From e5a96cb3b20d76ec29ceefa5a0d793cc01202194 Mon Sep 17 00:00:00 2001
From: nathan <nathan@dorkbox.com>
Date: Tue, 18 Dec 2018 23:45:56 +0100
Subject: [PATCH] For RMI registration, we check to see if the interface is
 already registered. If so, we override it with the implementation class. This
 enables us to simplify registering classes for RMI

---
 src/dorkbox/network/connection/KryoExtra.java |  5 +++
 .../EditableDefaultClassResolver.java         | 36 +++++++++++++++++++
 .../network/serialization/Serialization.java  | 23 ++++++++++--
 3 files changed, 61 insertions(+), 3 deletions(-)
 create mode 100644 src/dorkbox/network/serialization/EditableDefaultClassResolver.java

diff --git a/src/dorkbox/network/connection/KryoExtra.java b/src/dorkbox/network/connection/KryoExtra.java
index aeb7dc3a..f274122b 100644
--- a/src/dorkbox/network/connection/KryoExtra.java
+++ b/src/dorkbox/network/connection/KryoExtra.java
@@ -22,10 +22,13 @@ import org.bouncycastle.crypto.modes.GCMBlockCipher;
 import org.bouncycastle.crypto.params.ParametersWithIV;
 
 import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.util.DefaultStreamFactory;
+import com.esotericsoftware.kryo.util.MapReferenceResolver;
 
 import dorkbox.network.pipeline.ByteBufInput;
 import dorkbox.network.pipeline.ByteBufOutput;
 import dorkbox.network.serialization.CryptoSerializationManager;
+import dorkbox.network.serialization.EditableDefaultClassResolver;
 import dorkbox.util.bytes.BigEndian;
 import dorkbox.util.bytes.OptimizeUtilsByteArray;
 import dorkbox.util.bytes.OptimizeUtilsByteBuf;
@@ -85,6 +88,8 @@ class KryoExtra<C extends CryptoConnection> extends Kryo {
 
     public
     KryoExtra(final CryptoSerializationManager serializationManager) {
+        super(new EditableDefaultClassResolver(), new MapReferenceResolver(), new DefaultStreamFactory());
+
         this.serializationManager = serializationManager;
     }
 
diff --git a/src/dorkbox/network/serialization/EditableDefaultClassResolver.java b/src/dorkbox/network/serialization/EditableDefaultClassResolver.java
new file mode 100644
index 00000000..5da48053
--- /dev/null
+++ b/src/dorkbox/network/serialization/EditableDefaultClassResolver.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2018 dorkbox, llc
+ *
+ * Licensed 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 dorkbox.network.serialization;
+
+import com.esotericsoftware.kryo.util.DefaultClassResolver;
+import com.esotericsoftware.kryo.util.Util;
+
+public
+class EditableDefaultClassResolver extends DefaultClassResolver {
+    public
+    EditableDefaultClassResolver() {
+    }
+
+    public
+    void deleteRegistrationType(Class type) {
+        if (type.isPrimitive()) {
+            classToRegistration.remove(Util.getWrapperClass(type));
+        }
+        else {
+            classToRegistration.remove(type);
+        }
+    }
+}
diff --git a/src/dorkbox/network/serialization/Serialization.java b/src/dorkbox/network/serialization/Serialization.java
index d5d2e084..5efc0839 100644
--- a/src/dorkbox/network/serialization/Serialization.java
+++ b/src/dorkbox/network/serialization/Serialization.java
@@ -31,6 +31,7 @@ import org.slf4j.Logger;
 import com.esotericsoftware.kryo.ClassResolver;
 import com.esotericsoftware.kryo.Kryo;
 import com.esotericsoftware.kryo.KryoException;
+import com.esotericsoftware.kryo.Registration;
 import com.esotericsoftware.kryo.Serializer;
 import com.esotericsoftware.kryo.factories.ReflectionSerializerFactory;
 import com.esotericsoftware.kryo.factories.SerializerFactory;
@@ -381,9 +382,25 @@ class Serialization<C extends CryptoConnection> implements CryptoSerializationMa
                             //  the server will ONLY send this object to the client, where on the client it becomes the proxy/interface.
                             RemoteImplClass remoteImplClass = (RemoteImplClass) clazz;
 
-                            // registers the implementation, so that when it is WRITTEN, it becomes a "magic" proxy object
-                            int id = kryo.register(remoteImplClass.implClass, remoteObjectSerializer)
-                                         .getId();
+                            int id;
+
+                            // check to see if the interface is already registered. If so, we override it with the implementation class
+                            EditableDefaultClassResolver classResolver = (EditableDefaultClassResolver) kryo.getClassResolver();
+                            Registration registration = classResolver.getRegistration(remoteImplClass.ifaceClass);
+                            if (registration != null) {
+                                // override it with the implementation
+                                int oldId = registration.getId();
+                                id = kryo.register(remoteImplClass.implClass, remoteObjectSerializer, oldId).getId();
+
+                                // delete the old one (since it shouldn't be stored anywhere)
+                                classResolver.deleteRegistrationType(remoteImplClass.ifaceClass);
+                            }
+                            else {
+                                // we have a new registration.
+
+                                // registers the implementation, so that when it is WRITTEN, it becomes a "magic" proxy object
+                                id = kryo.register(remoteImplClass.implClass, remoteObjectSerializer).getId();
+                            }
 
                             // sets up the RMI, so when we receive the iface class from the client, we know what impl to use
                             // if this is over-written, we don't care.