMapStatus}
import org.apache.spark.storage._
import org.apache.spark.util.{BoundedPriorityQueue, ByteBufferInputStream, SerializableConfiguration, SerializableJobConf, Utils}
import org.apache.spark.util.collection.CompactBuffer
/**
* A Spark serializer that uses the
* Kryo serialization library.
*
* @note This serializer is not guaranteed to be wire-compatible across different versions of
* Spark. It is intended to be used to serialize/de-serialize data within a single
* Spark application.
*/
class KryoSerializer(conf: SparkConf)
extends org.apache.spark.serializer.Serializer
with Logging
with Serializable {
private val bufferSizeKb = conf.getSizeAsKb("spark.kryoserializer.buffer", "64k")
if (bufferSizeKb >= ByteUnit.GiB.toKiB(2)) {
throw new IllegalArgumentException("spark.kryoserializer.buffer must be less than " +
s"2048 mb, got: + ${ByteUnit.KiB.toMiB(bufferSizeKb)} mb.")
}
private val bufferSize = ByteUnit.KiB.toBytes(bufferSizeKb).toInt
val maxBufferSizeMb = conf.getSizeAsMb("spark.kryoserializer.buffer.max", "64m").toInt
if (maxBufferSizeMb >= ByteUnit.GiB.toMiB(2)) {
throw new IllegalArgumentException("spark.kryoserializer.buffer.max must be less than " +
s"2048 mb, got: + $maxBufferSizeMb mb.")
}
private val maxBufferSize = ByteUnit.MiB.toBytes(maxBufferSizeMb).toInt
private val referenceTracking = conf.getBoolean("spark.kryo.referenceTracking", true)
private val registrationRequired = conf.getBoolean("spark.kryo.registrationRequired", false)
private val userRegistrators = conf.get("spark.kryo.registrator", "")
.split(',').map(_.trim)
.filter(!_.isEmpty)
private val classesToRegister = conf.get("spark.kryo.classesToRegister", "")
.split(',').map(_.trim)
.filter(!_.isEmpty)
private val avroSchemas = conf.getAvroSchema
// whether to use unsafe based IO for serialization
private val useUnsafe = conf.getBoolean("spark.kryo.unsafe", false)
def newKryoOutput(): KryoOutput =
if (useUnsafe) {
new KryoUnsafeOutput(bufferSize, math.max(bufferSize, maxBufferSize))
} else {
new KryoOutput(bufferSize, math.max(bufferSize, maxBufferSize))
}
def newKryo(): Kryo = {
val instantiator = new EmptyScalaKryoInstantiator
val kryo = instantiator.newKryo()
kryo.setRegistrationRequired(registrationRequired)
val oldClassLoader = Thread.currentThread.getContextClassLoader
val classLoader = defaultClassLoader.getOrElse(Thread.currentThread.getContextClassLoader)
// Allow disabling Kryo reference tracking if user knows their object graphs don't have loops.
// Do this before we invoke the user registrator so the user registrator can override this.
kryo.setReferences(referenceTracking)
for (cls <- KryoSerializer.toRegister) {
kryo.register(cls)
}
for ((cls, ser) <- KryoSerializer.toRegisterSerializer) {
kryo.register(cls, ser)
}
// For results returned by asJavaIterable. See JavaIterableWrapperSerializer.
kryo.register(JavaIterableWrapperSerializer.wrapperClass, new JavaIterableWrapperSerializer)
// Allow sending classes with custom Java serializers
kryo.register(classOf[SerializableWritable[_]], new KryoJavaSerializer())
kryo.register(classOf[SerializableConfiguration], new KryoJavaSerializer())
kryo.register(classOf[SerializableJobConf], new KryoJavaSerializer())
kryo.register(classOf[PythonBroadcast], new KryoJavaSerializer())
kryo.register(classOf[GenericRecord], new GenericAvroSerializer(avroSchemas))
kryo.register(classOf[GenericData.Record], new GenericAvroSerializer(avroSchemas))
try {
// scalastyle:off classforname
// Use the default classloader when calling the user registrator.
Thread.currentThread.setContextClassLoader(classLoader)
// Register classes given through spark.kryo.classesToRegister.
classesToRegister
.foreach { className => kryo.register(Class.forName(className, true, classLoader)) }
// Allow the user to register their own classes by setting spark.kryo.registrator.
userRegistrators
.map(Class.forName(_, true, classLoader).newInstance().asInstanceOf[KryoRegistrator])
.foreach { reg => reg.registerClasses(kryo) }
// scalastyle:on classforname
} catch {
case e: Exception =>
throw new SparkException(s"Failed to register classes with Kryo", e)
} finally {
Thread.currentThread.setContextClassLoader(oldClassLoader)
}
// Register Chill's classes; we do this after our ranges and the user's own classes to let
// our code override the generic serializers in Chill for things like Seq
new AllScalaRegistrar().apply(kryo)
// Register types missed by Chill.
// scalastyle:off
kryo.register(classOf[Array[Tuple1[Any]]])
kryo.register(classOf[Array[Tuple2[Any, Any]]])
kryo.register(classOf[Array[Tuple3[Any, Any, Any]]])
kryo.register(classOf[Array[Tuple4[Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple5[Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple6[Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple7[Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple8[Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple9[Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple10[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple11[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple12[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple13[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple14[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple15[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple16[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple17[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple18[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple19[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple20[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple21[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
kryo.register(classOf[Array[Tuple22[Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any, Any]]])
// scalastyle:on
kryo.register(None.getClass)
kryo.register(Nil.getClass)
kryo.register(Utils.classForName("scala.collection.immutable.$colon$colon"))
kryo.register(Utils.classForName("scala.collection.immutable.Map$EmptyMap$"))
kryo.register(classOf[ArrayBuffer[Any]])
// We can't load those class directly in order to avoid unnecessary jar dependencies.
// We load them safely, ignore it if the class not found.
Seq(
"org.apache.spark.sql.catalyst.expressions.UnsafeRow",
"org.apache.spark.sql.catalyst.expressions.UnsafeArrayData",
"org.apache.spark.sql.catalyst.expressions.UnsafeMapData",
"org.apache.spark.ml.feature.Instance",
"org.apache.spark.ml.feature.LabeledPoint",
"org.apache.spark.ml.feature.OffsetInstance",
"org.apache.spark.ml.linalg.DenseMatrix",
"org.apache.spark.ml.linalg.DenseVector",
"org.apache.spark.ml.linalg.Matrix",
"org.apache.spark.ml.linalg.SparseMatrix",
"org.apache.spark.ml.linalg.SparseVector",
"org.apache.spark.ml.linalg.Vector",
"org.apache.spark.ml.tree.impl.TreePoint",
"org.apache.spark.mllib.clustering.VectorWithNorm",
"org.apache.spark.mllib.linalg.DenseMatrix",
"org.apache.spark.mllib.linalg.DenseVector",
"org.apache.spark.mllib.linalg.Matrix",
"org.apache.spark.mllib.linalg.SparseMatrix",
"org.apache.spark.mllib.linalg.SparseVector",
"org.apache.spark.mllib.linalg.Vector",
"org.apache.spark.mllib.regression.LabeledPoint"
).foreach { name =>
try {
val clazz = Utils.classForName(name)
kryo.register(clazz)
} catch {
case NonFatal(_) => // do nothing
case _: NoClassDefFoundError if Utils.isTesting => // See SPARK-23422.
}
}
kryo.setClassLoader(classLoader)
kryo
}
override def newInstance(): SerializerInstance = {
new KryoSerializerInstance(this, useUnsafe)
}
private[spark] override lazy val supportsRelocationOfSerializedObjects: Boolean = {
// If auto-reset is disabled, then Kryo may store references to duplicate occurrences of objects
// in the stream rather than writing those objects' serialized bytes, breaking relocation. See
// https://groups.google.com/d/msg/kryo-users/6ZUSyfjjtdo/FhGG1KHDXPgJ for more details.
newInstance().asInstanceOf[KryoSerializerInstance].getAutoReset()
}
}
private[spark]
class KryoSerializationStream(
serInstance: KryoSerializerInstance,
outStream: OutputStream,
useUnsafe: Boolean) extends SerializationStream {
private[this] var output: KryoOutput =
if (useUnsafe) new KryoUnsafeOutput(outStream) else new KryoOutput(outStream)
private[this] var kryo: Kryo = serInstance.borrowKryo()
override def writeObject[T: ClassTag](t: T): SerializationStream = {
kryo.writeClassAndObject(output, t)
this
}
override def flush() {
if (output == null) {
throw new IOException("Stream is closed")
}
output.flush()
}
override def close() {
if (output != null) {
try {
output.close()
} finally {
serInstance.releaseKryo(kryo)
kryo = null
output = null
}
}
}
}
private[spark]
class KryoDeserializationStream(
serInstance: KryoSerializerInstance,
inStream: InputStream,
useUnsafe: Boolean) extends DeserializationStream {
private[this] var input: KryoInput =
if (useUnsafe) new KryoUnsafeInput(inStream) else new KryoInput(inStream)
private[this] var kryo: Kryo = serInstance.borrowKryo()
override def readObject[T: ClassTag](): T = {
try {
kryo.readClassAndObject(input).asInstanceOf[T]
} catch {
// DeserializationStream uses the EOF exception to indicate stopping condition.
case e: KryoException
if e.getMessage.toLowerCase(Locale.ROOT).contains("buffer underflow") =>
throw new EOFException
}
}
override def close() {
if (input != null) {
try {
// Kryo's Input automatically closes the input stream it is using.
input.close()
} finally {
serInstance.releaseKryo(kryo)
kryo = null
input = null
}
}
}
}
private[spark] class KryoSerializerInstance(ks: KryoSerializer, useUnsafe: Boolean)
extends SerializerInstance {
/**
* A re-used [[Kryo]] instance. Methods will borrow this instance by calling `borrowKryo()`, do
* their work, then release the instance by calling `releaseKryo()`. Logically, this is a caching
* pool of size one. SerializerInstances are not thread-safe, hence accesses to this field are
* not synchronized.
*/
@Nullable private[this] var cachedKryo: Kryo = borrowKryo()
/**
* Borrows a [[Kryo]] instance. If possible, this tries to re-use a cached Kryo instance;
* otherwise, it allocates a new instance.
*/
private[serializer] def borrowKryo(): Kryo = {
if (cachedKryo != null) {
val kryo = cachedKryo
// As a defensive measure, call reset() to clear any Kryo state that might have been modified
// by the last operation to borrow this instance (see SPARK-7766 for discussion of this issue)
kryo.reset()
cachedKryo = null
kryo
} else {
ks.newKryo()
}
}
/**
* Release a borrowed [[Kryo]] instance. If this serializer instance already has a cached Kryo
* instance, then the given Kryo instance is discarded; otherwise, the Kryo is stored for later
* re-use.
*/
private[serializer] def releaseKryo(kryo: Kryo): Unit = {
if (cachedKryo == null) {
cachedKryo = kryo
}
}
// Make these lazy vals to avoid creating a buffer unless we use them.
private lazy val output = ks.newKryoOutput()
private lazy val input = if (useUnsafe) new KryoUnsafeInput() else new KryoInput()
override def serialize[T: ClassTag](t: T): ByteBuffer = {
output.clear()
val kryo = borrowKryo()
try {
kryo.writeClassAndObject(output, t)
} catch {
case e: KryoException if e.getMessage.startsWith("Buffer overflow") =>
throw new SparkException(s"Kryo serialization failed: ${e.getMessage}. To avoid this, " +
"increase spark.kryoserializer.buffer.max value.", e)
} finally {
releaseKryo(kryo)
}
ByteBuffer.wrap(output.toBytes)
}
override def deserialize[T: ClassTag](bytes: ByteBuffer): T = {
val kryo = borrowKryo()
try {
if (bytes.hasArray) {
input.setBuffer(bytes.array(), bytes.arrayOffset() + bytes.position(), bytes.remaining())
} else {
input.setBuffer(new Array[Byte](4096))
input.setInputStream(new ByteBufferInputStream(bytes))
}
kryo.readClassAndObject(input).asInstanceOf[T]
} finally {
releaseKryo(kryo)
}
}
override def deserialize[T: ClassTag](bytes: ByteBuffer, loader: ClassLoader): T = {
val kryo = borrowKryo()
val oldClassLoader = kryo.getClassLoader
try {
kryo.setClassLoader(loader)
if (bytes.hasArray) {
input.setBuffer(bytes.array(), bytes.arrayOffset() + bytes.position(), bytes.remaining())
} else {
input.setBuffer(new Array[Byte](4096))
input.setInputStream(new ByteBufferInputStream(bytes))
}
kryo.readClassAndObject(input).asInstanceOf[T]
} finally {
kryo.setClassLoader(oldClassLoader)
releaseKryo(kryo)
}
}
override def serializeStream(s: OutputStream): SerializationStream = {
new KryoSerializationStream(this, s, useUnsafe)
}
override def deserializeStream(s: InputStream): DeserializationStream = {
new KryoDeserializationStream(this, s, useUnsafe)
}
/**
* Returns true if auto-reset is on. The only reason this would be false is if the user-supplied
* registrator explicitly turns auto-reset off.
*/
def getAutoReset(): Boolean = {
val field = classOf[Kryo].getDeclaredField("autoReset")
field.setAccessible(true)
val kryo = borrowKryo()
try {
field.get(kryo).asInstanceOf[Boolean]
} finally {
releaseKryo(kryo)
}
}
}
/**
* Interface implemented by clients to register their classes with Kryo when using Kryo
* serialization.
*/
trait KryoRegistrator {
def registerClasses(kryo: Kryo): Unit
}
private[serializer] object KryoSerializer {
// Commonly used classes.
private val toRegister: Seq[Class[_]] = Seq(
ByteBuffer.allocate(1).getClass,
classOf[StorageLevel],
classOf[CompressedMapStatus],
classOf[HighlyCompressedMapStatus],
classOf[CompactBuffer[_]],
classOf[BlockManagerId],
classOf[Array[Boolean]],
classOf[Array[Byte]],
classOf[Array[Short]],
classOf[Array[Int]],
classOf[Array[Long]],
classOf[Array[Float]],
classOf[Array[Double]],
classOf[Array[Char]],
classOf[Array[String]],
classOf[Array[Array[String]]],
classOf[BoundedPriorityQueue[_]],
classOf[SparkConf]
)
private val toRegisterSerializer = Map[Class[_], KryoClassSerializer[_]](
classOf[RoaringBitmap] -> new KryoClassSerializer[RoaringBitmap]() {
override def write(kryo: Kryo, output: KryoOutput, bitmap: RoaringBitmap): Unit = {
bitmap.serialize(new KryoOutputObjectOutputBridge(kryo, output))
}
override def read(kryo: Kryo, input: KryoInput, cls: Class[RoaringBitmap]): RoaringBitmap = {
val ret = new RoaringBitmap
ret.deserialize(new KryoInputObjectInputBridge(kryo, input))
ret
}
}
)
}
/**
* This is a bridge class to wrap KryoInput as an InputStream and ObjectInput. It forwards all
* methods of InputStream and ObjectInput to KryoInput. It's usually helpful when an API expects
* an InputStream or ObjectInput but you want to use Kryo.
*/
private[spark] class KryoInputObjectInputBridge(
kryo: Kryo, input: KryoInput) extends FilterInputStream(input) with ObjectInput {
override def readLong(): Long = input.readLong()
override def readChar(): Char = input.readChar()
override def readFloat(): Float = input.readFloat()
override def readByte(): Byte = input.readByte()
override def readShort(): Short = input.readShort()
override def readUTF(): String = input.readString() // readString in kryo does utf8
override def readInt(): Int = input.readInt()
override def readUnsignedShort(): Int = input.readShortUnsigned()
override def skipBytes(n: Int): Int = {
input.skip(n)
n
}
override def readFully(b: Array[Byte]): Unit = input.read(b)
override def readFully(b: Array[Byte], off: Int, len: Int): Unit = input.read(b, off, len)
override def readLine(): String = throw new UnsupportedOperationException("readLine")
override def readBoolean(): Boolean = input.readBoolean()
override def readUnsignedByte(): Int = input.readByteUnsigned()
override def readDouble(): Double = input.readDouble()
override def readObject(): AnyRef = kryo.readClassAndObject(input)
}
/**
* This is a bridge class to wrap KryoOutput as an OutputStream and ObjectOutput. It forwards all
* methods of OutputStream and ObjectOutput to KryoOutput. It's usually helpful when an API expects
* an OutputStream or ObjectOutput but you want to use Kryo.
*/
private[spark] class KryoOutputObjectOutputBridge(
kryo: Kryo, output: KryoOutput) extends FilterOutputStream(output) with ObjectOutput {
override def writeFloat(v: Float): Unit = output.writeFloat(v)
// There is no "readChars" counterpart, except maybe "readLine", which is not supported
override def writeChars(s: String): Unit = throw new UnsupportedOperationException("writeChars")
override def writeDouble(v: Double): Unit = output.writeDouble(v)
override def writeUTF(s: String): Unit = output.writeString(s) // writeString in kryo does UTF8
override def writeShort(v: Int): Unit = output.writeShort(v)
override def writeInt(v: Int): Unit = output.writeInt(v)
override def writeBoolean(v: Boolean): Unit = output.writeBoolean(v)
override def write(b: Int): Unit = output.write(b)
override def write(b: Array[Byte]): Unit = output.write(b)
override def write(b: Array[Byte], off: Int, len: Int): Unit = output.write(b, off, len)
override def writeBytes(s: String): Unit = output.writeString(s)
override def writeChar(v: Int): Unit = output.writeChar(v.toChar)
override def writeLong(v: Long): Unit = output.writeLong(v)
override def writeByte(v: Int): Unit = output.writeByte(v)
override def writeObject(obj: AnyRef): Unit = kryo.writeClassAndObject(output, obj)
}
/**
* A Kryo serializer for serializing results returned by asJavaIterable.
*
* The underlying object is scala.collection.convert.Wrappers$IterableWrapper.
* Kryo deserializes this into an AbstractCollection, which unfortunately doesn't work.
*/
private class JavaIterableWrapperSerializer
extends com.esotericsoftware.kryo.Serializer[java.lang.Iterable[_]] {
import JavaIterableWrapperSerializer._
override def write(kryo: Kryo, out: KryoOutput, obj: java.lang.Iterable[_]): Unit = {
// If the object is the wrapper, simply serialize the underlying Scala Iterable object.
// Otherwise, serialize the object itself.
if (obj.getClass == wrapperClass && underlyingMethodOpt.isDefined) {
kryo.writeClassAndObject(out, underlyingMethodOpt.get.invoke(obj))
} else {
kryo.writeClassAndObject(out, obj)
}
}
override def read(kryo: Kryo, in: KryoInput, clz: Class[java.lang.Iterable[_]])
: java.lang.Iterable[_] = {
kryo.readClassAndObject(in) match {
case scalaIterable: Iterable[_] => scalaIterable.asJava
case javaIterable: java.lang.Iterable[_] => javaIterable
}
}
}
private object JavaIterableWrapperSerializer extends Logging {
// The class returned by JavaConverters.asJava
// (scala.collection.convert.Wrappers$IterableWrapper).
import scala.collection.JavaConverters._
val wrapperClass = Seq(1).asJava.getClass
// Get the underlying method so we can use it to get the Scala collection for serialization.
private val underlyingMethodOpt = {
try Some(wrapperClass.getDeclaredMethod("underlying")) catch {
case e: Exception =>
logError("Failed to find the underlying field in " + wrapperClass, e)
None
}
}
}
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