| package io.pivotal.gemfire.spark.connector.internal.oql |
| |
| import com.esotericsoftware.kryo.{Kryo, Serializer} |
| import com.esotericsoftware.kryo.io.{Output, Input} |
| import com.gemstone.gemfire.cache.query.QueryService |
| import com.gemstone.gemfire.cache.query.internal.Undefined |
| |
| /** |
| * This is the customized serializer to serialize QueryService.UNDEFINED, |
| * i.e. com.gemstone.gemfire.cache.query.internal.Undefined, in order to |
| * guarantee the singleton Undefined after its deserialization within Spark. |
| */ |
| class UndefinedSerializer extends Serializer[Undefined] { |
| |
| def write(kryo: Kryo, output: Output, u: Undefined) { |
| //Only serialize a byte for Undefined |
| output.writeByte(u.getDSFID) |
| } |
| |
| def read (kryo: Kryo, input: Input, tpe: Class[Undefined]): Undefined = { |
| //Read DSFID of Undefined |
| input.readByte() |
| QueryService.UNDEFINED match { |
| case null => new Undefined |
| case _ => |
| //Avoid calling Undefined constructor again. |
| QueryService.UNDEFINED.asInstanceOf[Undefined] |
| } |
| } |
| } |
