Deduplicate some ModFileScanData

src/main/java/org/embeddedt/modernfix/ModernFix.java

@@ -17,6 +17,7 @@ import net.minecraftforge.fml.network.FMLNetworkConstants;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.embeddedt.modernfix.classloading.ModFileScanDataDeduplicator;
 import org.embeddedt.modernfix.core.config.ModernFixConfig;
 import org.embeddedt.modernfix.entity.EntityDataIDSyncHandler;
 import org.embeddedt.modernfix.packet.PacketHandler;
@@ -79,6 +80,7 @@ public class ModernFix {
             MinecraftForge.EVENT_BUS.register(KubeUtil.class);
         MinecraftForge.EVENT_BUS.register(EntityDataIDSyncHandler.class);
         PacketHandler.register();
+        ModFileScanDataDeduplicator.deduplicate();
     }
 
     private static boolean dfuModPresent() {

src/main/java/org/embeddedt/modernfix/classloading/ModFileScanDataDeduplicator.java

@@ -0,0 +1,86 @@
+package org.embeddedt.modernfix.classloading;
+
+import com.google.common.collect.Interner;
+import com.google.common.collect.Interners;
+import net.minecraftforge.fml.ModList;
+import net.minecraftforge.fml.loading.moddiscovery.ModFile;
+import net.minecraftforge.forgespi.language.ModFileScanData;
+import org.objectweb.asm.Type;
+
+import java.lang.reflect.Field;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class ModFileScanDataDeduplicator {
+    private final Interner<Type> typeInterner = Interners.newStrongInterner();
+
+    private static Field classClazzField, parentField, interfacesField, annotationClazzField, annotationTypeField;
+    private static final boolean reflectionSuccessful;
+
+    static {
+        boolean success = false;
+        try {
+            classClazzField = ModFileScanData.ClassData.class.getDeclaredField("clazz");
+            classClazzField.setAccessible(true);
+            parentField = ModFileScanData.ClassData.class.getDeclaredField("parent");
+            parentField.setAccessible(true);
+            interfacesField = ModFileScanData.ClassData.class.getDeclaredField("interfaces");
+            interfacesField.setAccessible(true);
+            annotationClazzField = ModFileScanData.AnnotationData.class.getDeclaredField("clazz");
+            annotationClazzField.setAccessible(true);
+            annotationTypeField = ModFileScanData.AnnotationData.class.getDeclaredField("annotationType");
+            annotationTypeField.setAccessible(true);
+            success = true;
+        } catch(ReflectiveOperationException | RuntimeException e) {
+        }
+        reflectionSuccessful = success;
+    }
+
+    ModFileScanDataDeduplicator() {
+    }
+
+    private void runDeduplication() {
+        ModList.get().forEachModFile(this::deduplicateFile);
+    }
+
+    private void deduplicateFile(ModFile file) {
+        ModFileScanData data = file.getScanResult();
+        if(data != null) {
+            data.getClasses().forEach(this::deduplicateClass);
+            data.getAnnotations().forEach(this::deduplicateAnnotation);
+        }
+    }
+
+    private void deduplicateClass(ModFileScanData.ClassData data) {
+        try {
+            Type type = (Type)classClazzField.get(data);
+            type = typeInterner.intern(type);
+            classClazzField.set(data, type);
+            type = (Type)parentField.get(data);
+            type = typeInterner.intern(type);
+            parentField.set(data, type);
+            Set<Type> types = (Set<Type>)interfacesField.get(data);
+            types = types.stream().map(typeInterner::intern).collect(Collectors.toSet());
+            interfacesField.set(data, types);
+        } catch(ReflectiveOperationException e) {
+        }
+    }
+
+    private void deduplicateAnnotation(ModFileScanData.AnnotationData data) {
+        try {
+            Type type = (Type)annotationClazzField.get(data);
+            type = typeInterner.intern(type);
+            annotationClazzField.set(data, type);
+            type = (Type)annotationTypeField.get(data);
+            type = typeInterner.intern(type);
+            annotationTypeField.set(data, type);
+        } catch(ReflectiveOperationException e) {
+        }
+    }
+
+    public static void deduplicate() {
+        if(!reflectionSuccessful)
+            return;
+        new ModFileScanDataDeduplicator().runDeduplication();
+    }
+}