SeqBuilderSerializationExample.kt

package kryo

import com.esotericsoftware.kryo.Kryo
import com.esotericsoftware.kryo.io.Input
import com.esotericsoftware.kryo.io.Output
import com.esotericsoftware.kryo.serializers.ClosureSerializer
import com.esotericsoftware.kryo.util.DefaultInstantiatorStrategy
import com.esotericsoftware.kryo.util.MapReferenceResolver
import nl.adaptivity.android.kryo.AndroidKotlinResolver
import nl.adaptivity.android.kryo.KotlinObjectInstantiatorStrategy
import nl.adaptivity.android.kryo.serializers.SafeContinuationSerializer
import nl.adaptivity.android.kryo.serializers._SafeContinuation
import org.objenesis.strategy.StdInstantiatorStrategy
import java.io.File
import java.io.FileInputStream
import java.io.FileOutputStream
import java.io.Serializable
import java.lang.invoke.SerializedLambda


class SimpleProcess(seq: Sequence<String>) : Serializable {
    val iterator = seq.iterator()
}


fun main() {
    val sim = SimpleProcess(sequence {
        yield("foo")
        yield("bar")
    })

    // consume the sequence once
    println(sim.iterator.next())

    val kryo = buildProcKryo()

    val saveFile = File("file.bin")

    val output = Output(FileOutputStream(saveFile))
    kryo.writeClassAndObject(output, sim)
    output.close()

    val input = Input(FileInputStream(saveFile));
    val restored = kryo.readClassAndObject(input) as SimpleProcess

    // consume it again
    println(restored.iterator.next())
}

fun buildProcKryo(): Kryo {
    val kryo = Kryo(AndroidKotlinResolver(), MapReferenceResolver())

    kryo.instantiatorStrategy = KotlinObjectInstantiatorStrategy(DefaultInstantiatorStrategy(StdInstantiatorStrategy()))

    //TODO no longer needed, really?
    kryo.register(_SafeContinuation, SafeContinuationSerializer(kryo))
    /* TODO While this doesn't affect instantiation (The KotlinObjectStantiatorStrategy handles that)
     * this may be needed to not serialize/deserialize the actual pool state.
     */
    // FIXME CommonPool seems not longer part of coroutine API
//    val commonPoolClass = Class.forName("kotlinx.coroutines.CommonPool")
//    register(commonPoolClass, ObjectSerializer(this,commonPoolClass))

    kryo.setOptimizedGenerics(false)
    kryo.references = true
    kryo.isRegistrationRequired = false

    kryo.register(SerializedLambda::class.java)
    kryo.register(ClosureSerializer.Closure::class.java, ClosureSerializer())

    return kryo
}