From 128b2035252b79259c48f6521afcb0c99192498e Mon Sep 17 00:00:00 2001
From: oris garno <dwitrista.garno@traveloka.com>
Date: Tue, 21 Jan 2025 23:18:16 +0700
Subject: [PATCH] fix(java): try replace classdef inplace

---
 .../java/org/apache/fury/meta/ClassDef.java   | 28 ++++++++++++-------
 .../org/apache/fury/meta/ClassDefEncoder.java |  6 +++-
 .../java/org/apache/fury/meta/ClassSpec.java  |  2 +-
 .../org/apache/fury/resolver/ClassInfo.java   |  2 +-
 .../apache/fury/resolver/ClassResolver.java   |  8 ++++--
 5 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/java/fury-core/src/main/java/org/apache/fury/meta/ClassDef.java b/java/fury-core/src/main/java/org/apache/fury/meta/ClassDef.java
index 9426dc3121..d1d7e87b90 100644
--- a/java/fury-core/src/main/java/org/apache/fury/meta/ClassDef.java
+++ b/java/fury-core/src/main/java/org/apache/fury/meta/ClassDef.java
@@ -48,6 +48,7 @@
 import org.apache.fury.memory.Platform;
 import org.apache.fury.reflect.ReflectionUtils;
 import org.apache.fury.reflect.TypeRef;
+import org.apache.fury.resolver.ClassInfo;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.serializer.CompatibleSerializer;
 import org.apache.fury.serializer.NonexistentClass;
@@ -105,13 +106,13 @@ public class ClassDef implements Serializable {
         }
       };
 
-  private final ClassSpec classSpec;
-  private final List<FieldInfo> fieldsInfo;
-  private final boolean isObjectType;
+  private ClassSpec classSpec;
+  private List<FieldInfo> fieldsInfo;
+  private boolean isObjectType;
   // Unique id for class def. If class def are same between processes, then the id will
   // be same too.
-  private final long id;
-  private final byte[] encoded;
+  private long id;
+  private byte[] encoded;
   private transient List<Descriptor> descriptors;
 
   ClassDef(
@@ -788,9 +789,16 @@ public static ClassDef buildClassDef(
     return ClassDefEncoder.buildClassDef(classResolver, type, fields, isObjectType);
   }
 
-//  public ClassDef replaceRootClassTo(
-//      Class<?> targetCls
-//  ) {
-//    this.classSpec.entireClassName = targetCls.getName();
-//  }
+  public void replaceRootClassTo(
+      ClassResolver classResolver,
+      ClassInfo targetCls
+  ) {
+    ClassDef classDef = ClassDefEncoder.buildClassDefWithFieldInfos(classResolver, targetCls.getCls(), targetCls.classDef.getFieldsInfo(), true);
+    this.fieldsInfo = classDef.fieldsInfo;
+    this.classSpec = classDef.classSpec;
+    this.id = classDef.id;
+    this.encoded = classDef.encoded;
+    this.descriptors = classDef.descriptors;
+    this.isObjectType = classDef.isObjectType;
+  }
 }
diff --git a/java/fury-core/src/main/java/org/apache/fury/meta/ClassDefEncoder.java b/java/fury-core/src/main/java/org/apache/fury/meta/ClassDefEncoder.java
index c1ac5ebdce..21fb2fba54 100644
--- a/java/fury-core/src/main/java/org/apache/fury/meta/ClassDefEncoder.java
+++ b/java/fury-core/src/main/java/org/apache/fury/meta/ClassDefEncoder.java
@@ -105,7 +105,11 @@ static List<FieldInfo> buildFieldsInfo(ClassResolver resolver, List<Field> field
   /** Build class definition from fields of class. */
   static ClassDef buildClassDef(
       ClassResolver classResolver, Class<?> type, List<Field> fields, boolean isObjectType) {
-    List<FieldInfo> fieldInfos = buildFieldsInfo(classResolver, fields);
+    return buildClassDefWithFieldInfos(classResolver, type, buildFieldsInfo(classResolver, fields), isObjectType);
+  }
+
+  static ClassDef buildClassDefWithFieldInfos(
+      ClassResolver classResolver, Class<?> type, List<ClassDef.FieldInfo> fieldInfos, boolean isObjectType) {
     Map<String, List<FieldInfo>> classLayers = getClassFields(type, fieldInfos);
     fieldInfos = new ArrayList<>(fieldInfos.size());
     classLayers.values().forEach(fieldInfos::addAll);
diff --git a/java/fury-core/src/main/java/org/apache/fury/meta/ClassSpec.java b/java/fury-core/src/main/java/org/apache/fury/meta/ClassSpec.java
index d32eca8bbf..774ea72e04 100644
--- a/java/fury-core/src/main/java/org/apache/fury/meta/ClassSpec.java
+++ b/java/fury-core/src/main/java/org/apache/fury/meta/ClassSpec.java
@@ -22,7 +22,7 @@
 import org.apache.fury.type.TypeUtils;
 
 public class ClassSpec {
-  public final String entireClassName;
+  public String entireClassName;
 
   /** Whether current class is enum of component is enum if current class is array. */
   public final boolean isEnum;
diff --git a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassInfo.java b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassInfo.java
index 3ca0c85587..0881616465 100644
--- a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassInfo.java
+++ b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassInfo.java
@@ -48,7 +48,7 @@ public class ClassInfo {
   // use primitive to avoid boxing
   // class id must be less than Integer.MAX_VALUE/2 since we use bit 0 as class id flag.
   short classId;
-  ClassDef classDef;
+  public ClassDef classDef;
   boolean needToWriteClassDef;
 
   ClassInfo(
diff --git a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
index 4db676088e..9f89c83e12 100644
--- a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
+++ b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
@@ -1678,8 +1678,12 @@ public ClassInfo readClassInfo(MemoryBuffer buffer, Class<?> targetClass) {
     if (metaContextShareEnabled) {
       ClassInfo classInfo = readClassInfoWithMetaShare(buffer, fury.getSerializationContext().getMetaContext());
       ClassInfo targetClassInfo = getClassInfo(targetClass);
-      Serializer<Object> serializer = targetClassInfo.getSerializer();
-      classInfo.setSerializer(this, serializer);
+
+      buildClassDef(classInfo);
+      buildClassDef(targetClassInfo);
+
+      classInfo.classDef.replaceRootClassTo(this, targetClassInfo);
+
       return classInfo;
     }