[CORDA-2422] - Remove interfaces from carpenting (#4687)

Remove interfaces from carpenting.

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

@@ -2,6 +2,7 @@ package net.corda.nodeapi.internal.serialization.amqp
 
 import com.google.common.primitives.Primitives
 import com.google.common.reflect.TypeResolver
+import net.corda.core.internal.VisibleForTesting
 import net.corda.core.internal.uncheckedCast
 import net.corda.core.serialization.ClassWhitelist
 import net.corda.nodeapi.internal.serialization.carpenter.CarpenterMetaSchema
@@ -44,7 +45,8 @@ open class SerializerFactory(
     cl: ClassLoader,
     private val evolutionSerializerGetter: EvolutionSerializerGetterBase = EvolutionSerializerGetter()
 ) {
-    private val serializersByType = ConcurrentHashMap<Type, AMQPSerializer<Any>>()
+    @VisibleForTesting
+    internal val serializersByType = ConcurrentHashMap<Type, AMQPSerializer<Any>>()
     private val serializersByDescriptor = ConcurrentHashMap<Any, AMQPSerializer<Any>>()
     private val customSerializers = CopyOnWriteArrayList<SerializerFor>()
     private val transformsCache = ConcurrentHashMap<String, EnumMap<TransformTypes, MutableList<Transform>>>()
@@ -216,16 +218,38 @@ open class SerializerFactory(
 
     /**
      * Iterate over an AMQP schema, for each type ascertain whether it's on ClassPath of [classloader] and,
-     * if not, use the [ClassCarpenter] to generate a class to use in it's place.
+     * if not, use the [ClassCarpenter] to generate a class to use in its place.
+     *
+     * The processing of the schema is performed in the following steps:
+     * - All the (non-interface) types are attempted to be loaded from the current classpath.
+     * - For any of those types that cannot be found in the current classpath:
+     *      - The associated interfaces are loaded from the classpath.
+     *      - These types are added to the CarpenterMetaSchema, which contains everything in need of carpenting
+     *
+     * As a result, interfaces are only loaded on-demand, according to the needs for carpenting.
+     * This is done in order to preserve backwards compatibility, in cases where 2 nodes communicate and one of the transported classes
+     * implements an interface that one of them is unaware of (i.e. introduced by a subsequent version). In this case, this node is not
+     * expected to make use of this interface anyway, since the associated CorDapps will be developed in versions that do not contain it,
+     * so it should not attempt to load it all.
      */
     private fun processSchema(schemaAndDescriptor: FactorySchemaAndDescriptor) {
+        val schemaTypes = schemaAndDescriptor.schemas.schema.types
+        val interfacesPerClass = schemaTypes.associateBy({it.name},
+                {type -> schemaTypes.filter { it.name in type.provides }}
+        )
+        val allInterfaceNames = interfacesPerClass.values.asSequence().flatten().map { it.name }
+
         val metaSchema = CarpenterMetaSchema.newInstance()
-        val notationByName = schemaAndDescriptor.schemas.schema.types.associate { it.name to it }
-        val noCarpentryRequired = notationByName.mapNotNull { (name, notation) ->
+        val notationByNameForNonInterfaceTypes = schemaTypes
+                .filterNot { it.name in allInterfaceNames }
+                .associateBy({it.name}, {it})
+        val noCarpentryRequired = notationByNameForNonInterfaceTypes.mapNotNull { (name, notation) ->
             try {
                 logger.debug { "descriptor=${schemaAndDescriptor.typeDescriptor}, typeNotation=$name" }
                 name to processSchemaEntry(notation)
             } catch (e: ClassNotFoundException) {
+                // class missing from the classpath, so load its interfaces and add it for carpenting (see method docs).
+                interfacesPerClass[name]!!.forEach { processSchemaEntry(it) }
                 metaSchema.buildFor(notation, classloader)
                 null
             }
@@ -236,14 +260,14 @@ open class SerializerFactory(
             mc.build()
         }
 
-        val carpented = notationByName.minus(noCarpentryRequired.keys).mapValues { (name, notation) ->
+        val carpented = notationByNameForNonInterfaceTypes.minus(noCarpentryRequired.keys).mapValues { (name, notation) ->
             processSchemaEntry(notation)
         }
 
         val allLocalSerializers = noCarpentryRequired + carpented
 
         allLocalSerializers.forEach { (name, serializer) ->
-            val typeNotation = notationByName[name]!!
+            val typeNotation = notationByNameForNonInterfaceTypes[name]!!
             if (serializer.typeDescriptor != typeNotation.descriptor.name ) {
                 getEvolutionSerializer(typeNotation, serializer, schemaAndDescriptor.schemas)
             }

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

@@ -232,26 +232,4 @@ class DeserializeNeedingCarpentryTests : AmqpCarpenterBase(AllWhitelist) {
         }
     }
 
-    @Test
-    fun unknownInterface() {
-        val cc = ClassCarpenter(whitelist = AllWhitelist)
-
-        val interfaceClass = cc.build(InterfaceSchema(
-                "gen.Interface",
-                mapOf("age" to NonNullableField(Int::class.java))))
-
-        val concreteClass = cc.build(ClassSchema(testName(), mapOf(
-                "age" to NonNullableField(Int::class.java),
-                "name" to NonNullableField(String::class.java)),
-                interfaces = listOf(I::class.java, interfaceClass)))
-
-        val serialisedBytes = TestSerializationOutput(VERBOSE, sf1).serialize(
-                concreteClass.constructors.first().newInstance(12, "timmy"))
-        val deserializedObj = DeserializationInput(sf2).deserialize(serialisedBytes)
-
-        assertTrue(deserializedObj is I)
-        assertEquals("timmy", (deserializedObj as I).getName())
-        assertEquals("timmy", deserializedObj::class.java.getMethod("getName").invoke(deserializedObj))
-        assertEquals(12, deserializedObj::class.java.getMethod("getAge").invoke(deserializedObj))
-    }
 }

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

@@ -1,15 +1,17 @@
 package net.corda.nodeapi.internal.serialization.amqp
 
+import net.corda.core.contracts.Attachment
+import net.corda.core.contracts.AttachmentConstraint
 import net.corda.core.serialization.ClassWhitelist
 import net.corda.core.serialization.SerializedBytes
 import net.corda.nodeapi.internal.serialization.AllWhitelist
+import net.corda.nodeapi.internal.serialization.amqp.testutils.TestSerializationOutput
 import net.corda.nodeapi.internal.serialization.carpenter.ClassCarpenter
 import org.assertj.core.api.Assertions
+import org.assertj.core.api.Assertions.assertThat
 import org.junit.Test
 import java.io.File
 import java.io.NotSerializableException
-import java.lang.reflect.Type
-import java.util.concurrent.ConcurrentHashMap
 import kotlin.test.assertEquals
 
 class InStatic : Exception("Help!, help!, I'm being repressed")
@@ -50,14 +52,10 @@ class StaticInitialisationOfSerializedObjectTest {
 
         val sf = SerializerFactory(AllWhitelist, ClassLoader.getSystemClassLoader())
 
-        val typeMap = sf::class.java.getDeclaredField("serializersByType")
-        typeMap.isAccessible = true
-
-        @Suppress("UNCHECKED_CAST")
-        val serialisersByType = typeMap.get(sf) as ConcurrentHashMap<Type, AMQPSerializer<Any>>
+        val serializersByType = sf.serializersByType
 
         // pre building a serializer, we shouldn't have anything registered
-        assertEquals(0, serialisersByType.size)
+        assertEquals(0, serializersByType.size)
 
         // build a serializer for type D without an instance of it to serialise, since
         // we can't actually construct one
@@ -65,7 +63,31 @@ class StaticInitialisationOfSerializedObjectTest {
 
         // post creation of the serializer we should have one element in the map, this
         // proves we didn't statically construct an instance of C when building the serializer
-        assertEquals(1, serialisersByType.size)
+        assertEquals(1, serializersByType.size)
+    }
+
+    @Test
+    fun interfacesAreNotLoadedWhenNotNeeded() {
+        data class DummyClass(val c: Int): AttachmentConstraint {
+            override fun isSatisfiedBy(attachment: Attachment): Boolean = true
+        }
+
+        val schemaForClass = TestSerializationOutput(EnumEvolvabilityTests.VERBOSE).serializeAndReturnSchema(DummyClass(2)).schema
+        val schemaTypes = schemaForClass.types
+        val classType = schemaTypes.find { it.name.contains("DummyClass") }!!
+        val interfaceType = schemaTypes.find { it.name.contains("AttachmentConstraint") }!!
+        val schemas = SerializationSchemas(schemaForClass, TransformsSchema(emptyMap()))
+
+        val factory = SerializerFactory(AllWhitelist, ClassLoader.getSystemClassLoader())
+        val serializersByType = factory.serializersByType
+
+        factory.get(classType.descriptor.name!!, schemas)
+
+        // Class D is in the classpath (no need to carpent it), so the interface should not be loaded
+        val loadedTypes = serializersByType.keys().toList().map { it.typeName }
+        assertThat(loadedTypes)
+                .contains(classType.name)
+                .doesNotContain(interfaceType.name)
     }
 
 
@@ -143,4 +165,5 @@ class StaticInitialisationOfSerializedObjectTest {
             DeserializationInput(sf2).deserialize(SerializedBytes<D>(bytes))
         }.isInstanceOf(NotSerializableException::class.java)
     }
+
 }