Change descriptor name from string to symbol on the wire to adhere to section 1.5 of the AMQP 1.0 spec (#1423)

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/AMQPSerializationScheme.kt

@@ -27,7 +27,7 @@ fun SerializerFactory.addToWhitelist(vararg types: Class<*>) {
 abstract class AbstractAMQPSerializationScheme : SerializationScheme {
     internal companion object {
         private val pluginRegistries: List<CordaPluginRegistry> by lazy {
-            ServiceLoader.load(CordaPluginRegistry::class.java, this.javaClass.classLoader).toList()
+            ServiceLoader.load(CordaPluginRegistry::class.java, this::class.java.classLoader).toList()
         }
 
         fun registerCustomSerializers(factory: SerializerFactory) {

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/AMQPPrimitiveSerializer.kt

@@ -1,6 +1,7 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
 import org.apache.qpid.proton.amqp.Binary
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.lang.reflect.Type
 
@@ -10,7 +11,7 @@ import java.lang.reflect.Type
  * [ByteArray] is automatically marshalled to/from the Proton-J wrapper, [Binary].
  */
 class AMQPPrimitiveSerializer(clazz: Class<*>) : AMQPSerializer<Any> {
-    override val typeDescriptor: String = SerializerFactory.primitiveTypeName(clazz)!!
+    override val typeDescriptor = Symbol.valueOf(SerializerFactory.primitiveTypeName(clazz)!!)
     override val type: Type = clazz
 
     // NOOP since this is a primitive type.

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/AMQPSerializer.kt

@@ -1,5 +1,6 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.lang.reflect.Type
 
@@ -18,7 +19,7 @@ interface AMQPSerializer<out T> {
      *
      * This should be unique enough that we can use one global cache of [AMQPSerializer]s and use this as the look up key.
      */
-    val typeDescriptor: String
+    val typeDescriptor: Symbol
 
     /**
      * Add anything required to the AMQP schema via [SerializationOutput.writeTypeNotations] and any dependent serializers

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/ArraySerializer.kt

@@ -1,5 +1,6 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.io.NotSerializableException
 import java.lang.reflect.Type
@@ -31,12 +32,12 @@ open class ArraySerializer(override val type: Type, factory: SerializerFactory)
             "${type.componentType().typeName}$arrayType"
         }
 
-    override val typeDescriptor by lazy { "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}" }
+    override val typeDescriptor by lazy { Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}") }
     internal val elementType: Type by lazy { type.componentType() }
     internal open val typeName by lazy { calcTypeName(type) }
 
     internal val typeNotation: TypeNotation by lazy {
-        RestrictedType(typeName, null, emptyList(), "list", Descriptor(typeDescriptor, null), emptyList())
+        RestrictedType(typeName, null, emptyList(), "list", Descriptor(typeDescriptor), emptyList())
     }
 
     override fun writeClassInfo(output: SerializationOutput) {

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/CollectionSerializer.kt

@@ -1,6 +1,7 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
 import net.corda.core.utilities.NonEmptySet
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.io.NotSerializableException
 import java.lang.reflect.ParameterizedType
@@ -15,7 +16,7 @@ import kotlin.collections.Set
  */
 class CollectionSerializer(val declaredType: ParameterizedType, factory: SerializerFactory) : AMQPSerializer<Any> {
     override val type: Type = declaredType as? DeserializedParameterizedType ?: DeserializedParameterizedType.make(SerializerFactory.nameForType(declaredType))
-    override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
+    override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}")
 
     companion object {
         // NB: Order matters in this map, the most specific classes should be listed at the end
@@ -58,7 +59,7 @@ class CollectionSerializer(val declaredType: ParameterizedType, factory: Seriali
 
     private val concreteBuilder: (List<*>) -> Collection<*> = findConcreteType(declaredType.rawType as Class<*>)
 
-    private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(declaredType), null, emptyList(), "list", Descriptor(typeDescriptor, null), emptyList())
+    private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(declaredType), null, emptyList(), "list", Descriptor(typeDescriptor), emptyList())
 
     override fun writeClassInfo(output: SerializationOutput) {
         if (output.writeTypeNotations(typeNotation)) {

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/CustomSerializer.kt

@@ -1,6 +1,7 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
 import net.corda.nodeapi.internal.serialization.amqp.SerializerFactory.Companion.nameForType
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.lang.reflect.Type
 
@@ -49,8 +50,8 @@ abstract class CustomSerializer<T> : AMQPSerializer<T> {
 
         override fun isSerializerFor(clazz: Class<*>): Boolean = clazz == this.clazz
         override val type: Type get() = clazz
-        override val typeDescriptor: String = "$DESCRIPTOR_DOMAIN:${fingerprintForDescriptors(superClassSerializer.typeDescriptor, nameForType(clazz))}"
+        override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForDescriptors(superClassSerializer.typeDescriptor.toString(), nameForType(clazz))}")
-        private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(clazz), null, emptyList(), SerializerFactory.nameForType(superClassSerializer.type), Descriptor(typeDescriptor, null), emptyList())
+        private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(clazz), null, emptyList(), SerializerFactory.nameForType(superClassSerializer.type), Descriptor(typeDescriptor), emptyList())
         override fun writeClassInfo(output: SerializationOutput) {
             output.writeTypeNotations(typeNotation)
         }
@@ -72,7 +73,7 @@ abstract class CustomSerializer<T> : AMQPSerializer<T> {
      */
     abstract class CustomSerializerImp<T>(protected val clazz: Class<T>, protected val withInheritance: Boolean) : CustomSerializer<T>() {
         override val type: Type get() = clazz
-        override val typeDescriptor: String = "$DESCRIPTOR_DOMAIN:${nameForType(clazz)}"
+        override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${nameForType(clazz)}")
         override fun writeClassInfo(output: SerializationOutput) {}
         override val descriptor: Descriptor = Descriptor(typeDescriptor)
         override fun isSerializerFor(clazz: Class<*>): Boolean = if (withInheritance) this.clazz.isAssignableFrom(clazz) else this.clazz == clazz

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/EnumSerializer.kt

@@ -1,8 +1,9 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
-import java.lang.reflect.Type
 import java.io.NotSerializableException
+import java.lang.reflect.Type
 
 /**
  * Our definition of an enum with the AMQP spec is a list (of two items, a string and an int) that is
@@ -10,13 +11,13 @@ import java.io.NotSerializableException
  */
 class EnumSerializer(declaredType: Type, declaredClass: Class<*>, factory: SerializerFactory) : AMQPSerializer<Any> {
     override val type: Type = declaredType
-    override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
+    override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}")
     private val typeNotation: TypeNotation
 
     init {
         typeNotation = RestrictedType(
                 SerializerFactory.nameForType(declaredType),
-                null, emptyList(), "list", Descriptor(typeDescriptor, null),
+                null, emptyList(), "list", Descriptor(typeDescriptor),
                 declaredClass.enumConstants.zip(IntRange(0, declaredClass.enumConstants.size)).map {
                     Choice(it.first.toString(), it.second.toString())
                 })

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/MapSerializer.kt

@@ -1,5 +1,6 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.io.NotSerializableException
 import java.lang.reflect.ParameterizedType
@@ -17,7 +18,7 @@ private typealias MapCreationFunction = (Map<*, *>) -> Map<*, *>
  */
 class MapSerializer(private val declaredType: ParameterizedType, factory: SerializerFactory) : AMQPSerializer<Any> {
     override val type: Type = declaredType as? DeserializedParameterizedType ?: DeserializedParameterizedType.make(SerializerFactory.nameForType(declaredType))
-    override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
+    override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}")
 
     companion object {
         // NB: Order matters in this map, the most specific classes should be listed at the end
@@ -60,7 +61,7 @@ class MapSerializer(private val declaredType: ParameterizedType, factory: Serial
 
     private val concreteBuilder: MapCreationFunction = findConcreteType(declaredType.rawType as Class<*>)
 
-    private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(declaredType), null, emptyList(), "map", Descriptor(typeDescriptor, null), emptyList())
+    private val typeNotation: TypeNotation = RestrictedType(SerializerFactory.nameForType(declaredType), null, emptyList(), "map", Descriptor(typeDescriptor), emptyList())
 
     override fun writeClassInfo(output: SerializationOutput) {
         if (output.writeTypeNotations(typeNotation)) {

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/ObjectSerializer.kt

@@ -3,6 +3,7 @@ package net.corda.nodeapi.internal.serialization.amqp
 import net.corda.core.utilities.debug
 import net.corda.core.utilities.loggerFor
 import net.corda.nodeapi.internal.serialization.amqp.SerializerFactory.Companion.nameForType
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.io.NotSerializableException
 import java.lang.reflect.Type
@@ -24,10 +25,10 @@ open class ObjectSerializer(val clazz: Type, factory: SerializerFactory) : AMQPS
 
     private val typeName = nameForType(clazz)
 
-    override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
+    override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}")
     private val interfaces = interfacesForSerialization(clazz, factory) // We restrict to only those annotated or whitelisted
 
-    open internal val typeNotation : TypeNotation by lazy {CompositeType(typeName, null, generateProvides(), Descriptor(typeDescriptor, null), generateFields()) }
+    open internal val typeNotation: TypeNotation by lazy { CompositeType(typeName, null, generateProvides(), Descriptor(typeDescriptor), generateFields()) }
 
     override fun writeClassInfo(output: SerializationOutput) {
         if (output.writeTypeNotations(typeNotation)) {

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/Schema.kt

@@ -2,10 +2,11 @@ package net.corda.nodeapi.internal.serialization.amqp
 
 import com.google.common.hash.Hasher
 import com.google.common.hash.Hashing
-import net.corda.core.utilities.toBase64
 import net.corda.core.utilities.OpaqueBytes
 import net.corda.core.utilities.loggerFor
+import net.corda.core.utilities.toBase64
 import org.apache.qpid.proton.amqp.DescribedType
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.amqp.UnsignedInteger
 import org.apache.qpid.proton.amqp.UnsignedLong
 import org.apache.qpid.proton.codec.Data
@@ -13,7 +14,6 @@ import org.apache.qpid.proton.codec.DescribedTypeConstructor
 import java.io.NotSerializableException
 import java.lang.reflect.*
 import java.util.*
-
 import net.corda.nodeapi.internal.serialization.carpenter.Field as CarpenterField
 import net.corda.nodeapi.internal.serialization.carpenter.Schema as CarpenterSchema
 
@@ -106,7 +106,9 @@ data class Schema(val types: List<TypeNotation>) : DescribedType {
     override fun toString(): String = types.joinToString("\n")
 }
 
-data class Descriptor(val name: String?, val code: UnsignedLong? = null) : DescribedType {
+data class Descriptor(val name: Symbol?, val code: UnsignedLong? = null) : DescribedType {
+    constructor(name: String?) : this(Symbol.valueOf(name))
+
     companion object : DescribedTypeConstructor<Descriptor> {
         val DESCRIPTOR = DescriptorRegistry.OBJECT_DESCRIPTOR.amqpDescriptor
 
@@ -122,7 +124,7 @@ data class Descriptor(val name: String?, val code: UnsignedLong? = null) : Descr
 
         override fun newInstance(described: Any?): Descriptor {
             val list = described as? List<*> ?: throw IllegalStateException("Was expecting a list")
-            return Descriptor(list[0] as? String, list[1] as? UnsignedLong)
+            return Descriptor(list[0] as? Symbol, list[1] as? UnsignedLong)
         }
     }
 

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SerializerFactory.kt

@@ -18,16 +18,12 @@ data class schemaAndDescriptor(val schema: Schema, val typeDescriptor: Any)
 /**
  * Factory of serializers designed to be shared across threads and invocations.
  */
-// TODO: object references - need better fingerprinting?
-// TODO: class references? (e.g. cheat with repeated descriptors using a long encoding, like object ref proposal)
-// TODO: Inner classes etc. Should we allow? Currently not considered.
 // TODO: support for intern-ing of deserialized objects for some core types (e.g. PublicKey) for memory efficiency
 // TODO: maybe support for caching of serialized form of some core types for performance
 // TODO: profile for performance in general
 // TODO: use guava caches etc so not unbounded
 // TODO: do we need to support a transient annotation to exclude certain properties?
 // TODO: allow definition of well known types that are left out of the schema.
-// TODO: found a document that states textual descriptors are Symbols.  Adjust schema class appropriately.
 // TODO: document and alert to the fact that classes cannot default superclass/interface properties otherwise they are "erased" due to matching with constructor.
 // TODO: type name prefixes for interfaces and abstract classes?  Or use label?
 // TODO: generic types should define restricted type alias with source of the wildcarded version, I think, if we're to generate classes from schema

node-api/src/main/kotlin/net/corda/nodeapi/internal/serialization/amqp/SingletonSerializer.kt

@@ -1,5 +1,6 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import org.apache.qpid.proton.amqp.Symbol
 import org.apache.qpid.proton.codec.Data
 import java.lang.reflect.Type
 
@@ -9,12 +10,13 @@ import java.lang.reflect.Type
  * want converting back to that singleton instance on the receiving JVM.
  */
 class SingletonSerializer(override val type: Class<*>, val singleton: Any, factory: SerializerFactory) : AMQPSerializer<Any> {
-    override val typeDescriptor = "$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}"
+    override val typeDescriptor = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${fingerprintForType(type, factory)}")
+
     private val interfaces = interfacesForSerialization(type, factory)
 
     private fun generateProvides(): List<String> = interfaces.map { it.typeName }
 
-    internal val typeNotation: TypeNotation = RestrictedType(type.typeName, "Singleton", generateProvides(), "boolean", Descriptor(typeDescriptor, null), emptyList())
+    internal val typeNotation: TypeNotation = RestrictedType(type.typeName, "Singleton", generateProvides(), "boolean", Descriptor(typeDescriptor), emptyList())
 
     override fun writeClassInfo(output: SerializationOutput) {
         output.writeTypeNotations(typeNotation)

node-api/src/test/kotlin/net/corda/nodeapi/internal/serialization/amqp/EvolvabilityTests.kt

@@ -1,8 +1,7 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
-import net.corda.core.serialization.SerializedBytes
 import net.corda.core.serialization.DeprecatedConstructorForDeserialization
-
+import net.corda.core.serialization.SerializedBytes
 import org.junit.Test
 import java.io.File
 import java.io.NotSerializableException